oil pump

Abstract

To provide an oil pump that can smoothly pass oil while being inexpensive.SOLUTION: A body (20) of an oil pump (10, 10A, or 10B) is provided with a return flow passage wall part (25) having almost the same height as that of a side surface (40a) of a rotor (40), along an outer peripheral surface (40b) of the rotor (40) so as to partition a return flow passage (R3). When a region of a cover (30, 30A, or 30B) opposed to the return flow passage wall part (25) is defined as a wall part opposed part (37, 37A, or 37B), at least a portion between the return flow passage wall part (25) and the wall part opposed part (37, 37A, or 37B) is defined as a shortcut flow passage (R4, R4A, or R4B) capable of returning oil released by a hydraulic valve (50), toward the side surface (40a) of the rotor (40).SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an oil pump for circulating oil. [Background technology]

[0002] For example, engines, automatic transmissions, turbochargers, and the like mounted on vehicles need to be lubricated and cooled. Many vehicles are equipped with oil pumps to circulate oil for lubricating and cooling these components. Patent Document 1 discloses a prior art related to oil pumps.

[0003] An oil pump such as that shown in Patent Document 1 has a body (housing 2), a cover (pump cover 9) that fits over the body and forms a flow path through which oil is circulated together with the body, rotors (outer rotor 6 and inner rotor 7) that are rotatably mounted in the space formed by the body and cover and are capable of circulating oil, and a hydraulic valve (spool 21) that is mounted in the flow path and is capable of releasing oil when the hydraulic pressure in the flow path is higher than a predetermined pressure.

[0004] The body is provided with a return flow passage wall along the side surface of the rotor to separate the relief passages 20, and a portion of the return flow passage wall is formed as a groove-shaped communicating groove 23. In addition, a plurality of groove-shaped rotor grooves 15 are formed in the radial direction on the side surface of the outer rotor.

[0005] A portion of the oil released by the hydraulic valve 21 passes from the communication groove 23 to the rotor groove 15 and is circulated by the rotor, thereby enabling the oil to circulate efficiently. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Utility Model Application Publication No. 4-113794 Summary of the Invention [Problem to be solved by the invention]

[0007] According to the oil pump of Patent Document 1, it is necessary to form rotor grooves 15 in order to circulate oil efficiently. This increases the cost of machining the rotor and the cost of the mold for manufacturing the rotor. The high cost of the rotor also increases the cost of the entire oil pump.

[0008] An object of the present invention is to provide an oil pump that is inexpensive yet allows oil to flow smoothly. [Means for solving the problem]

[0009] According to the present invention, a hydraulic oil supply system has a body, a cover that is placed over the body and that forms a flow path through which oil is circulated together with the body, a rotor that is rotatably disposed in a space formed by the body and the cover and that can circulate oil, and a hydraulic valve that is disposed in the flow path and that can release oil when the hydraulic pressure in the flow path is higher than a predetermined pressure, In the oil pump, the flow path includes an intake port through which oil is drawn into the body, and a return flow path that returns oil released by the hydraulic valve to the intake port, a return flow path wall portion having a height substantially equal to that of a side surface of the rotor and extending along an outer peripheral surface of the rotor to separate the return flow path; When a portion of the body facing the return flow path wall portion is set as a wall portion facing portion of the cover, An oil pump is provided, characterized in that at least a portion between the return flow path wall portion and the wall opposing portion is a shortcut flow path that can return oil released by the hydraulic valve toward the outer peripheral surface of the rotor. [Effects of the Invention]

[0010] The present invention can provide an oil pump that is inexpensive yet allows oil to flow smoothly. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a front view of an oil pump according to a first embodiment. [Figure 2] FIG. 2 is an exploded view of the oil pump shown in FIG. 1. [Figure 3] FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. [Figure 4] 4A is a cross-sectional view for explaining the operation, and 4B is a view for explaining the operation with the cover removed. [Figure 5] FIG. 10 is a cross-sectional view of an oil pump according to a second embodiment. [Figure 6] FIG. 11 is a bottom view of the cover of the oil pump according to the third embodiment. [Figure 7] FIG. 7 is an enlarged view of part 7 in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] An embodiment of the present invention will be described below with reference to the accompanying drawings.

[0013] Example 1 Please refer to Figures 1 and 2. The left side of Figure 2 shows the oil pump 10 with the cover 30 removed, and the right side shows the cover 30 as viewed from the side. The oil pump 10 shown in Figure 1 with the cover 30 in place is shown in Figure 2.

