Information
-
Patent Grant
-
6254361
-
Patent Number
6,254,361
-
Date Filed
Thursday, July 29, 199925 years ago
-
Date Issued
Tuesday, July 3, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Freay; Charles G.
- Evora; Robert Z.
Agents
-
CPC
-
US Classifications
Field of Search
US
- 417 42314
- 417 4237
- 417 4238
- 417 357
- 417 366
-
International Classifications
-
Abstract
A pump having a generally hollow housing, an annular rotor rotatively mounted inside the housing, an annular stator fixedly mounted inside the housing and peripherally surrounding the rotor and a closed impeller axially aligned with the annular rotor. The impeller includes a tubular fluid inlet member fixedly mounted within the annular rotor, such that the rotor rotatively drives the impeller.
Description
FIELD OF THE INVENTION
This invention relates to a canned rotor inline pipe pump and, more particularly, to a shaftless canned rotor inline pipe pump.
BACKGROUND OF THE INVENTION
Pumps are used in many applications for moving various types of fluids. For example, pumps are used in pipeline systems that supply water to boilers. Pumps are also used in pipeline systems that circulate cooling water for coolers and condensers and transferring fuel oil. Many chemical processes employ pumps in pipelines that circulate industrial chemicals in reactors, distribution columns, kettles and the like.
One commonly known pump for moving fluids in pipeline systems is a canned rotor (motor) inline pipe pump. A typical canned rotor inline pipe pump includes a motor positioned on one side of a pump. The motor has an enclosed or canned rotor with a drive shaft that is coupled to the pump's impeller for rotation thereof, and an enclosed or canned stator which peripherally surrounds the canned rotor. Fluid pumping is achieved through electromagnetic interaction between the canned rotor and the canned stator which produces high speed rotation of the rotor. The rotation of the rotor causes the impeller to rotate via the drive shaft which couples the impeller to the rotor.
Canned rotor pumps utilize a portion of the pump-treating fluid which is typically withdrawn from the suction port of the pump section and circulated through the motor to lubricate the motor and drive shaft bearings as well as remove heat which is generated due to the inefficiency of the motor. This portion of the fluid is then reintroduced into the suction port of the pump section.
There are some disadvantages associated with conventional canned rotor pumps. The drive shaft's bearings and other related mechanical components add complexity and increase the cost of such pumps. Further, the drive shaft and its related components can require a considerable amount of maintenance. Additionally, the drive shaft increases the length of the pump, thus limiting the available location of the pump in pipeline systems.
Pumps traditionally mounted on a baseplate can be subjected to many external forces and moments due to excessive pipe loads. These forces and moments can lead to premature pump failure. If the pump can reside within the piping system, all pipe loads will be eliminated.
Therefore, a need exits for a shaftless canned rotor inline pipeline pump.
SUMMARY OF THE INVENTION
A pump comprises a generally hollow housing, an annular rotor rotatively mounted inside the housing, an annular stator fixedly mounted inside the housing and peripherally surrounding the rotor and a closed impeller axially aligned with the annular rotor. The impeller includes a tubular fluid inlet member fixedly mounted within the annular rotor, such that the rotor rotatively drives the impeller.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages, nature and various additional features of the invention will appear more fully upon consideration of the illustrative embodiments now to be described in detail in connection with accompanying drawings wherein:
FIG. 1
is a sectional view of a pump according to an embodiment of the invention;
FIG. 2
is an exploded sectional view of the drive section of the pump of
FIG. 1
;
FIG. 3
is an exploded sectional view of the diffuser pump section of the pump of
FIG. 1
; and
FIG. 4
is a sectional view of the pump of
FIG. 1
showing fluid flow through the pump during operation thereof.
It should be understood that these drawings are for purposes of illustrating the concepts of the invention and are not to scale.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1
shows a pump
10
according to an embodiment of the invention. The pump
10
is adapted as an inline pump for use in pipeline systems and installed between an inlet pipe
11
and an outlet pipe
13
of such a system. Since the pump
10
resides within the piping system, all pipe loads are substantially eliminated. Ordinary skilled artisans will recognize that the pump
10
can also be adapted for other applications as well.
