Vane pump
The vane pump with multiple discharge ports and varying flow resistances addresses vane jumping and high torque issues, ensuring quick startup by controlling vane ejection and optimizing oil flow.
Patent Information
- Application Number
- JP2024003732
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-01-15
- Publication Date
- 2025-07-28
AI Technical Summary
Vane pumps in automotive transmissions experience vane jumping out issues, especially at low temperatures, leading to increased driving torque and slow startup due to high oil viscosity and unnecessary hydraulic oil requirements.
A vane pump design with multiple discharge ports having varying flow resistances to control vane protrusion, including ports that promote and suppress vane ejection, reducing driving torque and enabling quick startup.
The design reduces driving torque and facilitates rapid startup by managing vane protrusion effectively, preventing sliding resistance and optimizing oil flow at low temperatures.
Smart Images
Figure 2025110036000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a vane pump used as a hydraulic pressure generating pump for an automotive transmission or a lubrication cooling pump for an electric car (EV).
Background Art
[0002] As an example, when applying a vane pump to an automotive transmission, two types of pressured oil, high pressure and low pressure, are required. Patent Document 1 describes a vane pump that discharges two types of pressured oil, high pressure and low pressure, as a single unit without requiring separate hydraulic equipment such as a distribution valve.
[0003] In the vane pump of Patent Document 1, in the first side plate having two discharge ports, an oil passage communicating from the discharge port to the back pressure groove of the vane is provided to improve the jumping-out property of the vane. In particular, by providing a portion with a narrow groove width in the oil passage, it is possible to discharge a predetermined hydraulic pressure from the start (low temperature).
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] In the vane pump of Patent Document 1, the vane is likely to jump out with respect to the cam ring from the start. However, if the vane jumps out, sliding resistance with the inner peripheral surface of the cam ring naturally occurs. Also, at low temperatures, the viscosity of the oil is high, so the driving torque for rotation also increases. On the other hand, there is also hydraulic oil that is not so necessary at the start, such as the hydraulic oil used for cooling.
[0006] In view of such problems, the present invention provides a vane pump having two or more discharge ports, and by providing a discharge port that promotes the ejection of vanes at low temperatures and a discharge port that suppresses it, the driving torque at startup (low temperatures) is reduced, and an object of the present invention is to provide a vane pump that can start quickly.
Means for Solving the Problems
[0007] To solve the above problems, a typical configuration of the vane pump according to the present invention includes a pump body having a suction port, a pump cover having a discharge port and covering a recess of the pump body, a rotor disposed in the recess of the pump body and rotatable about an axis, a plurality of vane grooves radially formed on an outer peripheral surface of the rotor, a plurality of vanes fitted into the plurality of vane grooves and slidably protruding from the rotating rotor, a first side plate disposed on a discharge port side of the rotor, and a second side plate disposed on a suction port side of the rotor. The first side plate has a plurality of discharge ports formed on the rotor side, a plurality of back pressure grooves formed on the rotor side and communicable with the plurality of vane grooves of the rotor, and a plurality of oil passages respectively communicating from the plurality of discharge ports to the plurality of back pressure grooves and having a difference in flow resistance.
[0008] Preferably, there are two each of the plurality of discharge ports, back pressure grooves, and oil passages described above, and the flow resistance of one oil passage is low and the flow resistance of one oil passage is high.
[0009] Preferably, there are three each of the plurality of discharge ports, back pressure grooves, and oil passages described above, and the flow resistance of one oil passage is low and the flow resistance of two oil passages is high.
[0010] Preferably, there are three each of the plurality of discharge ports, back pressure grooves, and oil passages described above, and the flow resistance of two oil passages is low and the flow resistance of one oil passage is high.
Effects of the Invention
[0011] According to the present invention, in a vane pump having two or more discharge ports, by providing a discharge port that promotes the protrusion of the vane and a discharge port that suppresses it at low temperatures, it is possible to provide a vane pump that reduces the driving torque at startup (low temperature) and enables rapid startup.
Brief Description of the Drawings
[0012]
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Mode for Carrying Out the Invention
[0013] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in such embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals to omit redundant description, and elements not directly related to the present invention are not shown.
[0014] FIG. 1 is a cross-sectional view of a vane pump 100 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line X-X of the vane pump 100 of FIG. 1. FIG. 3 is a cross-sectional view taken along the line Y-Y of the vane pump 100 of FIG. 1. The vane pump 100 is used, for example, as a hydraulic pressure generating pump for an automotive transmission or a lubrication cooling pump for an EV car (electric car).