[0014] The oil pump 10 is, for example, an internal gear pump used in a vehicle and operated by engine power, and is connected to the engine crankshaft via a chain or gears or directly.

[0015] The oil pump 10 has as its main components a body 20 as a housing, a cover 30 that covers the body 20, a rotor 40 that is rotatably mounted in the space formed by the body 20 and the cover 30, and a hydraulic valve 50 that is housed in the body 20 and is activated when the hydraulic pressure exceeds a predetermined pressure.

[0016] The space formed by the body 20 and the cover 30 is made into flow paths R1 to R4 through which oil flows. The flow paths R1 to R4 include an intake port R1 through which oil is drawn into the body 20, a discharge port R2 through which the oil drawn in from the intake port R1 passes through the rotor 40 and is discharged to the outside, a return flow path R3 that returns the oil released from the discharge port R2 by the hydraulic valve 50 to the intake port R1, and a shortcut flow path R4 that branches off from the return flow path R3 and is capable of returning the oil toward the side surface 40a of the rotor 40.

[0017] The body 20 has an introduction section 21 through which oil is introduced from the outside and which is connected to the intake port R1, a rotor storage wall section 22 which is raised along the outer peripheral surface 40b of the rotor 40 and which is connected to the discharge port R2, a valve storage section 23 which stores the hydraulic valve 50, a plurality of return openings 24 which are opened in the valve storage section 23 and through which oil flows when the oil pressure is higher than a predetermined force, a return flow path wall section 25 which is formed near the return openings 24 and is provided along the outer peripheral surface 40b of the rotor 40 so as to separate the return flow path R3, and a plurality of body-side bolt insertion holes 26 which are opened along the outer peripheral edge and through which bolts are passed.

[0018] The cover 30 has a discharge port 31 that faces the discharge port R2 and discharges oil to the outside, rotor retaining portions 32, 35 that protrude from the general surface toward the rotor 40 and have their tips abutting against the side surface 40a of the rotor 40, and a plurality of cover-side bolt insertion holes 36 that are drilled along the outer periphery and through which bolts are passed. The cover 30 and the body 20 are fastened together by bolts that are passed through the bolt insertion holes 26, 36.

[0019] 2 and 3, the portion of the cover 30 that faces the return flow path wall 25 is called a wall-facing portion 37. The wall-facing portion 37 is formed in a flat shape (so-called flush) that continues from the general surface of the cover 30. In other words, nothing is formed on the wall-facing portion 37. Therefore, a gap is formed between the return flow path wall 25 and the wall-facing portion 37, allowing oil to pass through.

[0020] The flow path between the return flow path wall 25 and the wall-facing portion 37 is referred to as the shortcut flow path R4. At least a portion of the shortcut flow path R4 between the return flow path wall 25 and the wall-facing portion 37 can be said to be a flow path that can return oil released by the hydraulic valve 50 toward the side surface 40a of the rotor 40.

[0021] See Figure 2. The rotor 40 is made up of an inner rotor 41 that rotates when the engine is running, and an outer rotor 42 that is disposed on the outer periphery of the inner rotor 41 and rotates when the inner rotor 41 rotates.

[0022] The inner rotor 41 is restricted from being displaced in the axial direction by the rotor retainer 32, and the outer rotor 42 is restricted from being displaced in the axial direction by the rotor retainer 35.

[0023] See Figure 3. The hydraulic valve 50 can be a well-known hydraulic valve. For example, it is composed of a valve body 51 that can open and close the return opening 24, and a spring 52 that urges the valve body 51 to close the return opening 24. When the hydraulic pressure increases, the valve body 51 moves backward against the urging force of the spring 52. When the valve body 51 moves backward, the return opening 24 opens, and oil flows into the return flow path R3 (see Figure 2).

[0024] The operation of the oil pump 10 described above will now be described.

[0025] See Figure 2. For example, when the engine is running while the vehicle is running, the inner rotor 41 and the outer rotor 42 rotate. The rotation of the inner rotor 41 and the outer rotor 42 circulates oil. The oil is introduced through the inlet portion 21, passes through the suction port R1, the rotor 40, and the discharge port R2, and is discharged to the outside through the discharge port 31. The oil discharged from the discharge port 31 passes through the engine and the like, and is returned to the oil pump 10 through the inlet portion 21.

[0026] Also see Figure 3. When oil is circulating, the oil pressure at the discharge port R2 may increase. When the oil pressure at the discharge port R2 increases, the oil pushes down the valve body 51, opening the return opening 24. When the return opening 24 is opened, some of the oil flows from the return opening 24 to the return flow path R3. Some of the oil that flows into the return flow path R3 is returned to the suction port R1.