As shown in
FIG. 1
, the pump
10
generally comprises a drive section
12
and a diffuser pump section
14
having an impeller
16
that is integral with the drive section
12
thus, eliminating the driveshaft used in conventional pumps. Eliminating the driveshaft advantageously reduces the mechanical complexity and maintenance requirements of the pump
10
and decreases its length, thus permitting the pump
10
to be positioned within a pipeline system in locations where conventional pumps can not be placed.
As collectively shown in
FIGS. 1 and 2
, the drive section
12
of the inventive pump
10
comprises a conventional motor
18
encased within a housing
20
. The housing
20
generally includes a cylindrical sidewall
22
closed at one end by an endwall
24
having a fluid inlet opening
26
. The outer surface
28
of the endwall
24
includes a raised circular inlet pipe mounting flange
30
surrounding the fluid inlet opening
26
. The inner surface
32
of the endwall
24
defines a concentric arrangement of elements that includes a cylindrical flange
34
surrounding the fluid inlet opening
26
, an annular recess
36
at the foot of the cylindrical flange
34
, and an annular groove
38
that surrounds the cylindrical flange
34
and the annular recess
36
. A cylindrical first rotor bearing
40
is fixedly mounted on the outer surface of the cylindrical flange
34
, and a first annular rotor thrust bearing
42
is seated in the annular recess
36
. The cylindrical sidewall
22
of the housing
20
includes an aperture
44
that communicates with the interior
46
of the housing
20
to permit electrical connection to the motor
18
. The open end of the cylindrical sidewall
22
defines a circular mounting flange
48
for mounting the diffuser pump section
14
to the drive section
12
. An annular relief
50
is provided on the inner periphery of the mounting flange
48
.
The motor
18
of the drive section
12
can be an AC induction motor, a permanent magnet motor, a switch reluctance motor, or any other suitable motor capable of driving, a diffuser pump. In the shown embodiment, the motor
18
generally includes a rotor
52
rotatively mounted inside the housing
20
, and a stator
54
fixedly mounted inside the housing
20
, peripherally surrounding the rotor
52
.
The stator
54
is constructed in an annular configuration and is typically hermetically sealed or canned by a stator enclosure
56
comprised of a cylindrical wall member
58
and an outwardly extending ring-shaped wall member
60
. The free end
62
of the cylindrical wall member
58
is sealingly affixed in the annular groove
38
of the housing end wall
24
and the outermost portion of the ring-shaped wall member
60
sealingly resides in the annular relief
50
of the circular mounting flange
48
of the housing
20
.
The rotor
52
is also constructed in an annular configuration and typically hermetically sealed or canned by a rotor enclosure
62
(canned rotor
64
) that encases the rotor
52
. The canned rotor
64
has first and second end surfaces
66
,
67
and outer and inner cylindrical surfaces
68
,
70
extending between the end surfaces
66
,
67
. A rotor bearing
72
is fixedly mounted to the portion of the canned rotor
64
where the first end surface
66
and the inner cylindrical surface
70
meet. The rotor bearing
72
has a second annular rotor thrust bearing member
74
seated on the first end surface
66
of the canned rotor
64
, and a second cylindrical rotor bearing member
76
seated on the cylindrical inner surface
70
of the canned rotor
64
. A shroud engagement recess
78
is formed in the inner cylindrical surface
70
of the canned rotor
64
adjacent the second end surface
67
thereof.
Referring collectively to
FIGS. 1 and 3
, the diffuser pump section
14
comprises the impeller
16
and a fluid collector or diffuser
80
fixedly mounted to the open end of the housing
20
. The impeller
16
is typically constructed in a conventional closed configuration and comprises a disc member
82
with inner and outer surfaces
84
,
86
, a centrally disposed hub
88
emerging from the inner surface
84
thereof, a plurality of vanes
90
extending radially from the hub
88
on the inner surface
84
of the disc member
82
, and a shroud
92
enclosing the vanes
90
, the shroud
92
including a tubular inlet
94
defining an impeller inlet opening
95
. The vanes
90
and shroud
92
define a plurality of conventional, radially extending impeller discharge ports
96
. The outer surface
86
of the disc
82
includes an annular recess
98
that retains a first ring-shaped impeller thrust bearing
99
, and a centrally disposed cylindrical pilot member
100
.
