Electric vehicle driving source of RV speed reducer type hub motor

Abstract

An electric vehicle driving source of an RV reducer type hub motor comprises a permanent magnet synchronous servo motor, the fixed end of the permanent magnet synchronous servo motor is connected with a suspension connecting piece, the power output end of the permanent magnet synchronous servo motor is connected with the power input end of an RV reducer, and the power output end of the RV reducer is connected with a tire module; the power output of the permanent magnet synchronous servo motor and the power input and output of the RV speed reducer are the same main shaft; the wheel is compositely driven by the high-speed permanent-magnet synchronous servo motor and the large-transmission-ratio RV speed reducer, the power performance of the whole vehicle can be greatly improved, the structure is simple, the size is small, the weight is light, the larger transmission ratio can be provided under the smaller size due to the application of the RV speed reducer, and the service life of the vehicle is prolonged. The high-speed permanent magnet synchronous servo motor is adopted, so that the motor has the advantages of good starting capability, strong low-speed dragging capability, high power density and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of wheel hub motors in electric vehicles, and in particular relates to a driving source for electric vehicles of a RV (Rotary Vector, large reduction ratio rotary vector type) reducer type wheel hub motor. Background Art

[0002] Electric vehicles have taken a leading role in the development of the new energy vehicle industry, thanks to the rapid development of three-electric technology and the high quality and low price of electricity resources. The driving forms of electric vehicles are mainly divided into centralized motor drive and distributed motor drive. Distributed motor drive electric vehicles can be divided into hub motor drive and wheel side motor drive according to the type of drive system. Hub motor drive electric vehicles, with their advantages of high transmission efficiency, compact structure and high passability, are called the ideal ultimate solution for electric vehicles by the industry.

[0003] The wheel hub motor configuration is driven directly by a single motor. The motor output torque of this configuration is low and it is only suitable for light load occasions. Generally, a brushless DC motor is used. Although it runs smoothly and has high reliability, the speed and torque are difficult to control accurately. Correspondingly, there is a single motor reduction drive wheel hub motor with a single motor composite reducer. The torque output is improved through the reduction mechanism, but the maximum speed is limited and the applicable working conditions are limited. The low speed and low voltage of the motor result in low energy utilization.

[0004] The reducers in the hub motors are mostly planetary gear reducers, which have a relatively small reduction ratio, usually 3-5, so multi-stage reducers are required, which makes the mechanical structure relatively large, which is not conducive to the design of hub motors with tight space dimensions.

[0005] In summary, the current wheel hub motors for electric vehicles have the following shortcomings: 1) The motor speed used in the existing wheel hub motor configuration is low and the power supply voltage is low, which makes the motor large in size and the space structure tight, and the energy utilization rate of the motor is low; 2) The reducer used in the existing wheel hub motor has a relatively small reduction ratio and requires multi-stage reduction, which makes the mechanical structure of the reducer very large and the weight of the wheel hub is also very large. 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 a driving source for electric vehicles with an RV reducer type hub motor, which drives the wheels by a compound of a 10,000-rpm high-speed permanent magnet synchronous servo motor and a large transmission ratio RV reducer, which can greatly improve the power performance of the whole vehicle. It has a simple structure, small size and light weight. The application of the RV reducer makes it possible to provide a larger transmission ratio in a smaller volume. The use of a high-speed permanent magnet synchronous servo motor makes it have the advantages of good starting ability, strong low-speed dragging ability, high power density, etc. The maximum speed of the motor can reach 21,000 rpm and the reducer transmission ratio is 36.

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

[0008] A driving source for an electric vehicle with an RV reducer-type hub motor comprises a permanent magnet synchronous servo motor I, wherein a fixed end of the permanent magnet synchronous servo motor I is connected to a suspension connector IV, a power output end of the permanent magnet synchronous servo motor I is connected to a power input end of an RV reducer II, and a power output end of the RV reducer II is connected to a tire module III; the power output of the permanent magnet synchronous servo motor I and the power input and output of the RV reducer II are on the same main shaft.

