Electric vehicle stator exposed natural cooling motor and WW type planetary reduction combination device

Abstract

A kind of electric vehicle stator exposed natural cooling motor and WW type planetary reduction combination device, including a stator exposed natural cooling motor and WW type planetary gear reducer connected with motor coaxially;Stator exposed natural cooling motor is combined with WW type planetary reducer, and the structure of motor and reducer is integrated, water cooling and forced air cooling are omitted, system is simple, maintenance difficulty is small, motor cost is small;Without large gear ring, low in cost, small in size;Without shaft coupling, less parts, simple structure.

Description

Technical Field

[0001] The present invention belongs to the field of electric vehicle driving and transmission, and in particular relates to a stator-exposed natural cooling motor and a WW type planetary reduction combination device for an electric vehicle. Background Art

[0002] To achieve a longer driving range, traditional new energy vehicles are constantly pursuing lightweight, miniaturized, and high-speed drive motors. To achieve higher power density while meeting the motor's heat dissipation requirements, higher power density means greater current, so the motor's copper windings generate greater Joule heating. The heat-generating stator windings of existing motors, made of silicon steel sheets, are enclosed in a closed casing, severely hindering heat convection and radiation dissipation from the stator windings. As a result, new energy vehicle manufacturers currently rely on water or oil cooling for heat dissipation (US20220115924A1). However, water or oil cooling of the stator heat requires an external cooling system, which is complex and carries the risk of leakage, resulting in high maintenance costs and higher overall costs. Therefore, in the automotive environment, the motor itself dissipates heat through strong convection with the external air, making the design of new energy drive motors with natural cooling particularly important.

[0003] Traditional new energy vehicle drive motors have gradually moved towards higher speeds. In order to obtain the required torque at the tire end of new energy vehicles, a reducer with a larger reduction ratio is needed to meet the usage requirements. The reducers used are NGW planetary gear reducers or multi-stage cylindrical gear reducers. However, the NGW planetary gear reducer (CN 221195937 U) requires the processing of the inner ring gear, so the radial dimension is large and the processing is difficult. In addition, the reduction ratio of a single-stage planetary reducer is generally 3-5, so multi-stage gear reduction is required to meet the current higher-speed motor requirements, resulting in a large reduction system size and high cost.

[0004] The motors and reducers of current electric vehicles are manufactured by different motor and reducer manufacturers, respectively. Therefore, a coupling is required between the two, which increases the axial size of the drive motor and reducer assembly, increases the number of parts, and makes the structure complex and costly (Robinette, D. Electric Motor and Transmission Integration for Light-Duty Electric Vehicles: A 2023 Benchmarking Perspective and Component Sizing for a Fleet Approach. Vehicles 2023, 5, 1167-1195. https: / / doi.org / 10.3390 / vehicles5030065).

[0005] In summary, the current electric vehicle motors and their reduction devices have the following shortcomings: 1) The stator winding silicon steel sheet stator that generates heat in the motor has a shell, which seriously hinders the normal heat dissipation of the Joule heat of the stator winding, requiring forced air cooling and water cooling. The system is complex, maintenance is difficult, and the motor cost is high; 2) NGW-type planetary gear reducers are widely used. This reduction method has a large radial dimension due to the presence of a large ring gear in the structure, and the large ring gear parts are difficult to manufacture and the cost is high; and the reduction ratio is only 3-5, requiring a multi-stage planetary reduction with a large size; 3) The motor and reducer generally adopt a standard form, and a coupling is required to connect the two, resulting in a long axial dimension, many parts, a complex structure and high cost. Summary of the Invention

[0006] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide an electric vehicle stator exposed naturally cooled motor and WW type planetary reduction combination device, which combines the naturally cooled motor with the WW type planetary reduction to form a highly integrated structure of the motor and reducer structure, omitting water cooling and forced air cooling, resulting in a simple system, low maintenance difficulty, and low motor cost; no large ring gear is required, low cost and small size; no coupling is required, few parts and simple structure.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A combination device of an exposed stator naturally cooling motor and a WW type planetary reduction gear for an electric vehicle, comprising an exposed stator naturally cooling motor and a WW type planetary gear reduction gear coaxially connected to the motor;

