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

Abstract

The invention relates to a stator-exposed natural cooling motor and WW-type planetary reduction combined device of an electric vehicle. The stator-exposed natural cooling motor and WW-type planetary reduction combined device comprises a stator-exposed natural cooling motor and a WW-type planetary gear reducer which is coaxially connected with the motor, the stator-exposed natural cooling motor is combined with the WW type planetary reducer to form a highly integrated structure of the motor and the reducer, water cooling and forced air cooling are omitted, the system is simple, the maintenance difficulty is low, and the motor cost is low; a large gear ring is not needed, the cost is low and the size is small; no coupler is needed, parts are few, and the structure is simple.

Description

Technical Field

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

[0002] In order to obtain a wider driving range, the overall drive motor of traditional new energy vehicles is constantly pursuing lightweight, miniaturization and high speed. In order to obtain higher power density and meet the heat dissipation requirements of the motor, higher power density means greater current, so the copper winding of the motor will generate greater Joule heat. The stator winding silicon steel sheet stator that generates heat in the existing motor has a closed shell, which seriously hinders the heat convection and heat radiation dissipation of the stator winding, resulting in the current new energy vehicle manufacturers basically using water cooling or oil cooling technology for heat dissipation (US20220115924A1), and the stator heat water cooling or oil cooling of the motor requires an external cooling system with a complex structure and the risk of leakage, resulting in high maintenance costs and higher overall costs. Therefore, in the use environment of the car, the motor itself is in strong convection heat dissipation with the external air, and it is particularly important to design a new energy drive motor with natural cooling.

[0003] Traditional new energy vehicle drive motors have gradually moved towards higher speeds. In order to allow the tire end of new energy vehicles to obtain the required torque, a reducer with a larger reduction ratio is required to meet the use requirements. The reducer used is an NGW planetary gear reducer, or a multi-stage cylindrical gear reducer; and the NGW planetary gear reducer (CN 221195937 U) requires processing of the inner ring gear, so the radial size 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 manufacturers and reducer manufacturers respectively, so 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, and the system is complex, difficult to maintain, and the motor cost is high; 2) NGW-type planetary gear reducers are widely used. This type of reduction method has a large radial dimension due to the presence of a large gear ring in the structure, and the large gear ring 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 natural cooling motor and WW type planetary reduction combination device, which combines the natural cooling motor with the WW type planetary reduction to form a highly integrated structure of the motor and the reducer structure, omitting water cooling and forced air cooling, and the system is simple, the maintenance difficulty is small, and the motor cost is low; no large gear ring is required, the cost is low, and the size is small; no coupling is required, the parts are few, and the structure is simple.

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

[0008] A stator exposed natural cooling motor and WW type planetary reduction combination device for electric vehicles, comprising a stator exposed natural cooling motor and a WW type planetary gear reducer coaxially connected to the motor;

[0009] The stator exposed natural cooling motor includes a motor stator 43, both ends of which are fixed by a stator left pressure plate 35 and a stator right pressure plate 31, and the stator left pressure plate 35 and the stator right pressure plate 31 are fixed between a motor left frame 38 and a 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 32; the rotor positioning sleeve 30 on the left side of the motor rotor 42 is positioned by a left bearing system, a motor left bearing end cover 39 and a shaft shoulder, and the rotor positioning sleeve 30 on the right side of the motor rotor 42 is positioned by a right bearing system, a motor right bearing and a reducer input bearing common end cover 28 and a shaft shoulder; the motor left bearing end cover 39 is fixed on the motor left frame 38; the motor right bearing and a reducer input bearing common end cover 28 are fixed on the motor right frame 29.

[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 means of long flat keys 33 .

[0011] 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. An output signal interface 44 is provided on the magnetic encoder 37. The output speed of the motor output shaft 32 is adjusted by feedback from the magnetic encoder 37.

[0012] A plurality of motor tie 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 includes a reducer input end 3, which is connected to the motor output shaft 32, and 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 a bearing system; the reducer input end 3 fixes the double planetary gear 25 through a planetary carrier rod 23, a second roller bearing 22, an intermediate dividing sleeve 21, and a first roller bearing 20, and the second roller bearing 22 and the first roller bearing 20 are fixed by a double planetary gear inner circle retaining ring 18, and both ends of the planetary carrier rod 23 are fixed between the reducer input end 3 and the planetary carrier disc 8 through an end clamp outer circle elastic retaining ring 24; the planetary carrier disc 8 is supported at the fixed end by a bearing system On the sun gear 11; the tooth shape 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, and the fixed end sun gear 11 is supported on the output shaft 13 of the reducer through 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 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; 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 the pull rod 6 and the nut.

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

[0015] The three double planetary gears 25 are distributed circumferentially along the output shaft 13 of the reducer.

[0016] The reducer input end 3 and the planet carrier disc 8 are fixed by 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 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.