[0009] The permanent magnet synchronous servo motor I adopts a surface-mounted convex inner rotor design, the stator slots are oblique shoulder flat-bottom slots, and the windings adopt integer slot distributed double-layer single-speed symmetrical windings; the permanent magnet synchronous servo motor I includes a main shaft 1, two first axial positioning sleeves 2 are installed on the main shaft 1, and the permanent magnet 4, silicon steel sheet 3 and winding are arranged on the outside of the main shaft 1 between the two first axial positioning sleeves 2 to form the motor stator; a motor housing 6 is provided on the outside of the motor stator, one end of the motor housing 6 is connected to the left end cover 5 of the motor, and the other end is connected to the right end cover 7 of the motor, and the main shaft 1 passes through the left end cover 5 and the right end cover 7 of the motor; the left end of the main shaft 1 is connected to the suspension connector IV.

[0010] The suspension connecting member IV is connected to the left end cover 5 of the motor.

[0011] A hollow magnetic encoder 33 is mounted on the right end cover 7 of the motor. The hollow magnetic encoder 33 feeds back the angular velocity signal of the main shaft 1 in real time. The angular velocity signal is proportionally amplified by an amplifier and used as a wheel speed signal.

[0012] The RV reducer II includes a sun gear 8 connected to the right end of the main shaft 1, and the sun gear 8 and the first planetary gear 9, the second planetary gear 10, and the third planetary gear 11 are meshed with each other to form a planetary gear train, which is a primary transmission mechanism; a first planetary carrier 22 is installed on the left side of the planetary gear train, and the first planetary carrier 22 is connected to the pinion housing 20 by a first deep groove ball bearing 21, and a second planetary carrier 18 is installed on the other side of the pinion housing 20, which is connected by a second deep groove ball bearing 19, and the second planetary carrier 18 is connected to the right end cover 7 of the motor; a first cycloidal wheel 28 and a second cycloidal wheel 29 are installed between the first planetary carrier 22 and the second planetary carrier 18; the first planetary gear 9 is installed on the right end of the first crankshaft 12, the second planetary gear 10 is installed on the right end of the second crankshaft 13, and the third planetary gear 11 is installed on the right end of the third crankshaft 14;

[0013] The main shaft 1, the first crankshaft 12, the second crankshaft 13, the third crankshaft 14, the first fixed shaft 15, the second fixed shaft 16, and the third fixed shaft 17 all pass through the second planetary carrier 18, the first cycloid wheel 28, the second cycloid wheel 29, and the first planetary carrier 22 in sequence. A first angular contact ball bearing 30 and a second angular contact ball bearing 31 are installed between the main shaft 1 and the second planetary carrier 18 and the first planetary carrier 22. The two bearings are installed close to the second axial positioning sleeve 32. The supporting bearings of the sun gear 8 are symmetrically placed using angular contact ball bearings. A first cycloid wheel 28, a second cycloid wheel 29, and the first crankshaft 12 are installed between the first cycloid wheel 28 and the second cycloid wheel 29. The first K-type radial needle roller bearing 25, the second K-type radial needle roller bearing 26, and two bearings of the same type as the first K-type radial needle roller bearing 25 are installed at the same position between the second crankshaft 13, the third crankshaft 14 and the first cycloidal wheel 28, the second cycloidal wheel 29; the first tapered roller bearing 24 and the second tapered roller bearing 27 are installed between the second planetary carrier 18, the first planetary carrier 22 and the second crankshaft 13; and two bearings of the same type as the tapered roller bearing 24 are installed at the same position between the second crankshaft 13, the third crankshaft 14 and the second planetary carrier 18, the first planetary carrier 22.

[0014] A tire end cover 23 is installed on the rightmost side of the RV reducer II.

[0015] The tire module III includes a wheel hub 35 , the inner side of the wheel hub 35 is in contact with a brake drum friction member 36 , the brake drum friction member 36 is tightly connected to the pinion housing 20 , and a tire 34 is mounted on the outer side of the wheel hub 35 .

