Lubricating oil pipe
The lubricating oil pipe addresses wear and leakage issues by ensuring surface contact and thrust force alignment, effectively reducing friction and maintaining lubrication.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- TOYOTA JIDOSHA KK
- Filing Date
- 2024-12-20
- Publication Date
- 2026-07-02
AI Technical Summary
Relative rotation between connected shafts and pipes leads to wear due to sliding friction, which is not addressed by existing designs.
A lubricating oil pipe with one end inserted into a supply-side component and the other end into a demand-side component, featuring a larger surface area at one end face to suppress wear and oil leakage by ensuring surface contact and thrust force alignment.
Suppresses wear and oil leakage by ensuring surface contact and thrust force alignment, reducing friction and maintaining effective lubrication.
Smart Images
Figure 2026109691000001_ABST
Abstract
Description
Technical Field
[0005]
[0001] This invention relates to a lubricating oil pipe.
Background Art
[0002] Patent Document 1 discloses the structure of a vacuum pump that operates by receiving power transmission from a camshaft of an internal combustion engine. The rotor of this vacuum pump has a shaft that rotates integrally with the camshaft. Inside the camshaft, an oil passage through which lubricating oil flows is formed. The lubricating oil inside the camshaft is supplied to the shaft of the rotor through an oil supply pipe inserted inside the shafts of the camshaft and the rotor.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] In the connection part where power transmission is performed as described above, it is necessary to restrict the relative rotation between the connected shafts. Therefore, the connected shafts are fitted together so as to engage with each other in the circumferential direction for connection. On the other hand, in the connection part where power transmission is not performed, it is not necessary to perform the processing for fitting the connected shafts together so as to engage with each other in the circumferential direction as described above. However, if the above processing is not performed, relative rotation occurs between parts such as the connected shafts and pipes. When relative rotation occurs, the shafts, pipes, etc. are likely to wear due to sliding friction.
Means for Solving the Problems
[0005] To solve the above problem, a lubricating oil pipe is provided, with one end inserted into a supply-side component that discharges lubricating oil, and the other end inserted into a demand-side component that receives the lubricating oil. This lubricating oil pipe is a hollow, cylindrical pipe that supplies lubricating oil from the supply-side component to the demand-side component. The surface area of the end face of the end inserted into the supply-side component is larger than the surface area of the end face of the end inserted into the demand-side component. [Effects of the Invention]
[0006] According to the above-described lubricating oil pipe, wear of the lubricating oil pipe is suppressed by making surface contact between the end face of the lubricating oil pipe and the demand-side component, and oil leakage at the insertion point where the lubricating oil pipe is inserted into the demand-side component can be suppressed. [Brief explanation of the drawing]
[0007] [Figure 1] Figure 1 is a schematic diagram showing a portion of the lubricating oil supply path in a transaxle equipped with a lubricating oil pipe according to one embodiment. [Figure 2] Figure 2 is a schematic cross-sectional view of the lubricating oil pipe shown in Figure 1. [Figure 3] Figure 3 is a schematic diagram showing the end face of the first end of the lubricating oil pipe shown in Figure 1. [Figure 4] Figure 4 is a schematic diagram showing the end face of the second end of the lubricating oil pipe shown in Figure 1. [Figure 5] Figure 5 is a schematic cross-sectional view of the lubricating oil pipe of the second embodiment. [Figure 6] Figure 6 is a schematic diagram showing the end face of the third end of the lubricating oil pipe shown in Figure 5. [Modes for carrying out the invention]
[0008] Hereinafter, a first embodiment of the lubricating oil pipe 13, which is one embodiment of the lubricating oil pipe, will be described with reference to Figures 1 to 4. <Lubricant supply path in transaxle 22> Figure 1 is a schematic diagram showing part of the lubrication oil supply path in a transaxle 22 equipped with a lubrication oil pipe 13. The transaxle 22 is, for example, a transaxle mounted in a front-wheel-drive hybrid vehicle.
[0009] As shown in Figure 1, the transaxle 22 is equipped with an oil pump 11 that supplies lubricating oil to each component of the transaxle 22. The transaxle 22 has passages inside for the lubricating oil discharged from the oil pump 11. The dashed lines in Figure 1 indicate the passages for the lubricating oil. The passages for the lubricating oil shown in Figure 1 consist of an oil supply passage 12, a lubricating oil pipe 13, and an input shaft 14. The oil supply passage 12 is provided inside the housing of the transaxle 22. The input shaft 14 is a hollow cylindrical shape, and its interior constitutes the passage for the lubricating oil. The oil pump 11 is connected to the oil supply passage 12. One end of the lubricating oil pipe 13 is inserted into the opening of the oil supply passage 12 in the housing. The lubricating oil pipe 13 is hollow and cylindrical. For example, the lubricating oil pipe 13 is hollow and cylindrical. The other end of the lubricating oil pipe 13 is inserted into the end of the input shaft 14. The lubricating oil discharged from the oil pump 11 flows through the oil supply passage 12 to the lubricating oil pipe 13. The lubricating oil then flows through the inside of the lubricating oil pipe 13 to the input shaft 14.
