Alternator

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to alternators and methods for producing alternators, and more particularly, but not by way of limitation, to an improved alternator having a higher electrical current output at low speeds of revolutions and having an improved battery terminal assembly and to methods of producing such an improved alternator.

2. Brief Description of the Prior Art

Alternators for vehicles are well known in the art. The prior art alternators, such as the CS-130 alternator manufactured by General Motors, are presently provided with a housing defining an alternator interior space adapted to receive a rotor having a rotor coil. The rotor coil is rotated by the vehicle's engine and generates a moving magnetic field which induces an alternating current in three-phase stator windings disposed near the rotor coil. The speed at which the rotor coil rotates and the intensity of the rotor coil's magnetic field determine the voltage and current characteristics of the electricity generated by the prior art alternator.

Because the vehicle's engine speed varies considerably under normal driving conditions, the prior art alternators are provided with a voltage regulator which controls the intensity of the magnetic field generated by the rotor coil so that the alternator's output voltage remains within predefined limits. However, as the engine speed varies, the current of the electricity produced by the alternator also varies. That is, as the engine speed is reduced the electrical current produced by the prior art alternators is also reduced, and as the engine speed is increased the electrical current produced by the prior art alternators is also increased.

The output of the prior art alternators is electrically connected to the battery and electrical system of the vehicle to recharge the battery and to meet the current demands of the electrical system. However, if the prior art alternators are not generating a sufficient amount of electrical current to meet the demands of the electrical system then such electrical system draws electrical current from the battery to meet this deficiency. Because excess use of the battery shortens the useful life of same, it is undesirable for the battery to supply electrical current to the electrical system except during starting.

The prior art alternators typically produce a sufficient amount of electrical current to effectively charge the battery and to meet the demands of the electrical system when the prior art alternators are operating at high speeds. However, when the prior art alternators are operating at idle or low speeds, the prior art alternators produce an insufficient amount of electrical current to meet the demands of the electrical system. Thus, the battery supplies electrical current to the electrical system when the engine is operating at low speeds which shortens the useful life of the battery.

The voltage regulators of the prior art alternators are typically disposed in the alternator interior space of the housing where they are subjected to both external and internal heat. It should be noted that the number one cause of alternator failure is an overheated voltage regulator. The external heat described above is supplied to the voltage regulator by the engine and the internal heat described above is supplied to the voltage regulator by the electric current flowing through the voltage regulator.

While these prior art voltage regulators maintain the alternator's output within predefined limits, heat sinks provided on the back plate of the regulator do not effectively transfer the external and internal heat away from the voltage regulator. Thus, the voltage regulator overheats and is either destroyed or caused to malfunction.

To supply electricity to the rotor coil of the prior art alternators so that the rotor coil can generate the moving magnetic field, the rotor is provided with a pair of slip rings which are adapted to mate against a pair of corresponding brushes. The prior art alternators are provided with a brush assembly which includes a brush housing having a pair of brush chambers formed therein. A cylindrically shaped brush spring and one of the brushes is disposed in each of the brush chambers such that the spring force of each brush spring forces one of the brushes against the corresponding slip ring of the rotor.

Upon assembly of the prior art alternators, a portion of the brush may be inadvertently locked between one of the loops of the brush spring and the brush housing thereby preventing the brush spring from forcing the brush against the slip ring of the rotor coil. Thus, electricity is not supplied to the rotor coil and the alternator malfunctions.

The brushes in the prior art alternator are electrically connected to their respective electrical field circuits provided externally of the brush housing by flexible braided wires extending from the respective brushes to the field circuit connections. Because the brush housings of the prior art alternators provide no guarding or channeling mechanisms for the braided wires, these wires can be pinched, trapped, severed or otherwise damaged. If any of these conditions occur, the electrical connection to the field circuit can be lost and the prior art alternator will fail.

In addition, the prior art alternators are provided with a rectifier which rectifies the output of the alternator. The rectifier has a conductive surface with an opening formed therethrough. The voltage regulator of the prior art alternators is provided with a conductive surface which has an opening formed therethrough. The conductive surface of the voltage regulator is adapted to mate against the conductive surface of the rectifier such that the opening in the voltage regulator is aligned with the opening in the rectifier and such that electrical current flows between the conductive surfaces.

The voltage regulator and the rectifier are disposed in the alternator interior space of the housing of the alternator and a bolt is inserted through a plastic insulator, an opening formed in the housing of the alternator and the aligned openings in the voltage regulator and the rectifier such that a threaded end of the bolt extends from the voltage regulator into the alternator interior space. A nut is disposed on the threaded end of the bolt and is tightened to clamp the voltage regulator and the rectifier to the housing and to simultaneously clamp the mating conductive surfaces of the voltage regulator and the rectifier together.

However, the clamp formed from the nut and the bolt must be maintained at a precise predetermined tension. When the clamp is too loose, a gap forms between the mating conducting surfaces of the voltage regulator and the rectifier. Electricity arcs across the gap and generates heat which can overheat the voltage regulator, the rectifier and/or the battery. When the clamp is too tight, the plastic insulator can break or crack and then the clamp becomes too loose and excess heat is generated as previously discussed.

The voltage regulator of the prior art alternator is provided with an electronic switch for controlling the field current in the rotor of the alternator. If a fault such as a short circuit occurs in the rotor, the current through the electronic switch increases significantly. This increased current can destroy the electronic switch and generate excess heat.

Finally, the prior art voltage regulators control a lamp in the automobile's dash for communicating an alternator failure to a driver. Conventionally, the means for controlling the lamp was disposed internally in the logic control unit. The logic control unit was destroyed in the event of a lamp short caused by the insulation being rubbed off a wire, or the incorrect wiring of the automobile or in the event that the ignition key was left in the lamp on-engine off position for an extended period of time, for example. This was costly in terms of dollars and inconvenience to the user.

To this end, a need has long existed for an improved alternator with a higher electrical current output at low speeds of revolutions and with increased heat dissipation qualities and decreased heat generation qualities. It is to such an improved alternator that the present invention is directed.

BRIEF SUMMARY OF THE INVENTION

Not applicable.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1

is a partially cutaway perspective view of a prior art CS-130 alternator.

FIG. 2A

is an exploded perspective view of a portion of a replacement alternator which is constructed in accordance with the present invention.

FIG. 2B

is an exploded perspective view of another portion of the replacement alternator of

FIG. 2A

which is constructed in accordance with the present invention.

FIG. 3

is a plan view of a rotor assembly of the replacement alternator of

FIGS. 2A and 2B

.

FIG. 4A

is a partially cutaway frontal perspective view of a brush assembly of the replacement alternator of

FIGS. 2A and 2B

.

FIG. 4B

is a rear perspective view of the brush assembly depicted in FIG.

4

A.

FIG. 4C

is a perspective view of a brush spring disposed between a terminal end of a rigid conductor and a brush wherein the terminal end is connected to the brush via a flexible conductor extending through an opening provided through the brush spring.

FIG. 5

is a plan view of a brush spring of the brush assembly of FIG.

4

.

FIG. 6

is a plan view of a stator lamination of a stator assembly of the replacement alternator of

FIGS. 2A and 2B

, the stator lamination having a plurality of slots formed therein.

FIG. 7

is a fragmental plan view of a portion of the stator lamination of FIG.

6

.

FIG. 8

is a side view of a stator assembly of the replacement alternator of

FIGS. 2A and 2B

showing the stator assembly formed from a plurality of stator windings wound onto the stator lamination of

FIGS. 6 and 7

.

FIG. 9

is a fragmental plan view of a portion of the stator assembly of

FIG. 8

showing

12

stator windings of #14AWG wire disposed in each slot formed in the stator lamination of FIG.

6

.

FIG. 10

is a plan view of an elongated shaft which is constructed in accordance with the present invention.