[0009] The stator exposed natural cooling motor includes a motor stator 43, the two ends of which are fixed by a stator left pressure plate 35 and a stator right pressure plate 31. The stator left pressure plate 35 and the stator right pressure plate 31 are fixed between the motor left frame 38 and the motor right frame 29 through a motor pull rod positioning sleeve 36 and a motor pull rod 34; a stator winding 41 is installed inside the motor stator 43, and a motor rotor 42 that cooperates with the motor stator 43 is connected to the motor output shaft 32; the rotor positioning sleeve 30 on the left side of the motor rotor 42 is positioned by the left bearing system, the left bearing end cover 39 of the motor and the shaft shoulder, and the rotor positioning sleeve 30 on the right side of the motor rotor 42 is positioned by the right bearing system, the end cover 28 shared by the right bearing of the motor and the reducer input bearing and the shaft shoulder; the left bearing end cover 39 of the motor is fixed on the left frame 38 of the motor; the right bearing of the motor and the reducer input bearing share the end cover 28 fixed on the right frame 29 of the motor.

[0010] Key slots are provided on the stator left pressure plate 35 and the stator right pressure plate 31 , and key slots are also provided on the motor stator 43 . The motor stator 43 is circumferentially fixed to the stator left pressure plate 35 and the stator right pressure plate 31 by long flat keys 33 .

[0011] The left side bearing end cover 39 of the motor is equipped with a magnetic encoder 37 required by the motor. The magnetic encoder 37 is fixed on the left side bearing end cover 39 of the motor. The magnetic encoder 37 is provided with an output signal interface 44. The motor output shaft 32 adjusts its output speed through feedback from the magnetic encoder 37.

[0012] A plurality of motor pull rods 34 are evenly arranged along the circumferential direction along the outer ring of the motor stator 43 .

[0013] The WW type planetary gear reducer comprises a reducer input end 3, the reducer input end 3 is connected with a motor output shaft 32, the reducer input end 3 supports a reducer left frame 1 through a bearing system, and the reducer input end 3 is connected with a reducer output shaft 13 through a bearing system; the reducer input end 3 fixes a double planetary gear 25 through a planet carrier rod 23, a second roller bearing 22, an intermediate split sleeve 21 and a first roller bearing 20, the second roller bearing 22 and the first roller bearing 20 are fixed through a double planetary gear inner circle snap spring 18, the planet carrier rod 23 is fixed between the reducer input end 3 and a planet carrier disc 8 through end part outer circle elastic retainer rings 24 at both ends of the planet carrier rod 23; the planet carrier disc 8 is supported on a fixed end sun gear 11 through a bearing system; a tooth shape 7 on the end of the fixed end sun gear 11 is engaged with one side planetary gear of the double planetary gear 25, the fixed end sun gear 11 is supported on the reducer output shaft 13 through a first inner ringless roller bearing 15, a second inner ringless roller bearing 17 and a ball bearing system, the first inner ringless roller bearing 15 and the second inner ringless roller bearing 17 are separated through an intermediate sleeve 16 and are positioned through two end inner circle elastic retainer rings 19, and the fixed end sun gear 11 is fixed with a reducer right frame 9; the other side planetary gear of the double planetary gear 25 is engaged with an output end sun gear 5, the output end sun gear 5 is connected with the reducer output shaft 13; the reducer left frame 1 and the reducer right frame 9 are fixed through a pull rod 6 and a nut.

[0014] The WW type planetary gear reducer adopts a single-stage WW type planetary gear reducer with a transmission ratio of 10.

[0015] The double planetary gear 25 is distributed in three circumferential directions along the reducer output shaft 13.

[0016] The reducer input end 3 and the planet carrier disc 8 are fixed through a plurality of planet carrier fixing shafts 4 and locking nuts 2.

[0017] The fixed end sun gear 11 is supported on the reducer output shaft 13 through a ball bearing, and the ball bearing is positioned and sealed through a bearing end cover 12.

[0018] The reducer housing 26 is fixed on the reducer left frame 1 and the reducer right frame 9 through steps of the reducer left frame 1 and the reducer right frame 9 and screws.

[0019] The end of the reducer output shaft 13 is driven to the input end of an electric vehicle differential, a wheel or a universal coupling through a spline 14.