[0010] As shown in Figure 1, the transaxle 22 comprises a rotating machine 23 and a planetary gear mechanism 24. The rotating machine 23 is, for example, a motor generator that functions as a generator and electric motor. The lubricating oil pipe 13 passes through the inside of the rotor shaft of the rotating machine 23. The planetary gear mechanism 24 is, for example, a gear unit comprising a sun gear, a ring gear, and three pinion gears.
[0011] The input shaft 14 is connected to the crankshaft of the internal combustion engine at the end opposite to the end into which the lubricating oil pipe 13 is inserted. The input shaft 14 rotates by receiving power from the internal combustion engine via the crankshaft. The input shaft 14 passes through the interior of the planetary gear mechanism 24. More specifically, the input shaft 14 passes through the interior of the rotating shaft to which the sun gear of the planetary gear mechanism 24 is fixed. A planetary carrier connecting the three pinion gears of the planetary gear mechanism 24 is also fixed to the input shaft 14. The input shaft 14 transmits power from the internal combustion engine to the three pinion gears of the planetary gear mechanism 24 via the planetary carrier.
[0012] <Lubricating oil pipe 13 configuration> As shown in Figure 1, one end of the lubricating oil pipe 13 is inserted into the portion of the housing where the oil supply passage 12 is open. The housing, which is connected to the oil pump 11 and has an oil supply passage 12 that discharges lubricating oil into the lubricating oil pipe 13, is the lubricating oil supply side component. Hereinafter, the end of the lubricating oil pipe 13 that is inserted into the portion of the housing where the oil supply passage 12 is open will be referred to as the first end 41.
[0013] The lubricating oil pipe 13 has an insertion section 10, shown by a dashed line in Figure 1, where the end opposite the first end 41 is inserted into the input shaft 14. Hereinafter, the end of the lubricating oil pipe 13 that is inserted into the input shaft 14 will be referred to as the second end 42. The input shaft 14 is a demand-side component that receives lubricating oil from the lubricating oil pipe 13. The lubricating oil supplied to the input shaft 14 flows out of the input shaft 14 through oil holes provided on the side of the input shaft 14, lubricating the gears and rotating shafts that make up the planetary gear mechanism 24.
[0014] That is, the lubricating oil pipe 13 has its first end 41 inserted into the portion of the housing where the oil supply passage 12 for discharging the lubricating oil opens. The lubricating oil pipe 13 has its second end 42 inserted into the input shaft 14 that receives the supply of the lubricating oil. The lubricating oil pipe 13 supplies the lubricating oil from the oil supply passage 12 to the input shaft 14.
[0015] FIG. 2 is a cross-sectional view obtained by cutting the lubricating oil pipe 13 along the diameter of the pipe in the longitudinal direction of the pipe. The end face of the first end 41 of the lubricating oil pipe 13 is the first end face 31. The end face of the second end 42 of the lubricating oil pipe 13 is the second end face 32. FIG. 2 is illustrated such that the left side of FIG. 2 is the side of the oil supply passage 12 of the lubricating oil pipe 13, and the right side of FIG. 2 is the side of the input shaft 14 of the lubricating oil pipe 13.
[0016] FIG. 3 shows the first end face 31 of the lubricating oil pipe 13. The first end face 31 has an outer diameter of R1 and an inner diameter of Q1. FIG. 4 shows the second end face 32 of the lubricating oil pipe 13. The second end face 32 has an outer diameter of R2 and an inner diameter of Q1. However, R2 is smaller than R1.
[0017] As shown in FIGS. 3 and 4, the lubricating oil pipe 13 has the same inner diameter of the second end face 32 and the first end face 31. The lubricating oil pipe 13 has an outer diameter of the second end face 32 smaller than the outer diameter of the first end face 31. That is, the area of the first end face 31 having a larger outer diameter than the second end face 32 is larger than the area of the second end face 32.
