Power assembly

Abstract

The power assembly comprises a planet wheel, a planet carrier, a sun wheel and a guide sleeve. The planet carrier supports the planet wheel. The sun gear includes a first shaft portion and a second shaft portion, the first shaft portion and the second shaft portion being coaxially arranged. A plurality of gear teeth are arranged on the periphery of the first shaft part, and a tooth groove is formed between every two adjacent gear teeth. The sun gear is meshed with the planet gear through gear teeth. A guide groove is formed in the periphery of the second shaft part and spirally extends in the axial direction and the circumferential direction of the sun gear. The guide groove is communicated with the tooth groove. The guide sleeve is sleeved on the second shaft part and covers at least one part of the guide groove. In this way, the power assembly can actively convey the lubricating oil to the gear pair.

Description

Technical Field

[0001] This application relates to the field of transmissions, and more particularly to a powertrain. Background Art

[0002] Chinese Patent Application CN111683835A discloses a power system for a vehicle and the vehicle. The sun gear of the planetary gear set is torsionally connected coaxially with the hollow shaft, and the carrier of the planetary gear set is rotatably supported on the common housing through bearings. The torque output by the motor is transmitted from the sun gear into the planetary gear set through the hollow shaft and output from the carrier.

[0003] However, there may be a problem of poor lubrication in the gear pair composed of the sun gear and the planetary gears. When the vehicle is stationary and the oil level of the lubricating oil is lower than the gear pair, the lubrication of the gear pair depends on the splashing of the lubricating oil. In some compact designs, the bearings are mounted on the common housing through bearing plates. The bearing plates will hinder the splashing of the lubricating oil towards the gear pair, making it difficult to supply the lubricating oil to the gear pair. Summary of the Invention

[0004] This application is made in view of the state of the above-mentioned prior art. The purpose of this application is to provide a powertrain that can overcome or mitigate at least one of the disadvantages described in the above background art.

[0005] To achieve the above purpose, the following technical solutions are adopted in this application.

[0006] This application provides a powertrain as follows, including: planetary gears; a carrier that supports the planetary gears; and a sun gear, the sun gear includes a first shaft portion and a second shaft portion, the first shaft portion and the second shaft portion are coaxially arranged, a plurality of teeth are provided on the outer periphery of the first shaft portion, a tooth groove is formed between adjacent teeth, the sun gear meshes with the planetary gears through the teeth, a guide groove is provided on the outer periphery of the second shaft portion, the guide groove spirally extends along the axial and circumferential directions of the sun gear, the guide groove communicates with the tooth groove, the powertrain further includes a guide sleeve, the guide sleeve is sleeved on the second shaft portion and covers at least a part of the guide groove.

[0007] In an alternative solution, it further includes: a bearing that supports the carrier; and a bearing plate that supports the bearing, the bearing plate is sleeved on the second shaft portion, wherein the lubricating oil on the bearing plate can drip to the part of the guide groove of the second shaft portion that is not covered by the guide sleeve, and the sun gear can rotate to convey the lubricating oil to the tooth groove through the guide groove.

[0008] In another alternative solution, the tooth groove is provided on one axial side of the guide groove, and the depth of the guide groove gradually decreases from one axial side to the other axial side.

[0009] In another alternative, the sun gear is a helical gear, the spiral direction of the guide groove is the same as that of the gear teeth, and / or the spiral angle of the guide groove is the same as that of the gear teeth.

[0010] In another alternative, an installation groove is provided on the outer periphery of the sun gear, the installation groove is recessed inward in the radial direction of the sun gear, an installation rib is provided on the inner periphery of the guide sleeve, the installation rib protrudes inward in the radial direction of the guide sleeve, and the installation rib is snapped into the installation groove so that the guide sleeve is fixed relative to the sun gear in the axial direction.

[0011] In another alternative, a guide rib is provided on the inner periphery of the guide sleeve, the guide rib protrudes inward in the radial direction of the guide sleeve, the guide rib spirally extends along the axial direction and the circumferential direction, and the guide sleeve can rotate with the sun gear to convey lubricating oil to the tooth groove through the guide rib.

[0012] In another alternative, the spiral direction of the guide groove is the same as that of the guide rib, and / or the spiral angle of the guide groove is the same as that of the guide rib.