FIG. 11

is a partial perspective view of the replacement alternator of

FIGS. 2A and 2B

showing a replacement battery terminal assembly which is constructed in accordance with the present invention.

FIG. 12

is a plan view of an insulator which is constructed in accordance with the present invention.

FIG. 13

is a cross-sectional view of the insulator of

FIG. 12

, taken along the lines

13

—

13

of FIG.

12

.

FIG. 14

is a side view of a first nut which is constructed in accordance with the present invention.

FIG. 15

is an end view of the first nut of

FIG. 14

, taken along the lines

15

—

15

of FIG.

14

.

FIG. 16

is a partial cutaway perspective view of a slip ring end housing which is constructed in accordance with the present invention.

FIG. 17

is a chart comparing the electrical current output by the prior art alternator of

FIG. 1

with the electrical current output by the replacement alternator of

FIGS. 2A and 2B

at different speeds of such alternators.

FIG. 18

is a schematic diagram of one embodiment of a voltage regulator circuit constructed in accordance with the present invention for use in a voltage regulator depicted in FIG.

2

B.

FIG. 19

is a partial cross-sectional view taken along the line

19

—

19

in

FIG. 16

to more clearly show heat sink fins on a slip ring end housing, constructed in accordance with the present invention, extending outwardly to be about level with an outer surface of a bearing well.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings and in particular to

FIG. 1

, a typical prior art or existing CS-130 alternator for use in a vehicle (not shown) is depicted. The prior art alternator

10

is provided with a housing

12

(

FIG. 1

) defining an alternator interior space

14

. The housing

12

is provided with a drive end housing

16

and a slip ring end housing

18

. The drive end housing

16

is provided with a plurality of air vents

22

formed therethrough and the slip ring end housing

18

is provided with a plurality of air vents

22

formed therethrough so that air can flow into the alternator interior space

14

through the air vents

20

in the slip ring end housing

18

and out of the alternator interior space

14

through the air vents

20

in the drive end housing

16

.

The alternator interior space

14

of the housing

12

is adapted to receive a rotor

24

having a drive shaft

26

. The drive end housing

16

is provided with a bearing well

28

adapted to receive a drive end bearing

30

for rotatably supporting one end of the drive shaft

26

of the rotor

24

. The slip ring end housing

18

is provided with a bearing well

32

adapted to receive a slip ring end bearing

34

for rotatably supporting the other end of the drive shaft

26

of the rotor

24

.

The housing of the prior art alternator has a first side

36

, a second side

38

, a top end

40

, a bottom end

42

, a predetermined length

44

, a predetermined width

46

, and a predetermined height

48

. The predetermined length

44

of the housing

12

extends generally between an outermost portion of the bearing well

28

of the drive end housing

16

and an outermost portion of the bearing well

32

of the slip ring end housing

18

. The predetermined width

46

of the housing

12

extends generally between the first side

36

and the second side

38

thereof. The predetermined height

48

of the housing

12

extends generally between the top end

40

and the bottom end

42

thereof.

In an installed position, the prior art alternator

10

is disposed in a predetermined alternator space (not shown) within the vehicle. The alternator space has a predetermined length, a predetermined width and a predetermined height which correspond to the length

44

, width

46

, and height

48

, respectively, of the prior art alternator

10

.

The rotor

24

(

FIG. 1

) of the prior art alternator

10

is provided with a rotor coil

50

in which a magnetic field is generated. The prior art alternator

10

is provided with a stator assembly

52

(

FIG. 1

) which surrounds the rotor coil

50

and is positioned in the magnetic field generated by the rotor coil

50

. The stator assembly

52

has a plurality of stator windings

54

wound about a stator lamination

56

, typically in a three-phase configuration.

The rotor coil

50

is rotated by the automobile's engine via the drive shaft

26

of the rotor

24

so that a current is induced in the stator windings

54

such that the prior art alternator

10

generates electricity. A voltage regulator

58

(

FIG. 1

) is provided in the alternator interior space

14

of the housing

12

and is electrically connected to the rotor coil

50

via slip rings

60

provided on the drive shaft

26

of the rotor

24

for controlling the intensity of the magnetic field generated by the rotor coil

50

such that the voltage output of the alternator

10

is maintained within predefined limits.

Shown in

FIGS. 2A and 2B

is an exploded view of a replacement alternator

70

which is constructed to replace the prior art CS-130 alternator

10

in the vehicle (not shown) where the existing CS-130 alternator

10

was disposed in the predetermined alternator space within the vehicle as discussed previously. In other words, the replacement alternator

70

has a predetermined length (not shown), a predetermined width (not shown) and a predetermined height (not shown) which are substantially identical in magnitude as the length

44

, width

46

, and height

48

of the prior art alternator

10

. The replacement alternator

70

of the present invention provides a stabilized current output of at least about 43 amperes at about 1600 RPMs and typically outputs about 26 percent more electrical current at about 1600 RPMs than the prior art alternator

10

discussed above which permits the replacement alternator

70

of the present invention to meet or exceed the demands of the electrical system of the vehicle at low or idle speeds of the replacement alternator

70

. Thus, the replacement alternator

70

of the present invention extends the useful life of the battery of the vehicle and thereby represents an advance in the state of the art relating to alternators for use in vehicles. It should be noted that the phrase “about 43 amperes” as used herein means an electrical current reading from about 41 amperes to about 45 amperes depending on the particular test stand which is being used to test the alternator

70

.

The alternator

70

includes a drive end housing

72

(

FIG. 2A

) and a slip ring end housing

74

(

FIG. 2B

) which cooperate to form a housing. The drive end housing

72

and the slip ring end housing

74

define an alternator interior space

76

adapted to receive a rotor assembly

78

(

FIGS. 2A and 3

) which is constructed in accordance with the present invention.

The rotor assembly

78

is shown in more detail in FIG.

3

. Referring now to

FIG. 2A

in combination with

FIG. 3

, the rotor assembly is provided with a drive shaft

80

having a drive end

82

and a slip ring end

84

. A first hub

86

and a second hub

88

are fixedly secured to the drive shaft

80

in a spaced-apart relation. The first and second hubs

86

and

88

have a substantially similar diameter

90

which is typically about 95.91 millimeters to about 96.07 millimeters.

The rotor assembly

78

is provided with a plurality of circumferentially spaced first claw-pole fingers

92

which are supported by the first hub

86

and which extend from the first hub

86

towards the second hub

88

. Only two of the first claw-pole fingers are labeled in

FIG. 3

as

92

a

and

92

b

for purposes of clarity. The first claw-pole fingers

92

are constructed of a magnetically permeable material.

The rotor assembly

78

is further provided with a plurality of circumferentially spaced second claw-pole fingers

94

which are supported by the second hub

88

and which extend from the second hub

88

towards the first hub

86

such that the second claw-pole fingers

94

are interleaved with the first claw-pole fingers

92

. Only two of the second claw pole fingers are labeled in

FIG. 3

as

94

a

and

94

b

for purposes of clarity. The second claw-pole fingers

94

are constructed of a magnetically permeable material.

A rotor coil form

96

is fixedly supported by the drive shaft

80

of the rotor assembly

78

and is disposed generally between the first hub

86

and the second hub

88

. The rotor coil form

96

is disposed radially intermediate or below the first and second claw-pole fingers

92

and

94

. A rotor fan

98

is disposed on the drive shaft

80

and is connected to the second hub

88

of the rotor assembly

78

.

The rotor coil form

96

is wound with a suitable length of wire

100

thereby forming a rotor coil. The rotor coil form

96

can be wound with between about 320 to about 340 turns of about 18 to about 20 gauge wire, and is desirably wound with between about 325 to about 338 turns of about 19 gauge wire and is more desirably wound with about 335 turns of about 19 gauge wire. The rotor coil form

96

can be wound with a GP-200 insulated copper magnet wire obtainable from Essex Group, Inc., of Fort Wayne, Ind.