[0020] Compared with the prior art, the present application has the following beneficial effects:

[0021] (1) The internal motor winding enameled wire stator is exposed to the air, and the outer side of the stator circle is connected with a rectangular long key to transmit torque. The two ends of the long key are fastened together with the stator clamping plate. The clamping plates at both ends of the stator are axially clamped into one with tension bolts, so that the heat of the motor stator is quickly dissipated. Through natural cooling, water cooling and forced air cooling devices are omitted. The system is simple, maintenance is easy, and the motor cost is low.

[0022] (2) It uses a single-stage WW type planetary gear reducer with a transmission ratio of up to 10, which has a small radial size and omits the inner gear ring of the expensive and large NGW type planetary reducer, resulting in low cost;

[0023] (3) The motor output shaft is used as the input shaft of the WW type planetary gear reducer. The integrated structure is compact and low in cost, with high working reliability and low vibration and noise. There is no need for a coupling, fewer parts, and a simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a front cross-sectional view of an embodiment of the present invention.

[0025] Figure 2 It is a left view of an embodiment of the present invention.

[0026] Figure 3 This is a structural diagram of the WW planetary gear train and the output end sun gear according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The present invention is described in detail below with reference to the embodiments and accompanying drawings.

[0028] like Figure 1 As shown, a stator-exposed natural cooling motor and WW type planetary reduction combination device for electric vehicles includes a stator-exposed natural cooling motor and a WW type planetary gear reducer coaxially connected to the motor;

[0029] The stator exposed natural cooling motor includes a motor stator 43, both ends of the motor stator 43 are fixed by the stator left pressure plate 35 and the stator right pressure plate 31, a motor pull rod positioning sleeve 36 is provided between the stator left pressure plate 35 and the motor left frame 38, and between the stator right pressure plate 31 and the motor right frame 29, the stator left pressure plate 35 and the stator right pressure plate 31 are fixed between the motor left frame 38 and the motor right frame 29 through the motor pull rod positioning sleeve 36 and the motor pull rod 34; the motor pull rod 34 has threads at both ends, and the motor pull rod 34 is tightened by a nut; so that the motor left frame 38, the motor pull rod positioning sleeve 36, the motor stator left pressure plate 35, the motor stator right pressure plate 31, the motor pull rod positioning sleeve 36 and the motor right frame 29 are firmly connected and positioned; six motor pull rods 34 are evenly arranged along the circumferential direction of the outer ring of the motor stator 43, so that the motor stator 43 is firmly connected axially; on the stator left pressure plate 3 5 and the stator right pressure plate 31 are provided with keyways, and the motor stator 43 is also provided with keyways, and the motor stator 43 is circumferentially fixed to the stator left pressure plate 35 and the stator right pressure plate 31 by the long flat key 33; at this point, the motor stator 43 is positioned in the axial and circumferential directions; the stator winding 41 is installed inside the motor stator 43, and the motor rotor 42 matched with the motor stator 43 is connected to the motor output shaft 32 by the rotor fixing flat key 40; the rotor positioning sleeve 30 on the left side of the motor rotor 42 is positioned by the left bearing system, the left bearing end cover 39 of the motor and the shaft shoulder, and the rotor positioning sleeve 30 on the right side of the motor rotor 42 is positioned by the right bearing system, the end cover 28 shared by the right bearing of the motor and the reducer input bearing and the shaft shoulder; the left bearing end cover 39 of the motor is fixed to the left frame 38 of the motor by six bolts distributed along the circumference, and the magnetic encoder 37 required by the motor is installed on the left bearing end cover 39 of the motor, as shown in FIG. Figure 2 As shown, the magnetic encoder 37 is fixed to the left bearing end cover 39 of the motor by bolts, and an output signal interface 44 is provided on the magnetic encoder 37; the end cover 28 shared by the right bearing of the motor and the reducer input bearing is fixed to the right frame 29 of the motor by six bolts distributed along the circumference; the output speed of the motor output shaft 32 is adjusted by feedback from the magnetic encoder 37;