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) The permanent magnet synchronous servo motor adopted in the present invention has good starting ability, strong low-speed dragging ability, high power density, and compared with the brushless DC motor, it has a simple structure, small size, and light weight, and can maximize the performance of the hub motor within the limited hub space; at the same time, the permanent magnet synchronous servo motor has the advantages of high voltage (800V-1000V) and high speed (maximum 21000rpm). The high voltage can further reduce the size of the motor and optimize the spatial structure of the hub motor. The high speed greatly improves the energy utilization rate of the motor.

[0018] (2) The RV reducer of the present invention is composed of a cycloidal pinwheel and a planetary bracket. It is widely used in various mechanical equipment due to its compact structure, small size, strong impact resistance, large torque, high positioning accuracy, large reduction ratio and other advantages. Compared with the planetary gear reducer, the RV reducer can provide a larger transmission ratio in a smaller volume, effectively improving the performance of the hub motor, and allowing the hub motor to use a higher speed motor. The motor magnetic encoder replaces the wheel speed sensor, real-time feedback of the wheel speed, and replaces the traditional speed sensor to save space. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0020] Figure 2 is a cross-sectional view of an embodiment of the present invention.

[0021] Figure 3 It is a side schematic diagram of an embodiment of the present invention.

[0022] Figure 4 It is a schematic structural diagram of an AC permanent magnet synchronous servo motor I according to an embodiment of the present invention.

[0023] Figure 5 It is a schematic structural diagram of the RV reducer II according to an embodiment of the present invention.

[0024] Figure 6 It is a transmission schematic diagram of the RV reducer II according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with embodiments and drawings.

[0026] Reference Figure 1, a driving source for electric vehicles with an RV reducer type hub motor, composed of four parts: a permanent magnet synchronous servo motor I, an RV reducer II, a tire module III and a suspension connector IV; the fixed end of the permanent magnet synchronous servo motor I is connected to the suspension connector IV, the power output end of the permanent magnet synchronous servo motor I is connected to the power input end of the RV reducer II, and the power output end of the RV reducer II is connected to the tire module III; the power output of the permanent magnet synchronous servo motor I and the power input and output of the RV reducer II are the same main shaft, so that the AC permanent magnet synchronous servo motor I drives the automobile tire to rotate through the RV reducer II.

[0027] Reference Figure 2 , Figure 3 and Figure 4 The permanent magnet synchronous servo motor I adopts a surface-mounted convex inner rotor design, the stator slot is an inclined shoulder flat bottom slot, and the winding adopts an integer slot distributed double-layer single-speed symmetrical winding; the permanent magnet synchronous servo motor I includes a main shaft 1, two first axial positioning sleeves 2 are installed on the main shaft 1, and the permanent magnet 4, silicon steel sheet 3 and winding are arranged on the outside of the main shaft 1 between the two first axial positioning sleeves 2 to form a motor stator; a motor housing 6 is arranged on the outside of the motor stator, one end of the motor housing 6 is connected to the left end cover 5 of the motor, and the other end is connected to the right end cover 7 of the motor, the left end cover 5 of the motor, the motor housing 6 and the right end cover 7 of the motor form a motor housing, and the main shaft 1 passes through the left end cover 5 and the right end cover 7 of the motor; the left end of the main shaft 1 is connected to the suspension connector IV.

[0028] Reference Figure 2 , the suspension connecting member IV is connected to the left end cover 5 of the motor.

[0029] A hollow magnetic encoder 33 is installed on the right end cover 7 of the motor. The hollow magnetic encoder 33 feeds back the angular velocity signal of the main shaft 1 in real time. After the angular velocity signal is proportionally amplified by the amplifier, it is used as the wheel speed signal, which can save the installation space of the wheel speed sensor and further simplify the in-wheel structure.