It should be noted that the rotor coil form

96

of the present invention is wound with about 17 additional turns or windings of wire of a slightly larger gauge as the wire wound on the rotor coil form of the prior art alternator

10

. These additional turns or windings of wire have contributed to the increased electrical output of the alternator

70

of the present invention and lower field current.

Winding systems and services for winding the wire

100

about the rotor coil form

96

are available from BACHI, L. P., Itasca, Ill.

To supply electricity to the wire

100

which is wound about the rotor coil form

96

so that the wire

100

generates a rotating magnetic field as the rotor assembly

78

rotates, the rotor assembly

78

is provided with a pair of slip rings

102

and

104

which are electrically connected to the wire

100

and which are disposed on the drive shaft

80

, near the slip ring end

84

thereof.

To supply electricity to the slip rings

102

and

104

of the rotor assembly

78

, the alternator

70

is provided with a brush assembly

106

(

FIGS. 2B and 4

) which is disposed in the alternator interior space

76

formed by the drive end housing

72

and the slip ring end housing

74

. The brush assembly

106

includes a first brush

108

and a second brush

110

. In an assembled condition of the alternator

70

, the first brush

108

slidingly engages the slip ring

102

and the second brush

110

slidingly engages the slip ring

104

so as to provide electricity to the wire

100

which is wound about the rotor coil form

96

.

The brush assembly

106

is shown in more detail in

FIGS. 4A and 4B

. Referring now to

FIG. 2B

in combination with

FIGS. 4A and 4B

, the brush assembly

106

is provided with a brush housing

111

having a first end

112

, a second end

113

, and a pair of brush chambers

114

a

and

114

b.

The brush chambers

114

a

and

114

b

openly communicate with the first end

112

of the brush housing

111

and extend into the brush housing

111

from the first end

112

thereof generally toward the second end

113

thereof. The brush assembly

106

is provided with two rigid conductors

115

a

and

115

b

matingly disposed on at least a portion of the exterior of the brush housing

111

. Each of the rigid conductors

115

a

and

115

b

is provided with a first terminal end

116

a

and

116

b,

respectively, and a second terminal end

117

a

and

117

b,

respectively. The first terminal ends

116

a

and

116

b

of the rigid conductors

115

a

and

115

b

are each electrically connected to respective brushes

108

and

110

via flexible conductors

118

a

(not shown) and

118

b.

The first terminal ends

116

a

and

116

b

are identical in construction. The second terminal ends

117

a

and

117

b

are electrically connected to terminals (not shown) provided on the replacement alternator

70

in a similar manner as terminals (not shown) are provided on the prior art alternator

10

for supplying electrical power to the brushes

108

and

110

of the brush assembly

106

.

The brush housing

111

is further provided with a backplate

121

disposed through a backplate opening

119

located near the second end

113

of the brush housing

111

. The backplate

121

serves to substantially cover the brush chambers

114

a

and

114

b

near the second end

113

of the brush housing

111

and to maintain the rigid conductors

115

a

and

115

b

on the brush housing

111

. The backplate

121

can be secured to the brush housing

111

via snaps (not shown) or any other means capable of maintaining the backplate

121

on the brush housing

111

.

The brush assembly

106

is further provided with a pair of brush springs

120

. Only one of the brush springs

120

is depicted in

FIG. 4A

for purposes of clarity. The brush spring

120

is shown in more detail in FIG.

5

. The brush spring

120

has an intrinsic spring force, a first end

122

, a second end

124

and an opening

125

extending therebetween.

Referring to

FIGS. 4A and 4C

in combination with

FIG. 5

, one of the brush springs

120

is disposed between the first terminal end

116

b

and the brush

110

, and another one of the brush springs

120

is disposed between the first terminal end

116

a

and the brush

108

. The flexible conductors

118

a

and

118

b

connecting the first terminal ends

116

a

and

116

b

to the brushes

108

and

110

, respectively, extend through the openings

125

formed through the brush springs

120

.

As shown in

FIG. 5

, the brush spring

120

can be characterized as having a first end portion

126

, a second end portion

128

, and a medial portion

130

. The first end portion

126

extends a predetermined distance from the first end

122

towards the second end

124

. The medial portion

130

extends a predetermined distance from the first end portion

126

towards the second end

124

. The second end portion

128

extends a predetermined distance from the medial portion

130

to the second end

124

. The medial portion

130

of the brush spring

120

has a substantially uniform diameter

132

. The first end portion

126

of the brush spring

120

tapers radially inwardly towards the first end

122

of the brush spring

120

, and the second end portion

128

of the brush spring

120

tapers radially inwardly towards the second end

124

thereof such that the first end

122

and the second end

124

have a diameter

134

which is less than the diameter

132

of the medial portion

130

. Each of the brush springs

120

is disposed in one of the brush chambers

114

a

and

114

b

(

FIG. 4A

) of the brush housing

111

such that the first end

122

of the brush spring

120

is disposed in close proximity to the first end

112

of the brush housing

111

.

To assemble the brush assembly

106

, one end of the flexible conductor

118

b

is connected to the brush

110

(FIG.

4

C). The other end of the flexible conductor

118

b

is then disposed through the opening

125

in the brush spring

120

such that at least a portion of the flexible conductor

118

b

protrudes from the end of the brush spring

120

opposite the brush

110

. The protruding end of the flexible conductor

118

b

is then connected to the first terminal end

116

b

of the rigid conductor

115

b

via soldering or welding, for example. The brush

110

and the brush spring

120

are then inserted into the brush chamber

114

b

through the second end

113

of the brush housing

111

until an upper end

136

b

of the first terminal end

116

b

is disposed in a recess

138

b

provided in the brush housing

111

. The above described procedure is then repeated to connect the brush

108

to the first terminal end

116

a

of the rigid conductor

115

a

to permit electrical communication therebetween. Once the brushes

108

and

110

and brush springs

120

are assembled and disposed in respective brush chambers

114

a

and

114

b,

the backplate

121

is slid through the backplate opening

119

provided near the second end

113

of the brush housing

111

to maintain the rigid conductors

115

a

and

115

b

in place.

Once each of the brush springs

120

is disposed in one of the brush chambers

114

a

and

114

b,

each of the first and second brushes

108

,

110

can reciprocate in respective brush chambers

114

a

and

114

b

of the brush housing

111

against the spring force of the brush spring

120

such that the first end

122

of one of the brush springs

120

engages the first brush

108

, for example, and urges at least a portion of the first brush

108

beyond the first end

112

of the brush housing

111

, as depicted in FIG.

4

A.

It should be noted that the tapering of the brush spring

120

throughout the first end portion

126

thereof prevents the first and second brushes

108

and

110

from being inadvertently locked between one of the loops of the brush spring

120

and the brush housing

111

. The first and second brushes

108

and

110

can be the brushes which are utilized in an existing CS-130 alternator, such as the alternator

10

. In addition, the rigid conductors

115

a

and

115

b

extending exteriorly of the brush housing

111

are an improvement over the prior art brush housings (not shown) having the exteriorly extending flexible conductors in that the rigid conductors

115

a

and

115

b

are much more resistant to the problems of pinching and cutting of the flexible conductors, as hereinbefore described. Thus, the replacement alternator

70

having the brush housing

111

and the brush spring

120

is more reliable than the prior art alternator

10

.

Referring now to

FIG. 2A

, the drive end housing

72

is provided with a bearing well

140

adapted to receive a drive end bearing

142

, an opening

144

adapted to receive the drive shaft

80

of the rotor assembly

78

near the drive end

82

thereof, and a plurality of air vents

146

adapted to permit air to flow out of the alternator interior space

76

of the alternator

70

. Only one of the air vents

146

is labeled in

FIG. 2A

for purposes of clarity.

