Lubrication structure

Abstract

To suppress a decrease in the amount of oil discharged from a through hole of a shaft.SOLUTION: A lubrication structure comprises a cylindrical shaft having an oil flow passage formed inside, a first through hole penetrating the shaft from its inner peripheral surface to its outer peripheral surface, a second through hole that is provided on the downstream side of the first through hole in the oil flow passage and penetrates the shaft from the inner peripheral surface to the outer peripheral surface, and at least one spiral groove that is formed on the inner peripheral surface of the shaft and is formed spirally around the central axis of the shaft. None of the spiral grooves passes through the first through hole, and any of the spiral grooves passes through the second through hole.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a lubrication structure. [Background technology]

[0002] Conventionally, transmissions mounted on vehicles such as automobiles include various gears and shafts to change the torque, rotation speed, and rotation direction of the driving force output from a drive source such as an engine or a motor, and transmit the driving force.To lubricate parts to be lubricated, such as the engagement parts between the shaft and gears within the transmission and the engagement parts between gears, a lubrication structure is known in which an oil flow path is formed inside the shaft and oil is supplied from the oil flow path to the parts to be lubricated outside the shaft.

[0003] For example, Patent Document 1 discloses forming an oil flow path inside a cylindrical shaft in an automatic transmission, and forming through holes that penetrate the shaft from its inner circumferential surface to its outer circumferential surface. A plurality of these through holes are formed along the central axis of the shaft. When the shaft rotates, centrifugal force causes oil flowing through the oil flow path to be discharged outside the shaft through the plurality of through holes, and the discharged oil can lubricate a plurality of lubrication target parts outside the shaft. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-115701 Summary of the Invention [Problem to be solved by the invention]

[0005] The amount of oil flowing through the oil flow path decreases according to the amount of oil discharged from the through-hole in the shaft. Therefore, the amount of oil flowing through the oil flow path decreases as the oil moves downstream of the oil flow path. Therefore, the amount of oil discharged from the through-hole located further downstream in the oil flow path decreases.

[0006] Furthermore, the higher the rotation speed of the shaft, the greater the centrifugal force acting on the oil. Therefore, when the shaft rotates at high speeds, the amount of oil discharged from the through-holes located upstream of the oil flow path increases, while the amount of oil discharged from the through-holes located downstream of the oil flow path decreases. The smaller the amount of oil discharged from a through-hole, the more likely air is to flow into that through-hole. The air that flows into the through-hole reaches the oil flow path and forms an air layer inside the oil flow path. When an air layer is formed inside the oil flow path, the air layer makes it difficult for oil to flow through the oil flow path. Therefore, the amount of oil discharged from the through-holes located near the air layer decreases.

[0007] Therefore, an object of the present invention is to provide a lubrication structure that can suppress a decrease in the amount of oil discharged from the through hole of the shaft. [Means for solving the problem]

[0008] In order to solve the above problem, a lubrication structure according to one embodiment of the present invention comprises: a cylindrical shaft having an oil flow path formed therein; a first through hole that penetrates the shaft from an inner peripheral surface to an outer peripheral surface of the shaft; a second through hole provided downstream of the first through hole in the oil flow path and penetrating the shaft from the inner circumferential surface to the outer circumferential surface of the shaft; At least one spiral groove formed on the inner circumferential surface of the shaft and spirally formed around the central axis of the shaft; Equipped with None of the spiral grooves pass through the first through hole, Any one of the spiral grooves passes through the second through hole. [Effects of the Invention]

[0009] According to the present invention, it is possible to suppress a decrease in the amount of oil discharged from the through hole of the shaft. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing a vehicle according to the first embodiment. [Figure 2] FIG. 2 is a schematic diagram showing an example of the internal structure of the transmission according to the first embodiment. [Figure 3] FIG. 3 is a schematic diagram illustrating a plurality of spiral grooves according to the first embodiment. [Figure 4] FIG. 4 is a schematic diagram illustrating a plurality of spiral grooves according to the second embodiment. [Figure 5] FIG. 5 is a schematic diagram illustrating a plurality of spiral grooves according to the third embodiment. [Figure 6] FIG. 6 is a schematic diagram illustrating a lubrication structure according to a fourth embodiment. [Figure 7] FIG. 7 is an enlarged view of a protrusion according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Specific dimensions, materials, numerical values, etc. shown in the embodiments are merely examples for facilitating understanding of the invention and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention are not shown.