[0015] The vane pump 100 includes a pump body 102 and a pump cover 104 shown in FIG. 1. One suction port 106 is provided in the pump body 102. Two discharge ports 108a and 108b shown in FIG. 2 are provided in the pump cover 104. The pump cover 104 covers the inside (recess 110) of the pump body 102.
[0016] The vane pump 100 further includes a rotor 112, a shaft 114, and a cam ring 116. The rotor 112 is disposed in the recess 110 of the pump body 102 and is rotatable about the shaft 114. The shaft 114 is rotatably attached in a state of passing through a central hole of the rotor 112 and a hole provided at the center of the pump cover 104 as shown in FIG. 1.
[0017] A ring-shaped cam ring 116 is accommodated in the recess 110 of the pump body 102 as shown in FIGS. 2 and 3. Further, the rotor 112 is accommodated inside the cam ring 116. In this way, the cam ring 116 and the rotor 112 are accommodated in the recess 110 of the pump body 102 in a nested manner.
[0018] Furthermore, the vane pump 110 includes a plurality of vane grooves 118, a plurality of vanes 120, a first side plate 122, and a second side plate 124. The plurality of vane grooves 118 are radially provided on the outer peripheral surface of the rotor 112. The plurality of vanes 120 are fitted into the plurality of vane grooves 118, are in a state of being able to enter and exit in the radial direction of the rotor 112, and project slidably from the rotating rotor 112. As a result, the plurality of vanes 120 rotate and move along the inner side of the cam ring 116 and move in and out toward the cam ring 116 as the rotor 112 rotates.
[0019] Also, on both end faces of the cam ring 116, substantially disk-shaped first side plate 122 and second side plate 124 are arranged so as to sandwich the rotor 112 from both sides as shown in FIG. 1. The first side plate 122 is on one end face side of the cam ring 116 and the rotor 112, and is arranged at a position close to the discharge ports 108a, 108b. The second side plate 124 is on the other end face side of the cam ring 116 and the rotor 112, and is arranged at a position close to the suction port 106.
[0020] Furthermore, the first side plate 122 partitions the high-pressure chambers 128a, 128b together with the recesses 126a, 126b of the pump cover 104 as shown in FIG. 1. In the vane pump 100, oil is sucked into the inside from the suction port 106 of the pump body 102, and is sent in the direction of the discharge ports 108a, 108b of the pump cover 104 in a state of being pressurized in the high-pressure chambers 128a, 128b. Then, the oil inside the vane pump 100 is discharged (ejected) from the discharge ports 108a, 108b of the pump cover 104.
[0021] Here, the plate structure and the oil passage structure in the case where the first side plate 122A of (the conventional structure) as a comparative example is applied to the vane pump 100 in FIG. 1 instead of the first side plate 122 will be described.
[0022] FIG. 4 is a view showing the first side plate 122A of the comparative example (conventional structure). FIG. 4(a) is a view showing the rotor 112 side (inside) of the first side plate 122A. FIG. 4(b) is a view showing the pump cover 104 side (outside) of the first side plate 122A.
[0023] On the rotor 112 side of the first side plate 122, as shown in FIG. 4(a), a first suction port 130, a second suction port 132, a first discharge port 134, a second discharge port 136, and a pair of back pressure grooves 138, 140 are formed. After oil is sucked into the vane pump 100 through the suction port 106 shown in FIG. 1, the first suction port 130 and the second suction port 132 send the oil in the direction of the rotor 112. The first discharge port 134 and the second discharge port 136 send the oil discharged from the rotor 112 in the directions of the discharge ports 108a, 108b shown in FIG. 2.
[0024] As shown in FIG. 4(a), the pair of back pressure grooves 138, 140 are provided in an arc shape and face each other around the central hole 142 passing through the shaft 114 (see FIG. 2). The pair of back pressure grooves 138, 140 are communicable with a plurality of vane grooves 118 shown in FIGS. 2 and 3 provided on the outer peripheral surface of the rotor 112.
[0025] Furthermore, back pressure ports 144, 146 are respectively provided in the pair of back pressure grooves 138, 140 as shown in FIGS. 4(a) and 4(b). The back pressure ports 144, 146 connect the front and back of the first side plate 122, that is, the rotor 112 side and the pump cover 104 side. These back pressure ports 144, 146 are connected to the high pressure chambers 128a, 128b shown in FIG. 1 formed between the first side plate 122 and the pump cover 104. Furthermore, the high pressure chambers 128a, 128b are respectively connected to the discharge ports 108a, 108b shown in FIG. 2.