[0030] Reference Figure 3 and Figure 5 The RV reducer II includes a sun gear 8 connected to the right end of the main shaft 1, and the sun gear 8 and the first planetary gear 9, the second planetary gear 10, and the third planetary gear 11 are meshed with each other to form a planetary gear train, which is a primary transmission mechanism; a first planetary carrier 22 is installed on the left side of the planetary gear train, and the first planetary carrier 22 is connected to the pinion housing 20 by a first deep groove ball bearing 21, and a second planetary carrier 18 is installed on the other side of the pinion housing 20, which is connected by a second deep groove ball bearing 19, and the second planetary carrier 18 is connected to the right end cover 7 of the motor by bolts; a first cycloid wheel 28 and a second cycloid wheel 29 are installed between the first planetary carrier 22 and the second planetary carrier 18;

[0031] The first planetary gear 9 is mounted on the right end of the first crankshaft 12, the second planetary gear 10 is mounted on the right end of the second crankshaft 13, and the third planetary gear 11 is mounted on the right end of the third crankshaft 14;

[0032] The main shaft 1, the first crankshaft 12, the second crankshaft 13, the third crankshaft 14, the first fixed shaft 15, the second fixed shaft 16, and the third fixed shaft 17 all pass through the second planetary carrier 18, the first cycloid wheel 28, the second cycloid wheel 29, and the first planetary carrier 22 in sequence. A first angular contact ball bearing 30 and a second angular contact ball bearing 31 are installed between the main shaft 1 and the second planetary carrier 18 and the first planetary carrier 22. The two bearings are installed close to the second axial positioning sleeve 32. The supporting bearings of the sun gear 8 are symmetrically placed using angular contact ball bearings, and the bearing speed requirement is high. A first K-type radial needle roller bearing 25 is installed between the first cycloid wheel 28, the second cycloid wheel 29 and the first crankshaft 12 , the second K-type radial needle roller bearing 26 supports the circular motion of the cycloid wheel, and two bearings of the same type as the first K-type radial needle roller bearing 25 are installed at the same position between the second crankshaft 13, the third crankshaft 14 and the first cycloid wheel 28, the second cycloid wheel 29; the first tapered roller bearing 24 and the second tapered roller bearing 27 are installed between the second planetary carrier 18, the first planetary carrier 22 and the second crankshaft 13, which on the one hand support and position the crankshaft and on the other hand limit the axial movement of the cycloid wheel; two bearings of the same type as the tapered roller bearing 24 are installed at the same position between the second crankshaft 13, the third crankshaft 14 and the second planetary carrier 18, the first planetary carrier 22.

[0033] A tire end cover 23 is installed on the rightmost side of the RV reducer II.

[0034] Reference Figure 2 The tire module III includes a wheel hub 35 , the inner side of the wheel hub 35 is in contact with a brake drum friction member 36 , the brake drum friction member 36 is fastened to the pinion housing 20 by bolts, and a tire 34 is mounted on the outer side of the wheel hub 35 .

[0035] The working principle of the present invention is:

[0036] The present invention consists of four parts: a permanent magnet synchronous servo motor I integrated in a wheel hub, an RV reducer II, a tire module III and a suspension connector IV. The permanent magnet synchronous servo motor I is used to drive the wheel hub motor of the RV reducer II with a large reduction ratio. The power input and output of the permanent magnet synchronous servo motor I and the RV reducer II are completed by the same main shaft. The pin gear housing of the RV reducer II is fastened to the tire module III, so that the permanent magnet synchronous servo motor I drives the tire module III to rotate through the RV reducer II.

[0037] The AC permanent magnet synchronous servo motor I is used as a power source, and the RV reducer II is used as a transmission mechanism. The power is transmitted to the tire 34 through the connection and installation between the outer side of the pin gear housing 20 and the wheel hub 35 and the brake drum friction member 36. The AC permanent magnet synchronous servo motor I is connected and installed with the vehicle suspension mechanism or other mechanisms through the reserved suspension connector IV and thus installed on the vehicle.

