MULTIPLE LOBE VANE FLUID PUMP HAVING ENHANCED UNDER-VANE CAVITY PRESSURIZATION

Abstract

A multiple lobe vane fluid pump having enhanced under-vane cavity pressurization for cold start priming includes a pressure plate having a first flow passage and a second flow passage, the first flow passage being configured to allow fluid flow between a primary under-vane cavity and a primary discharge port, the second flow passage being configured to allow fluid flow between the primary discharge port and a secondary under-vane cavity. Additionally, the pump includes a thrust plate including the primary under-vane cavity, a first adjacent under-vane cavity having one open end in fluid communication with a first end on the primary under-vane cavity, and a second adjacent under-vane cavity having one open end in fluid communication with a second end of the primary under-vane cavity.

Claims

1. A multiple lobe vane fluid pump having enhanced under-vane cavity pressurization for cold start priming comprising: a pressure plate having a first flow passage and a second flow passage, the first flow passage being configured to allow fluid flow between a primary under-vane cavity and a primary discharge port, the second flow passage being configured to allow fluid flow between the primary discharge port and a secondary under-vane cavity; and a thrust plate including the primary under-vane cavity, a first adjacent under-vane cavity having one open end in fluid communication with a first end of the primary under-vane cavity, and a second adjacent under-vane cavity having one open end in fluid communication with a second end of the primary under-vane cavity.

2. The pump of claim 1 further comprising each of the first and second adjacent under-vane cavities being aligned with inward radial vane motion caused by a multiple lobe cam profile during rotor rotation.

3. The pump of claim 1 wherein the first flow passage is configured to be a predetermined smaller size than the second flow passage.

4. The pump of claim 3 wherein the first flow passage is less than half the size of the second flow passage.

5. The pump of claim 3 wherein the first flow passage is less than or equal to one third the size of the second flow passage.

6. A multiple lobe vane fluid pump having enhanced under-vane cavity pressurization for cold start priming comprising: a pressure plate having a first flow passage and a second flow passage, the first flow passage being configured to allow fluid flow between a primary under-vane cavity and a primary discharge port, the second flow passage being configured to allow fluid flow between the primary discharge port and a secondary under-vane cavity; and a thrust plate including the primary under-vane cavity, a first adjacent under-vane cavity having one open end in fluid communication with a first end on the primary under-vane cavity, and a second adjacent under-vane cavity having one open end in fluid communication with a second end of the primary under-vane cavity, wherein each of the first and second adjacent under-vane cavities being aligned with inward radial vane motion caused by a multiple lobe cam profile during rotor rotation.

7. The pump of claim 6 wherein the first flow passage is configured to be a predetermined smaller size than the second flow passage.

8. The pump of claim 7 wherein the first flow passage is less than half the size of the second flow passage.

9. The pump of claim 7 wherein the first flow passage is less than or equal to one third the size of the second flow passage.

10. A multiple lobe vane fluid pump having enhanced under-vane cavity pressurization for cold start priming comprising: a pressure plate having a first flow passage and a second flow passage, the first flow passage being configured to allow fluid flow between a primary under-vane cavity and a primary discharge port, the second flow passage being configured to allow fluid flow between the primary discharge port and a secondary under-vane cavity, wherein the first flow passage is configured to be a predetermined smaller size than the second flow passage; and a thrust plate including the primary under-vane cavity, a first adjacent under-vane cavity having one open end in fluid communication with a first end on the primary under-vane cavity, and a second adjacent under-vane cavity having one open end in fluid communication with a second end of the primary under-vane cavity, wherein each of the first and second adjacent under-vane cavities being aligned with inward radial vane motion caused by a multiple lobe cam profile during rotor rotation.

11. The pump of claim 10 wherein the first flow passage is less than half the size of the second flow passage.

12. The pump of claim 10 wherein the first flow passage is less than or equal to one third the size of the second flow passage.

