Information
-
Patent Grant
-
6461117
-
Patent Number
6,461,117
-
Date Filed
Tuesday, February 27, 200123 years ago
-
Date Issued
Tuesday, October 8, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Freay; Charles G.
- Belena; John F
Agents
- Calfa; Jeffrey P.
- Powell; Neil T.
- Sullivan; Dennis Kelly
-
CPC
-
US Classifications
Field of Search
US
- 417 244
- 417 279
- 417 293
- 417 297
- 417 470
- 417 490
- 417 510
- 251 248
- 251 279
- 131 56517
- 131 56537
-
International Classifications
-
Abstract
A fluid pump is provided that produces an outflow of fluid that is not proportional to the speed of the input drive. Thus, the fluid pump can be tuned to provide a substantially constant outflow of fluid irrespective of the speed of the input drive. The fluid pump also provides fluid outflow when the rotational direction of the input drive is reversed.
Description
FIELD OF THE INVENTION
The present invention relates generally to fluid pumps, and particularly, to a lubrication pump capable of providing a substantially constant outflow of fluid.
BACKGROUND
As is well-known to those skilled in the art of automotive vehicle, but also known by those in other arts, mechanical assemblies often require fluid lubrication for optimal performance and reliability. Typical examples where this need for lubrication is especially important in automotive vehicles include piston engines, transmissions, and other drivetrain components. Commonly, lubrication is provided to these components with a fluid pump that produces an outflow of fluid from a fluid reservoir. The outflow of fluid is then directed throughout the component that requires lubrication by a number of narrow passages or hoses.
To optimize lubrication, the fluid is often routed directly to critical friction surfaces within the component. Typically, these critical friction surfaces involve mating metal surfaces that slide against each other under high speed or high load. A common example of a critical friction surface that requires lubrication is the journal and bearing surface of a rotating bearing. Lubrication of moving parts generally provides two benefits. First, the fluid minimizes wear between the moving parts, thus lengthening the operating life of the component and also increasing efficiency of the component. Second, the fluid absorbs heat that is generated by the friction between the moving parts, thus dissipating the heat away from the moving parts and cooling the component. As is well-known by those in the art, a variety of fluids can be used to lubricate critical friction surfaces, and the choice is usually influenced by a number of different design considerations. Petrochemical oils with varying viscosities are commonly used for lubrication and are satisfactory for many applications. One example of a well-known and often used lubricant is automatic transmission fluid, or also referred to as Dextron II.
Traditionally, lubrication of automotive vehicle components has been provided by mechanically driven fluid pumps. Accordingly, the fluid pump is usually mounted directly to or close by the drivetrain component, and power is provided to the pump from rotating drive members in the component. A variety of drive systems have been employed to power lubrication fluid pumps, with one common example including an input drive shaft that extends into the fluid pump and a gear from the drivetrain component that drives the input drive shaft.
One characteristic of mechanically driven fluid pumps is that the volume of fluid outflow from the pump usually varies as the speed of the input drive shaft varies. Thus, as the speed of the drive gear from the component increases (and consequently the speed of the input drive shaft increases), the volume of fluid flowing from the pump will increase. Similarly, as the speed of the component decreases, the outflow from the pump also decreases. Thus, a proportional relationship generally exists between the speed of the component and the outflow of fluid from the pump.
Usually, this variation in outflow from the pump does not present any significant problems to the performance of an automotive vehicle. Typically, the engine in an automotive vehicle operates within a relatively narrow range of rotational speeds. Thus, the maximum speed of the engine is often about 3,000 rpm and the slowest speed of the engine is about 500 rpm when the engine is idling. The rotational speed of the drivetrain components are likewise relatively narrow. Therefore, because the speed of the input drive shaft for the fluid pump varies within a relatively narrow range, the resulting variation in lubricating fluid flow is also minimal. This limited variation in lubricating fluid flow generally has few adverse effects on the drivetrain components because a range of flow volume is acceptable.