[0013] In another alternative, the guide rib is at least partially embedded in the guide groove so that the guide sleeve is fixed relative to the sun gear in the circumferential direction.

[0014] In another alternative, the inner peripheral surfaces of the guide sleeve and the bearing plate are offset in the axial direction.

[0015] In another alternative, a shoulder is provided on the outer periphery of the second shaft portion, the shoulder protrudes outward in the radial direction of the second shaft portion, the inner peripheral surface of the bearing plate is located between the gear teeth and the shoulder in the axial direction, and the shoulder can prevent the lubricating oil on the second shaft portion from flowing away from the tooth groove.

[0016] With the above technical solution, by sleeving the guide sleeve on the second shaft portion provided with the guide groove, the lubricating oil dripping onto the second shaft portion can flow into the guide groove, and the lubricating oil flowing into the guide groove can be conveyed to the tooth groove when the sun gear rotates. The guide sleeve can avoid or reduce the lubricating oil from leaving the second shaft portion due to centrifugal force, so that the powertrain can actively convey the lubricating oil to the gear pair. Description of the Drawings

[0017] Figure 1 A cross-sectional view of a powertrain according to an embodiment of the present application is shown, in which some components are omitted.

[0018] Figure 2 Shows Figure 1Partial enlarged view of the powertrain in

[0019] Figure 3 shows Figure 1 Cross-sectional view of the sun gear and the guide sleeve of the powertrain in

[0020] Figure 4 shows Figure 1 Schematic diagram of the sun gear of the powertrain in

[0021] Figure 5 shows Figure 1 Schematic diagram of the guide sleeve of the powertrain in

[0022] Description of reference numerals

[0023] 1 Motor; 11 Laminations; 12 Permanent magnets; 13 Rotor shaft; 14 Bearing; 15 Bearing;

[0024] 2 Planetary gear train; 21 Planet gear; 22 Planet carrier; 23 Planet gear shaft; 24 Bearing; 25 Bearing plate; 26 Sun gear; 261 First shaft portion; 262 Second shaft portion; 263 Tooth; 264 First shaft shoulder; 265 Second shaft shoulder; 26a Tooth groove; 26b Guide groove; 26c Mounting groove; 27 Ring gear;

[0025] 3 Guide sleeve; 31 Guide rib; 32 Mounting rib; 3a Notch;

[0026] 4 Output shaft;

[0027] 5 Bearing;

[0028] 6 Housing; 6a Working cavity;

[0029] A Axial direction; C Circumferential direction. Detailed implementation manners

[0030] The exemplary embodiments of the present application will be described below with reference to the drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present application, rather than to exhaust all feasible ways of the present application, nor to limit the scope of the present application.

[0031] In the present application, unless otherwise specified, a "gear pair" refers to a gear pair composed of a planet gear and a sun gear.

[0032] Figures 1 to 5 A powertrain according to an embodiment of the present application is shown, in particular a powertrain suitable for an electric vehicle or a hybrid vehicle.

[0033] Referring to Figure 1 , the powertrain may include a motor 1, a planetary gear train 2, a guide sleeve 3, an output shaft 4, a bearing 5, and a housing 6.

[0034] Referring toFigure 1 The motor 1 may include a plurality of laminations 11, a plurality of permanent magnets 12, a rotor shaft 13, bearings 14, and bearings 15. The laminations 11 may be made of a soft magnetic material, and the permanent magnets 12 may be placed on the laminations 11. For example, the laminations 11 may be silicon steel sheets. The rotor shaft 13 may be a hollow shaft, and the plurality of laminations 11 may be fixedly sleeved on the rotor shaft 13. The bearings 14 and 15 may be sleeved on the rotor shaft 13 to support the rotation of the rotor shaft 13. The bearing 14 may be disposed on one axial side of the laminations 11 ( Figure 1 the right side in Figure 1 ), and the bearing 15 may be disposed on the other axial side of the laminations 11 ( Figure 1 the left side in

[0035] Refer to Figure 1 , the planetary gear train 2 may include a plurality of planet gears 21, a planet carrier 22, a plurality of planet gear shafts 23, bearings 24, a bearing plate 25, a sun gear 26, and a ring gear 27. The whole of the planetary gear train 2 may be disposed in the working chamber 6a, and the bearing plate 25 and the ring gear 27 may be fixedly installed on the housing 6. The sun gear 26 may be sleeved on one axial side end of the rotor shaft 113 ( Figure 1 the right end in