Description

DRAWINGS

[0010] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

[0011] FIG. 1 is an illustration of an exploded view of a multiple lobe vane fluid pump having enhanced under-vane cavity pressurization for cold start priming in accordance with aspects of an exemplary embodiment; and

[0012] FIG. 2 is an illustration of a perspective view of a pressure plate, a cam and rotor assembly, and a thrust plate of a multiple lobe vane fluid pump in accordance with aspects of the exemplary embodiment.

DETAILED DESCRIPTION

[0013] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.

[0014] With reference to FIG. 1, an exploded view of a multiple lobe vane fluid pump 10 having enhanced under-vane cavity pressurization for cold start priming in accordance with aspects of an exemplary embodiment is provided. The pump 10 includes a rotor assembly 12, a pressure plate 14, a thrust plate 16, a body assembly 18, an end plate 20 with dowels 22, and a plurality of fastening bolts 24.

[0015] Generally, the rotor assembly 12 includes a cycloidal cam 50 and a slotted rotor 52 that is centrically supported in the cam 50 (see FIG. 2) on a pump shaft 13 (see FIG. 1) such that as the pump shaft 13 and slotted rotor 52 rotates and fluid (not shown) enters the pump 10, centrifugal force and/or under-vane hydraulic pressure push vanes 54 radially outward to the inner wall of the cam 50. The vanes 54 are caused to move radially inward within the slotted rotor 52 when rotating through an inner cam wall surfaces 56, and to move radially outward within the slotted rotor 52 when rotating through a primary inner cam wall surface 58.

[0016] The pressure plate 14 includes a first flow passage 60 and a second flow passage 62, the first flow passage 60 is configured to allow fluid flow between a primary under-vane cavity 68 of the thrust plate 16 and a primary discharge port 64. The second flow passage 62 is configured to allow fluid flow between the primary discharge port 64 and a secondary under-vane cavity 66 of the thrust plate 16. In accordance with aspects of the exemplary embodiment, the first flow passage 60 is configured to be a predetermined smaller size than the second flow passage 62. In one embodiment, the first flow passage 60 is configured to be less than half the size of the second flow passage 62, and in another embodiment the first flow passage 60 is less than or equal to one third the size of the second flow passage 62. It is appreciated that the size of the second flow passage 62 will be predetermined based on desired pump under-vane pressurization characteristics under cold start conditions, and as such other flow passage size criteria may be contemplated by other without exceeding the scope of this disclosure.

[0017] The thrust plate 16 includes the primary under-vane cavity 68, a first adjacent under-vane cavity 70 having one open end 72 in fluid communication with a first end 74 of the primary under-vane cavity 68, and a second adjacent under-vane cavity 76 having one open end 78 in fluid communication with a second end 80 of the primary under-vane cavity 68. As noted above, the thrust plate also includes a secondary under-vane cavity 66 in fluid communication with the second flow passage 62 of the pressure plate 14.

[0018] In accordance with aspects of the exemplary embodiment, each of the first 70 and second 76 adjacent under-vane cavities are aligned with inward radial vane 54 motion caused by a multiple lobe cam 50, inner cam wall surfaces 56, profile during rotation of the slotted rotor 52. The inward radial motion of the vanes 54 when rotating through the inner cam wall surfaces 56 is used to pump oil and pressurize the primary cavity 68 of the thrust plate 16 as the vanes 54 of the slotted rotor 52 rotate through the primary inner cam wall surface 58 of the cam 50. The level of pressurization is controlled by the first 60 and second 62 flow passages, and the under-vane cavities. A benefit is that the vanes 54 for the primary under-vane cavity 68 will seal with the primary inner cam wall surface 58 to thereby prime the pump and cause the pump to provide the pressure and flow characteristics required for the transmission and to provide proper lubrication during a cold start condition. Existing vane pumps do not use vane radial displacements from the second adjacent under-vane cavity 76 to pressurize the primary under-vane cavity 68 in accordance with aspects of the exemplary embodiment.

[0019] The description of the invention is merely exemplary in nature and variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.