Planetary gear device

Abstract

To provide a planetary gear device capable of supplying oil to a pinion gear with a simple configuration.SOLUTION: A planetary gear device 100 comprises: a shaft member 10 that rotates around an axis (rotation axis A); a carrier 70 that rotates around the axis; a pinion shaft 30 supported on the carrier 70; and a pinion gear 20 rotatably supported on the pinion shaft 30. In the pinion shaft 30, an oil passage 31 is formed through which oil flows to lubricate the pinion gear 20. The carrier 70 has an oil supply unit (oil passage 52, circumferential groove 53) that supplies oil to the oil passage 31.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a planetary gear device. [Background technology]

[0002] Patent Document 1 discloses a conventional planetary gear device. This planetary gear device has multiple pinion gears and a carrier that supports pinion shafts, which are the rotation axes of the multiple pinion gears. An oil receiver is attached to the end face of the carrier to guide lubricating oil supplied from the radially inner side to the pinion gears. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-150638 Summary of the Invention [Problem to be solved by the invention]

[0004] In this type of planetary gear device, it is sufficient that the oil supply to the pinion gears is sufficient to function properly, and it is preferable that the structure be simpler.

[0005] Therefore, an object of the present disclosure is to provide a planetary gear device that can supply oil to pinion gears with a simple configuration. [Means for solving the problem]

[0006] The planetary gear device of the present disclosure is a planetary gear device comprising: a shaft member that rotates around an axis; a carrier that rotates around the axis; a pinion shaft supported by the carrier; and a pinion gear rotatably supported by the pinion shaft, wherein an oil passage is formed in the pinion shaft to allow oil to flow for lubricating the pinion gear, and the carrier has an oil supply section that supplies oil to the oil passage. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a planetary gear device that can supply oil to pinion gears with a simple configuration. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a planetary gear device according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is an enlarged cross-sectional view of a main part showing the planetary gear device of the first embodiment. [Figure 3] FIG. 3 is a partial cross-sectional perspective view showing the carrier of the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Description of the embodiments of the present disclosure] First, embodiments of the present disclosure will be listed and described. The planetary gear device of the present disclosure is (1) A planetary gear device comprising: a shaft member that rotates around an axis; a carrier that rotates around the axis; a pinion shaft supported by the carrier; and a pinion gear that is rotatably supported by the pinion shaft, wherein an oil passage is formed in the pinion shaft to allow oil to flow for lubricating the pinion gear; and the carrier has an oil supply section that supplies oil to the oil passage.

[0010] According to the above configuration, the carrier has an oil supply section that supplies oil to the oil passage of the pinion shaft. In this way, the planetary gear device according to the present disclosure has the carrier itself equipped with the function of supplying oil to the oil passage of the pinion shaft, eliminating the need for a receiver separate from the carrier as in the conventional system. Therefore, the planetary gear device according to the present disclosure can supply oil to the pinion gear with a simple configuration.

[0011] (2) The carrier has an inner peripheral surface facing the outer peripheral surface of the shaft member, The oil supply portion may have a carrier-side oil passage that opens to the inner peripheral surface of the carrier and extends toward the pinion shaft. According to the above configuration, a configuration capable of supplying oil to the pinion shaft without requiring a receiver as in the conventional case can be realized in an extremely simple manner.

[0012] (3) The oil supply portion may have a circumferential groove extending circumferentially around the inner circumferential surface of the carrier, and the carrier-side oil passage may open to a bottom surface of the circumferential groove. According to the above configuration, when introducing oil into the carrier side oil passage, the oil supply section can introduce not only oil that enters directly into the opening of the carrier side oil passage, but also oil that is received by the circumferential groove into the carrier side oil passage.

[0013] (4) The oil passage of the pinion shaft may open to one end face of the pinion shaft, the carrier may have a bottomed insertion hole into which the one end face side of the pinion shaft is inserted, and the carrier-side oil passage may open to the bottom face of the insertion hole and communicate with the oil passage. According to this configuration, a closed oil passage can be formed that extends from the opening on the inner peripheral surface side of the carrier-side oil passage through the insertion hole to the oil passage, so that oil can be effectively supplied to the oil passage of the pinion shaft.