A bearing spacer

148

is disposed on the drive shaft

80

of the rotor assembly

78

to space the first hub

86

from the drive end bearing

142

. The drive end bearing

142

can be a 6-203-2 bearing, the bearing spacer

148

can be a 46-1602 spacer, and the drive end housing

72

can be a 21-117 housing which are obtainable from General Motors.

The drive end bearing

142

has an opening

150

formed therethrough. The opening

150

is sized to matingly receive the drive shaft

80

of the rotor assembly

78

near the drive end

82

thereof. In an assembled condition of the alternator

70

, the drive end bearing

142

is disposed in the bearing well

140

of the drive end housing

72

and the drive shaft

80

extends through the openings

144

and

150

provided in the drive end housing

72

and the drive end bearing

142

, respectively, so that the drive end housing

72

rotatably supports the rotor assembly

78

.

A drive pulley

152

and a fan

154

are disposed on a portion of the drive shaft

80

of the rotor assembly

78

which is disposed externally of the drive end housing

72

in an assembled condition of the alternator

70

. The drive pulley

152

and the fan

154

are secured on the drive shaft

80

via a nut

156

and a lock washer

158

. The drive pulley

152

can be a 24-1250 pulley and the fan

154

can be a 25-108 fan which are obtainable from General Motors.

The drive pulley

152

is spaced a distance from the fan

154

by a pulley spacer

160

disposed coaxially on the drive shaft

80

of the rotor assembly

78

and the fan

154

is spaced a distance from the drive end housing

72

by a fan spacer

162

disposed coaxially on the drive shaft

80

of the rotor assembly

78

. The drive pulley

152

is shaped to receive a drive belt (not shown) which couples the drive pulley

152

to the drive shaft of an engine (not shown) in a manner well known in the art so that the rotor assembly

78

can be selectively rotated at a speed of at least 1600 RPMs. The pulley spacer

160

can be a 46-1601 spacer and the fan spacer

162

can be a 46-1616 spacer which are obtainable from General Motors.

The alternator

70

is further provided with a stator assembly

170

which is constructed in accordance with the present invention. The stator assembly

170

of the present invention cooperates with the rotor assembly

78

to increase the electrical current output of the alternator

70

by about 26 percent at about 1600 RPMs as compared to the prior art alternator

10

. The stator assembly

170

is positioned in the rotating magnetic field generated by the wire

100

of the rotor assembly

78

and is clamped between the drive end housing

72

and the slip ring end housing

74

(

FIG. 2B

) such that the stator assembly

170

is supported by the housing of the alternator

70

when the alternator

70

is in an assembled condition.

The stator assembly

170

is shown in more detail in

FIGS. 6-9

. Referring now to

FIG. 2A

in combination with

FIGS. 6-9

, the stator assembly

170

is provided with a stator lamination

172

(

FIGS. 2A

,

6

,

7

,

8

, and

9

) and a plurality of stator windings

174

(

FIGS. 2A

,

8

, and

9

) wound about the stator lamination

172

.

The stator lamination

172

is formed from a plurality of layers (

FIG. 8

) of a laminated magnetically permeable material (as depicted by the spaced apart vertical lines on the stator lamination

172

) which have been bonded together in a conventional manner. The stator lamination

172

has an outer peripheral surface

176

(FIG.

6

), a first side

178

(FIG.

8

), a second side

180

(FIG.

8

), an opening

182

(

FIG. 6

) extending between the first side

178

and the second side

180

of the stator lamination

172

and a plurality of equally spaced-apart poles

184

(

FIG. 6

) disposed circumferentially about the opening

182

of the stator lamination

172

. Only three of the poles are labeled in

FIG. 6

by the general reference numerals

184

a,

184

b,

and

184

c

for purposes of clarity.

Each adjacently disposed pair of poles

184

defines a slot

186

(

FIGS. 6

,

7

, and

9

) therebetween which is adapted to receive the stator windings

174

therein (FIGS.

8

and

9

). Only two of the slots

186

are labeled in

FIGS. 6 and 7

by the general reference numerals

186

a

and

186

b

for purposes of clarity. Each slot

186

has an inwardly disposed end

188

, an outwardly disposed end

190

and a length

192

extending generally between the inwardly disposed end

188

and the outwardly disposed end

190

thereof. The length

192

of each of the slots

186

is about 19.23 millimeters to about 19.43 millimeters. Desirably, the stator lamination

172

is provided with 36 poles

184

to provide the stator lamination

172

with 36 equally spaced slots

186

.

A plurality of uniformly spaced-apart notches

200

(

FIGS. 6 and 7

) are formed in the outer peripheral surface

176

of the stator lamination

172

. Only two of the notches

200

are labeled in

FIG. 6

by the general reference numerals

200

a

and

200

b

for purposes of clarity. Each of the notches

200

extends generally between the first side

178

and the second side

180

of the stator lamination

172

. The notches

200

serve to allow clearance for through bolts. Each pair of adjacently disposed notches

200

are spaced about 60 degrees apart.

It should be noted that a reference notch

202

(

FIG. 6

) is provided in the outer peripheral surface

176

of the stator lamination

172

. The reference notch

202

extends generally between the first side

178

and the second side

180

of the stator lamination

172

. The reference notch

202

is disposed about 10 degrees from one of the notches

200

.

A plurality of equally spaced-apart holes

204

(

FIG. 6

) are formed in the stator lamination

172

. Only two of the holes

204

are labeled in

FIG. 6

by the general reference numerals

204

a

and

204

b

for purposes of clarity. The holes

204

extend generally between the first side

178

and the second side

180

of the stator lamination

172

. Each pair of equally spaced holes

204

are spaced about 60 degrees apart. It should be noted that one of the holes

204

is disposed at a mid-point between each pair of adjacently disposed notches

200

. The holes

204

serve to join the stator lamination

172

with rivets (not shown).

The opening

182

of the stator lamination

172

is sized to receive the first and second hubs

86

and

88

of the rotor assembly

78

such that the rotor assembly

78

can freely rotate therein. The stator lamination

172

has an inside diameter

206

(

FIG. 6

) extending across the opening

182

therein, an outside diameter

208

(

FIG. 6

) and a thickness

210

(

FIG. 7

) extending between the outwardly disposed end

190

of the slots

186

and the outer peripheral surface

176

of the stator lamination

172

. The inside diameter

206

of the stator lamination

172

is about 96.57 millimeters to about 96.67 millimeters. The outside diameter

208

of the stator lamination

172

can vary between about 129.75 millimeters to about 132.50 millimeters. The thickness

210

of the stator lamination

172

can be about 4.94 millimeters to about 5.04 millimeters.

It should be noted that the construction of the stator lamination

172

is substantially identical to the construction of the stator lamination

56

of the prior art alternator

10

shown in FIG.

1

. However, it should be noted that the length

192

of the slots

186

of the stator lamination

172

can be increased as compared to the slots (not shown) in the stator lamination

56

of the prior art alternator. In this embodiment, the inside diameter

206

of the stator lamination

172

is substantially identical to the inside diameter (not shown) of the stator lamination

56

of the prior art alternator

10

and the thickness

210

of the stator lamination

172

is substantially identical to the thickness (not shown) of the stator lamination

56

of the prior art alternator

10

. However, the outside diameter

208

of the stator lamination

172

of the present invention is about 2 millimeters greater than the outside diameter (not shown) of the stator lamination

56

of the prior art alternator

10

so that the length

192

of the slots

186

formed in the stator lamination

172

is about 1 millimeter longer than the length (not shown) of the slots formed in the stator lamination

56

of the prior art alternator

10

. The increased outside diameter

208

(about 132.00 millimeters) of the stator lamination

172

increases the volume of the stator lamination

172

and the increased length of the slots

186

increases the number of turns or windings of wire which can be made on the stator lamination

172

. An additional turn or winding of wire per each slot

186

formed in the stator lamination

172

has contributed to the increased electrical current output by the stator assembly

170

of the present invention while also permitting the alternator

70

to be disposed in the predetermined alternator space within the vehicle where the prior art CS-130 alternator

10

was disposed. It should be noted that in one embodiment of the present invention at least 12 turns of about 14 gauge wire is provided in each of the slots

186

formed in the stator lamination

172

having substantially the same dimensions as the stator lamination

56

.