[0012] Fig. 1 is a schematic diagram showing a vehicle 100 according to a first embodiment. In Fig. 1, arrow F indicates the forward direction of the vehicle, arrow B indicates the backward direction of the vehicle, arrow R indicates the right direction of the vehicle, and arrow L indicates the left direction of the vehicle.

[0013] Vehicle 100 is a hybrid vehicle equipped with two drive sources, an engine 110 and a motor 120. However, vehicle 100 may have only engine 110 or only motor 120 as its drive source, and various vehicle types such as engine vehicles and electric vehicles may be employed. Here, configurations related to the features of the first embodiment will be described in detail, and configurations unrelated to the features of the first embodiment will not be described.

[0014] As shown in FIG. 1, the vehicle 100 includes an engine 110, a motor 120, a clutch 130, a transmission 140, an inverter 150, a battery 160, a propeller shaft 170, a front differential gear 180, a front drive shaft 190, front wheels 200, a rear differential gear 210, a rear drive shaft 220, rear wheels 230, and a control device 300.

[0015] The engine 110 is a gasoline engine or a diesel engine, and obtains driving force by burning fuel such as gasoline or diesel fuel supplied from a fuel tank (not shown).

[0016] Specifically, engine 110 is provided with an injector (not shown) and a spark plug (not shown). The injector injects fuel to supply the fuel into a combustion chamber (not shown). The tip of the spark plug is disposed within the combustion chamber and ignites the mixture of fuel and air supplied into the combustion chamber. The mixture of fuel and air is ignited by the spark plug at a predetermined timing and combusted. Through this combustion, engine 110 can obtain driving force.

[0017] Engine 110 transmits the resulting driving force to transmission 140 via clutch 130. Engine 110 is connected to control device 300, and the operation of the injectors and spark plugs is controlled based on control commands from control device 300, thereby adjusting the driving force.

[0018] The motor 120 is disposed coaxially with the engine 110. The motor 120 obtains driving force from electric power supplied from a battery 160 via an inverter 150. The motor 120 transmits the obtained driving force to the transmission 140. The motor 120 also functions as a generator when it is not receiving electric power. The electric power generated by the motor 120 is stored in the battery 160 via the inverter 150. The inverter 150 is also connected to a control device 300, and the supplied electric power, i.e., the driving force of the motor 120, is adjusted based on a control command from the control device 300.

[0019] The driving force output from a driving source such as engine 110 or motor 120 is adjusted in torque, rotation speed, and rotation direction by transmission 140 and transmitted to propeller shaft 170. The driving force transmitted to propeller shaft 170 is transmitted to front wheels 200 via front differential gear 180 and front drive shaft 190. The driving force transmitted to propeller shaft 170 is also transmitted to rear wheels 230 via rear differential gear 210 and rear drive shaft 220.

[0020] The control device 300 controls the entire vehicle 100. The control device 300 has one or more processors 300a and one or more memories 300b connected to the processor 300a. The processor 300a includes, for example, a CPU (Central Processing Unit). The memory 300b includes, for example, a ROM (Read Only Memory) and a RAM (Random Access Memory). The ROM is a storage element that stores programs and calculation parameters used by the CPU. The RAM is a storage element that temporarily stores data such as variables and parameters used in processing executed by the CPU.

[0021] The transmission 140 includes various gears and shafts for changing the torque, rotation speed, and rotation direction of the driving force output from the engine 110 and the motor 120 and transmitting the driving force.

[0022] Fig. 2 is a schematic diagram showing an example of the internal structure of the transmission 140 according to the first embodiment. As shown in Fig. 2, the transmission 140 includes a first lubrication target part T1, a second lubrication target part T2, a third lubrication target part T3, and a lubrication system 400 that lubricates these parts.

[0023] The first lubrication target portion T1, the second lubrication target portion T2, and the third lubrication target portion T3 are engagement portions between a shaft and a gear, which are components that make up the transmission 140, or engagement portions between gears.