[0026] Also, as shown in FIG. 4(b), two oil passages 148 are formed on the pump cover 104 side of the first side plate 122A. The two oil passages 148 respectively communicate from the first discharge port 134 and the second discharge port 136 to a pair of back-pressure grooves 138 and 140 via the back-pressure ports 144 and 146. Since the two oil passages 148 in this comparative example (conventional structure) have the same structure, there is no difference in flow resistance.
[0027] FIG. 5 is a diagram showing an oil passage structure using the first side plate 122A of the comparative example in FIG. 4. FIG. 5(a) is a diagram showing the pump cover 104 indicated by a chain line superposed on the first side plate 122A in FIG. 4(a). FIG. 5(b) is a cross-sectional view taken along line A-A of FIG. 5(a).
[0028] The oil passage 148 shown in FIG. 5(b) is a space partitioned by a groove formed on the pump cover 104 side of the first side plate 122A and the pump cover 104. The groove may be formed on the pump cover 104 instead of the first side plate 122A. Further, the oil passage 148 communicates from the first discharge port 134 leading from the inside to the outside of the first side plate 122A as shown in FIG. 5(b) to the back-pressure groove 140 via the back-pressure port 146. Furthermore, the oil passage 148 is formed by a deep groove having a dimension La, and has a larger cross-sectional area compared to the oil passage 148A (see FIGS. 6(a) and 6(b)) of the first side plate 122 to be described later.
[0029] Note that the first suction port 150, the second suction port 152, the first storage groove 154, and the second storage groove 156 shown in FIG. 3 are formed in the second side plate 124. After oil is sucked into the vane pump 100 through the suction port 106, the first suction port 150 and the second suction port 152 send the oil in the direction of the rotor 112. The first storage groove 154 and the second storage groove 156 store a certain amount of oil inside the vane pump 100.
[0030] Here, the operation of the vane pump 100 to which the first side plate 122A of the comparative example (conventional structure) is applied will be described.
[0031] When the shaft 114 rotates, the vane 120 protrudes from the vane groove 118 along the shape of the inner peripheral surface of the cam ring 116, and the volume between the plurality of vanes 120 (pump chamber) expands. The oil sucked from the suction port 106 of the vane pump 100 enters the pump chamber via the first suction ports 130 and 132 of the first side plate 122A, the first suction ports 150 and 152 of the second side plate 124, and the like.
[0032] As the rotation of the shaft 114 further progresses, the vane 120 acts in a direction to be accommodated in the vane groove 118 of the rotor 112 along the shape of the inner peripheral surface of the cam ring 116. Since the volume of the pump chamber decreases, the oil in the pump chamber is discharged from the first discharge ports 134 and 136.
[0033] At this time, oil flows from the first discharge ports 134 and 136 through the oil passages 148 and into the back pressure grooves 138 and 140 via the back pressure ports 144 and 146. Since the back pressure grooves 138 and 140 communicate with the vane groove 118 of the rotor 112, a pressure in the direction of protruding outside the rotor 112 is applied to the vane 120.
[0034] As described above, in the first side plate 122A of the comparative example (conventional structure), two oil passages 148 having the same structure are provided. Thereby, the vane 120 can be easily made to protrude by the pressure (back pressure) of the oil that has moved from the back pressure grooves 138 and 140 to the vane groove 118.
[0035] However, if the vane 120 protrudes, sliding resistance with the inner peripheral surface of the cam ring 116 occurs. Also, at low temperatures, the viscosity of the oil is high, so the driving torque for rotation also increases. On the other hand, there is also hydraulic oil such as that used for cooling, which is not so necessary at startup (low temperatures).
[0036] Therefore, in the vane pump 100 according to the embodiment of the present invention, a configuration is adopted in which a difference is provided in the flow resistance of a plurality of oil passages, thereby reducing the driving torque at the start (low temperature) and enabling a quick start.
[0037] FIG. 6 is a view showing the first side plate 122 of the embodiment. FIG. 6(a) is a view showing the pump cover 104 side (outer side) of the first side plate 122, corresponding to FIG. 4(b). FIG. 6(b) is a cross-sectional view taken along line B-B of FIG. 6(a). FIG. 6(c) is a view for explaining the protrusion of the vane 120.
[0038] As shown in FIGS. 6(a) and 6(b), the first side plate 122 is different from the above-described first side plate 122A as a comparative example in that it is provided with a plurality of oil passages 148 and 148A having different flow resistances.