[0036] Refer to Figures 2 to 4 , the sun gear 26 may include a first shaft portion 261 and a second shaft portion 262. The first shaft portion 261 and the second shaft portion 262 may be coaxially arranged, and the first shaft portion 261 may be disposed on one axial side of the second shaft portion 262 ( Figure 3 the right side in Figure 3 ). A plurality of gear teeth 263 may be provided on the outer periphery of the first shaft portion 261, and tooth grooves 26a are formed between adjacent gear teeth 263. The sun gear 26 may be a helical gear, and the gear teeth 263 may be teeth helically extending along the axial direction A and the circumferential direction C. A first shaft shoulder 264 and a second shaft shoulder 265 may be provided on the outer periphery of the second shaft portion 262. The first shaft shoulder 264 may be disposed at the other axial side end of the second shaft portion 262 ( Figure 3 the left end inFigure 3 the right end portion in [reference], for example, adjacent to the tooth 263 and protruding radially outward from the second shaft portion 262.

[0037] Refer to Figure 4 , a plurality of guide grooves 26b and mounting grooves 26c may be provided on the outer periphery of the second shaft portion 262. The guide grooves 26b may be provided between the tooth 263 and the first shoulder 264 in the axial direction A and extend helically along the axial direction A and the circumferential direction C. The guide grooves 26b may penetrate through the second shoulder 265, and one axial end of the guide groove 26b may be directly and smoothly communicated with the tooth groove 26a. The number of the guide grooves 26b may be the same as the number of the tooth grooves 26a, and each guide groove 26 may correspond to one tooth groove 26a. The depth of the guide groove 26b may gradually decrease from one axial end to the other axial end, that is, decrease toward the side away from the tooth 263. For example, the depth of one axial end may be the same as the depth of the tooth groove 26a, and the depth of the other axial end may be zero. The spiral direction and spiral angle of the guide groove 26b may be the same as the spiral direction and spiral angle of the tooth 263. The mounting groove 26c may be provided on the outer periphery of the second shoulder 265 and recess radially inward from the second shoulder 265. The mounting groove 26c may extend along the circumferential direction C and correspond to the entire second shoulder 265 in the circumferential direction C.

[0038] Refer to Figure 5 , a plurality of guide ribs 31 and a plurality of mounting ribs 32 may be provided on the inner periphery of the guide sleeve 3. The guide ribs 31 may protrude radially inward from the guide sleeve 3 and extend helically along the axial direction A and the circumferential direction C. The number of the guide ribs 31 may be less than the number of the guide grooves 26b, and each guide rib 31 may correspond to one guide groove 26b. The spiral direction and spiral angle of the guide rib 31 may be the same as the spiral direction and spiral angle of the guide groove 26b. The mounting ribs 32 may protrude radially inward from the guide sleeve 3 and extend along the circumferential direction C. The number of the mounting ribs 32 may be the same as the number of the guide ribs 31, and each mounting rib 32 may be provided between two adjacent guide ribs 31. The mounting ribs 32 may be provided at one axial end portion of the guide sleeve 3, and a notch 3a may be formed between the adjacent guide ribs 31 and mounting ribs 32.

[0039] Refer to Figure 2 and Figure 3, the bearing plate 25 and the guide sleeve 3 can be sleeved on the second shaft portion 262. The inner peripheral surface of the bearing plate 25 can be located between the first shaft shoulder 264 and the guide sleeve 3 in the axial direction A. In other words, the inner peripheral surface of the bearing plate 25, the first shaft shoulder 264, and the guide sleeve 3 are offset from each other in the axial direction A. The guide sleeve 3 can cover at least a part of the guide groove 26b. For example, the axial other end of the guide groove 26b is not covered by the guide sleeve 3. The notch 3a can communicate with the axial other end of the tooth groove 26a. In other words, when observed in the axial direction A, there is a part where the notch 3a and the axial other end of the tooth groove 26a overlap each other. A part of each guide rib 31 can be embedded in a guide groove 26b on the second shaft shoulder 265, so that the guide sleeve 3 is fixed relative to the sun gear 26 in the circumferential direction C. The mounting rib 32 can be snapped into the mounting groove 26c, so that the guide sleeve 3 is fixed relative to the sun gear 26 in the axial direction A.