[0024] The lubrication system 400 includes an oil pump 410 and a lubrication structure 500. The oil pump 410 is a supply source that supplies oil to the lubrication structure 500. The lubrication structure 500 has a shaft 510, an oil flow path 520, a plurality of through holes 530, and at least one spiral groove 600 (see FIG. 3).

[0025] The shaft 510 is formed in a cylindrical shape and has an outer circumferential surface 510a and an inner circumferential surface 510b. An oil flow path 520 is formed inside the shaft 510. The oil flow path 520 is formed to extend along the central axis of the shaft 510.

[0026] Oil supplied from oil pump 410 is guided to one end 520a of oil flow path 520, and introduced from one end 520a into oil flow path 520 formed inside shaft 510. Oil flow path 520 guides the supplied oil from one end 520a to the other end 520b.

[0027] The plurality of through holes 530 are through holes that penetrate the shaft 510 from the inner circumferential surface 510b to the outer circumferential surface 510a of the shaft 510. In the first embodiment, the plurality of through holes 530 include a first through hole 532, a second through hole 534, and a third through hole 536. The first through hole 532, the second through hole 534, and the third through hole 536 are formed side by side in a direction parallel to the central axis of the shaft 510. However, the first through hole 532, the second through hole 534, and the third through hole 536 only need to be formed at different positions from one another in the central axial direction of the shaft 510, and may be formed at different positions from one another in the circumferential direction of the shaft 510, for example.

[0028] The first through hole 532 is provided on the upstream side of the oil flow path 520 relative to the second through hole 534 and the third through hole 536. The first through hole 532 is the through hole provided most upstream of the oil flow path 520 among the multiple through holes 530. The first through hole 532 is formed to extend in the radial direction of the shaft 510. In the radial direction of the shaft 510, the first through hole 532 is provided at a position facing the first lubrication target portion T1. When the shaft 510 rotates, a centrifugal force acts on the oil flowing through the oil flow path 520. This centrifugal force causes the oil to be discharged in the radial direction from the oil flow path 520 through the first through hole 532. A portion of the oil discharged in the radial direction reaches the first lubrication target portion T1 and lubricates the first lubrication target portion T1.

[0029] The second through hole 534 is provided between the first through hole 532 and the third through hole 536. The second through hole 534 is formed to extend in the radial direction of the shaft 510. In the radial direction of the shaft 510, the second through hole 534 is provided at a position facing the second lubrication target portion T2. Due to centrifugal force generated when the shaft 510 rotates, oil is discharged in the radial direction from the oil flow path 520 through the second through hole 534. A portion of the oil discharged in the radial direction reaches the second lubrication target portion T2 and lubricates the second lubrication target portion T2.

[0030] The third through hole 536 is provided downstream of the oil flow path 520 relative to the first through hole 532 and the second through hole 534. The third through hole 536 is the through hole provided furthest downstream of the oil flow path 520 among the multiple through holes 530. The third through hole 536 is formed to extend in the radial direction of the shaft 510. In the radial direction of the shaft 510, the third through hole 536 is provided at a position facing the third lubrication target part T3. Due to centrifugal force generated when the shaft 510 rotates, oil is discharged radially from the oil flow path 520 through the third through hole 536. A portion of the oil discharged radially reaches the third lubrication target part T3 and lubricates the third lubrication target part T3.

[0031] The amount of oil flowing through oil flow path 520 decreases according to the amount of oil discharged from through hole 530 of shaft 510. Therefore, the amount of oil flowing through oil flow path 520 decreases as it progresses downstream of oil flow path 520. Therefore, the amount of oil discharged decreases as the through hole 530 is located closer to the downstream side of oil flow path 520.

[0032] Furthermore, the higher the rotation speed of the shaft 510, the greater the centrifugal force acting on the oil. Therefore, when the shaft 510 rotates at a high rotation speed, the amount of oil discharged from the through-holes 530 located closer to the upstream side of the oil flow path 520 increases, and the amount of oil discharged from the through-holes 530 located closer to the downstream side of the oil flow path 520 decreases. The smaller the amount of oil discharged from the through-holes 530, the more easily air flows into the through-holes 530. The air that flows into the through-holes 530 reaches the oil flow path 520 and forms an air layer inside the oil flow path 520. When an air layer is formed inside the oil flow path 520, the air layer makes it difficult for oil to flow through the oil flow path 520. Therefore, the amount of oil discharged from the through-holes 530 located near the air layer decreases.