However in some lubricating systems, a proportional relationship between component speed and pump outflow is unsatisfactory. One such example involves electric motor driven drivetrains. In these systems the electric motor can operate at much faster speeds than traditional drivetrain components. In addition, the electric motor can operate at very low speeds below the traditional 500 rpm idling speed, including speeds nearing zero rpm. In these types of drivetrains, the normal variation in outflow from a traditional fluid pump is too large to provide acceptable lubrication of the drivetrain components. The problem is especially acute at low speeds, where the outflow of fluid from a traditional pump is reduced significantly and approaches zero as the electric motor nears zero rpm. In contrast, the electric motor in these systems tends to operate at its worst efficiency and generates the most heat at low speeds. Thus, in drivetrains where the fluid pump is used to lubricate and cool the electric motor in addition to other drivetrain components, a traditional fluid pump is inadequate to provide acceptable fluid flow.
Another problem with mechanically driven fluid pumps is the inability to provide fluid outflow when the rotational direction of the input drive shaft reverses. This is generally not a problem with piston engine drivetrains because the major drivetrain components always rotate in the same direction and never reverse their direction of rotation. However, when an electric motor is used in the drivetrain, the rotational direction of the drivetrain components can easily be reversed by simply switching the direction of rotation of the electric motor through its logic controller. Thus, traditional fluid pumps are also inadequate for electric motor drivetrains because they do not provide lubrication fluid when the electric motor reverses direction.
One alternative to a traditional mechanically driven fluid pump is an electric powered fluid pump. In this alternative, the electrical system of the automotive vehicle supplies power to the fluid pump. The pump and the resulting outflow of fluid can then be controlled by a logic controller. Thus, the fluid outflow can be controlled irrespective of the speed or direction of rotation of the drivetrain. Accordingly, the volume of fluid outflow from the pump can be maintained at a substantially constant volume throughout the entire range of drivetrain component speeds. The electric pump is also unaffected by the rotational direction of the drivetrain, and thus lubrication fluid can be provided when the drivetrain is operated in a reverse direction.
Several problems exist with electric pumps however. Electric pumps generally operate less efficiently than mechanically driven fluid pumps. For example, in mechanically driven pumps the drive system is often about 96% efficient in providing power to the pumping assembly. On the other hand, an electric drive system is usually only about 80% efficient in providing power to the pumping assembly. Electric pumps are also usually less reliable than mechanically driven pumps during the operating life of the automotive vehicle. This lower reliability typically occurs because electric pumps are more complicated, thus providing more potential sources of failures. Electric pumps are also the source of more failures because the electric pump is usually mounted to the chassis of the automotive vehicle and is connected to the drivetrain components with fluid hoses and electrical wiring. As a result, these extra hoses and wires become susceptible to damage from being town, worn or cut. In contrast, mechanically driven pumps are often designed to be integral with a drivetrain component, making excess hoses and wires unnecessary. In addition, another problem with electric pumps is the difficulty of designing an electric pump into the electrical system of an automotive vehicle. Typically, automotive vehicles are provided with a 12V electrical system to power a variety of accessories. If an electric motor drivetrain is used in the automotive vehicle, another higher voltage electrical system may be provided for the electric motor. However, the electric pump is not always easily designed into either of these electrical systems because of load and efficiency considerations. One final problem with electric pumps is their cost, which is usually higher in automotive vehicles than mechanical pumps. As is well-known, automotive vehicles are typically produced by manufacturers in high volumes. As a result, mechanically driven pumps are usually less expensive since the capital cost of designing a specially adapted pump can be averaged across a large number of vehicles.
SUMMARY
Accordingly, a mechanically driven fluid pump is provided for producing a fluid outflow that is not proportional to the speed of the input drive. The pump includes a control valve that directs some of the fluid from the pump assembly to an outflow port and some of the fluid to a diversion port. As the speed of the input drive charges, the position of the valve is altered, thus altering the proportion of fluid directed to the outflow and diversion ports. A mechanical governor that applies centrifugal force to swing arms can be used to alter the position of the control valve proportionately to the speed of the input drive.