As shown in more detail in

FIG. 7

, each of the poles

184

has a first side

220

, a second side

224

, a first end

226

and a second end

228

. The first end

226

of each pole

184

is disposed substantially adjacent the opening

182

formed in the stator lamination

172

.

The first end

226

of each pole

184

is provided with a first lip

230

and a second lip

232

. The first lip

230

extends a distance past the first side

220

of the pole

184

and the second lip

232

extends a distance past the second side

224

of the pole

184

. It should be noted that the first lip

230

of one pole

184

is spaced a distance

234

of about 3.48 millimeters to about 3.58 millimeters from the second lip

232

of an adjacently disposed pole

184

to form a wire receiving passageway

236

therebetween.

As depicted in

FIG. 8

, the stator windings

174

of the stator assembly

170

are wound through the slots

186

formed in the stator lamination

172

, typically in a delta connected, three phase configuration. The stator windings

174

are looped between the slots

186

formed in the stator lamination

172

to form a plurality of first wire loop portions

240

extending a distance outwardly beyond the first side

178

of the stator lamination

172

and a plurality of second wire loop portions

242

extending outwardly beyond the second side

180

of the stator lamination

172

. Only two of the first wire loop portions are labeled in

FIG. 8

as

240

a

and

240

b

for purposes of clarity and only two of the second wire loop portions are labeled in

FIG. 8

as

242

a

and

242

b

for purposes of clarity. The stator assembly

170

has a width

244

extending between an outermost portion of the first wire loop portions

240

and an outermost portion of the second wire loop portions

242

and the stator lamination

172

has a width

246

extending between the first side

178

and the second side

180

thereof.

The width

246

of the stator lamination

172

of the present invention is substantially identical to the width (not shown) of the stator lamination

56

of the prior art alternator

10

. However, it should be noted that it is desirable that the width

244

of the stator assembly

170

be as small as possible to reduce electrical resistance losses and to reduce magnetic flux leakage. The width

244

of the stator assembly

170

of the present invention is desirably less than about 58.00 mm and more desirably less than about 55.50 mm, which is less than the width (not shown) of the stator assembly

52

of the prior art alternator

10

. The decreased width of the stator assembly

170

contributes to the increased electrical current output of the alternator

70

of the present invention.

The stator windings

174

can be maintained within the slots

186

in the stator lamination

172

by any manner known in the art. For example, a wedge

248

(

FIG. 9

) can be inserted into each of the slots

186

formed in the stator lamination

172

after the stator windings

174

are disposed therein. The wedge

248

engages the first and second lips

230

and

232

of the poles

184

to maintain the stator windings

174

within the slots

186

.

Systems and services for winding the stator windings

174

onto the stator lamination

172

are available from Windamatic Systems of Hunterstown, Ind. or Advanced Machine and Tool of Fort Wayne, Ind.

Referring now to

FIG. 2A

, in operation, the wire

100

of the rotor assembly

78

is supplied with electricity via the first and second slip rings

102

and

104

and the wire

100

is rotated by the engine of the vehicle via the drive pulley

152

so that the magnetic field generated by DC current through the wire

100

rotates. The rotating magnetic field induces an electrical current in the stator windings

174

of the stator assembly

170

. The electrical current induced in the stator windings

174

is supplied to a rectifier

252

(

FIG. 2B

) via three output leads

254

which are either connected to or formed integrally with the stator windings

174

and which are electrically connected to the rectifier

252

. The output leads are designated in

FIG. 2A

by the reference numerals

254

a,

254

b,

and

254

c.

The rectifier

252

is mounted to the slip ring end housing

74

by a pair of mounting bolts

255

and is disposed in the alternator interior space

76

. It should be noted that one of the bolts

255

has an insulator

256

disposed coaxially thereon for insulating the slip ring end housing

74

from the rectifier

252

. The rectifier

252

has an opening

258

formed therethrough for a purpose to be described below. The rectifier

252

can be a 31-113 rectifier obtainable from General Motors.

The alternator

70

is provided with a voltage regulator

260

which is disposed in the alternator interior space

76

. The voltage regulator

260

has a positive power terminal

262

and a ground terminal forming an input, a field terminal

394

and a ground terminal

264

forming an output, a first opening

266

formed through the positive power terminal

262

, and a second opening

268

formed through the ground terminal

264

. The input of the voltage regulator

260

receives electricity from an electrical system of the vehicle via a battery terminal assembly

270

(

FIG. 11

) which is constructed in accordance with the present invention.

The output of the voltage regulator

260

is electrically connected to the brush assembly

106

adjacent the second opening

268

via a mounting bolt

272

disposed through the second opening

268

. It should be noted that the mounting bolt

272

also serves to mount the brush assembly

106

and the voltage regulator

260

to the slip ring end housing

74

. The voltage regulator

260

will be described in more detail hereinafter with reference to FIG.

18

.

The battery terminal assembly

270

is shown in more detail in

FIGS. 10-15

. Referring now to

FIGS. 2A and 2B

in combination with

FIGS. 10-15

, the battery terminal assembly

270

is provided with an elongated shaft

274

(

FIG. 10

) having a first end

276

and a second end

278

. The elongated shaft

274

can be characterized as having a first end portion

280

, a medial portion

282

and a second end portion

284

. The first end portion

280

extends from the first end

276

of the elongated shaft

274

a predetermined distance towards the second end

278

of the elongated shaft

274

. The medial portion

282

extends a predetermined distance from the first end portion

280

towards the second end

278

of the elongated shaft

274

. The second end portion

284

extends a predetermined distance from the medial portion

282

to the second end

278

of the elongated shaft

274

.

The medial portion

282

of the elongated shaft

274

is configured to be matingly disposed in the opening

258

formed in the rectifier

252

to provide a press-fit connection between the elongated shaft

274

and the rectifier

252

. The medial portion

282

of the elongated shaft

274

is knurled to provide additional strength to the press-fit connection between the elongated shaft

274

and the positive heat sink of the rectifier

252

.

The first end portion

280

of the elongated shaft

274

is configured to be disposed in an opening

286

(

FIGS. 11 and 16

) in the slip ring end housing

74

such that an externally threaded portion

288

(

FIGS. 10 and 11

) of the first end portion

280

of the elongated shaft

274

extends outwardly from the slip ring end housing

74

.

To insulate the elongated shaft

274

from the slip ring end housing

74

, an insulator

290

(

FIGS. 2B

,

11

,

12

, and

13

) is disposed on the first end portion

280

of the elongated shaft

274

such that the insulator

290

is positioned adjacent the exterior of the slip ring end housing

74

. A first nut

292

(

FIGS. 2B

,

11

,

14

, and

15

) is provided on the outwardly extending threaded portion

288

of the first end portion

280

of the elongated shaft

274

for exerting a first clamping force between the insulator

290

and the rectifier

252

to clamp the rectifier

252

to the slip ring end housing

74

such that the elongated shaft

274

, insulator

290

, and rectifier

252

are maintained in a stable position relative to the slip ring end housing

74

.