[0039] As shown in FIG. 6(a), the oil passage 148 communicates from the second discharge port 136 through the back pressure port 144 to the back pressure groove 138, and is formed by a deep groove having a dimension La as shown in FIG. 6(b). Therefore, the oil passage 148 has a wide cross-sectional area and a small flow resistance.
[0040] As shown in FIG. 6(a), the oil passage 148A communicates from the first discharge port 134 through the back pressure port 146 to the back pressure groove 140, and is formed by a shallow groove having a dimension Lb as shown in FIG. 6(b). Therefore, the oil passage 148A has a narrow cross-sectional area and a large flow resistance. In this way, the first side plate 122 is provided with a plurality of oil passages 148 and 148A having different flow resistances.
[0041] The oil passages 148 and 148A are spaces partitioned by the groove formed on the pump cover 104 side of the first side plate 122 and the pump cover 104 (see FIG. 5(b)). Therefore, instead of the first side plate 122, a plurality of oil passages having different flow resistances may be formed by forming grooves in the pump cover 104.
[0042] Furthermore, to create a difference in the flow resistance of the oil passages 148 and 148A, it is not limited to simply narrowing or widening the cross-sectional area. The throttle sections 139 and 141 (see Fig. 4(a)) can be lengthened to increase the flow resistance, or shortened to decrease the flow resistance.
[0043] Here, the case where the vane pump 100 is used as a cooling / lubrication pump will be described. In this case, the hydraulic pressure used for cooling in the vane pump 100 is unnecessary during startup (low temperature). Therefore, in the vane pump 100, the flow resistance of the oil passage 148A connecting the discharge port used for cooling (for example, the first discharge port 134) and the backpressure groove 140 is increased, thereby increasing the resistance of the oil flowing into the backpressure groove 140.
[0044] As a result, it becomes difficult for oil to be supplied to the backpressure groove 140 shown in Fig. 6(c), and it becomes difficult for the backpressure to rise, thereby suppressing the protrusion of the upper vane 120 in the figure. As a result, the tip of the vane 120 and the inner peripheral surface of the cam ring 116 no longer slide, and the generation of sliding torque can be prevented. Furthermore, when the vane 120 no longer protrudes with respect to the cam ring 116, it no longer functions as a pump and the driving torque can be reduced.
[0045] Also, in the vane pump 100, the flow resistance of the oil passage 148 connecting the discharge port (for example, the second discharge port 136) that requires hydraulic pressure even at low temperatures and the backpressure groove 138 is reduced to suppress the resistance of the oil flowing into the backpressure groove 138. As a result, it becomes easier for oil to be supplied to the backpressure groove 138 shown in Fig. 6(c), and it becomes easier for the backpressure to rise, thereby improving the protrusion property of the lower vane 120 in the figure and enabling quick startup.
[0046] In this way, according to the vane pump 100, by providing the first discharge port 134 that suppresses the protrusion of the vane 120 at low temperatures and the second discharge port 136 that promotes the protrusion of the vane 120 at low temperatures, the driving torque during startup (low temperature) can be reduced and startup can be performed quickly.
[0047] FIG. 7 is a diagram for explaining an oil passage structure using the first side plate 122B of a modified example. FIG. 7(a) is a diagram showing the pump cover 104 side of the first side plate 122B of the modified example, corresponding to FIG. 6(a). FIG. 7(b) is a cross-sectional view taken along the line C-C of FIG. 7(a).
[0048] Three discharge ports 158a, 158b, 158c, three backpressure grooves 160a, 160b, 160c, and three backpressure ports 162a, 162b, 162c are formed in the first side plate 122B. Further, three oil passages 164a, 164b, 164c having differences in flow resistance are provided in the first side plate 122B. However, among the three oil passages 164a, 164b, 164c, two oil passages 164b, 164c have the same structure and no difference in flow resistance.
[0049] As shown in FIG. 7(a), the oil passage 164a communicates from the discharge port 158a through the backpressure port 162a to the backpressure groove 160a, and is formed of a deep groove having a dimension La as shown in FIG. 7(b). Therefore, the oil passage 164a has a wide cross-sectional area and a small flow resistance.
[0050] As shown in FIG. 7(a), the oil passages 164b, 164c communicate from the discharge ports 158b, 158c through the backpressure ports 162b, 162c to the backpressure grooves 160b, 160c, respectively. The oil passages 164b, 164c have the same structure and are formed of shallow grooves having a dimension Lb as shown in FIG. 7(b), for example. Therefore, the oil passages 164b, 164c have a narrow cross-sectional area and a large flow resistance.