The diffuser
80
comprises a cylindrical skirt
102
having an open end
104
with a circular mounting flange
106
that abuts against the mounting flange
48
of the housing
20
, and a closed end
108
defined by circular outer and inner walls
110
,
112
. The outer wall
110
has a centrally disposed fluid outlet opening
114
. The exterior surface
116
of the outer wall
110
includes a raised circular outlet pipe mounting flange
118
that surrounds the fluid outlet opening
114
. The skirt
102
and walls
110
,
112
define a plurality of conventional diffuser channel
134
that provide a fluid path between the impeller discharge ports
96
and the fluid outlet opening
114
. The inner wall
112
has a centrally disposed hub member
120
which extends toward the fluid outlet opening
114
of the outer wall
110
. The interior surface
122
of the inner wall
112
includes an annular recess
124
that retains a second ring-shaped impeller thrust bearing
126
, and a centrally disposed pilot member receiving aperture
128
. A cylindrical impeller bearing
132
is seated in a correspondingly shaped bearing seat
130
defined in the wall
129
of the pilot member receiving aperture
128
.
As shown in
FIG. 1
, the shroud tubular inlet member
94
of the impeller
16
is nonrotatively seated in the engagement recess
78
of the canned rotor
64
thus, forming an integral canned rotor/impeller assembly
136
. The canned rotor/impeller assembly is rotatively disposed between the housing
20
and the diffuser
80
with the canned rotor
64
mounted on the housing cylindrical flange
34
in axial alignment with the housing inlet opening
26
and the impeller
16
rotatively disposed in the diffuser
80
via the pilot member
100
and the pilot member receiving aperture
128
. The rotor and the impeller bearings
40
,
42
,
72
,
99
,
126
,
132
permit free rotation of canned rotor/impeller assembly
136
. Fluid pumping is achieved through electromagnetic interaction between the rotor
52
and the stator
54
which produces high speed rotation of the canned rotor/impeller assembly
136
.
As further shown in
FIG. 1
, the pump
10
includes first and second fluid cooling/lubrication passageways
140
and
142
. The first passageway
140
is formed by gaps defined between the canned stator
54
and the canned rotor
64
, the canned rotor
64
and the housing end wall
24
, and the canned rotor
64
and the tubular liner
138
. The second passageway is formed by a gap defined between the impeller
16
and the diffuser inner wall
112
.
FIG. 4
shows fluid flow during operation of the pump
10
. Fluid is drawn into the pump
10
through the housing inlet opening
26
. A tubular liner
138
attached to the housing cylindrical flange
34
, extends substantially through the canned rotor
64
, aids in guiding the fluid into the impeller
16
and substantially eliminates any potential rotationally induced flow disturbances. The fluid enters the inlet
95
of the impeller
16
and is discharged through the impeller discharge ports
96
. A portion of this discharged fluid enters the passageways
140
,
142
at locations identified by numerals
144
,
146
. The fluid circulating through the passageways
140
,
142
cools and lubricates the rotor and impeller bearings
40
,
42
,
72
,
99
,
126
,
132
and also cools the stator
54
and canned rotor
64
. The fluid circulating in the first passageway
140
exits at a location identified by numeral
148
and reenters the impeller inlet
96
. The fluid circulating in the second passageway
142
exits via an aperture
150
in the diffuser hub
120
for discharged through the fluid outlet opening
114
. The remaining portion of the discharged fluid is directed through the diffuser
80
and discharges axially through the fluid outlet opening
114
.
While the foregoing invention has been described with reference to the above embodiment, various modifications and changes can be made without departing from the spirit of the invention. Accordingly, all such modifications and changes are considered to be within the scope of the appended claims.
Claims
- 1. A pump comprising:a generally hollow housing; an annular rotor rotatively mounted inside the housing; an annular stator fixedly mounted inside the housing and peripherally surrounding the rotor; and a closed impeller axially aligned with the annular rotor, the impeller including a tubular fluid inlet member fixedly mounted to the annular rotor, the rotor rotatively driving the impeller.