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

[0020] Compared with the prior art, the present invention 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 difficulty is small, 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 dimension and omits the inner gear ring of the expensive and large NGW type planetary reducer, which is low in 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. No coupling is required, the number of parts is small, and the structure is simple. 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 It is a structural diagram of the WW planetary gear train and the output end sun gear of an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The present invention is described in detail below in conjunction with embodiments and 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 which are fixed by a stator left pressure plate 35 and a stator right pressure plate 31, a motor tie 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 tie rod positioning sleeve 36 and the motor tie rod 34; both ends of the motor tie rod 34 are rolled with threads, and the motor tie rod 34 is tightened by a nut; so that the motor left frame 38, the motor tie rod positioning sleeve 36, the motor stator left pressure plate 35, the motor stator right pressure plate 31, the motor tie rod positioning sleeve 36 and the motor right frame 29 are firmly connected and positioned; six motor tie rods 34 are evenly arranged along the circumferential direction along 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 right stator 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 left stator pressure plate 35 and the right stator pressure plate 31 by means of the long flat key 33; at this point, the motor stator 43 is positioned in both the axial and circumferential directions; the motor stator 43 is provided with a stator winding 41, and the motor rotor 42 matched with the motor stator 43 is connected to the motor output shaft 32 by means of the rotor fixing flat key 40; the rotor positioning sleeve 30 on the left side of the motor rotor 42 is positioned by means of 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 means of the right side bearing system, the common end cover 28 of the right side bearing of the motor and the reducer input bearing, and the shaft shoulder; the left side bearing end cover 39 of the motor is fixed to the left frame 38 of the motor by means of six bolts distributed along the circumferential direction, and the left side bearing end cover 39 of the motor is provided with a magnetic encoder 37 required by the motor, as shown in FIG. Figure 2 As shown, the magnetic encoder 37 is fixed to the left side bearing end cover 39 of the motor by bolts, and an output signal interface 44 is provided on the magnetic encoder 37; the right side bearing of the motor and the reducer input bearing share an end cover 28 which is fixed to the right frame 29 of the motor by six bolts distributed along the circumferential direction; the output shaft 32 of the motor adjusts its output speed through 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 motor output shaft 32 rotates to drive 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 a planetary carrier rod 23, a second roller bearing 22, an intermediate dividing sleeve 21, and a first roller bearing 20. The second roller bearing 22 and the first roller bearing 20 are fixed by a double planetary gear inner circle retaining ring 18. Both ends of the planetary carrier rod 23 are fixed between the reducer input end 3 and the planetary carrier disk 8 through an 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 in three directions along the reducer output shaft 13, such as Figure 3 As shown, in order to improve its output load capacity; in order to allow the planet carrier disc 8 and the reducer input end 3 to firmly fix the double planetary gear 25 along the axial direction of the planet carrier rod 23, the reducer input end 3 and the planet carrier disc 8 are fixed by three planet carrier fixed shafts 4 and locking nuts 2, and the planet carrier disc 8 is supported on the fixed end sun gear 11 through a bearing system, as shown in FIG. Figure 3 As shown; the tooth profile 7 rolled on the end of the fixed end sun gear 11 meshes with the planetary gear on one side of the double planetary gear 25, and the fixed end sun gear 11 is supported on the output shaft 13 of the reducer through 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 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 through the positioning pin 10, and the double 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 double planetary gear 25 meshes with the output end sun gear 5, and the output end sun gear 5 is connected to the output shaft 13 of the reducer through a spline or a flat key, so that the power is transmitted to the output end sun gear 5 through the double planetary gear 25 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 tie rods 6 distributed along the circumferential direction.

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

[0034] The working principle of the present invention is:

[0035] After the stator winding 41 is energized, it can drive the motor rotor 42 to rotate, and the motor rotor 42 drives the motor output shaft 32 to rotate. The motor output shaft 32 achieves closed-loop speed regulation through the magnetic encoder 37. The motor output shaft 32 transmits power to the reducer input end 3. The rotation of the reducer input end 3 drives the double planetary gear 25 on the planetary carrier rod 23 to rotate. Since one planetary gear of the double planetary gear 25 is engaged with the fixed end sun gear 11, the double planetary gear 25 outputs power to the output end sun gear 5, and the output end sun gear 5 drives the reducer output shaft 13 to rotate, thereby outputting power.

[0036] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that modifications or equivalent replacements of the technical solutions of the present invention are all within the protection scope of the present invention.

Claims

1. A combination device of an electric vehicle stator exposed natural cooling motor and a WW type planetary reduction gear, characterized in that: It includes a naturally cooled motor with an exposed stator and a WW type planetary gear reducer coaxially connected to the motor; The stator exposed natural cooling motor comprises a motor stator (43), two 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 a motor left frame (38) and a motor right frame (29) by a motor pull rod positioning sleeve (36) and a motor pull rod (34); a stator winding (41) is arranged 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).

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 on 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 outer ring of the motor stator (43) in the circumferential direction.

5. The combined device according to claim 1, characterized in that: The WW type planetary gear reducer comprises 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 a planetary carrier rod (23), a second roller bearing (22), an intermediate dividing 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 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 end clamp outer circle elastic retaining rings (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 toothed shape (7) rolled on the end of the fixed end sun gear (11) meshes 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 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 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) meshes 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.

6. The combined device according to claim 5, 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.

7. The combined device according to claim 5, characterized in that: The three double planetary gears (25) are distributed circumferentially along the output shaft (13) of the reducer.

8. The combined device according to claim 5, characterized in that: The reducer input end (3) and the planet carrier disc (8) are fixed by a plurality of planet carrier fixing shafts (4) and locking nuts (2).

9. The combined device according to claim 5, characterized in that: The fixed end sun gear (11) is supported on the reducer output shaft (13) via a ball bearing, and the ball bearing is positioned and sealed via a bearing end cover (12).

10. The combined device according to claim 5, characterized in that: The end of the output shaft (13) of the reducer drives the input end of the electric vehicle differential, wheel or universal joint through a spline (14).

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