[0033] Therefore, the lubrication structure 500 of the first embodiment has a plurality of spiral grooves 600 formed on the inner surface 510b of the shaft 510 and spirally formed around the central axis of the shaft 510 in order to suppress a decrease in the amount of oil discharged from the plurality of through holes 530 of the shaft 510.

[0034] FIG. 3 is a schematic diagram illustrating a plurality of spiral grooves 600 according to the first embodiment. As shown in FIG. 3, the plurality of spiral grooves 600 include a first spiral groove 610 and a second spiral groove 620. The first spiral groove 610 and the second spiral groove 620 do not intersect with each other and are formed independently. As shown in FIG. 3, the first embodiment describes an example in which the first spiral groove 610 and the second spiral groove 620 are formed on the inner circumferential surface 510b of the shaft 510. However, it is sufficient that at least one spiral groove 600 is formed on the inner circumferential surface 510b of the shaft 510. For example, it is possible that only the first spiral groove 610 is formed on the inner circumferential surface 510b of the shaft 510 and the second spiral groove 620 is not formed on the inner circumferential surface 510b of the shaft 510. Furthermore, it is also possible that only the second spiral groove 620 is formed on the inner circumferential surface 510b of the shaft 510 and the first spiral groove 610 is not formed on the inner circumferential surface 510b of the shaft 510.

[0035] The inclination angle of the first spiral groove 610 relative to the central axis of the shaft 510 when viewed in the radial direction of the shaft 510 is the same as the inclination angle of the second spiral groove 620 relative to the central axis of the shaft 510 when viewed in the radial direction of the shaft 510. Hereinafter, "same" means both the exact same and deviations from the exact same within the allowable error range.

[0036] The first spiral groove 610 has, for example, a rectangular cross-sectional shape in a cross section perpendicular to the extension direction of the first spiral groove 610, and has a first width and a first depth. Here, in the cross section, the depth direction is the radial direction of the shaft 510, and the width direction is a direction perpendicular to the depth direction. The second spiral groove 620 has, for example, a rectangular cross-sectional shape in a cross section perpendicular to the extension direction of the second spiral groove 620, and has a second width and a second depth. Here, an example in which the first spiral groove 610 and the second spiral groove 620 have rectangular cross-sectional shapes will be described, but this is not limiting. For example, the first spiral groove 610 and the second spiral groove 620 may have semicircular, semi-elliptical, triangular, or polygonal cross-sectional shapes. Furthermore, the first spiral groove 610 and the second spiral groove 620 do not have to have the same cross-sectional shape, but may have different cross-sectional shapes.

[0037] The cross-sectional area of the first spiral groove 610 is the same as the cross-sectional area of the second spiral groove 620. Here, the cross-sectional area of the first spiral groove 610 refers to the cross-sectional area in a cross section perpendicular to the extension direction of the first spiral groove 610. Similarly, the cross-sectional area of the second spiral groove 620 refers to the cross-sectional area in a cross section perpendicular to the extension direction of the second spiral groove 620. In the first embodiment, the cross-sectional shapes of the first spiral groove 610 and the second spiral groove 620 are the same, and the first width and first depth of the first spiral groove 610 are the same as the second width and second depth of the second spiral groove 620. However, this is not limited thereto, and the inclination angle, cross-sectional area, cross-sectional shape, width, and depth of the first spiral groove 610 and the second spiral groove 620 may be different from each other. Note that in the first embodiment, even if the cross-sectional shapes of the first spiral groove 610 and the second spiral groove 620 are different from each other, their cross-sectional areas are the same.

[0038] The first spiral groove 610 does not pass through the first through hole 532 or the third through hole 536, but passes only through the second through hole 534. The second spiral groove 620 does not pass through the first through hole 532 or the second through hole 534, but passes only through the third through hole 536. In other words, none of the spiral grooves 600 pass through the first through hole 532, but one of the spiral grooves 600 passes through the second through hole 534 and the third through hole 536.