[0018] Also, as shown in FIG. 2, holes 15 for communicating the inside and outside of the lubricating oil pipe 13 are provided on the side surface of the lubricating oil pipe 13. The holes 15 are passages for the lubricating oil flowing inside the lubricating oil pipe 13 to flow out to the outside of the lubricating oil pipe 13. The lubricating oil that has flowed out to the outside of the lubricating oil pipe 13 lubricates the inside of the rotor shaft of the rotary machine 23 covering the outer periphery of the lubricating oil pipe 13. Further, the lubricating oil is used for cooling the rotor of the rotary machine 23 through oil holes provided on the side surface of the rotor shaft.
[0019] <Operation of the First Embodiment> When the lubricating oil pipe 13 for supplying lubricating oil is inserted into the portion where the oil supply passage 12 in the housing opens, pressure from the lubricating oil discharged from the oil supply passage 12 acts on the first end face 31. Due to this pressure, as shown in FIG. 2, a thrust force that causes the lubricating oil pipe 13 to face the input shaft 14 acts on the lubricating oil pipe 13. This thrust force increases as the area of the end face receiving the pressure from the lubricating oil increases. The magnitude of the thrust force that causes the lubricating oil pipe 13 to face the input shaft 14 increases as the area of the first end face 31 increases. Since a reverse thrust force also acts on the second end face 32 due to the pressure received from the lubricating oil, the magnitude of the thrust force that causes the lubricating oil pipe 13 to face the input shaft 14 decreases as the area of the second end face 32 of the second end portion 42 increases.
[0020] The lubricating oil pipe 13 has larger areas of the end faces 31 and 32 that receive pressure from the lubricating oil on the side of the oil supply passage 12 than on the side of the input shaft 14. Due to the difference in the areas of these end faces 31 and 32, the lubricating oil pipe 13 further increases the thrust force that causes the lubricating oil pipe 13 to face the input shaft 14 side. As a result, the second end face 32 of the lubricating oil pipe 13 is likely to be in a state of being pressed against the input shaft 14.
[0021] The lubricating oil pipe 13 inserted into the input shaft 14 rotates relative to the input shaft 14. Due to the relative rotation, wear progresses when the lubricating oil pipe 13 contacts and slides on the inner surface of the input shaft 14. When the lubricating oil pipe 13 tilts, the corner of the end of the lubricating oil pipe 13 on the input shaft 14 side contacts the inner surface of the input shaft 14 and becomes a single-contact state, making wear more likely to progress. The lubricating oil pipe 13 can suppress the tilt of the lubricating oil pipe 13 and suppress the wear of the lubricating oil pipe 13 by pressing the second end face 32 against the input shaft 14 with the thrust force from the lubricating oil.
[0022] By increasing the inner diameter of the insertion portion 10 of the input shaft 14 into which the lubricating oil pipe 13 is inserted, and providing clearance, contact and sliding between the second end portion 42 of the lubricating oil pipe 13 and the inner surface of the input shaft 14 can be suppressed. This suppresses wear of the lubricating oil pipe 13. However, by increasing the inner diameter of the insertion portion 10 of the input shaft 14 and providing clearance, the amount of lubricating oil leaking from the gap between the lubricating oil pipe 13 and the insertion portion 10 of the input shaft 14 increases, making insufficient lubrication more likely. The lubricating oil pipe 13 reduces the above gap by pressing its second end surface 32 against the input shaft 14 with thrust from the lubricating oil. The lubricating oil pipe 13 can suppress oil leakage caused by providing clearance in the insertion portion 10.
[0023] <Effects of the First Embodiment> (1-1) With the lubricating oil pipe 13, wear of the lubricating oil pipe 13 is suppressed by making the second end face 32 of the lubricating oil pipe 13 surface contact with the input shaft 14, and oil leakage in the insertion part 10 into which the lubricating oil pipe 13 is inserted is suppressed.
[0024] (1-2) The lubricating oil pipe 13 is cylindrical. The lubricating oil pipe 13 has an inner diameter equal to the inner diameter of the second end face 32 of the second end 42 inserted into the input shaft 14 and the inner diameter equal to the inner diameter of the first end face 31 of the first end 41 inserted into the oil supply passage 12. The lubricating oil pipe 13 has an outer diameter smaller than the outer diameter of the first end face 31 of the first end 41 inserted into the oil supply passage 12.
[0025] When the inner diameter of the end faces of the lubricating oil pipe 13 is the same, the larger the outer diameter, the larger the area of the end face. In the lubricating oil pipe 13, the area of the first end face 31, which has a larger outer diameter, is larger than the area of the second end face 32. The difference in the outer diameters of the end faces 31 and 32 increases the thrust that moves the lubricating oil pipe 13 toward the input shaft 14.
