A MOTOR PUMP AND CONTROL MANIFOLD ASSEMBLY

Abstract

A motor pump assembly is provided that comprises a motor, a drive shaft connected to the motor, a pump and control manifold including means for controlling fluid flow to and/or from the pump. The motor, drive shaft, pump and manifold are contained within a single common housing. The manifold forms an integral part of the housing and includes a pump chamber that contains the pump.

Claims

1. A motor pump and control manifold assembly comprising: a motor; a drive shaft connected to the motor; a pump; and a control manifold including means for controlling fluid flow to and/or from the pump, wherein the motor, drive shaft, pump and manifold are contained within a single common housing.

2. A motor pump and control manifold assembly according to claim 1 wherein the housing comprises a main housing body containing each of the motor, drive shaft, pump and manifold.

3. A motor pump and control manifold assembly according to claim 2 wherein the manifold is integrally formed as part of the housing body.

4. A motor pump and control manifold assembly according to claim 3 wherein the manifold includes an integrally formed pump chamber within which the pump is housed.

5. A motor pump and control manifold assembly according to claim 4 wherein the pump chamber is fluidly connected to the manifold within the housing body.

6. A motor pump and control manifold assembly according to claim 1 wherein the pump is a gear pump.

7. A motor pump and control manifold assembly according to claim 1 wherein the pump is a vane pump.

8. A motor pump and control manifold assembly according to claim 2 wherein the housing includes an integrally formed chamber for housing the motor.

9. A motor pump and control manifold assembly according to claim 1 wherein the drive shaft is a single piece common shaft connected to both the motor and the pump.

10. A motor pump and control manifold assembly according to claim 9 wherein only a single bearing is preferably provided along the drive shaft between the motor and the pump.

11. A motor pump and control manifold assembly according to claim 2 includes an inner wall located axially inwards of the pump that defines the porting face of the valve chamber and includes a plurality of ports formed therein arranged to port fluid to and from the pump.

12. A motor pump and control manifold assembly according to claim 11 where a closure member is provided at the axially opposing end of the pump chamber to the porting face to close the pump chamber and secure the pump therein.

13. A motor pump and control manifold assembly according to claim 12 wherein the closure member forms the axially outer side wall of the pump chamber.

14. A motor pump and control manifold assembly according to claim 2 wherein the control manifold is axially located between the pump chamber and the motor chamber.

15. A motor pump and control manifold assembly according to claim 14 wherein the housing includes one or more integrally formed heat exchange fluid channels arranged proximate the motor chamber to effect cooling thereof.

16. A motor pump and control manifold assembly according to claim 15 wherein a network of heat exchange fluid channels are formed within the housing proximate the axially inner wall of the motor chamber.

17. A motor pump and control manifold assembly according to claim 15 wherein the manifold is configured to control fluid through the heat exchange fluid channels.

18. A motor pump and control manifold assembly according to claim 1 comprising at least one control manifold module including one or more valves, the control manifold module being configured to connect to the control manifold to increase the control functionality of the motor pump assembly.

19. A motor pump and control manifold assembly according to claim 18, wherein the control manifold includes one or more fluid ports arranged for connection to the at least one control manifold module, the control manifold and control manifold module including corresponding connector elements to enable the control manifold module to be secured to the control manifold.

20. A motor pump and control manifold assembly according to claim 19 wherein the control manifold module includes connector elements arranged to enable a further control manifold module to be secured thereto.

21. A motor pump and control manifold assembly according to claim 1 wherein at least the part of the housing comprising the control manifold and the pump chamber is a single piece body.

22. A motor pump and control manifold assembly according to claim 21 wherein at least the part of the housing comprising the control manifold and the pump chamber is a single piece casting.

Description

[0018] The present invention will now be described by way of example only with reference to the following illustrative figures in which:

[0019] FIG. 1 shows a motor pump assembly according to the prior art; and

[0020] FIG. 2 shows a motor pump assembly according to an embodiment of the present invention.

[0021] Referring to FIG. 1 there is a provided a hydraulic drive system 18 comprising an electric motor 20, a gear pump 22 and control manifold 24. The motor 20 is preferably a permanent magnet motor. In the arrangement of FIG. 2 two permanent magnets are arranged in series, but it will be appreciated that in other embodiments one of more than two motors may be provided. A drive shaft 23 is connected to the motor 20 at a first end 21 and extends axially from the motor 20. The gear pump 22 is packaged within a pump cartridge 25 that is mounted to the shaft 23 at the second end 26 which functions as the pump rotor. Advantageously only a single common shaft is required within the assembly that directly couples to both the motor 20 and the pump 22.