[0039] When oil pump 410 is operated, a discharge force of oil pump 410 acts on the oil in oil flow path 520 in the direction of the central axis of shaft 510, from the upstream side to the downstream side of oil flow path 520. Furthermore, when shaft 510 rotates, a centrifugal force acts on the oil in oil flow path 520 in the radial direction of shaft 510. In other words, a resultant force of the discharge force of oil pump 410 in the direction of the central axis of shaft 510 and the centrifugal force in the radial direction of shaft 510 acts on the oil in oil flow path 520. This resultant force causes the oil to move in oil flow path 520 in a direction inclined with respect to the central axis of shaft 510.

[0040] The inclination angles of the first spiral groove 610 and the second spiral groove 620 are set to match the angle of the direction of the resultant force acting on the oil. When the inclination angles of the first spiral groove 610 and the second spiral groove 620 are the same as the angle of the direction of the resultant force acting on the oil, the resistance to the oil flowing through the first spiral groove 610 and the second spiral groove 620 can be minimized. Therefore, the oil can easily flow through the first spiral groove 610 and the second spiral groove 620.

[0041] The inclination angles of the first spiral groove 610 and the second spiral groove 620 are set according to the rotation range in which the shaft 510 rotates. For example, the higher the rotation range in which the shaft 510 rotates, the larger the inclination angles of the first spiral groove 610 and the second spiral groove 620 are set, and the lower the rotation range in which the shaft 510 rotates, the smaller the inclination angles of the first spiral groove 610 and the second spiral groove 620 are set. Specifically, the inclination angles of the first spiral groove 610 and the second spiral groove 620 are set so that the inclination angles approach 90 degrees as the rotation range in which the shaft 510 rotates increases, and the inclination angles approach 0 degrees as the rotation range in which the shaft 510 rotates decreases. Preferably, the inclination angles of the first spiral groove 610 and the second spiral groove 620 are set to 45 degrees or greater to accommodate various rotation ranges of the shaft 510.

[0042] As a result, when shaft 510 rotates, the oil acting on the resultant force of the discharge force of oil pump 410 and the centrifugal force is more likely to move along multiple spiral grooves 600 within oil flow path 520. Because first spiral groove 610 passes through second through hole 534 and second spiral groove 620 passes through third through hole 536, the amount of oil supplied to second through hole 534 and third through hole 536 can be increased compared to a case in which multiple spiral grooves 600 are not formed. As a result, when shaft 510 rotates, it is possible to suppress a decrease in the amount of oil discharged from second through hole 534 and third through hole 536, which are located downstream of first through hole 532.

[0043] As described above, according to the lubrication structure 500 of the first embodiment, none of the spiral grooves 600 passes through the first through hole 532, but one of the spiral grooves 600 passes through the second through hole 534 and the third through hole 536. This makes it possible to suppress a decrease in the amount of oil discharged from the second through hole 534 and the third through hole 536, which are located downstream of the first through hole 532, when the shaft 510 rotates.

[0044] Furthermore, the first spiral groove 610 of the first embodiment passes through the second through hole 534, and the second spiral groove 620 passes through the third through hole 536. This makes it possible to independently adjust the amount of oil supplied to the second through hole 534 via the first spiral groove 610 and the amount of oil supplied to the third through hole 536 via the second spiral groove 620. Therefore, compared to the case where one spiral groove 600 passes through the second through hole 534 and the third through hole 536, it is possible to suppress a decrease in the amount of oil discharged from the third through hole 536, which is provided downstream of the second through hole 534.

[0045] 4 is a schematic diagram illustrating a plurality of spiral grooves 1600 according to the second embodiment. Components that are substantially the same as those in the lubrication structure 500 of the first embodiment are given the same reference numerals and will not be described.

[0046] As shown in FIG. 4 , the multiple spiral grooves 1600 include a first spiral groove 1610 and a second spiral groove 1620. The first spiral groove 1610 and the second spiral groove 1620 do not intersect with each other and are formed independently. The first spiral groove 1610 does not pass through the first through hole 532 or the third through hole 536, but passes only through the second through hole 534. The second spiral groove 1620 does not pass through the first through hole 532 or the second through hole 534, but passes only through the third through hole 536. In other words, none of the spiral grooves 1600 pass through the first through hole 532, but one of the spiral grooves 1600 passes through the second through hole 534 and the third through hole 536.