[0051] In this way, one oil passage 164a having a small flow resistance and two oil passages 164b, 164c having a large flow resistance are provided in the first side plate 122B as shown in FIGS. 7(a) and 7(b). However, the configuration of the first side plate 122B is merely illustrative, and the combination of the three discharge ports 158a, 158b, 158c and the three oil passages 164a, 164b, 164c having differences in flow resistance can be changed as appropriate.
[0052] Figure 7(c) shows the combinations of the types of the discharge ports 158a, 158b, 158c and the oil passages 164a, 164b, 164c. Here, the type “1” of the oil passage is the one with a small flow resistance like the oil passage 164a, and the type “2” of the oil passage is the one with a large flow resistance like the oil passages 164b and 164c. Also, the discharge ports 158a, 158b, 158c are shown as “discharge port 1”, “discharge port 2”, and “discharge port 3”.
[0053] As shown in Figure 7(c), there are six combinations of the types of the discharge ports and the oil passages. As shown in this combination, in a vane pump including three discharge ports 158a, 158b, 158c, a configuration can be adopted in which one oil passage has a low flow resistance and two oil passages have a high flow resistance, or a configuration can be adopted in which two oil passages have a low flow resistance and one oil passage has a high flow resistance. Thereby, in a three-port vane pump, the driving torque at the start (low temperature) can be further reduced, or the start can be performed more promptly.
[0054] As described above, the preferred embodiments of the present invention have been described with reference to the accompanying drawings. Needless to say, the present invention is not limited to such examples. It is obvious that those skilled in the art can conceive various modification examples or correction examples within the scope described in the claims, and it is naturally understood that those also belong to the technical scope of the present invention.
Industrial Applicability
[0055] The present invention can be used as a vane pump used as a hydraulic pressure generating pump for an automotive transmission or a lubrication cooling pump for an EV vehicle (electric car).
Explanation of Signs
[0056] 100…Vane pump, 102…Pump body, 104…Pump cover, 106…Suction port, 108a, 108b…Discharge ports, 110…Recess of pump body, 112…Rotor, 114…Shaft, 116…Cam ring, 118…Vane groove, 120…Vane, 122, 122A, 122B…First side plate, 124…Second side plate, 126a, 126b…Recesses of pump cover, 128a, 128b…High-pressure chambers, 130, 150…First suction port, 132, 152…Second suction port, 134…First discharge port, 136…Second discharge port, 138, 140…Back-pressure grooves, 139, 141…Throttle sections, 142…Holes in the first side plate, 144, 146…Back-pressure ports, 148, 148A…Oil passages, 144…Drain port, 146…Spring chamber, 150…Suction port, 152…Discharge port, 154…First storage groove, 156…Second storage groove, 158a, 158b, 158c…Discharge ports, 160a, 160b, 160c…Back-pressure grooves, 162a, 162b, 162c…Back-pressure ports, 164a, 164b, 164c…Oil passages
Claims
1. A pump body having a suction port, A pump cover having a discharge port and covering the recess of the pump body, A rotor disposed in the recess of the pump body and rotatable about an axis, A plurality of vane grooves radially formed on the outer peripheral surface of the rotor, A plurality of vanes fitted into the plurality of vane grooves and slidably protruding from the rotating rotor, A first side plate disposed on the discharge port side of the rotor, A second side plate disposed on the suction port side of the rotor, and comprising: The first side plate, A plurality of discharge ports formed on the rotor side, A plurality of back pressure grooves formed on the rotor side and communicable with the plurality of vane grooves of the rotor, A vane pump, characterized in that it has a plurality of oil passages respectively communicating from the plurality of discharge ports to the plurality of back pressure grooves and having a difference in flow resistance.
2. The vane pump according to claim 1, wherein there are two each of the plurality of discharge ports, back pressure grooves and oil passages, one oil passage having a low flow resistance and one oil passage having a high flow resistance.
3. The vane pump according to claim 1, wherein there are three each of the plurality of discharge ports, back pressure grooves and oil passages, one oil passage having a low flow resistance and two oil passages having a high flow resistance.
4. The vane pump according to claim 1, wherein there are three each of the plurality of discharge ports, back pressure grooves and oil passages, two oil passages having a low flow resistance and one oil passage having a high flow resistance.
Citation Information
Patent Citations
vane pump
JP6773991B2