[0014] [Details of the embodiments of the present disclosure] Specific examples of the present disclosure will be described below with reference to the drawings. However, the present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0015] <Embodiment 1> A planetary gear device 100 according to a first embodiment of the present disclosure is provided in a transaxle of an electric vehicle such as an HEV (Hybrid Electric Vehicle) or a PHEV (Plug-in Hybrid Electric Vehicle). The planetary gear device 100 is housed in a casing (not shown) and rotates around a rotation axis A that is disposed substantially horizontally. As shown in FIGS. 1 and 2 , the planetary gear device 100 includes a shaft member 10, a carrier 70, a plurality of pinion shafts 30, and a plurality of pinion gears 20.

[0016] In the following description, the direction along the rotation axis A is defined as the axial direction, the direction around the rotation axis A as the circumferential direction, and the direction perpendicular to the rotation axis A as the radial direction. The directions in the description of each part of the planetary gear device 100 are based on the assembled state of each part.

[0017] The shaft member 10 is supported by a bearing (not shown) and rotates around a rotation axis A that is set coaxially with the central axis. The carrier 70 rotates around the rotation axis A. A plurality of pinion shafts 30 are supported by the carrier 70. A plurality of pinion gears 20 are rotatably supported by each of the plurality of pinion shafts 30.

[0018] The shaft member 10 is formed, for example, by forging and then machining. The shaft member 10 has a cylindrical shape with the central axis as the longitudinal direction. As shown in FIGS. 1 and 2 , an oil passage 11 through which lubricating oil flows is formed in the center of the shaft member 10 along the axial direction. The oil passage 11 has branch passages 11A that open to the outer circumferential surface of the shaft member 10. In this embodiment, multiple branch passages 11A are formed. The multiple branch passages 11A are formed radially at equal intervals around the rotation axis A. A gear 12 is formed integrally with the outer circumferential surface at one end of the shaft member 10. The gear 12 corresponds to the sun gear in the planetary gear device 100. The gear 12 protrudes radially from one end of the shaft member 10. The gear 12 meshes with a large pinion 21 (described later) of the pinion gear 20.

[0019] As shown in FIG. 2 , four pinion gears 20 are provided around the rotation axis A, spaced at equal intervals of 90°. Each pinion gear 20 has a large pinion 21 and a small pinion 22. The large pinion 21 and the small pinion 22 are helical gears. The large pinion 21 meshes with the gear 12 on the shaft member 10. The large pinion 21 is press-fitted onto the outer periphery of a cylindrical sleeve 23 extending from one axial end of the small pinion 22, and is integrated with the small pinion 22. The outer periphery of the small pinion 22 meshes with a ring gear (not shown). The carrier 70 itself is fixedly connected to another shaft member (not shown). As a result, the planetary gear device 100 constitutes a reducer that speeds up or slows down the rotation of either the shaft member 10 or the other shaft member (not shown) and transmits the rotation to the other.

[0020] The multiple pinion shafts 30 are arranged with their central axes parallel to the rotation axis A. An oil passage 31 is formed in each pinion shaft 30. The oil passage 31 has a first oil passage 31A extending along the axial direction of each pinion shaft 30 and a second oil passage 31B extending radially from the first oil passage 31A and opening onto the outer peripheral surface of the pinion shaft 30. The first oil passage 31A opens at one end in the axial direction of the pinion shaft 30 and is closed at the other end. Two second oil passages 31B are formed side by side in the axial direction of the pinion shaft 30.

[0021] Needle bearings 32 are arranged between the outer peripheral surface of the pinion shaft 30 and the inner peripheral surface of the pinion gear 20. The pinion shaft 30 supports the pinion gear 20 via the needle bearings 32. A pair of needle bearings 32 is arranged at each end of the pinion gear 20 in the axial direction. Two second oil passages 31B are formed in the axial direction of the pinion shaft 30 corresponding to the positions where the two pairs of needle bearings 32 are arranged.

[0022] As described above, the small pinions 22 of each pinion gear 20 mesh with a ring gear (not shown) on the outer periphery. The ring gear (not shown) rotates around the rotation axis A and is rotatable relative to the shaft member 10. In the planetary gear device 100, the pinion gears 20 are drivingly connected to, for example, an internal combustion engine via one of the shaft member 10, the ring gear (not shown), and another shaft member (not shown). Any other two of the shaft member 10, the ring gear (not shown), and another shaft member (not shown) are drivingly connected to, for example, a rotating electric machine and wheels, respectively. When torque from the internal combustion engine is input to the shaft member 10, for example, the planetary gear device 100 distributes a portion of the torque to the rotating electric machine via the other shaft member (not shown), and distributes the remaining torque to wheels via the ring gear (not shown).