[0047] In the second embodiment, the inclination angle of the first spiral groove 1610 with respect to the central axis of the shaft 510 when viewed in the radial direction of the shaft 510 is different from the inclination angle of the second spiral groove 1620 with respect to the central axis of the shaft 510 when viewed in the radial direction of the shaft 510. Specifically, the inclination angle of the first spiral groove 1610 is smaller than the inclination angle of the second spiral groove 1620. Note that, in the second embodiment, an example will be described in which the inclination angle of the first spiral groove 1610 is smaller than the inclination angle of the second spiral groove 1620, but this is not limiting, and for example, the inclination angle of the first spiral groove 1610 may be larger than the inclination angle of the second spiral groove 1620.

[0048] In the second embodiment, the inclination angle of second spiral groove 1620 is set to match the angle of the direction of the resultant force acting on the oil when shaft 510 rotates, and the inclination angle of first spiral groove 1610 is set to be smaller than the angle of the direction of the resultant force acting on the oil. Therefore, when shaft 510 rotates, the resistance to the oil flowing in second spiral groove 1620 can be made smaller than the resistance to the oil flowing in first spiral groove 610. This makes it possible to increase the amount of oil supplied to third through hole 536 compared to the amount of oil supplied to second through hole 534.

[0049] As described above, according to the second embodiment, the inclination angle of the first spiral groove 1610 with respect to the central axis of the shaft 510 when viewed in the radial direction of the shaft 510 is different from the inclination angle of the second spiral groove 1620 with respect to the central axis of the shaft 510 when viewed in the radial direction of the shaft 510. This makes it possible to increase the amount of oil supplied to the third through hole 536 via the second spiral groove 1620 compared to the amount of oil supplied to the second through hole 534 via the first spiral groove 1610 when the shaft 510 rotates. As a result, it is possible to further suppress a decrease in the amount of oil discharged from the third through hole 536 provided on the most downstream side compared to the first embodiment.

[0050] 5 is a schematic diagram illustrating a plurality of spiral grooves 2600 according to the third embodiment. Components that are substantially the same as those in the lubrication structure 500 of the first embodiment are given the same reference numerals and will not be described.

[0051] As shown in FIG. 5 , the multiple spiral grooves 2600 include a first spiral groove 2610 and a second spiral groove 2620. The first spiral groove 2610 and the second spiral groove 2620 do not intersect with each other and are formed independently. The first spiral groove 2610 does not pass through the first through hole 532 or the third through hole 536, but passes only through the second through hole 534. The second spiral groove 2620 does not pass through the first through hole 532 or the second through hole 534, but passes only through the third through hole 536. In other words, none of the spiral grooves 2600 pass through the first through hole 532, but one of the spiral grooves 2600 passes through the second through hole 534 and the third through hole 536.

[0052] The first spiral groove 2610 has, for example, a rectangular cross-sectional shape in a cross section perpendicular to the extension direction of the first spiral groove 2610, and has a first width and a first depth. The second spiral groove 2620 has, for example, a rectangular cross-sectional shape in a cross section perpendicular to the extension direction of the second spiral groove 2620, and has a second width and a second depth. Here, an example in which the first spiral groove 2610 and the second spiral groove 2620 have rectangular cross-sectional shapes will be described, but this is not limiting. For example, the first spiral groove 2610 and the second spiral groove 2620 may have semicircular, semi-elliptical, triangular, or polygonal cross-sectional shapes. Furthermore, the first spiral groove 2610 and the second spiral groove 2620 may not have the same cross-sectional shape, but may have different cross-sectional shapes.

[0053] In the third embodiment, the cross-sectional area of the first spiral groove 2610 is different from the cross-sectional area of the second spiral groove 2620. Here, the cross-sectional area of the first spiral groove 2610 refers to the cross-sectional area in a cross section perpendicular to the extension direction of the first spiral groove 2610. Similarly, the cross-sectional area of the second spiral groove 2620 refers to the cross-sectional area in a cross section perpendicular to the extension direction of the second spiral groove 2620. Note that in the third embodiment, whether the cross-sectional shapes of the first spiral groove 2610 and the second spiral groove 2620 are the same or different, the cross-sectional areas are different from each other. Specifically, the cross-sectional area of the second spiral groove 2620 is larger than the cross-sectional area of the first spiral groove 2610. For example, the cross-sectional shapes of the first spiral groove 2610 and the second spiral groove 2620 are the same, and the second width and second depth of the second spiral groove 2620 are larger than the first width and first depth of the first spiral groove 2610. However, without being limited thereto, either the width or the depth of the first spiral groove 2610 and the second spiral groove 2620 may be the same. For example, the depths of the first spiral groove 2610 and the second spiral groove 2620 may be the same, and the width of the second spiral groove 2620 may be set larger than the width of the first spiral groove 2610. Alternatively, the widths of the first spiral groove 2610 and the second spiral groove 2620 may be the same, and the depth of the second spiral groove 2620 may be set larger than the depth of the first spiral groove 2610.