Once the rectifier

252

and elongated shaft

274

are secured to the slip ring end housing

74

, a terminal

294

of the battery cable

296

of the vehicle is disposed on a portion of the elongated shaft

274

which is disposed externally of the first nut

292

. The terminal

294

is then secured in a stable position on the elongated shaft

274

via a second nut

298

.

The second end portion

284

of the elongated shaft

274

is configured to be disposed through the first opening

266

formed in the positive power terminal

262

of the voltage regulator

260

. The second end portion

284

of the elongated shaft

274

is externally threaded to receive a third nut

300

for exerting a second clamping force between the voltage regulator

260

and the rectifier

252

to clamp or maintain the voltage regulator

260

and the rectifier

252

in a stable or secure position.

Because the medial portion

282

of the elongated shaft

274

is connected to the rectifier

252

, the medial portion

282

serves to isolate the first clamping force from the second clamping force such that if one of the first and second clamping forces becomes loose, the other one of the first and second clamping forces is not affected.

The insulator

290

is shown in more detail in

FIGS. 12 and 13

. The insulator

290

has a radially extending outer or first portion

302

, an axially extending inner or second portion

304

and an opening

306

extending through the first and second portions

302

and

304

of the insulator

290

. The radially extending first portion

302

is configured to insulate the first nut

292

from the slip ring end housing

74

. The axially extending inner or second portion

304

of the insulator

290

is configured to be disposed in the opening

286

of the slip ring end housing

74

to insulate the elongated shaft

274

from the slip ring end housing

74

.

The radially extending outer or first portion

302

of the insulator

290

has a substantially circular configuration and the axially extending inner or second portion

304

has a substantially square-shaped configuration.

The insulator

290

is constructed of an electrically insulating heat-resistant material which can desirably withstand temperatures of at least about 480° Fahrenheit and more desirably of at least about 500° Fahrenheit. For example, the insulator

290

can be constructed out of a plastic which is sold under the trademark “SUPEC” and which is obtainable from General Electric.

The first nut

292

which is disposed adjacent the insulator

290

is shown in more detail in

FIGS. 14 and 15

. The first nut

292

has a first portion

310

, a second portion

312

, and a threaded bore

314

formed therethrough. The first portion

310

of the first nut

292

has a diameter

316

which is greater than a diameter

318

of the second portion

312

of the first nut

292

. The threaded bore

314

is adapted to matingly engage the threads of the threaded portion

288

of the elongated shaft

274

such that the second portion

312

is disposed adjacent the radially extending outer portion

302

of the insulator

290

to secure the insulator

290

in a stable position adjacent the slip ring end housing

74

of the alternator

70

.

It should be noted that the specific configuration of the first nut

292

contributes to the enhanced reliability of the replacement alternator

70

in that the second portion

312

of the first nut

292

cooperates with the first portion

310

of the first nut

292

to provide a heat sink such that upon connection of the terminal

294

of the battery cable

296

to the elongated shaft

274

, the first nut

292

prevents heat generated from a loose terminal

294

from being transferred through the elongated shaft

274

into the alternator interior space

76

of the alternator

70

. The first nut

292

can be fabricated of low-carbon steel and has a diameter of at least about 14.30 millimeters extending across the first portion

310

and a diameter (not shown) of at least about 13.97 millimeters extending across the second portion

312

.

Referring now to

FIG. 2B

in combination with

FIG. 16

, the slip ring end housing

74

of the alternator

70

of the present invention will now be described in detail. As described below, the slip ring end housing

74

of the present invention has been provided with additional heat sinks as compared to the slip ring end housing

18

of the prior art alternator

10

to lower the temperature of the rectifier

252

of the alternator

70

by about 15° Fahrenheit to about 20° Fahrenheit as compared to the rectifier of the prior art alternator

10

. This lower temperature enhances the reliability of the alternator

70

.

The slip ring end housing

74

has an open first end

320

, a second end

322

, and a sidewall

324

extending therebetween. The second end

322

of the slip ring end housing

74

includes a bearing well

326

having an inner side

328

(

FIG. 2B

) and an outer side

330

(FIG.

16

), and a plurality of spaced apart semi-circularly shaped heat sink fins

332

disposed around the bearing well

326

. Only two of the heat sink fins are labeled in

FIG. 16

as

332

a

and

332

b.

Each of the heat sink fins

332

has an inwardly disposed end

334

and an outwardly disposed end

336

.

It should be noted that the construction of the slip ring end housing

74

is substantially identical to the construction of the slip ring end housing

18

of the prior art alternator

10

, with the exception that the outwardly disposed end

336

of the heat sink fins

332

have been extended outwardly as compared to the heat sink fins of the slip ring end housing

18

of the prior art alternator

10

such that the outwardly disposed end

336

of the heat sink fins

332

of the present invention are disposed about level with the outer side

330

of the bearing well

326

for increasing the surface area of the heat sink fins

332

without significantly increasing the length of the alternator

70

.

The slip ring end housing

74

of the alternator

70

of the present invention was tested by operating substantially identical alternators with the slip ring end housing

74

of the present invention and the slip ring end housing

18

provided as original equipment on the prior art alternator

10

. The alternators were operated under substantially similar ambient temperatures for about 20 minutes at a constant output of about 90 amperes of current. Two temperature readings were taken on randomly picked but identical locations on the heat sink fins

332

of the slip ring end housing

74

of the alternator

70

and the heat sink fins of the slip ring end housing

18

of the prior art alternator

10

. The first temperature reading obtained on the slip ring end housing

74

of the present invention was determined to be about 199° Fahrenheit while the first temperature reading obtained from the same location of the slip ring end housing

18

of the prior art alternator

10

was determined to be about 217° Fahrenheit. The second temperature reading obtained on the slip ring end housing

74

of the present invention was determined to be about 207° Fahrenheit while the second temperature reading obtained from the same location of the slip ring end housing

18

of the prior art alternator

10

was determined to be about 221° Fahrenheit. This substantial reduction in temperature is caused by the increased surface area of the heat sink fins

332

. The decreased temperature of the heat sink fins

332

contributes to the enhanced reliability of the replacement alternator

70

.

The bearing well

326

of the slip ring end housing

74

of the present invention is sized to receive a bearing tolerance ring

340

. An opening

342

is formed in the bearing well

326

to receive the slip ring end

84

(

FIG. 2A

) of the drive shaft

80

of the rotor assembly

78

, and a plurality of air vents

344

are formed through the slip ring end housing

74

to permit air to flow into the alternator interior space

76

. The bearing tolerance ring

340

has an opening

346

formed therethrough for receiving a slip ring end bearing

348

(FIG.

2

A). The bearing tolerance ring

340

can be a 46-1562 bearing tolerance ring and the slip ring end bearing

348

can be a 6100-2 bearing which are obtainable from General Motors.

A dust cover

350

(

FIG. 2B

) is disposed over the air vents

344

of the slip ring end housing

74

to prevent dust from entering the alternator interior space

76

from the air vents

344

. The dust cover

350

is connected to the slip ring end housing

74

via a pair of outwardly extending pins

353

on the dust cover

350

which snap into a pair of corresponding bores (not shown) provided on the slip ring end housing

74

. The dust cover

350

can be a 46-1401 dust cover obtainable from General Motors.

The bearing tolerance ring

340

is disposed in the bearing well

326

of the slip ring end housing

74

and the slip ring end bearing

348

is disposed within the opening

346

formed in the bearing tolerance ring

340

. The slip ring end bearing

348

has an opening

352

formed therethrough for receiving the slip ring end

84

of the drive shaft

80

of the rotor assembly

78

. The slip ring end

84

of the drive shaft

80

of the rotor assembly

78

is disposed in the openings

352

and

342

which are formed in the slip ring end bearing

348

and the slip ring end housing

74

such that the slip ring end housing

74

rotatably supports the slip ring end

84

of the drive shaft

80

of the rotor assembly

78

.