[0022] A roller bearing 32 is located between the motor 20 and the pump cartridge 25 that rotationally supports the shaft 23. As the assembly utilises a common shaft, advantageously only a single bearing is required along the length of the shaft 23. In contrast, in arrangements such as that of FIG. 1, where a pump unit is bolted to a separate motor unit, two bearings are required along the shaft in the pump unit as well as in the motor unit. The applicant has further identified that the hydraulic pressure at the tips of the pump vanes supports the shaft 23 at the second end such that no additional bearing is required at the second end. The lower inherent side-load generated by the gear pump 22 as compared to other pump types further allows the shaft support bearing design to be optimized.

[0023] A housing 34 contains all of the components of the assembly. The housing is preferably a two part housing, although could be manufactured as a single piece casting. A first section of the housing 34 defines motor chamber 36 located at a first axial end of the housing 34. The motor housing 36 has an inner end wall 38 which closes the motor chamber 36. The end wall 38 includes an axial bore 40 through which the shaft 23 extends. The inner wall 38 may be formed as part of the first motor chamber section 35 of the second housing section 37. The bore 40 extends axially towards the second end and includes a first diameter section 42 that houses the bearing 32. A second stepped down section 44 of reduced diameter houses a shaft seal 45 to prevent egress of hydraulic fluid to the motor 20 along the shaft 23. A third section 46 defines a pump chamber having a diameter sized to receive the vane cartridge 25. Between the second and third sections the bore 40 has a diameter substantially equal to the diameter of the shaft 23, sized to permit free rotation of the shaft 23 within the bore 40.

[0024] The pump chamber 46 has an inner wall 48. A closure plate or cap 50 closes the open outer end of the pump chamber 46. The inner surface 52 of the end plate 50 defines the outer wall of the valve chamber 46. The closure plate 50 is bolted in position to the end wall of the housing 34, and acts to clamp the pump cartridge in position against the inner wall of the pump chamber 46. The inner wall 48 of the pump chamber 46 is preferably an integrally formed part of the housing 34, formed in the casting process. The ports for the pump 22 are formed in the inner wall 48. By clamping the vane cartridge between the closure plate 50 and the inner wall 48, and by forming the ports of the pump 22 in the end wall 48, the cheek plates that are conventionally provided to clamp and port and pump are no longer required, which reduces the number of parts, simplifies assembly and reduces cost.

[0025] The housing 34 further includes a control manifold section 54. The manifold section 54 is arranged between the pump 22 and the motor 20. The manifold section 54 is integrally formed as part of the single piece housing 34. The manifold section 54 includes a plurality of ports, such as port 56, arranged to receive control valves such as cartridge valve 58, to control fluid flow to and from the pump 22. The pump extends directly from the inner wall porting face 48 of the pump chamber 46 into the manifold section 54, with the outer face of the manifold 54 forming the porting face 48 of the pump 22. Integrating the control manifold directly in the assembly housing obviates the requirement for a system of pipework connecting the pump with a separate control manifold assembly, thereby enabling the overall size of the assembly to be drastically reduced. Integrating the manifold into the housing also significantly simplifies assembly and greatly reduces parts. The integrated manifold 54 also enables the flow to and from the pump 22 to be readily controlled such that either port of the pump may be pressurised. This enables the pump 22 to be operated in a first direction as a pump and in a second direction as a motor driving the electric motor 20 to function as a generator. The assembly is therefore ideally suited to applications in which energy recovery from a hydraulic system is required.

[0026] In a further advantage, fluid channels (not shown) may be formed in the manifold that are routed through the manifold 54 in a region immediately adjacent the inner wall 38 of the motor housing 36. The fluid flow through these channels may be arranged to provide cooling to the motor housing 36. This integrated cooling system of the motor housing 36 is enabled by the integration of the manifold 54 into the housing 34, and its axial location next to the motor housing 36, between the motor housing 36 and the pump housing 46.

[0027] The use of a pump 22 such as a gear pump or vane pump within the single housing integrated assembly of the embodiment of FIG. 2 is preferable as the pump 22 provides the assembly with a flexible range of operation. As the pump 22 is integrated into the assembly, it is desirable that the assembly is able to be specified across a wide range of operation without having to vary the size or configuration of the single piece housing 34.

[0028] In the arrangements of the prior art, if a system specification requires greater displacement from the pump a designer may simply specify an alternative pump and substitute this pump into the assembly. In the present embodiment, if it is required to vary the displacement of the pump, this may achieved by replacing the valve cartridge 25 with an alternative configuration. As it is only the internal configuration of the cam ring that varies, the pump cartridge 25 still occupies the same space within the housing 34.

[0029] A single assembly which includes an integrated pump, motor and control manifold package therefore optimizes the packaging and performance while minimizing the component parts required. The present embodiment advantageously reduces the number of parts and therefore cost and space claim. Motor pumps of the prior art typically use two shafts a coupling and four bearings. The present embodiment uses only one bearing with the pump 22 functioning like an oil bearing helping to support the shaft.

[0030] Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.