Two embodiments of a pump assembly are provided with both embodiments capable of producing fluid flow when the rotational direction of the input drive is reversed. One embodiment is an impeller pump assembly that includes an impeller with forward and reverse impeller sections. When the input drive rotates, one of the impeller sections is sealed by a dividing plate, thus producing fluid flow from one of the impeller sections. Another embodiment is a cam piston pump assembly. The cam piston pump assembly includes a cam attached to the input shaft and a pushrod biased against the cam. The pushrod reciprocates a piston which forces fluid through a control valve.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
The invention, including its construction and method of operation, is illustrated more or less diagrammatically in the drawings, in which:
FIG. 1
is a cross-sectional view of an impeller pump, showing an input drive, an impeller pump assembly, a governor and a control valve; and
FIG. 2
is a cross-sectional view of a cam piston pump, showing an input drive, a cam piston pump assembly, a governor and a control valve.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, two embodiments are provided of a fluid pump
10
,
100
for lubricating drivetrain components
2
in automotive vehicles or other such applications. The first embodiment, shown in
FIG. 1
, employs an impeller pump assembly
20
to provide fluid flow through the pump
10
. In comparison, the second embodiment, shown in
FIG. 2
, employs a cam piston pump assembly
110
to provide the fluid flow. Both pumps
10
,
100
are capable of providing a substantially constant outflow of fluid from the pump
10
,
100
irrespective of variations in the speed of the input drive
12
. Additionally, the pumps
10
,
100
can provide fluid outflow when the input drive
12
is rotated in either a forward or reverse direction. Thus, the first and second embodiments demonstrate a wide breadth of the present invention.
Turning to
FIG. 1
, the impeller pump
10
includes an input drive
12
. Various input drives are possible, but the preferred embodiment uses a drive gear
14
, a driven gear
16
, and an input shaft
18
. Preferably, the drive gear
14
is a power transmission gear that is integral with the drivetrain component
2
that is lubricated by the pump
10
. Typically, the rotational speed of the drive gear
14
will vary within a range as the speed of the drivetrain component
2
varies. These speed variations may include speeds approaching zero rpm. The drive gear
14
may also rotate in either a forward direction or a reverse direction (i.e. clockwise or counterclockwise). In some applications the drive gear
14
is connected either directly or indirectly to an electric drive motor, thus making large variations in rotational speed possible and making reversals in the rotational direction likely. The gear teeth of the drive gear
14
enmesh with the gear teeth of the driven gear
16
so that when the drive gear
14
rotates, the driven gear
16
rotates responsively. The input shaft
18
is fixedly attached to the driven gear
16
so that it also rotates responsively as the driven gear
16
rotates.
The input shaft
18
extends into the pump
10
and through the impeller pump assembly
20
and the mechanical governor assembly
50
. The input shaft
18
is rotationally mounted within the housing assembly
4
,
5
by tapered roller bearings
22
. Thus, one tapered roller bearing
22
is mounted on one side of the pump assembly
20
and another tapered roller bearing
22
is mounted on the other side of the pump assembly
20
. The tapered roller bearings
22
are matched and appropriately mounted to resist thrust forces that are generated by the impeller pump assembly
20
. The fluid in the pump assembly
20
is sealed from the input drive
12
and the governor assembly
50
by seals
24
that are mounted onto the input shaft
18
adjacent to the outside of each of the tapered roller bearings
22
. Therefore, the tapered roller bearings
22
are lubricated by the fluid that flows through the pump assembly
20
. The drive gear
14
and driven gear
16
are also preferably lubricated with a fluid, but the seal
24
between the pump assembly
20
and the input drive
12
allows a different type of fluid to be used if so desired. The governor assembly
50
is also preferably lubricated. However, a grease-type lubricant is preferable and can be applied a single time during assembly of the pump
20
. The seal
24
between the pump assembly
20
and the governor assembly
50
prevents fluid from entering the governor assembly
50
.
The input shaft
18
also includes a long-pitch thread section
26
that is positioned across the length of the pump cavity
28
. Various thread designs are possible but a thread
26
with about one thread revolution per inch is preferable. The thread
26
is illustrated in
FIG. 1
as a hidden, helical line on the input shaft
18
. A pair of snap rings
30
are also mounted onto the input shaft, with one snap ring
30
positioned on each side of the impeller
32
. The snap rings
30
are positioned so that the inside surfaces of the snap rings
30
are located slightly within the pump cavity
28
. Accordingly, the snap rings
30
stop the movement of the impeller
32
as it travels along the thread
26
when one side of the impeller
32
abuts against either of the snap rings
30
. However, many other types of stops may also be used to limit the travel of the impeller
32
.