[0023] The carrier 70 supports a plurality of pinion shafts 30. As shown in FIGS. 1 and 2, the carrier 70 is formed by arranging a pair of wall members 40, 50 facing each other with a gap in the axial direction. The central axes of the pair of wall members 40, 50 are arranged coaxially with the rotation axis A. The carrier 70 is supported rotatably about the rotation axis A via bearings (not shown) fitted in bearing seats 40A, 50A of the wall members 40, 50. In this embodiment, the carrier 70 is rotatable about the rotation axis A relative to the shaft member 10. Each pinion gear 20 is arranged between the pair of wall members 40, 50.

[0024] The pair of wall members 40, 50 are formed, for example, by forging and then machining. As shown in FIG. 1 , the pair of wall members 40, 50 are axially connected in the circumferential direction around the rotation axis A by a plurality of cylindrical connecting members 60 arranged between each pinion gear 20. The pair of wall members 40, 50 are each formed in an annular shape. The inner circumferential surface 40B of the wall member 40 faces the outer circumferential surface of another shaft member (not shown). The inner circumferential surface 50B of the wall member 50 faces the outer circumferential surface of the shaft member 10. The inner circumferential surface 50B of the wall member 50 is located at a position in the axial direction of the rotation axis A that is substantially the same as the position where the opening of the branch passage 11A of the oil passage 11 of the shaft member 10 is formed.

[0025] As shown in Fig. 2, the pair of wall members 40, 50 form a plurality of insertion holes 41, 51 into which the end portions of the pinion shafts 30 are inserted. The insertion hole 41 on one wall member 40 side and the insertion hole 51 on the other wall member 50 side are formed at the same circumferential position around the rotation axis A by so-called co-machining after the pair of wall members 40, 50 are connected by a connecting member 60. The plurality of insertion holes 41, 51 are each formed with an axial direction parallel to the extension direction of the rotation axis A. The insertion hole 41 on one wall member 40 side is formed as a through hole. The end portion of the pinion shaft 30 on the wall member 40 side is fixed to the wall member 40 by being crimped to the periphery of the insertion hole 41.

[0026] 2 and 3, the insertion hole 51 on the wall member 50 side of the pair of wall members 40, 50 is formed as a bottomed hole having a bottom surface 51A. The end of the pinion shaft 30 on the wall member 50 side is press-fitted and fixed into this insertion hole 51. Thrust washers 33 are disposed between both end surfaces of each pinion gear 20 and each wall member 40, 50. The thrust washers 33 have functions such as reducing friction between the pinion gear 20 and the wall members 40, 50 and maintaining the position of the needle bearings 32.

[0027] As shown in FIGS. 1 to 3 , the wall member 50 forms an oil passage 52 and a circumferential groove 53. The oil passage 52 and the circumferential groove 53 correspond to the oil supply portion according to the present disclosure. The oil passage 52 corresponds to the carrier-side oil passage according to the present disclosure. The oil passage 52 is formed penetrating from the inner circumferential surface 50B to the outer circumferential surface 50C of the wall member 50. A plurality of oil passages 52 are formed corresponding to each of the insertion holes 51. Each oil passage 52 is formed radially so as to pass through each insertion hole 51. Each oil passage 52 opens to a bottom surface 51A of each insertion hole 51. More specifically, the axial position of each oil passage 52 in the wall member 50 overlaps with the position of the bottom surface 51A of the insertion hole 51. In other words, each oil passage 52 passes through the bottom surface 51A of the insertion hole 51. As a result, a portion of the oil passage 52 is exposed at the bottom surface 51A of each insertion hole 51.

[0028] 2 and 3, the circumferential groove 53 is formed to extend circumferentially on the inner peripheral surface 50B of the wall member 50. The circumferential groove 53 is a square groove that is recessed radially outward on the inner peripheral surface 50B of the wall member 50 to have a concave cross section. The circumferential groove 53 is formed around the entire circumference of the inner peripheral surface 50B. In this embodiment, one end of the oil passage 52 on the inner peripheral surface 50B side opens to the back surface of the circumferential groove 53. One end of the oil passage 52 on the outer peripheral surface 50C side of the wall member 50 is closed by a plug member such as a set screw 54.