[0030] The WW type planetary gear reducer includes a reducer input end 3, which is connected to the motor output shaft 32 through a flat key 27. The rotation of the motor output shaft 32 drives the reducer input end 3 to rotate. The reducer input end 3 supports the reducer left frame 1 through a bearing system. The reducer input end 3 is connected to the reducer output shaft 13 through a bearing system; the reducer input end 3 fixes the double planetary gear 25 through the planetary carrier rod 23, the second roller bearing 22, the intermediate dividing sleeve 21, and the first roller bearing 20. The second roller bearing 22 and the first roller bearing 20 are fixed by the double planetary gear inner circle retaining spring 18. The two ends of the planetary carrier rod 23 are fixed between the reducer input end 3 and the planetary carrier disk 8 through the end clamp outer circle elastic retaining ring 24. The rotation of the reducer input end 3 will drive the planetary carrier rod 23 to rotate. Due to the action of the first roller bearing 20 and the second roller bearing 22, the double planetary gear 25 will rotate on the planetary carrier rod 23. The double planetary gear 25 is distributed along the circumference of the reducer output shaft 13. Figure 3 As shown, in order to improve its output load capacity; in order to allow the planetary carrier disc 8 and the reducer input end 3 to firmly fix the double planetary gear 25 along the axial direction of the planetary carrier rod 23, the reducer input end 3 and the planetary carrier disc 8 are fixed by three planetary carrier fixed shafts 4 and lock nuts 2, and the planetary carrier disc 8 is supported on the fixed end sun gear 11 through the bearing system, as shown Figure 3 As shown; the tooth profile 7 rolled on the end of the fixed end sun gear 11 is meshed with the planetary gear on one side of the duplex planetary gear 25, and the fixed end sun gear 11 is supported on the output shaft 13 of the reducer by the first inner ringless roller bearing 15, the second inner ringless roller bearing 17 and the ball bearing system. The first inner ringless roller bearing 15 and the second inner ringless roller bearing 17 are separated by the intermediate sleeve 16 and are positioned by the inner circle elastic retaining rings 19 at both ends, and the fixed end sun gear 11 is fixed to the right frame 9 of the reducer by the positioning pin 10, and the duplex planetary gear 25 will revolve around the fixed end sun gear 11. At the same time, the planetary gear on the other side of the duplex planetary gear 25 is meshed with the output end sun gear 5, and the output end sun gear 5 is connected to the output shaft 13 of the reducer by a spline or a flat key, thereby transmitting power through the duplex planetary gear 25 to the output end sun gear 5 and then to the output shaft 13 of the reducer, as shown Figure 3 As shown, the reducer left frame 1 and the reducer right frame 9 are fixed with nuts by six pull rods 6 distributed along the circumference.

[0031] In order to strengthen the support, the fixed end sun gear 11 is supported on the reducer output shaft 13 through a ball bearing, and the ball bearing is positioned and sealed through a bearing end cover 12.

[0032] The reducer housing 26 is fixed to the reducer left frame 1 and the reducer right frame 9 through the steps of the reducer left frame 1 and the reducer right frame 9 and screws.

[0033] The end of the output shaft 13 of the speed reducer drives the input end of the differential, wheel or universal coupling of the electric vehicle through the spline 14.

[0034] The working principle of the present application is as follows:

[0035] The stator winding 41 is energized to drive the motor rotor 42 to rotate, the motor rotor 42 drives the motor output shaft 32 to rotate, the motor output shaft 32 is closed-loop speed-regulated by the magnetic encoder 37, the motor output shaft 32 transmits power to the input end 3 of the speed reducer, the input end 3 of the speed reducer drives the double planetary gear 25 on the planet carrier rod 23 to rotate, since the double planetary gear 25 meshes with one planetary gear and the fixed end sun gear 11, the double planetary gear 25 outputs power to the output end sun gear 5, the output end sun gear 5 drives the output shaft 13 of the speed reducer to rotate, thereby outputting power.

[0036] The above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the protection scope of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents, and still fall within the protection scope of the present application.