The alternator

70

is provided with a baffle

354

which is disposed between the stator assembly

170

and the brush assembly

106

in the alternator interior space

76

. The baffle

354

is provided with an opening

356

formed therethrough. The opening

356

is sized to receive the rotor fan

98

so that the rotor fan

98

can freely rotate therein. The baffle

354

can be a 46-1856 baffle obtainable from General Motors.

The slip ring end housing

74

is connected to the drive end housing

72

so as to sandwich the stator assembly

170

therebetween via a plurality of mounting bolts

358

. Only one mounting bolt

358

is shown in

FIG. 2B

for purposes of clarity.

The power output of the replacement alternator

70

of the present invention and the prior art alternator

10

were tested and the results of such tests are depicted in the graph set forth as FIG.

17

. The test data obtained on the prior art alternator

10

are represented in

FIG. 17

by the dashed lines and the test data obtained on the replacement alternator

70

are represented in

FIG. 17

by the solid lines.

Initially, the replacement alternator

70

and the prior art alternator

10

were operated at a speed of about 5000 RPMs at a substantially uniform output voltage of about 13 volts for a period of time sufficient to stabilize the output current of such alternators (about 10 minutes). The replacement alternator

70

and the prior art alternator

10

were then selectively operated at speeds of: 1600 RPMs; 1800 RPMs; 2000 RPMs; 2500 RPMs; 4000 RPMs; and 6500 RPMs. The output currents of the alternators

10

and

70

were obtained at each of the speeds while the output voltages of such alternators were maintained at 13 volts.

As depicted in

FIG. 17

, at a speed of about 1600 RPMs the output current of the replacement alternator

70

was 49 amperes whereas the output current of the prior art alternator

10

was 39 amperes. Thus, the current output of the replacement alternator

70

is about 26% greater than the current output of the prior art alternator

10

when such alternators are operated at a speed of about 1600 RPMs, which shows a substantial unexpected improvement over the prior art alternator

10

. The replacement alternator

70

provides a stabilized current output of at least about 43 amperes in the stator windings

174

at about 1600 revolutions per minute of the rotor coil form

96

. The determination of the current induced in the stator windings

174

can vary depending on the particular test stand utilized. Thus, it should be understood that the term “about 43 amperes” refers to a current output range varying between about 41 amperes to about 45 amperes.

Shown in

FIG. 18

is the circuitry for one embodiment of the voltage regulator

260

utilized by the replacement alternator

70

of the present invention. The voltage regulator

260

of the replacement alternator

70

is provided with a logic control unit

380

and an electronic switch

382

. The logic control unit

380

has a local sense input

384

and an output

386

. The electronic switch

382

has an input

388

and an output

390

. The output

386

of the logic control unit

380

is electrically connected to the input

388

of the electronic switch

382

via a resistor

392

. The voltage regulator

260

which receives signals indicative. of the alternator output voltage via the local sense input

384

. In response thereto, the output

386

of the logic control unit

380

outputs signals indicative of predefined voltage regulation requirements to be received by the electronic switch

382

. The output

390

of the electronic switch

382

is electrically connected to the wire

100

wound on the rotor coil form

96

via the field terminal

394

. When the logic control unit

380

outputs signals to the electronic switch

382

indicative that the automobile requires more power, the electronic switch

382

increases the flow of current to the wire

100

wound on the rotor coil form

96

via signal path

394

thereby increasing the intensity of the magnetic field and increasing the voltage which the replacement alternator

70

outputs. When the logic control unit

380

outputs signals to the electronic switch

382

indicative that the automobile requires less power, the electronic switch

382

decreases the flow of current to the wire

100

wound on the rotor coil form

96

, thereby decreasing the intensity of the magnetic field and decreasing the voltage which the replacement alternator

70

outputs. The logic control unit

380

is typically an integrated circuit, such as an MC33092DW, obtainable from Motorola, Inc. However, it should be understood that the logic control unit

380

can be any circuit capable of functioning as a logic control unit, such as a suitably programmed microprocessor.

The electronic switch

382

of the voltage regulator

260

can be any electronic switch capable of controlling the current supplied to the wire

100

wound on the rotor coil form

96

such as a transistor, a JFET, a MOSFET, a relay or the like. However, the electronic switch

382

is typically a MOSFET having a low saturation voltage and a low on resistance so that the internal heat created by the electronic switch

382

is minimized. The saturation voltage of the electronic switch

382

is less than about 0.7 volts at 5 amperes and is desirably less than about 0.3 volts at 5 amperes. The on resistance of the electronic switch

382

is typically 0.045 ohms. The electronic switch

382

can be an MTD20N06HD, obtainable from Motorola, Inc.

The voltage regulator

260

is further provided with a shorted field protection circuit

396

connected in parallel with the electronic switch

382

. The shorted field protection circuit

396

functions to turn off the electronic switch

382

in the event of a fault in the wire

100

wound on the rotor coil form

96

to prevent the electronic switch

382

from being damaged thereby. The shorted field protection circuit

396

is connected to the positive power terminal

262

and is provided with a resistor

398

, a resistor

400

, a resistor

402

, a resistor

404

, a resistor

406

, a resistor

408

, an electronic switch

410

, an electronic switch

412

, and an electronic switch

414

connected substantially as shown in the drawings. It should be noted that the shorted field protection circuit

396

is connected between the positive power terminal

262

and the ground terminal

264

substantially as shown in FIG.

18

.

When the wire

100

wound on the rotor coil form

96

is in a non-shorted condition such that the replacement alternator

70

is operating normally, the electronic switch

382

is in an on condition, the electronic switch

410

is in an on condition, the electronic switch

412

is in an off condition, and the electronic switch

414

is in an off condition. However, if a fault such as a short circuit occurs in the wire

100

wound on the rotor coil form

96

, the current in the wire

100

increases. As the current in the wire

100

increases, the current passing through the electronic switch

382

increases causing the voltage across the electronic switch

410

to increase correspondingly. As the voltage across the electronic switch

410

increases, the voltage across the resistor

402

also increases. When the voltage across the resistor

402

exceeds a predetermined threshold, the increased voltage causes the electronic switch

412

to be switched to an on condition whereby current flows through the electronic switch

412

. The current flowing through the electronic switch

412

causes the voltage to increase above a predetermined threshold on the base of the electronic switch

414

to switch the electronic switch

414

to an on condition. When the electronic switch

414

is switched to the on condition, the voltage on the output

386

of the logic control unit

380

is almost grounded. In the meantime, the voltage on the input

388

of the electronic switch

382

is decreased below a predetermined threshold so as to switch the electronic switch

382

off. Thus, the shorted field protection circuit

396

functions to sense the increase in current passing through the wire

100

and when the current passing through the wire

100

exceeds a predetermined threshold of typically about 14 amperes, the shorted field protection circuit

396

switches the electronic switch

382

to an off or non-conducting condition so that the electronic switch

382

is not damaged by the occurrence of the fault in the wire

100

.

Once the fault or shorted condition is removed in the wire

100

, the voltage across the resistor

402

is decreased. This decreased voltage causes the electronic switch

412

to be switched to an off condition whereby current does not flow therethrough. This causes the voltage on the base of the electronic switch

414

to be decreased below a predetermined threshold so as to switch the electronic switch

414

to an off or non-conducting condition. When the electronic switch

414

is switched to the off or non-conducting condition, this causes the voltage on the output

386

of the logic control unit

380

to return to a normal condition, and the voltage on the input

388

of the electronic switch

382

to increase above a predetermined threshold to switch the electronic switch

382

to the on or conducting condition. Thus, the shorted field protection circuit

396

senses when the fault or short circuit is removed in the wire

100

and switches the electronic switch

382

back to the on or conducting condition to re-establish current in the wire

100

.