[0040] Referring to Figure 1 , the output shaft 4 can be mounted on the planetary gear train 2. The output shaft 4 and the bearing 5 can be arranged in the working chamber 6a, and the bearing 5 can be mounted on the housing 6. The bearing 5 can be sleeved on the output shaft 4 to support the rotation of the output shaft 4. The output shaft 4 can be fixedly mounted on the planet gear shaft 23. In other words, in this configuration, the motor 1 can transmit torque to the output shaft 4 through the planetary gear train 2.

[0041] The sun gear 26 and the guide sleeve 3 can transport lubricating oil to the tooth groove 26a. The lubricating oil splashed onto the bearing plate 25 can drip onto the second shaft portion 262. For example, it drips onto the area between the first shaft shoulder 264 and the guide sleeve 3 in the axial direction A. The lubricating oil attached to the outer periphery of the second shaft portion 262 can flow into the guide groove 26b. When the sun gear 26 rotates, the lubricating oil in the guide groove 26b can flow into the tooth groove 26a under the guidance of the guide groove 26b to lubricate the gear pair. The lubricating oil in the guide groove 26b may be thrown out of the guide groove 26b under the centrifugal force, and the thrown-out lubricating oil can adhere to the inner periphery of the guide sleeve 3. When the guide sleeve 3 rotates synchronously with the sun gear 26, the lubricating oil attached to the inner periphery of the guide sleeve 3 can flow into the tooth groove 26a through the notch 3a under the guidance of the guide rib 31.

[0042] The powertrain of this embodiment has at least the following advantages.

[0043] (i) The powertrain can actively deliver lubricating oil to the gear pair. By sleeving the guide sleeve 3 on the second shaft portion 262 provided with the guide groove 26b, the lubricating oil dripping onto the second shaft portion 262 can flow into the guide groove 26b, and the lubricating oil flowing into the guide groove 26b can be delivered to the tooth groove 26a when the sun gear 26 rotates. The guide sleeve 3 can prevent or reduce the lubricating oil from leaving the second shaft portion 262 due to centrifugal force, enabling the gear pair to be fully lubricated and avoiding the failure of the planet gear 21 and the sun gear 26 due to poor lubrication (such as gear wear or fracture). In addition, by sleeving the bearing plate 25 on the second shaft portion 262, the lubricating oil on the bearing plate 25 can drip onto the second shaft portion 262 and flow into the guide groove 26b, enabling the sun gear 26 to collect the lubricating oil on the bearing plate 25. Furthermore, by providing the guide rib 31, the lubricating oil adhering to the inner circumference of the guide sleeve 3 can be delivered to the tooth groove 26a when the guide sleeve 3 rotates.

[0044] (ii) The lubricating oil can be efficiently delivered to the gear pair. By making the number of guide ribs 31 less than the number of guide grooves 26b, the guide ribs 31 can occupy less of the guide grooves 26b, and the guide grooves 26b can have a larger cross-sectional area of the flow passage (the sum of the cross-sectional areas of multiple guide grooves 26b). In addition, by providing the notch 3a, the lubricating oil delivered by the guide rib 31 can directly flow into the tooth groove 3a via the notch 3a without passing through the guide groove 26b, enabling the lubricating oil to flow along a shorter path.

[0045] (iii) The loss of lubricating oil during transportation is small. By providing the first shaft shoulder 264, the first shaft shoulder 264 can prevent the lubricating oil on the second shaft portion from flowing in the direction away from the tooth groove ( Figure 2 and Figure 3 the left side in

[0046] ), making it easy for the lubricating oil to flow into the guide groove 26b.

[0047] It should be understood that the above embodiments are merely exemplary and do not limit the present application. Those skilled in the art can make various modifications and changes to the above embodiments under the teaching of the present application without departing from the scope of the present application.

[0048] (i) The sun gear 26 is not limited to being a helical gear and can be, for example, a spur gear.

[0049] (ii) The guide groove 26b is not limited to being directly connected to the tooth groove 26a and can be indirectly connected to the tooth groove 26a via other structures capable of guiding lubricating oil, for example.