[0026] The above effect can be achieved by creating a difference in the outer diameter of the end faces 31 and 32 of the lubricating oil pipe 13. (1-3) The side surface of the lubricating oil pipe 13 is provided with a hole 15 that connects the inside and outside.
[0027] In the lubricating oil pipe 13, the lubricating oil flowing inside the pipe 13 flows out of the pipe 13 through holes 15 provided on its side. As the amount of lubricating oil flowing inside the lubricating oil pipe 13 decreases, the pressure exerted by the lubricating oil on the second end face 32 of the lubricating oil pipe 13 decreases. As the difference between the pressure exerted by the lubricating oil on the oil supply passage 12 side and the pressure exerted by the lubricating oil on the input shaft 14 side increases, the thrust force pushing the lubricating oil pipe 13 against the input shaft 14 increases.
[0028] Furthermore, the lubricating oil pipe 13 lubricates the rotor shaft and rotor of the rotating machine 23, which is located around the lubricating oil pipe 13, with the lubricating oil that flows out from the hole 15. The lubricating oil pipe 13 makes it possible to suppress oil leakage in the insertion portion 10 and to lubricate surrounding parts at the same time.
[0029] <Example of modification of the first embodiment> The first embodiment described above can be implemented with the following modifications. The lubricating oil pipe 13 has a difference in the outer diameter between the first end face 31 and the second end face 32. In addition to the difference in the outer diameter between the first end face 31 and the second end face 32, the lubricating oil pipe 13 may also have a difference in the inner diameter between the first end face 31 and the second end face 32. In this case, the inner diameter of the first end face 31 is smaller than the inner diameter of the second end face 32. This makes it possible to make the area of the first end face 31 larger than the area of the second end face 32.
[0030] <Second Embodiment> The second embodiment of the lubricating oil pipe 13 will be described below with reference to Figures 3, 5, and 6. The following description will mainly focus on the differences from the first embodiment. Detailed descriptions of components that overlap with those in the first embodiment will be omitted.
[0031] In the second embodiment, the configuration of the lubricating oil pipe 13 differs from that of the lubricating oil pipe 13 in the first embodiment. In the second embodiment, the end of the lubricating oil pipe 13 inserted into the input shaft 14 is referred to as the third end 43. The end of the lubricating oil pipe 13 inserted into the oil supply passage 12 is the first end 41, as in the first embodiment. The lubricating oil pipe 13 is hollow cylindrical, as in the first embodiment.
[0032] <Configuration of the lubricating oil pipe 13 in the second embodiment> Figure 5 is a cross-sectional view of the lubricating oil pipe 13, cut along the diameter of the pipe in the direction of the pipe's long axis. The end face of the first end 41 of the lubricating oil pipe 13 is the first end face 31. The end face of the third end 43 of the lubricating oil pipe 13 is the third end face 33.
[0033] As shown in Figure 5, the lubricating oil pipe 13 has a larger inner diameter at the boundary portion 34, which is the boundary between the first end portion 41 and the third end portion 43. The boundary portion 34 is indicated by a dashed circle in Figure 5. The inner diameter of the lubricating oil pipe 13 on the third end portion 43 side of the boundary portion 34 is larger than the inner diameter from the first end portion 41 side to the boundary portion 34.
[0034] Figure 6 shows the third end face 33 of the lubricating oil pipe 13. The third end face 33 has an outer diameter of R1 and an inner diameter of Q2, where Q2 is greater than Q1. As shown in Figures 3 and 6, the lubricating oil pipe 13 has an outer diameter equal to that of the third end face 33 and the first end face 31. The lubricating oil pipe 13 has an inner diameter greater than that of the first end face 31. When the outer diameters of the lubricating oil pipe 13 are equal, the area of the end face of the lubricating oil pipe 13 is larger as the inner diameter of the end face decreases. In other words, the area of the first end face 31, which has a smaller inner diameter than the third end face 33, is larger than the area of the third end face 33.
[0035] <Operation of the second embodiment> When the outer diameter of the end faces of the lubricating oil pipe 13 is the same, the smaller the inner diameter, the larger the area of the end face. In the lubricating oil pipe 13, the area of the first end face 31, which has a smaller inner diameter, is larger than the area of the third end face 33. The difference in the inner diameters of the end faces 31 and 33 of the lubricating oil pipe 13 increases the thrust directed toward the input shaft 14.
[0036] <Effects of the second embodiment> The second embodiment has the following effects in addition to the effects of (1-1) and (1-3) of the first embodiment.