Claims

1. A combination of an electric vehicle stator-exposed naturally cooled motor and a WW-type planetary reduction gear, characterized by: It includes a naturally cooled motor with exposed stator and a WW type planetary gear reducer coaxially connected to the motor; The stator exposed natural cooling motor includes a motor stator (43), both ends of the motor stator (43) are fixed by a stator left pressure plate (35) and a stator right pressure plate (31), the stator left pressure plate (35) and the stator right pressure plate (31) are fixed between the motor left frame (38) and the motor right frame (29) through a motor pull rod positioning sleeve (36) and a motor pull rod (34); a stator winding (41) is installed inside the motor stator (43), and a motor rotor (42) matched with the motor stator (43) is connected to the motor output shaft (3 2); the rotor positioning sleeve (30) on the left side of the motor rotor (42) is positioned by the left bearing system, the left side bearing end cover (39) of the motor and the shaft shoulder, and the rotor positioning sleeve (30) on the right side of the motor rotor (42) is positioned by the right side bearing system, the motor right side bearing and the reducer input bearing common end cover (28) and the shaft shoulder; the motor left side bearing end cover (39) is fixed on the motor left frame (38); the motor right side bearing and the reducer input bearing common end cover (28) are fixed on the motor right frame (29); The WW type planetary gear reducer includes a reducer input end (3), the reducer input end (3) is connected to the motor output shaft (32) through a flat key (27), the reducer input end (3) supports the reducer left frame (1) through a bearing system, and the reducer input end (3) is connected to the reducer output shaft (13) through the bearing system; the reducer input end (3) fixes the double planetary gear (25) through the planetary carrier rod (23), the second roller bearing (22), the middle dividing sleeve (21), and the first roller bearing (20), the second roller bearing (22) and the first roller bearing (20) are fixed through the double planetary gear inner circle retaining ring (18), and the two ends of the planetary carrier rod (23) are fixed between the reducer input end (3) and the planetary carrier disc (8) through the end clamp outer circle elastic retaining ring (24); the planetary carrier disc (8) is supported by the bearing system. The fixed end sun gear (11) is supported on the fixed end sun gear (11); the tooth profile (7) rolled on the end of the fixed end sun gear (11) is meshed with the planetary gear on one side of the double planetary gear (25); the fixed end sun gear (11) is supported on the output shaft (13) of the reducer through a first roller bearing without an inner ring (15), a second roller bearing without an inner ring (17) and a ball bearing system; the first roller bearing without an inner ring (15) and the second roller bearing without an inner ring (17) are separated by an intermediate sleeve (16) and positioned by inner circle elastic retaining rings (19) at both ends; the fixed end sun gear (11) is fixed to the right frame (9) of the reducer; the planetary gear on the other side of the double planetary gear (25) is meshed with the output end sun gear (5), and the output end sun gear (5) is connected to the output shaft (13) of the reducer; the left frame (1) of the reducer and the right frame (9) of the reducer are fixed by a pull rod (6) and a nut.

2. The combined device according to claim 1, characterized in that: A keyway is provided on the stator left pressure plate (35) and the stator right pressure plate (31), and a keyway is also provided on the motor stator (43). The motor stator (43) is circumferentially fixed to the stator left pressure plate (35) and the stator right pressure plate (31) by means of a long flat key (33).

3. The combined device according to claim 1, characterized in that: The left side bearing end cover (39) of the motor is provided with a magnetic encoder (37) required by the motor. The magnetic encoder (37) is fixed on the left side bearing end cover (39) of the motor. The magnetic encoder (37) is provided with an output signal interface (44). The motor output shaft (32) adjusts its output speed through feedback from the magnetic encoder (37).

4. The combined device according to claim 1, characterized in that: A plurality of motor pull rods (34) are evenly arranged along the circumferential direction along the outer ring of the motor stator (43).

5. The combined device according to claim 1, characterized in that: The WW type planetary gear reducer adopts a single-stage WW type planetary gear reducer with a transmission ratio of up to 10.

6. The combined device according to claim 1, characterized in that: Three of the double planetary gears (25) are distributed circumferentially along the output shaft (13) of the reducer.

7. The combined device according to claim 1, characterized in that: The reducer input end (3) and the planet carrier disc (8) are fixed via a plurality of planet carrier fixing shafts (4) and locking nuts (2).

8. The combined device according to claim 1, characterized in that: The fixed end sun gear (11) is supported on the reducer output shaft (13) through a ball bearing, and the ball bearing is positioned and sealed through a bearing end cover (12).

9. The combined device according to claim 1, characterized in that: The end of the speed reducer output shaft (13) drives the input end of the electric vehicle differential, wheel or universal joint through the spline (14).

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