[0027] 4A and 4B, a portion of the oil flowing from the return opening 24 flows into a shortcut flow path R4 formed between the return flow path wall portion 25 and the cover 30. The oil that has flowed into the shortcut flow path R4 is circulated from the side surface 40a of the rotor 40 to the discharge port R2.

[0028] The oil pump 10 described above can be described as follows.

[0029] The oil pump 10 has a body 20, a cover 30 that covers the body 20 and forms, together with the body 20, a flow path through which oil is circulated, a rotor 40 that is rotatably mounted in the space formed by the body 20 and the cover 30 and is capable of circulating the oil, and a hydraulic valve 50 that is mounted in the flow path and is capable of releasing the oil when the hydraulic pressure in the flow path is higher than a predetermined pressure. The flow paths R1 to R4 also include an intake port R1 through which oil is drawn into the body 20, and a return flow path R3 that returns the oil released by the hydraulic valve 50 to the intake port R1.

[0030] The body 20 is provided with a return flow path wall 25 that is approximately the same height as the side surface 40a of the rotor 40 and that extends along the outer peripheral surface 40b of the rotor 40 to separate the return flow path R3. At least a portion of the space between the return flow path wall 25 and the opposing wall portion 37 is defined as a shortcut flow path R4 that allows oil released by the hydraulic valve 50 to return toward the side surface 40a of the rotor 40.

[0031] A portion of the oil returned to the return flow path R3 passes through the shortcut flow path R4 and is returned toward the side surface 40a of the rotor 40. This allows the oil to flow more smoothly than if all of the oil returned to the return flow path R3 were returned to the suction port R1. Because there is no need to form grooves on the side surface of the rotor to allow the oil to flow smoothly, a rotor 40 (outer rotor 42) that is less expensive than the rotor disclosed in Patent Document 1 can be used. This also reduces the overall cost of the oil pump 10.

[0032] The wall-facing portion 37 is formed in a flat shape that continues from the general surface of the cover 30. This reduces the cost of the mold and the like used to manufacture the cover 30, thereby further reducing the cost of the oil pump 10.

[0033] <Example 2> Next, a second embodiment of the present invention will be described with reference to the drawings.

[0034] Fig. 5 shows a cross-sectional configuration of an oil pump according to a second embodiment, and corresponds to Fig. 4A described above. The same reference numerals are used for parts common to the first embodiment, and detailed descriptions are omitted. In the oil pump 10A according to the second embodiment, the wall-facing portion 37A is formed by a protrusion that protrudes from the general surface of the cover 30A toward the return flow path wall portion 25. The other basic configuration is the same as that of the oil pump 10 according to the first embodiment (Fig. 2).

[0035] The oil pump 10A configured in this manner also achieves the desired effects of the present invention.

[0036] Furthermore, by forming the wall portion facing portion 37A by a protrusion, it is possible to set the size of the gap between the return flow path wall portion 25 and the wall portion facing portion 37 to any size. By setting the gap to any size, it is possible to set the flow path area of ​​the shortcut flow path R4A to any size, and it is possible to adjust the oil flow rate.

[0037] Example 3 Next, a third embodiment of the present invention will be described with reference to the drawings. The same reference numerals as in the first embodiment will be used and detailed description will be omitted.

[0038] FIG. 6 shows a cover 30B of an oil pump 10B according to the third embodiment as viewed from the rotor 40 side.

[0039] See Figures 6 and 7. A valve housing portion 33B that houses a hydraulic valve is formed in the cover 30B. Furthermore, a return opening 34B through which oil passes when the hydraulic valve is activated is opened in the area where the valve housing portion 33B is formed.

[0040] The return opening 34B is formed in a generally rectangular shape (long hole shape) extending in one direction, and a part of the shortcut flow path R4B is formed on an extension line L1 of the return opening 34B in the longitudinal direction.

[0041] The cover 30B has an opposing wall 38B that protrudes from the general surface toward the return flow path wall 25 (see FIG. 3) and has a tip that abuts against the return flow path wall 25. A part of the opposing wall 38B is a wall opposing portion 37B. A part of the tip of the opposing wall 38B is formed in a concave shape. This groove-shaped portion forms the shortcut flow path R4B.

[0042] In addition, an oil guide portion 39B is formed to guide oil from the vicinity of the return opening portion 34B toward the portion where the shortcut flow path R4B is formed. The oil guide portion 39B is also formed by forming a part of the opposing wall portion 38B into a concave shape.