[0054] This allows the amount of oil flowing through second spiral groove 2620 to be greater than the amount of oil flowing through first spiral groove 2610. As a result, the amount of oil supplied to third through hole 536 can be greater than the amount of oil supplied to second through hole 534.

[0055] As described above, according to the third embodiment, the cross-sectional area of the first spiral groove 2610 is different from the cross-sectional area of the second spiral groove 2620. This makes it possible to increase the amount of oil flowing through the second spiral groove 2620 compared to the amount of oil flowing through the first spiral groove 2610 when the shaft 510 rotates. As a result, compared to the first embodiment, it is possible to further suppress a decrease in the amount of oil discharged from the third through-hole 536 provided on the most downstream side. Note that, although the third embodiment has been described with reference to the case where the cross-sectional area of the second spiral groove 2620 is larger than the cross-sectional area of the first spiral groove 2610, the cross-sectional area of the second spiral groove 2620 may be smaller than the cross-sectional area of the first spiral groove 2610.

[0056] 6 is a schematic diagram illustrating a lubrication structure 3500 according to a fourth embodiment. Components that are substantially the same as those in the lubrication structure 500 of the first embodiment are given the same reference numerals and will not be described.

[0057] As shown in FIG. 6 , the lubrication structure 3500 has a plurality of spiral grooves 600 and protrusions 3700 provided on the plurality of spiral grooves 600. The protrusions 3700 protrude from the inner surfaces of the first spiral groove 610 and the second spiral groove 620. In the fourth embodiment, a plurality of protrusions 3700 are provided along the extension direction of the first spiral groove 610 and the second spiral groove 620. However, this is not limited thereto, and a single protrusion 3700 may be provided in the extension direction of the first spiral groove 610 and the second spiral groove 620. Furthermore, in the fourth embodiment, a pair of protrusions 3700 are provided in the width direction of the first spiral groove 610 and the second spiral groove 620. However, this is not limited thereto, and the protrusions 3700 may be provided only on one side in the width direction of the first spiral groove 610 and the second spiral groove 620.

[0058] Fig. 7 is an enlarged view of a protrusion 3700 according to the fourth embodiment. Fig. 7 shows the protrusion 3700 provided on the first spiral groove 610. The protrusion 3700 provided on the first spiral groove 610 will be described in detail below. Here, the protrusion 3700 provided on the first spiral groove 610 is the same as the protrusion 3700 provided on the second spiral groove 620, and therefore a detailed description of the protrusion 3700 provided on the second spiral groove 620 will be omitted.

[0059] As shown in FIG. 7 , the protrusion 3700 has a first surface 3710 facing the downstream side of the first spiral groove 610 and a second surface 3720 facing the upstream side of the first spiral groove 610. The first surface 3710 is, for example, a surface perpendicular to the inner surface of the first spiral groove 610 and has a rectangular shape. The second surface 3720 is, for example, a surface inclined with respect to the inner surface of the first spiral groove 610 and has a rectangular shape. However, the shapes of the first surface 3710 and the second surface 3720 are not limited thereto. Here, the angle of the first surface 3710 with respect to the inner surface of the first spiral groove 610 is larger than the angle of the acute angle of the second surface 3720 with respect to the inner surface of the first spiral groove 610. In a cross section parallel to the width direction perpendicular to the extension direction of the first spiral groove 610, the cross-sectional shape of the protrusion 3700 is triangular. The protrusion 3700 extends with the same cross-sectional shape in the radial direction of the shaft 510. As described above, in the fourth embodiment, the protrusion 3700 has a first surface 3710 and a second surface 3720. However, it is sufficient for the protrusion 3700 to have at least the first surface 3710, and the second surface 3720 is not essential. Therefore, the protrusion 3700 may be, for example, a flat protrusion having the first surface 3710 and not the second surface 3720. Specifically, the cross-sectional shape of the protrusion 3700 may be a quadrangle in a cross section parallel to the width direction perpendicular to the extension direction of the first spiral groove 610. The protrusion 3700 may extend with the same cross-sectional shape in the radial direction of the shaft 510.