Preferably, the impeller
32
is a single piece unit and may be made from die cast aluminum. The impeller
32
includes a forward impeller section
34
and a reverse impeller section
36
. Accordingly, the forward impeller section
34
has impeller blades
35
facing in one direction, and the reverse impeller section
36
has impeller blades
37
facing in the opposite direction. The two impeller sections
34
,
36
are separated by a dividing plate
38
that blocks fluid flow between the impeller blades
35
,
37
of the two sections
34
,
36
. The dividing plate
38
also extends outward from the outer diameter of the impeller sections
34
,
36
.
The impeller
32
also includes an inner bore (not indicated) that extends through the impeller
32
. The diameter of the inner bore mates with the diameter of the input shaft
18
so that the impeller
32
readily slides laterally along the input shaft
18
. The inner bore also includes a mating thread
26
to the long-pitch thread
26
of the input shaft
18
. Accordingly, the impeller
32
is threaded onto the thread
26
of the input shaft
18
, thus allowing the impeller
32
to move laterally along the input shaft
18
as the impeller
32
rotates about the long-pitch threads
26
. Matching springs
40
are provided to counter this movement of the impeller
32
. One of the springs
40
is. mounted between each side of the impeller
32
and the corresponding side of the pump housing
4
,
5
. Accordingly, each of the springs
40
apply a force against opposite sides of the impeller
32
and against each other
40
, thereby centering the impeller
32
within the pump cavity
28
.
The operation of the impeller pump assembly
20
is now apparent. When the drive gear
14
is not moving and the pump
10
is at rest, the impeller
32
is forced to the center of the pump cavity
28
by the springs
40
. However, when the drive gear
14
begins to rotate in a forward direction, inertia and resistance from the fluid on the impeller blades
35
,
37
cause the impeller
32
to rotate, or spin, on the input shaft
18
. As the impeller
32
rotates on the input shaft
18
, the impeller
32
overcomes the small bias provided by the springs
40
and travels along the long pitch threads
26
toward the reverse side sealing surfaces
43
. The movement of the impeller
32
is stopped by one of the snap rings
30
when the dividing plate
38
is positioned near to but not touching the reverse side sealing surfaces
43
. The reverse impeller section
36
is now sealed from the reservoir
9
and the control valve
70
, thus preventing the reverse facing impeller blades
37
from pumping fluid. Accordingly, the forward facing impeller blades
35
pump fluid through the pump assembly
20
from the reservoir
9
to the control valve
70
. Similarly, when the drive gear
14
begins to rotate in the reverse direction, an opposite sequence of events occurs. Instead of traveling toward the reverse sealing surfaces
43
, the impeller
32
follows the long-pitch threads
26
toward the forward sealing surfaces
42
until the impeller
32
abuts and stops against the other snap ring
30
, thus sealing the forward impeller section
34
. Because the reverse impeller blades
37
face in the opposite direction of the forward impeller blades
35
, the reverse impeller section
36
pumps fluid through the pump assembly
20
while the input shaft
18
rotates in reverse. Thus, regardless of the direction of rotation of the drive gear
14
, the impeller
32
provides fluid flow through the pump
10
.
The volume of fluid flow through the pump assembly
10
, however, is generally proportional to the speed of drive gear
14
. Therefore, a mechanical governor assembly
50
and a control valve
70
are provided to reduce the variation of fluid flow volume through the pump assembly
20
. The governor
50
includes a pair of first swing arms
52
that are pivotally attached at a first end
53
to the input shaft
18
. The second end
54
of the first swing arms
52
is pivotally attached to a second end
54
of a second pair of swing arms
56
. The second swing arm
56
is then pivotally attached at a first end
57
to a sleeve
58
. The sleeve
58
includes an inner bore
59
that is sized to easily slide along the input shaft
18
. The sleeve
58
also includes a slot
60
along the exterior of the sleeve
58
. A piston
62
, or drive member
62
, is installed within the slot
60
and is installed within a guide diameter
63
in the pump housing
6
. The piston
62
is also pivotally connected to one end of a lever
64
. The other end of the lever
64
is pivotally connected to a pushrod
66
, and a midpoint of the lever
64
is pivotally attached to the pump housing
5
.
The pushrod
66
is pivotally connected to the spool
72
of the control valve
70
. The spool
72
includes two passages
74
,
76
that extend through the spool
72
. One passage is an outflow passage
74
that is straight and connects the pump assembly
20
to the outflow port
75
of the pump
10
. The other passage is a diversion passage
76
that is angled and connects the pump assembly
20
to the diversion port
77
. The control valve
70
also includes a spring
78
that is retained between the spool
72
and a snap ring
80
attached to the pump housing
5
. Thus, the spring
78
forces the spool
72
away from the snap ring
80
. An O-ring seal
82
is also provided which prevents fluid from leaking through the control valve
70
and entering the governor
50
.