[0038] Reference Figure 3 , Figure 5 and Figure 6, RV reducer II is composed of a sun gear planetary gear primary transmission mechanism (KH type) and a cycloidal pin gear secondary transmission mechanism (KHV type); when power is input from the main shaft 1 (i.e., the sun gear core shaft), the sun gear 8 rotates counterclockwise, and the sun gear 8 is meshed with the first planetary gear 9, the second planetary gear 10, and the third planetary gear 11 distributed in a 120-degree circumference, and the power is transmitted from the sun gear 8 to the first planetary gear 9, the second planetary gear 10, and the third planetary gear 11 to complete the first stage of transmission; the first planetary gear 9, the second planetary gear 10, and the third planetary gear 11 are fixedly constrained by the first planet carrier 22 and only rotate clockwise, and the first planetary gear 9, the second planetary gear 10, and the third planetary gear 11 are meshed with the first planetary gear 9, the second planetary gear 10, and the third planetary gear 11. The first crankshaft 12, the second crankshaft 13, and the third crankshaft 14 are fixedly connected by a key connection to transmit power to the second-stage transmission mechanism; the first cycloid wheel 28 and the second cycloid wheel 29 are driven by the first crankshaft 12, the second crankshaft 13, and the third crankshaft 14, and the first cycloid wheel 28 and the second cycloid wheel 29 are meshed with the pin gear on the pin gear housing 20 to transmit power to the pin gear housing 20 for clockwise output; at this time, the pin gear housing 20 is supported by the first deep groove ball bearing 19 and the second deep groove ball bearing 20 to rotate around the second planetary carrier 18 and the first planetary carrier 22, and the stationary motion of the planetary carrier is transmitted through the first fixed shaft 15, the second fixed shaft 16, the third fixed shaft 17 and the first crankshaft 12, the second crankshaft 13, the third crankshaft 14. The shaft 14 is fed back to the first-stage transmission mechanism, constraining the first planetary gear 9, the second planetary gear 10, and the third planetary gear 11 to revolve around the sun gear 8 to form a closed motion loop; the number of bearings arranged in the RV reducer II is a total of 16. The sun gear 8 support bearing adopts the first angular contact ball bearing 30 and the second angular contact ball bearing 31, which are symmetrically placed, and the bearing speed requirement is high; the planetary gear support bearing adopts the first tapered roller bearing 24 and the second tapered roller bearing 27, which are symmetrically placed, on the one hand to support and position the crankshaft, and on the other hand to limit the axial movement of the cycloid wheel; the first K-type radial needle roller rolling bearing 25 and the second K-type radial needle roller rolling bearing 26 are used to support the first cycloid wheel 28 and the second cycloid wheel 2 9's circular motion; the main bearing adopts the first deep groove ball bearing 19 and the second deep groove ball bearing 20, which on the one hand bear almost all the external loads of the RV reducer II, and on the other hand ensure the stability of the output torque; the wheel speed sensor is replaced by a hollow magnetic encoder 33, and the wheel speed is fed back in real time. The input angle of the sun gear 8 is obtained through the hollow magnetic encoder, and the theoretical output angle of the wheel is obtained through the amplifier, and the amplifier gain coefficient is the transmission ratio 36 of the RV reducer II; based on the input characteristics such as load torque and motor speed, the transmission error is obtained through the predictor, and the predictor can be obtained through training based on existing samples; the transmission error is compensated for the theoretical output angle of the wheel, and finally the actual output angle of the wheel can be obtained.

Claims

1. A driving source for an electric vehicle with an RV reducer-type wheel hub motor, comprising a permanent magnet synchronous servo motor (I), characterized in that: The fixed end of the permanent magnet synchronous servo motor (I) is connected to the suspension connector (IV), the power output end of the permanent magnet synchronous servo motor (I) is connected to the power input end of the RV reducer (II), and the power output end of the RV reducer (II) is connected to the tire module (III); the power output of the permanent magnet synchronous servo motor (I) and the power input and output of the RV reducer (II) are the same main shaft.