[0043] The tip of the opposing wall portion 38B can come into contact with the side surface 40a (see FIG. 3) of the rotor 40. Furthermore, the shortcut flow path R4B does not come into contact with the side surface of the rotor of the opposing wall portion 38B, but is sandwiched between the portions that can come into contact.

[0044] The oil pump 10B configured in this manner also achieves the desired effects of the present invention.

[0045] Furthermore, in the oil pump 10B, a shortcut flow path R4B is formed in a recessed portion of the tip of the opposing wall portion 38B. By forming the shortcut flow path R4B in this manner, oil can be supplied to any desired location.

[0046] Furthermore, the tip of the opposing wall portion 38B can come into contact with the side surface 40a (see FIG. 3) of the rotor 40. This allows oil to flow into the shortcut flow path R4B while preventing the rotor 40 from being displaced in the axial direction.

[0047] Moreover, the shortcut flow path R4B is sandwiched on both sides by portions of the opposing wall portion 38B that can come into contact with the side surface 40a of the rotor 40. This makes it possible to suppress displacement of the rotor 40 and ensure that oil is supplied to the side surface 40a of the rotor 40.

[0048] Furthermore, at least a part of the shortcut flow passage R4B is formed on an extension line L1 in the longitudinal direction of the return opening 34B, so that oil can flow smoothly from the return opening 34B to the shortcut flow passage R4B.

[0049] Although the oil pump according to the present invention has been described using an example in which it is applied to a vehicle, it can also be applied to vehicles other than vehicles, construction machinery, etc., and is not limited to these types.

[0050] Furthermore, the oil pump is not limited to one that is operated by an external power source such as an engine, and the present invention can also be applied to an electrically operated oil pump.

[0051] Furthermore, the embodiments can be combined as appropriate. For example, the return opening of the oil pump shown in Figures 2 and 5 can be formed as an elongated hole extending in one direction, and at least a part of the shortcut flow path can be formed on an extension of the longitudinal axis of the return opening. Furthermore, the hydraulic valve and the return opening can be provided in either the body or the cover.

[0052] That is, the present invention is not limited to the examples as long as the functions and effects of the present invention are exhibited. [Industrial Applicability]

[0053] The oil pump of the present invention is suitable for use in a vehicle. [Explanation of symbols]

[0054] 10, 10A, 10B...Oil pump 20...Body 25...Return channel wall 30, 30A, 30B...Cover 34B...Return opening 37, 37A, 37B...wall facing part 38B…Opposing wall part 40... rotor, 40a... side surface, 40b... outer circumferential surface 50...Hydraulic valve R1...suction port R3: Return flow path R4, R4A, R4B...Shortcut flow path L1…extension line

Claims

1. The oil pump has a body, a cover that covers the body and forms a flow path through which oil is circulated together with the body, a rotor that is rotatably provided in a space formed by the body and the cover and is capable of circulating oil, and a hydraulic valve that is provided in the flow path and is capable of releasing oil when the hydraulic pressure in the flow path is higher than a predetermined pressure, In the oil pump, the flow path includes an intake port through which oil is drawn into the body, and a return flow path that returns oil released by the hydraulic valve to the intake port, a return flow path wall portion having a height substantially equal to that of a side surface of the rotor and extending along an outer peripheral surface of the rotor to separate the return flow path; When a portion of the body facing the return flow path wall portion is set as a wall portion facing portion of the cover, At least a portion between the return flow path wall portion and the wall portion opposing portion is a shortcut flow path that can return oil released by the hydraulic valve toward the outer circumferential surface of the rotor, the cover includes an opposing wall portion that protrudes from a general surface of the cover toward the return flow path wall portion and has a tip that abuts against the return flow path wall portion, The oil pump is characterized in that the shortcut flow path is formed in a portion of the tip of the opposing wall portion that is formed in a concave shape.

2. The oil pump according to claim 1 , wherein a tip of the opposing wall portion is capable of abutting against a side surface of the rotor.

3. The oil pump according to claim 2 , wherein the shortcut passage is sandwiched between portions of the rotor that can come into contact with a side surface of the rotor.

4. a return opening for returning oil to the return flow path when the hydraulic valve is activated is formed in the body or the cover; The oil pump according to any one of claims 1 to 3, wherein the return opening is formed in the shape of an elongated hole extending in one direction, and at least a portion of the shortcut flow path is formed on an extension line of the longitudinal direction of the return opening.

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