Accordingly, the manner in which the governor
50
and the control valve
70
compensate for the variable fluid flow through the pump assembly
20
is now apparent. When the drive gear
14
is not moving and the pump
10
is at rest, the spring
78
in the control valve
70
biases the spool
72
so that the entire outflow passage
74
connects the pump assembly
20
to the outflow port
75
. At this stage, the diversion passage
76
is biased away from the pump assembly
20
, thus preventing fluid from flowing to the diversion port
77
.
However, when the drive gear
14
begins to rotate, centrifugal force is generated and applied to the swing arms
52
,
56
, which pulls the second ends
54
of the swing arms
52
,
56
outward. As the swing arms
52
,
56
are forced outward, the swing arms
52
,
56
pull the sleeve
58
toward the first end
53
of the first swing arms
52
. Correspondingly, the piston
62
also moves towards the first end
53
of the first swing arms
52
, and the lever
64
rotates about its midpoint. The spool
72
is then forced against the spring
78
so that the diversion passage
76
moves toward the pump assembly
20
.
As is readily understood, an increasing amount of centrifugal force is applied to the swing arms
52
,
56
as the speed of the dive gear
14
increases, thus causing the spool
72
to move the diversion passage
76
proportionately further toward the pump assembly
20
. The outflow passage
74
and the diversion passage
76
are positioned sufficiently close to each other so that when the drive gear
14
reaches a particular speed, the pump assembly
20
will be connected to both passages
74
,
76
simultaneously. Therefore, some of the fluid flow will pass to the outflow port
75
and some of the fluid flow will pass to the diversion port
77
. As the speed of the driving gear
14
increases, the diversion passage
76
becomes increasingly more connected to the pump assembly
20
. As a result, the control valve
70
progressively provides less fluid flow to the outflow port
75
and more fluid to the diversion port
77
.
By tuning the governor assembly
50
and the control valve
70
, the desired volume of fluid outflow from the pump
10
can be achieved. Preferably, the desired outflow will be substantially constant irrespective of the speed of the drive gear
14
. Tuning will generally involve adjustments to the size and spacing of the passages
74
,
76
in the spool
72
and the inertia of the swing arms
52
,
56
. Additionally, a pressure regulating device Knot shown) such as an orifice or valve, may be desirable in the diversion port
77
to adjust the fluid pressure that is provided to the outflow port
75
. These tunings and others that may be necessary are all within the normal skill of those in the art and will depend on the particular application of the pump
10
and the desired fluid flow characteristics.
Preferably, the pump
10
is designed to be an integral assembly with the drivetrain component
2
that requires lubrication. Thus, the pump
10
can be directly mounted to the component
2
. Instead of an outflow port
75
, the outflow port
75
may also be a series of internal passages that directly connect the outflowing fluid to the desired lubricating areas. Likewise, the diversion port
77
may be a series of internal passages that eventually return the fluid to the reservoir
9
. However, the outflow port
75
is preferably connected to a heat exchanger that cools the fluid before returning the fluid to the reservoir
9
. To ease assembly of the pump
10
, the pump housing
4
,
5
,
6
may also include multiple housings that are connected together during assembly of the pump
10
. Thus, in the desired embodiment, three housing
4
,
5
,
6
are employed.
Turning now to FIG.
2
and the second embodiment, a fluid pump
100
with a cam piston pump assembly
110
is provided. The cam piston pump
100
is similar to the impeller pump
10
described above; therefore the input drive
12
, governor assembly
50
and control valve
70
do not need to be described further since their functions are generally the same as in the impeller pump
10
. In the cam piston pump
100
, the pump assembly
110
, which was represented by the impeller pump assembly
20
in the impeller pump
10
, includes a cam
112
and a piston
120
.
Accordingly, a cam
112
is fixedly attached to the input shaft
18
. The cam contacts a roller
114
that is pivotally attached to a pushrod
116
. The pushrod
116
is installed in a bore (not indicated) that allows the pushrod
116
to freely move up and down. However, a spring
118
is installed below the pushrod
116
to bias the pushrod
116
and roller
114
against the cam
112
. The pushrod
116
also includes a piston
120
at the bottom end of the pushrod
116
.