[0050] (iii) The shaft assembly is also a subject matter of the present application, and the shaft assembly may include the above-mentioned rotor shaft 13, guide sleeve 3, and sun gear 26.

[0051] It can be understood that the sun gear 26 can be formed separately from the rotor shaft 13 and then assembled together. In another alternative solution, the above-mentioned sun gear (tooth) can be formed at one axial end of the shaft 13, that is, the sun gear and the rotor shaft can be integrally formed.

Claims

1. A powertrain, comprising: Planet gear (21); a planet carrier (22) that supports the planet gear (21); and a sun gear (26), characterized in that the sun gear (26) includes a first shaft portion (261) and a second shaft portion (262), the first shaft portion (261) and the second shaft portion (262) are coaxially arranged, a plurality of gear teeth (263) are provided on the outer periphery of the first shaft portion (261), a tooth groove (26a) is formed between adjacent gear teeth (263), the sun gear (26) meshes with the planet gear (21) through the gear teeth (263), a guide groove (26b) is provided on the outer periphery of the second shaft portion (262), and the guide groove (26b) spirally extends along the axial direction (A) and the circumferential direction (C) of the sun gear (26), and the guide groove (26b) communicates with the tooth groove (26a), the powertrain further includes a guide sleeve (3), the guide sleeve (3) is sleeved on the second shaft portion (262) and covers at least a part of the guide groove (26b).

2. The powertrain according to claim 1, wherein Further included are: a bearing (24) that supports the planet carrier (22); and a bearing plate (25) that supports the bearing (24), the bearing plate (25) is sleeved on the second shaft portion (262), wherein the lubricating oil on the bearing plate (25) can drip onto the portion of the guide groove (26b) of the second shaft portion (262) that is not covered by the guide sleeve (3), and the sun gear (26) can rotate to convey the lubricating oil to the tooth groove (26a) through the guide groove (26b).

3. The powertrain according to claim 1 or 2, characterized in that, The tooth groove (26a) is provided on one axial side of the guide groove (26b), and the depth of the guide groove (26b) gradually decreases from one axial side to the other axial side.

4. The powertrain according to claim 1 or 2, characterized in that, The sun gear (26) is a helical gear, the spiral direction of the guide groove (26b) is the same as the spiral direction of the gear teeth (263), and / or the spiral angle of the guide groove (26b) is the same as the spiral angle of the gear teeth (263).

5. The powertrain according to claim 1 or 2, characterized in that, An installation groove (26c) is provided on the outer periphery of the sun gear (26), the installation groove (26c) is recessed radially inward of the sun gear (26), an installation rib (32) is provided on the inner periphery of the guide sleeve (3), the installation rib (32) protrudes radially inward of the guide sleeve (3), and the installation rib (32) is snapped into the installation groove (26c) so that the guide sleeve (3) is fixed relative to the sun gear (26) in the axial direction (A).

6. The powertrain according to claim 1 or 2, characterized in that, A guide rib (31) is provided on the inner periphery of the guide sleeve (3), the guide rib (31) protrudes radially inward of the guide sleeve (3), the guide rib (31) spirally extends along the axial direction (A) and the circumferential direction (C), and the guide sleeve (3) can rotate with the sun gear (26) to convey the lubricating oil to the tooth groove (26a) through the guide rib (31).

7. The powertrain according to claim 6, characterized in that the spiral direction of the guide groove (26b) is the same as the spiral direction of the guide rib (31), and / or The spiral angle of the guide groove (26b) is the same as that of the guide rib (31).

8. The powertrain according to claim 6, wherein The guide rib (31) is at least partially embedded in the guide groove (26b), so that the guide sleeve (3) is fixed relative to the sun gear (26) in the circumferential direction (C).

9. The powertrain according to claim 2, characterized in that, The inner circumferential surfaces of the guide sleeve (3) and the bearing plate (25) are offset in the axial direction (A).

10. The powertrain according to claim 2, characterized in that, A shoulder (264) is provided on the outer circumference of the second shaft portion (262), the shoulder (264) protruding radially outward of the second shaft portion (262), the inner circumferential surface of the bearing plate (25) being located between the tooth (263) and the shoulder (264) in the axial direction (A), and the shoulder (264) being able to prevent the lubricating oil on the second shaft portion (262) from flowing away from the tooth groove (26a).

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