- 2. The pump according to claim 1, further comprising a fluid collector fixedly mounted to the housing and encasing the impeller.
- 3. The pump according to claim 2, wherein the housing includes a circular flange extending from an inner surface thereof, the annular rotor rotatively mounted on the circular flange.
- 4. The pump according to claim 2, wherein the impeller further includes a pilot pin rotatively disposed in an aperture of the fluid collector.
- 5. The pump according to claim 2, wherein the fluid collector includes a fluid outlet opening which defines a pump outlet.
- 6. The pump according to claim 1, wherein the housing includes a fluid inlet opening that defines a pump inlet, the fluid inlet opening of the housing is axially aligned with the rotor.
- 7. The pump according to claim 6, wherein the fluid collector includes a fluid outlet opening that defines a pump outlet.
- 8. The pump according to claim 7, wherein the fluid outlet opening of the fluid collector is axially aligned with the rotor and the fluid inlet opening of the housing.
- 9. The pump according to claim 1, wherein the rotor and the stator are both hermetically sealed.
- 10. A pump comprising:a generally hollow housing; an annular rotor rotatively mounted inside the housing; an annular stator fixedly mounted inside the housing and peripherally surrounding the rotor; and a closed impeller axially aligned with the annular rotor, the impeller including a tubular fluid inlet member fixedly mounted to the annular rotor and a plurality of radially extending impeller discharge ports communicating with the fluid inlet member, the rotor rotatively driving the impeller; and a fluid collector fixedly mounted to the housing and encasing the impeller, the fluid collector communicating with the discharge ports of the impeller.
- 11. The pump according to claim 10, wherein the impeller further includes a pilot pin rotatively disposed in an aperture of the fluid collector and the housing includes a circular flange extending from an inner surface thereof, the annular rotor rotatively mounted on the circular flange.
- 12. The pump according to claim 11, further comprising a first bearing disposed between the inner periphery of the rotor and the circular flange and a second bearing disposed between the pilot pin and the aperture.
- 13. The pump according to claim 10, further comprising a thrust bearing disposed between axially opposing surfaces of the impeller and the fluid collector and a second thrust bearing disposed between axially opposing surfaces of the rotor and an inner surface of the housing.
- 14. The pump according to claim 10, wherein housing includes a fluid inlet opening that defines a pump inlet and the fluid collector includes a fluid outlet opening that defines a pump outlet.
- 15. The pump according to claim 14, wherein the fluid outlet opening of the fluid collector is axially aligned with the rotor and the fluid inlet opening of the housing.
- 16. The pump according to claim 10, wherein the rotor and the stator are both hermetically sealed.
- 17. A pump comprising:a generally hollow housing having a fluid inlet opening that defines a pump inlet; a hermetically sealed annular rotor rotatively mounted inside the housing; a hermetically sealed annular stator fixedly mounted inside the housing and peripherally surrounding the rotor; and a closed impeller axially aligned with the annular rotor, the impeller including a tubular fluid inlet member fixedly mounted to the annular rotor and a plurality of radially extending impeller discharge ports communicating with the fluid inlet member, the rotor rotatively driving the impeller; and a fluid collector fixedly mounted to the housing and encasing the impeller, the fluid collector communicating with the discharge ports of the impeller and including a fluid outlet opening that defines a pump outlet.
- 18. The pump according to claim 17, wherein the impeller further includes a pilot pin rotatively disposed in an aperture of the fluid collector and the housing includes a circular flange extending from an inner surface thereof, the annular rotor rotatively mounted on the circular flange.
- 19. The pump according to claim 18, further comprising a first bearing disposed between the inner periphery of the rotor and the circular flange and a second bearing disposed between the pilot pin and the aperture.
- 20. The pump according to claim 17, further comprising a thrust bearing disposed between axially opposing surfaces of the impeller and the fluid collector and a second thrust bearing disposed between axially opposing the rotor and an inner surface of the housing.
US Referenced Citations (11)