[0037] (2-1) The lubricating oil pipe 13 is cylindrical. The lubricating oil pipe 13 has an outer diameter equal to the outer diameter of the third end face 33 of the third end 43 inserted into the input shaft 14 and the outer diameter equal to the outer diameter of the first end face 31 of the first end 41 inserted into the oil supply passage 12. The lubricating oil pipe 13 has an inner diameter greater than the inner diameter of the first end face 31 of the first end 41 inserted into the oil supply passage 12.
[0038] With regard to the lubricating oil pipe 13, the same effect as in (1-1) above can be achieved by creating a difference in the inner diameter of both end faces 31 and 33 of the lubricating oil pipe 13. (2-2) The lubricating oil pipe 13 has a larger inner diameter at the boundary portion 34, which is the boundary between the first end portion 41 inserted into the oil supply passage 12 and the third end portion 43 inserted into the input shaft 14. The inner diameter of the lubricating oil pipe 13 on the side of the third end portion 43 inserted into the input shaft 14 is larger than the inner diameter from the first end portion 41 inserted into the oil supply passage 12 to the boundary portion 34.
[0039] The lubricating oil pipe 13 expands in diameter midway through its passage. As the diameter of the hollow section, which is the flow path for the lubricating oil, expands, pressure loss occurs in this expanded section due to the lubricating oil. As a result, the pressure of the lubricating oil on the input shaft 14 side of the lubricating oil pipe 13 becomes lower than the pressure of the lubricating oil on the oil supply passage 12 side. The lower the pressure on the input shaft 14 side is compared to the oil supply passage 12 side, the greater the thrust force pushing the lubricating oil pipe 13 against the input shaft 14.
[0040] With the lubricating oil pipe 13, the pressure difference at both end faces 31 and 33 of the lubricating oil pipe 13 can be used to strongly press the lubricating oil pipe 13 against the input shaft 14. <Example of modification of the second embodiment> The second embodiment described above can be implemented with the following modifications. The second embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.
[0041] The lubricating oil pipe 13 has an increased inner diameter at the boundary 34. Alternatively, the lubricating oil pipe 13 may have an inner diameter that continuously expands from the oil supply passage 12 side toward the input shaft 14 side without having a boundary 34.
[0042] The lubricating oil pipe 13 has a difference in the inner diameter of the first end face 31 and the third end face 33. In addition to the inner diameters of the first end face 31 and the third end face 33, the lubricating oil pipe 13 may also have a difference in the outer diameter of the first end face 31 and the third end face 33. In this case, the outer diameter of the first end face 31 is larger than the outer diameter of the third end face 33. This makes it possible to make the area of the first end face 31 larger than the area of the third end face 33.
[0043] <Example of changes> Other elements that can be modified in common with each of the above embodiments are as follows: The lubricating oil pipe 13 does not necessarily have to have holes 15. [Explanation of symbols]
[0044] 10…Insertion section, 11…Oil pump, 12…Oil supply passage, 13…Lubricating oil pipe, 14…Input shaft, 15…Hole, 22…Transaxle, 23…Rotating machine, 24…Planetary gear mechanism, 31…First end face, 32…Second end face, 33…Third end face, 34…Boundary section, 41…First end, 42…Second end, 43…Third end
Claims
1. A hollow, cylindrical lubricating oil pipe, one end of which is inserted into a supply-side component that discharges lubricating oil, and the other end of which is inserted into a demand-side component that receives lubricating oil, is used to supply lubricating oil from the supply-side component to the demand-side component, The area of the end face of the end inserted into the supply-side component is larger than the area of the end face of the end inserted into the demand-side component. Lubricating oil pipe.
2. The aforementioned lubricating oil pipe is cylindrical, The inner diameter of the end face of the end inserted into the demand-side component is equal to the inner diameter of the end face of the end inserted into the supply-side component. The outer diameter of the end face of the end inserted into the demand-side component is smaller than the outer diameter of the end face of the end inserted into the supply-side component. The lubricating oil pipe according to claim 1.
3. The aforementioned lubricating oil pipe is cylindrical, The outer diameter of the end face of the end inserted into the demand-side component is equal to the outer diameter of the end face of the end inserted into the supply-side component. The inner diameter of the end face of the end inserted into the demand-side component is larger than the inner diameter of the end face of the end inserted into the supply-side component. The lubricating oil pipe according to claim 1.
4. The lubricating oil pipe has a larger inner diameter in the portion between the end inserted into the supply-side component and the end inserted into the demand-side component, and the inner diameter of the end inserted into the demand-side component is larger than the inner diameter from the end inserted into the supply-side component to that portion. The lubricating oil pipe according to claim 3.
5. The side surface of the lubricating oil pipe is provided with a hole that allows communication between the inside and outside. A lubricating oil pipe according to any one of claims 1 to 4.