Fluid is routed from the reservoir
9
to the piston
1
:
20
through internal passages
102
,
104
. Preferably, the first passage
102
is connected to the pump assembly
110
to provide lubrication to the cam
112
and pushrod
116
. As with the impeller pump
10
, seals
24
are preferably provided on the outside of the bearings
106
to prevent fluid from entering the governor
50
and the input drive
12
. Unlike the impeller pump
10
, the bearings
106
may be roller ball bearings
106
instead of tapered roller bearings
22
since little thrust is expected from the pump assembly
20
. However, tapered roller bearings can be used in a particular application if the thrust generated by the governor
50
exceeds the capacity of the roller ball bearings
106
.
The fluid proceeds through a second passage
104
to the piston
120
. For manufacturing purposes, the lower portion
105
of the second passage
104
is drilled through the side of the pump housing
4
,
5
. Therefore, a plug
108
is installed into the outside portion of the passage
104
to block the end of the second passage
104
. Installed below the piston
120
is a check valve
122
. The check valve
122
includes an orifice
124
and a ball
126
that is forced against the orifice
124
by a spring
128
.
Accordingly, the operation of the cam piston pump
100
it now apparent. As the Input shaft
18
rotates, the cam
112
alternatively forces the pushrod
116
down, with the spring
118
biasing the pushrod up, so that the piston
120
reciprocates between up and down positions. As a result, when the pushrod
116
is in its upward position, the piston
120
is positioned above the lower portion
105
of the passage
104
. However, when the pushrod
116
moves to its downward position, the piston
120
travels through the lower portion
105
of the passage
104
, thereby forcing fluid down into the check valve
122
. The fluid then passes through the orifice
124
and forces the ball
126
down against the spring
128
, thus allowing the fluid to pass to the control valve
70
. Once the fluid passes through the check valve
122
, the piston
120
returns to its upward position and the valve
126
is forced back against the orifice
124
to prevent the fluid from passing back up to the lower portion
105
of the second passage
104
.
It can be readily seen, therefore, that the piston
120
pumps fluid to the control valve
70
regardless of the rotational direction of the input shaft
18
because the cam
112
reciprocates the pushrod
116
up and down in both forward and reverse speeds. Like the impeller pump
32
, however, the volume of fluid flow from the cam piston pump assembly
110
varies proportionately with the speed of the drive gear
14
. Therefore, the governor assembly
50
and the control valve
70
compensate for this variation as described above. Thus, by tuning the governor
50
and the control valve
70
, a desired outflow of fluid from the pump
100
can be accomplished. Preferably, this outflow is substantially constant irrespective of the speed of the drive gear
14
.
While a preferred embodiment of the invention has been described, it should be understood that the invention is not so limited, and modifications may be made without departing from the invention. The scope of the invention is defined by the appended claims, and all devices that come within the meaning of the claims, either literally or by equivalence, are intended to be embraced therein.
Claims
- 1. A fluid pump comprising a pump assembly generating a volume of fluid flow from a reservoir, said pump assembly being powered by an input drive; and a control valve disposed between said pump assembly and an outflow, wherein said control valve diverts to a diversion a portion of said volume directed to said outflow when speed of said input drive is changed; and a governor, wherein said governor alters a position of said control valve when said speed of said input drive is changed.
- 2. The fluid pump according to claim 1, further comprising a diversion, wherein said control valve alters a portion of said volume directed to said diversion in response to said portion directed to said outflow.
- 3. The fluid pump according to claim 2, further comprising an outflow passage extending through said control valve and a diversion passage extending through said control valve, said outflow passage being disposed to connect said pump assembly to said outflow and said diversion passage being disposed to connect said pump assembly to said diversion; wherein said control valve alters said outflow passage connection and said diversion passage connection thereby proportionately altering said portions directed to said outflow and said diversion.
- 4. The fluid pump according to claim 1, wherein said governor is a mechanical governor.
- 5. The fluid pump according to claim 4, wherein said portion of said volume directed to said outflow is substantially constant irrespective of said speed of said input drive.
- 6. The fluid pump according to claim 4, wherein said governor comprises swing arms pivotally attached to an input shaft of said input drive, wherein centrifugal force influences said swing arms when said speed of said input drive is changed thereby altering said position of said control valve.