It should be understood by those of ordinary skill in the art that the electronic switch

382

and the shorted field protection circuit

396

are disposed exteriorly of the logic control unit

380

between the positive power terminal

262

(the positive power terminal

262

is commonly referred to in the art as “B+”) and the ground terminal

264

. The electronic switch

382

being disposed between the positive power terminal

262

and the wire

100

being connected to the ground terminal

264

(as shown in

FIG. 18

) is commonly referred to in the art as a “high side drive”. The shorted field protection circuit

396

is adapted to work with alternators having a “high side drive”.

The voltage regulator

260

is further provided with a shorted lamp protection circuit

418

disposed externally of the logic control unit

380

, substantially as shown in

FIG. 18

for protecting the voltage regulator

260

so that the voltage regulator

260

can operate continuously under a shorted lamp condition. The shorted lamp protection circuit

418

is connected to an ignition terminal

419

(provided as a plug connection on the voltage regulator

260

in a manner well known in the art) via a current limiting means such as a resistor

420

. The ignition terminal

419

is connected to an ignition switch

431

provided in the dash of the automobile via a signal path

419

a.

The shorted lamp protection circuit

418

is also connected to a lamp terminal

421

which is connected to an indicator lamp

422

provided in the dash of the automobile via the signal path

422

a.

The shorted lamp protection circuit

418

is provided with a resistor

423

, a resistor

424

, a resistor

426

, an electronic switch

428

, and an electronic switch

430

. The lamp terminal

421

inputs a substantially continuous signal of about 14 v to the electronic switch

428

via the resistor

424

when the ignition switch

431

is in a closed condition. To turn the lamp

422

on to indicate a fault in the charging system of the automobile, such as when the alternator

70

has failed, or when the ignition switch

431

on the automobile is in a “key on-engine off” position, the logic control unit

380

outputs signals over the signal path

432

so as to turn the electronic switch

428

to an on or conducting condition to permit current to flow between the resistor

424

and the electronic switch

430

to bias the base of the electronic switch

430

above a predetermined threshold to switch the electronic switch

430

to an on or conducting condition. When the electronic switch

430

is switched to the on or conducting condition, current flows through the lamp

422

, the resistor

426

, and the electronic switch

430

.

It should be noted that the resistor

426

functions as a current limiting means so that the electronic switch

430

is not destroyed by over current in the event that the lamp

422

is in an on condition and the lamp

422

is shorted to the positive power terminal

262

(“B+”) or the signal paths

419

a

and

422

a

are shorted such as when the insulation on the signals paths

419

a

and/or

422

a

is rubbed through to expose a bare conductor or the lamp

422

, or the signal paths

419

a

and

422

a

were incorrectly switched or exchanged when the automobile was manufactured.

The voltage regulator

260

is provided with a resistor

434

, and a resistor

436

serially connected between a sense terminal

438

and the ground terminal

264

. The ground terminal

264

(the ground terminal

264

may be referred to herein as a “ground”) electrically communicates with the housing (not shown in

FIG. 18

) of the replacement alternator

70

. The resistors

434

and

436

form a voltage divider connected to an input

440

of the logic control unit

380

to provide a signal to the input

440

indicative of the output of the alternator

70

.

The voltage regulator

260

is further provided with a resistor

442

and a resistor

444

serially connected between a filter buffer output

446

of the logic control unit

380

and the ground terminal

264

. A signal path

448

is provided between the interconnection of the resistors

442

and

444

and an undervoltage input

450

of the logic control unit

380

to set the undervoltage trigger point of the logic control unit

380

. A diode

451

is provided between the signal path

394

and the ground terminal

264

to provide a current discharge path for the wire

100

which is wound on the rotor coil form

96

when the field current is switched from an on condition to an off condition.

A resistor

452

is provided between a source output

454

of the logic control unit

380

and the output

390

of the electronic switch

382

to bias the electronic switch

382

. A capacitor

456

is provided substantially as shown in

FIG. 18

for filtering out noise. A resistor

458

is provided between a VCC-

1

terminal

460

of the logic control unit

380

and the positive power terminal

262

, and a resistor

462

is provided between a VCC-

3

input

464

of the logic control unit

380

and the positive power terminal

262

. A resistor

466

, and a resistor

468

are provided in series between the positive power terminal

262

and the ground terminal

264

to form a voltage divider. The interconnection of the resistors

466

and

468

is connected to the local sense input

384

to sense the alternator output voltage. The resistors

466

and

468

are provided to limit input current and input voltage to the logic control unit

380

.

A resistor

472

and a resistor

474

are connected to form a voltage divider between a phase terminal

476

of the voltage regulator

260

and the ground terminal

264

. The interconnection of the resistors

472

and

474

is connected to a phase input

478

of the logic control unit

380

, substantially as shown. A resistor

480

is provided between an oscillator adjust input

482

of the logic control unit

380

and the ground terminal

264

.

In one embodiment, the voltage regulator

260

can be formed with the component values illustrated in the following table.

Component

Value

logic control unit 380

MC33092DW

electronic switch 382

MTD20N06HD

resistor 392

47000

Ohms

resistor 398

390000

Ohms

resistor 400

1000000

Ohms

resistor 402

130

Ohms

resistor 404

68

Ohms

resistor 406

1000

Ohms

resistor 408

13000

Ohms

electronic switch 410

2N7002LT1

electronic switch 412

BC856BLT1

electronic switch 414

MMBTAO6L

resistor 420

360

Ohms

resistor 423

2000

Ohms

resistor 424

270

Ohms

resistor 426

33

Ohms

electronic switch 428

MMBTA06L

electronic switch 430

MMBTA06L

resistor 434

30100

Ohms

resistor 436

4640

Ohms

resistor 442

82000

Ohms

resistor 444

20000

Ohms

diode 451

MURS120T3

resistor 452

2000

Ohms

capacitor 456

0.1 micro-farads

resistor 458

270

Ohms

resistor 462

1000

Ohms

resistor 466

29400

Ohms

resistor 468

4640

Ohms

resistor 472

47000

Ohms

resistor 474

13000

Ohms

resistor 480

82000

Ohms

From the above description it is clear that the present invention is well adapted to carry out the objects and to attain the advantages mentioned herein as well as those inherent in the invention. While a presently preferred embodiment of the invention has been described for purposes of this disclosure, it will be understood that numerous changes may be made which will readily suggest themselves to those skilled in the art. Thus, changes may be made in the embodiments of the invention described herein, or in the parts or the elements of the embodiments described herein, or in the steps or sequence of steps of the methods described herein, without departing from the spirit and/or the scope of the invention as defined in the following claims.

Number	Name	Date
RE. 31278	Schmider	Jun 1983
3733503	Potter	May 1973
3793544	Baumgartner et al.	Feb 1974
3818255	Wagner	Jun 1974
4087713	Binder	May 1978
4313262	Barnes et al.	Feb 1982
4636706	Bowman et al.	Jan 1987
4873962	Safranek	Oct 1989
4933581	Shramo	Jun 1990
4948997	Ohmitsu et al.	Aug 1990
5158912	Kellerman et al.	Oct 1992
5214563	Estes	May 1993
5233953	Whitehurst et al.	Aug 1993
5266746	Nishihara et al.	Nov 1993
5334899	Skybyk	Aug 1994
5467251	Katchmar	Nov 1995
5551896	DiStefano et al.	Sep 1996

	Number	Date	Country
Parent	09/245638	Feb 1999	US
Child	09/565977		US

Information

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Date Filed

Date Issued

Inventors

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Examiners

Agents

CPC

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US

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Abstract

Description

Claims

CROSS-REFERENCE TO RELATED APPLICATIONS

US Referenced Citations (17)

Non-Patent Literature Citations (1)

Continuations (1)