[0029] The operation of the planetary gear unit 100 configured as described above will now be described. Oil flowing through the oil passage 11 of the shaft member 10 enters each branch passage 11A. The oil that enters each branch passage 11A sprays out from openings in the branch passage 11A on the outer peripheral surface of the shaft member 10 toward the inner peripheral surface 50B of the wall member 50. A portion of the sprayed oil directly enters oil passage 52 that opens on the inner peripheral surface 50B. The oil that enters oil passage 52 is introduced into oil passage 31 of the pinion shaft 30 through the insertion hole 51. The oil introduced into oil passage 31 is then supplied between the outer peripheral surface of the pinion shaft 30 and the inner peripheral surface of the pinion gear 20 through the openings on the outer peripheral surface of the pinion shaft 30. As a result, the planetary gear unit 100 ensures lubrication between the pinion shaft 30 and the pinion gear 20 without requiring a receiver as in the conventional case.

[0030] Furthermore, oil passage 52 passes through a position overlapping bottom surface 51A of insertion hole 51 and opens to bottom surface 51A. One end of pinion shaft 30, which has one end of oil passage 31 open, is inserted into insertion hole 51 by press fitting. As a result, oil passage 52 formed in wall member 50 and oil passage 31 formed in pinion shaft 30 form a closed flow path via insertion hole 51. Therefore, oil introduced into oil passage 52 reaches oil passage 31 efficiently without being dissipated. Furthermore, oil passage 52 is formed from inner circumferential surface 50B to outer circumferential surface 50C of wall member 50. Therefore, centrifugal force acts on the oil in oil passage 52 due to the rotation of wall member 50 about rotation axis A. This centrifugal force acts on the oil in oil passage 52 to encourage it to flow radially outward from wall member 50. Therefore, the oil in oil passage 52 is encouraged to flow into oil passage 31. As a result, the pinion gear 20 can be efficiently supplied with oil that flows through the oil passage 52 and then the oil passage 31.

[0031] Furthermore, part of the oil spurting out from the opening of the branch passage 11A of the oil passage 11 collides with and adheres to the inner circumferential surface 50B of the wall member 50, while the other part scatters around. In this embodiment, a circumferential groove 53 is formed on the inner circumferential surface 50B of the wall member 50. The circumferential groove 53 is formed as a recess around the entire circumference of the inner circumferential surface 50B. As a result, part of the oil spurting out from the opening of the branch passage 11A is stored in the circumferential groove 53. The oil in the circumferential groove 53 moves circumferentially within the circumferential groove 53 due to the rotation of the carrier 70 about the rotation axis A. Furthermore, centrifugal force acts on the oil in the circumferential groove 53 due to the rotation of the carrier 70 about the rotation axis A. As a result, the oil in the circumferential groove 53 is guided to the oil passage 52 that opens at the back surface of the circumferential groove 53. In this way, the planetary gear device 100 can guide not only the oil that is injected from the opening of the branch passage 11A and enters the oil passage 52 directly from the opening, but also the oil that is received within the circumferential groove 53 to the oil passage 52. Therefore, compared to a case in which only the oil passage 52 is formed, the planetary gear device 100 introduces more oil into the oil passage 52, further ensuring lubrication between the pinion shaft 30 and the pinion gear 20.

[0032] As described above, in the planetary gear unit 100 according to this embodiment, the carrier 70 has the oil passage 52 and the circumferential groove 53 as an oil supply section, and these oil passages 52 and circumferential grooves 53 supply oil to the oil passage 31 of the pinion shaft 30. In the planetary gear unit 100, the carrier 70 itself has the function of supplying oil to the oil passage 31 of the pinion shaft 30, so there is no need to provide a receiver that is a separate member from the carrier as in the conventional case. Therefore, the planetary gear unit 100 can supply oil to the pinion gears with a simple configuration.

[0033] In this embodiment, carrier 70 has an inner peripheral surface 50B of wall member 50, which is the inner peripheral surface facing the outer peripheral surface of shaft member 10, and the oil supply portion has oil passage 52 that opens to inner peripheral surface 50B of wall member 50 and extends toward pinion shaft 30. Therefore, planetary gear unit 100 can extremely easily realize a configuration that can supply oil to pinion shaft 30 without requiring a receiver as in the conventional case.

[0034] In this embodiment, the wall member 50 of the carrier 70 has a circumferential groove 53 extending circumferentially around the inner circumferential surface 50B, and the oil passage 52 opens to the bottom surface of this circumferential groove 53. Therefore, not only oil that directly enters the opening on the inner circumferential surface 50B side of the wall member 50, but also oil received by the circumferential groove 53 is introduced into the oil passage 52. As a result, the planetary gear unit 100 can introduce a larger amount of oil into the oil passage 52.