- 7. The fluid pump according to claim 6, further comprising a spring biasing against said centrifugal force.
- 8. The fluid pump according to claim 7, wherein said swing arms are further pivotally attached to a rotating sleeve, said sleeve being engaged by a non-rotating drive member connected to said control valve.
- 9. The fluid pump according to claim 8, wherein said sleeve includes a slot and said drive member is disposed within said slot; and wherein said drive member is pivotally connected to a lever, said lever being pivotally connected to a housing and pivotally connected to a pushrod, said pushrod being pivotally connected to said control valve.
- 10. The fluid pump according to claim 3, wherein said input drive comprises a drive gear from a drivetrain component, said drive gear being enmeshed with a driven gear fixedly attached to an input shaft, said input shaft thereby rotatably powering said pump.
- 11. The fluid pump according to claim 3, wherein said pump assembly generates said volume of fluid flow regardless of a rotational direction of said drive input.
- 12. The fluid pump according to claim 11, wherein said pump assembly is a cam piston pump assembly.
- 13. The fluid pump according to claim 12, wherein said input drive comprises an input shaft rotatably powering said pump assembly; and wherein said pump assembly comprises a cam attached to said input shaft, a pushrod being biased against said cam, and a piston being attached to said pushrod; said piston thereby generating said volume of fluid flow.
- 14. The fluid pump according to claim 13, wherein said piston reciprocates through a passage filled with fluid from said reservoir thereby forcing fluid to said control valve.
- 15. The fluid pump according to claim 14, wherein said pump assembly comprises a check valve disposed between said passage and said control valve thereby preventing said forced fluid from returning to said passage when said piston reciprocates.
- 16. The fluid pump according to claim 15, wherein said reservoir is connected to said cam and said pushrod thereby lubricating said cam and said pushrod.
- 17. The fluid pump according to claim 16, wherein said pump assembly comprises roller ball bearings and seals mounted on said input shaft on opposite sides of said cam, said bearings being disposed between said cam and said seals.
- 18. The fluid pump according to claim 3, further comprising a mechanical governor, wherein said governor alters a position of said control valve when said speed of said input drive is changed; and wherein said pump assembly is a cam piston pump assembly, said pump assembly generating said volume of fluid flow regardless of a rotational direction of said drive input, wherein said input drive comprises an input shaft rotatably powering said pump assembly, and wherein said pump assembly comprises a cam attached to said input shaft, a pushrod being biased against said cam, and a piston being attached to said pushrod, said piston thereby generating said volume of fluid flow.
- 19. The fluid pump according to claim 18, wherein said piston reciprocates through a passage filled with fluid from said reservoir thereby forcing fluid to said control valve, said pump assembly comprising a check valve disposed between said passage and said control valve thereby preventing said forced fluid from returning to said passage when said piston reciprocates.
- 20. The fluid pump according to claim 19, wherein said governor comprises swing arms pivotally attached to said input shaft of said input drive, wherein centrifugal force influences said swing arms when said speed of said input drive is changed thereby altering said position of said control valve, wherein a spring biases against said centrifugal force, said swing arms being further pivotally attached to a rotating sleeve, said sleeve being en(gaged by a non-rotating drive member connected to said control valve.
- 21. The fluid pump according to claim 20, wherein said portion of said volume directed to said outflow is substantially constant irrespective of said speed of said input drive.
- 22. The fluid pump according to claim 20, wherein said input drive comprises a drive gear from a drivetrain component, said drive gear enmeshed with a driven gear fixedly attached to said input shaft, said input shaft thereby rotatably powering said pump.
- 23. A fluid pump comprising a pump assembly rotatable attached to an input shaft, said pump assembly generating a volume of fluid flow from a reservoir proportional to a speed of said input shaft; and a governor altering the position of a control valve proportionately to said speed of said input shaft, said control valve directing a portion of said volume of fluid flow to an outflow and another portion to a diversion; wherein said outflow portion decreases as said speed of said input shaft increases.
- 24. The fluid pump according to claim 23, wherein said pump assembly generates said volume regardless of a rotational direction of said input shaft.
- 25. The fluid pump according to claim 24, wherein said outflow portion is substantially constant irrespective of said speed of said input shaft.
US Referenced Citations (20)