[0060] According to the fourth embodiment, there is provided a protruding portion 3700 that protrudes from the inner surface of the spiral groove 600 and has a first surface 3710 facing downstream. As a result, air that enters the first spiral groove 610 and the second spiral groove 620 via the second through hole 534 and the third through hole 536 is blocked by the first surface 3710, and it is possible to suppress the entry of air into the oil flow path 520.

[0061] While the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such embodiments. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that such modifications and alterations also fall within the technical scope of the present invention.

[0062] In the above embodiment, an example in which two spiral grooves are formed in the shaft 510 has been described, but this is not limited thereto, and the shaft 510 may have a single spiral groove or three or more spiral grooves. For example, in the above embodiment, an example in which the shaft 510 has the third through hole 536 and the second spiral grooves 620, 1620, 2620 has been described. However, this is not limited thereto, and the shaft 510 may not have the third through hole 536 formed therein. Furthermore, the shaft 510 may not have the second spiral grooves 620, 1620, 2620 formed therein.

[0063] In the above embodiment, an example has been described in which the shaft 510 has the second through hole 534 and the first spiral groove 610, 1610, 2610. However, this is not limited thereto, and the second through hole 534 may not be formed in the shaft 510. Furthermore, the first spiral groove 610, 1610, 2610 may not be formed in the shaft 510. Note that in the above embodiment, an example has been described in which the shaft 510 is a shaft provided in the transmission 140. However, this is not limited thereto, and the shaft 510 may be a shaft provided other than the transmission 140. [Explanation of symbols]

[0064] T1 First lubrication target area T2 Second lubrication target area T3 Third lubrication target area 100 vehicles 140 Transmission 400 Lubrication System 410 Oil Pump 500 Lubrication structure 510 shaft 510a Outer surface 510b Inner surface 520 Oil flow path 520a one end 520b other end 530 Through hole 532 First through hole 534 Second Through Hole 536 Third Through Hole 600 spiral groove 610 1st spiral groove 620 2nd spiral groove 1600 spiral groove 1610 1st spiral groove 1620 2nd spiral groove 2600 spiral groove 2610 1st spiral groove 2620 2nd spiral groove 3500 Lubrication structure 3700 Protrusion 3710 Page 1 3720 2nd page

Claims

1. a cylindrical shaft having an oil flow path formed therein; a first through hole that penetrates the shaft from an inner peripheral surface to an outer peripheral surface of the shaft; a second through hole provided downstream of the first through hole in the oil flow path and penetrating the shaft from an inner circumferential surface to an outer circumferential surface of the shaft; At least one spiral groove formed on the inner circumferential surface of the shaft and spirally formed around the central axis of the shaft; Equipped with None of the spiral grooves pass through the first through hole, Any of the spiral grooves passes through the second through hole. Lubricated structure.

2. a third through hole that is provided downstream of the second through hole in the oil flow path and penetrates the shaft from the inner peripheral surface to the outer peripheral surface of the shaft; Equipped with The spiral groove is a first spiral groove passing through the second through hole; a second spiral groove passing through the third through hole; Including, The lubrication structure according to claim 1 .

3. an inclination angle of the first spiral groove with respect to a central axis of the shaft when viewed in a radial direction of the shaft is different from an inclination angle of the second spiral groove with respect to the central axis of the shaft when viewed in the radial direction of the shaft; The lubrication structure according to claim 2 .

4. The cross-sectional area of the first spiral groove is different from the cross-sectional area of the second spiral groove. The lubrication structure according to claim 2 .

5. a protrusion provided in the spiral groove, protruding from the inner surface of the spiral groove and having a surface facing downstream; Equipped with The lubrication structure according to any one of claims 1 to 4.

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