2. The driving source according to claim 1, characterized in that: The permanent magnet synchronous servo motor (I) adopts a surface mounted convex inner rotor design, the stator slot is an inclined shoulder flat bottom slot, and the winding adopts an integer slot distributed double-layer single-speed symmetrical winding; the permanent magnet synchronous servo motor (I) comprises a main shaft (1), two first axial positioning sleeves (2) are installed on the main shaft (1), and the permanent magnet (4), silicon steel sheet (3) and winding are arranged on the outer side of the main shaft (1) between the two first axial positioning sleeves (2) to form a motor stator; a motor housing (6) is arranged on the outer side of the motor stator, one end of the motor housing (6) is connected to the left end cover (5) of the motor, and the other end is connected to the right end cover (7) of the motor, and the main shaft (1) passes through the left end cover (5) and the right end cover (7) of the motor; the left end of the main shaft (1) is connected to the suspension connector (IV).

3. The driving source according to claim 2, characterized in that: The suspension connecting member (IV) is connected to the left end cover (5) of the motor.

4. The driving source according to claim 2, characterized in that: A hollow magnetic encoder (33) is installed on the right end cover (7) of the motor. The hollow magnetic encoder (33) feeds back the angular velocity signal of the main shaft (1) in real time. The angular velocity signal is proportionally amplified by an amplifier and used as a wheel speed signal.

5. The driving source according to claim 2, characterized in that: The RV reducer (II) comprises a sun gear (8) connected to the right end of the main shaft (1), and the sun gear (8) and the first planetary gear (9), the second planetary gear (10), and the third planetary gear (11) mesh with each other to form a planetary gear train, which is a primary transmission mechanism; a first planetary carrier (22) is installed on the left side of the planetary gear train, and the first planetary carrier (22) is connected to the pinion housing (20) by a first deep groove ball bearing (21); a second planetary carrier (18) is installed on the other side of the pinion housing (20), and is connected by a second deep groove ball bearing (19); the second planetary carrier (18) is connected to the right end cover (7) of the motor; a first cycloid wheel (28) and a second cycloid wheel (29) are installed between the first planetary carrier (22) and the second planetary carrier (18); the first planetary gear (9) is installed on the right end of the first crankshaft (12), the second planetary gear (10) is installed on the right end of the second crankshaft (13), and the third planetary gear (11) is installed on the right end of the third crankshaft (14); The main shaft (1), the first crankshaft (12), the second crankshaft (13), the third crankshaft (14), the first fixed shaft (15), the second fixed shaft (16), and the third fixed shaft (17) all pass through the second planetary carrier (18), the first cycloid wheel (28), the second cycloid wheel (29), and the first planetary carrier (22) in sequence; a first angular contact ball bearing (30) and a second angular contact ball bearing (31) are installed between the main shaft (1) and the second planetary carrier (18) and the first planetary carrier (22); the supporting bearings of the sun gear (8) are symmetrically arranged using angular contact ball bearings; a first K-type centripetal roller bearing is installed between the first cycloid wheel (28), the second cycloid wheel (29) and the first crankshaft (12) The invention discloses a plurality of bearings of the same type as the first K-type radial needle roller bearing (25) and a second K-type radial needle roller bearing (26); two bearings of the same type as the first K-type radial needle roller bearing (25) are installed at the same position between the second crankshaft (13), the third crankshaft (14) and the first cycloidal wheel (28), and the second cycloidal wheel (29); a first tapered roller bearing (24) and a second tapered roller bearing (27) are installed between the second planetary carrier (18), the first planetary carrier (22) and the second crankshaft (13); and two bearings of the same type as the tapered roller bearing (24) are installed at the same position between the second crankshaft (13), the third crankshaft (14) and the second planetary carrier (18), and the first planetary carrier (22).

6. The driving source according to claim 5, characterized in that: A tire end cover (23) is installed on the rightmost side of the RV reducer (II).

7. The driving source according to claim 5, characterized in that: The tire module III comprises a wheel hub (35), the inner side of the wheel hub (35) is in contact with a brake drum friction piece (36), the brake drum friction piece (36) is tightly connected to the pinion housing (20), and a tire (34) is mounted on the outer side of the wheel hub (35).

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