[0035] In this embodiment, oil passage 31 of pinion shaft 30 opens to one end face of pinion shaft 30, wall member 50 of carrier 70 has a bottomed insertion hole 51 into which the open end face of oil passage 31 of pinion shaft 30 is inserted, and oil passage 52 opens to a bottom face 51A of this insertion hole 51 and communicates with oil passage 31 of pinion shaft 30. Therefore, in planetary gear unit 100, a closed oil passage can be formed that runs from the opening of oil passage 52 on the inner circumferential surface 50B side of wall member 50, through bottomed insertion hole 51, to oil passage 31 of pinion shaft 30. As a result, in planetary gear unit 100, oil introduced into oil passage 52 can be effectively supplied to oil passage 31 of pinion shaft 30 without being dispersed along the way.

[0036] [Another embodiment of the present disclosure] The embodiments disclosed herein should be considered in all respects as illustrative and not restrictive.

[0037] In the above embodiment, four pinion gears are provided. However, in other embodiments, the number of pinion gears may be three or five or more. Also, it is not essential that each pinion gear be configured with a large pinion and a small pinion. Each pinion gear may consist of one gear, or may consist of three or more gears.

[0038] In the above embodiment, the carrier is rotatable about the axis relative to the shaft member, but in another embodiment, the carrier may be fixed to the shaft member and not rotatable relative to the shaft member.

[0039] In the above embodiment, a circumferential groove is formed on the inner peripheral surface of the carrier. However, in another embodiment, the inner peripheral surface of the carrier does not necessarily need to be formed with a circumferential groove. Alternatively, instead of a circumferential groove, a recess may be formed on the periphery of the opening on the inner peripheral surface of the carrier-side oil passage. In this case, more oil can be introduced into the carrier-side oil passage than when only an opening on the inner peripheral surface of the carrier-side oil passage is formed.

[0040] In the above embodiment, the oil passage of the pinion shaft opens to one end face of the pinion shaft, the carrier has a bottomed insertion hole into which one end face of the pinion shaft is inserted, and the carrier-side oil passage opens to the bottom face of the insertion hole and communicates with the oil passage of the pinion shaft. In contrast, in another embodiment, the oil passage of the pinion shaft may open to the outer peripheral surface of one end side of the pinion shaft, and the carrier-side oil passage may open to the inner peripheral surface of the insertion hole of the carrier at a position facing the outer peripheral surface of one end side of the pinion shaft. In this case, the insertion hole of the carrier may be bottomed or may be a through hole. [Explanation of symbols]

[0041] 10...Shaft member 11…Oil road 11A...Fork 12...Gear 20...Pinion gear 21...Large pinion 22...Small pinion 23...Sleeve 30...Pinion shaft 31…Oil road 31A…No. 1 oil road 31B…Second oilway 32...Needle bearing 33...Thrust washer 40...Wall components 40A…Bearing seat 40B…Inner peripheral surface 41...insertion hole 50...Wall components 50A…Bearing seat 50B…Inner peripheral surface 50C…Outer surface 51...insertion hole 51A…Bottom surface 52...Oil road 53...Circumferential groove 54...Set screw 60...Connecting member 70...Career 100...Planetary gear device A...Rotation axis

Claims

1. a shaft member that rotates around an axis; a carrier that rotates around the axis; a pinion shaft supported by the carrier; a pinion gear rotatably supported on the pinion shaft, an oil passage for supplying oil to lubricate the pinion gear is formed in the pinion shaft; The planetary gear device, wherein the carrier has an oil supply portion that supplies oil to the oil passage.

2. the carrier has an inner circumferential surface facing the outer circumferential surface of the shaft member, 2. The planetary gear device according to claim 1, wherein the oil supply portion has a carrier-side oil passage that opens to the inner circumferential surface side of the carrier and extends toward the pinion shaft.

3. 3. The planetary gear device according to claim 2, wherein the oil supply portion has a circumferential groove extending circumferentially on the inner circumferential surface of the carrier, and the carrier-side oil passage opens to a bottom surface of the circumferential groove.

4. The oil passage of the pinion shaft opens to one end surface of the pinion shaft, the carrier has a bottomed insertion hole into which the one end face side of the pinion shaft is inserted, 4. The planetary gear device according to claim 2, wherein the carrier-side oil passage is open to a bottom surface of the insertion hole and communicates with the oil passage.

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