Heavy-duty vehicle electric wheel structure and using method thereof

Abstract

The invention discloses a heavy-duty vehicle electric wheel structure and a using method thereof, and belongs to the technical field of electric vehicle drive.The heavy-duty vehicle electric wheel structure comprises a rim, a planetary reducer and a drum brake are connected to the inner surface of the rim, a cavity is formed in the drum brake, and a hub motor is installed in the cavity; the hub motor is connected with the planetary reducer through a motor shaft, the planetary reducer comprises a sun gear, a planet gear, a gear ring and a planetary reducer shell which are sequentially connected, the sun gear is connected with the motor shaft, the planetary reducer shell is connected with the rim, and a motor shell, a motor outer end cover and a motor inner end cover are arranged on the outer side of the hub motor. The two sides of the motor shell are connected with the motor outer end cover and the motor inner end cover respectively, the drum brake comprises a brake drum, a brake shoe and a brake wheel cylinder which are connected in sequence, the brake wheel cylinder is connected with the motor inner end cover, the brake drum is connected with the rim, the motor shell is connected with the brake drum, the design and assembly processes of independent components are reduced, and therefore the manufacturing cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of electric vehicle driving, and in particular relates to an electric wheel structure of a heavy-duty vehicle and a use method thereof. Background Art

[0002] The design of electric wheels has gradually emerged with the development of the electric vehicle industry. As an environmentally friendly and efficient means of transportation, electric vehicles have a significantly different driving method from traditional internal combustion engine vehicles. The core of the electric wheel design lies in the hub motor technology, which integrates the power, transmission and braking devices into the wheel hub, closely combines the power output with the wheel, eliminates the traditional drive shaft and differential, simplifies the vehicle structure, and improves the power transmission efficiency of the vehicle; because each electric wheel can be controlled independently, the vehicle's maneuverability is greatly improved, especially in conditions such as turning and changing lanes.

[0003] At present, some schools pay more attention to thermal management, control system optimization and industrial application, while enterprises focus on the integration and mass production of complete vehicles. Their electric wheels have been used in some high-end new energy vehicle models. Protean Electric's electric wheels have been tested on multiple prototype vehicles and have shown good handling and power response. Overall, the future of electric wheel technology lies in further improving its energy efficiency, reducing manufacturing costs, solving heat dissipation problems, and deeply integrating with autonomous driving technology.

[0004] Due to the advantages of disc brakes in their own design characteristics, disc brakes are currently commonly used in electric wheels. Although they can keep the vehicle at a high speed with good braking performance, the production cost is high, and most heavy-duty vehicles in China still do not use disc brakes. Drum brakes have better braking performance under low-speed conditions, and the structure is strong and wear-resistant, with low production or replacement costs. For heavy-duty vehicles with relatively low speeds in daily operating conditions, the design of integrating drum brakes into the electric wheels of heavy-duty vehicles is a space-saving and compact technical solution. However, drum brakes for heavy-duty vehicles or special-purpose vehicles may be larger to withstand higher loads and braking requirements. This is contrary to the principle of high integration of electric wheels, so how to integrate drum brakes, wheel hub motors and reducers into the wheel rim in a good combination is a difficult point.

[0005] At present, there are patent applications that use electric wheel solutions with integrated drum brakes. For example, the Chinese patent application with publication number "CN109823163A" uses an integrated solution in which a planetary reducer, an inner rotor hub motor and a drum brake are arranged side by side inside the wheel rim, wherein the hub motor is sandwiched between the planetary reducer and the drum brake. This solution is not conducive to dissipating the heat generated by the hub motor when outputting the driving torque. The drum brake will also generate a lot of heat during friction braking and further increase the temperature of the motor, resulting in a serious temperature rise of the motor. The arrangement of the drum brake is not ideal enough. Especially for heavy-duty vehicles, the brake drum usually needs to be designed to be larger. A larger brake drum can provide a larger friction surface area, thereby enhancing the braking effect. In addition, a larger brake drum also helps to dissipate heat better and reduce brake degradation (weakened braking performance) caused by overheating. Therefore, for the electric wheel of a heavy-duty vehicle, it is difficult to integrate a larger drum brake, a hub motor and a reducer into the electric wheel in a good combination while ensuring the heat dissipation efficiency of the hub motor and the drum brake. Summary of the invention

[0006] The present invention provides an electric wheel structure for a heavy-loaded vehicle and a method for using the same, which solves the problem that for an electric wheel of a heavy-loaded vehicle, the installation positions of a hub motor and a drum brake are difficult to integrate a larger drum brake, a hub motor and a reducer into the interior of the electric wheel in a good combination while ensuring the heat dissipation efficiency of the hub motor and the drum brake.

[0007] To achieve the above object, the present invention provides the following technical solutions: A heavy-duty vehicle electric wheel structure comprises a wheel rim, a planetary reducer and a drum brake are connected to the inner surface of the wheel rim, a cavity is arranged inside the drum brake, a wheel hub motor is installed in the cavity, and the wheel hub motor is connected to the planetary reducer through a motor shaft; The planetary reducer includes a sun gear, a planetary gear, a ring gear and a planetary reducer housing connected in sequence, the sun gear is connected to the motor shaft, the planetary reducer housing is connected to the rim, the outside of the hub motor is provided with a motor housing, a motor outer end cover and a motor inner end cover, the two sides of the motor housing are respectively connected to the motor outer end cover and the motor inner end cover, the drum brake includes a brake drum, a brake shoe and a brake wheel cylinder connected in sequence, the brake wheel cylinder is connected to the motor inner end cover, the brake drum is connected to the rim, and the motor housing is connected to the brake drum.

[0008] Preferably, a support arm is provided on the outer end cover of the motor, the support arm is connected to the axle of the vehicle, and a reinforcing rib is provided at the end of the support arm.

[0009] Preferably, the motor housing is connected to the brake drum through a cylindrical roller bearing, and positioning shoulders are provided on the motor housing and the motor outer end cover. The positioning shoulders of the motor housing and the motor outer end cover fix the inner ring of the cylindrical roller bearing, and the outer ring of the cylindrical roller bearing rotates with the brake drum.

[0010] Preferably, an ear plate is provided on one side of the motor housing close to the inner end cover of the motor, and the ear plate is fixedly connected to the inner end cover of the motor by screws. Brake shoe support blocks are provided on the upper and lower sides of the outer side of the motor housing close to the inner end cover of the motor, which are used to support and fix the axial position of the brake shoe on the surface of the motor housing.

[0011] Preferably, both ends of the brake wheel cylinder are provided with brake wheel cylinder H-shaped keys, and both ends of the brake shoe are provided with grooves, the brake wheel cylinder H-shaped key cooperates with the groove on the brake shoe to fix the axial and radial position of the brake shoe, and a return spring is installed on one side of the groove at both ends of the brake shoe, and the return spring is close to the center of the brake shoe, and a friction lining is provided between the brake shoe and the inner surface of the brake drum.

[0012] Preferably, a planetary gear positioning column is connected to the inner end cover of the motor, a first planet carrier and a second planet carrier arranged in parallel are connected to the planetary gear positioning column, a planetary wheel bearing is connected between the first planet carrier and the second planet carrier, and the planetary wheel bearing is connected to the planetary wheel.

[0013] Preferably, the first planet carrier and the second planet carrier are both provided with planet wheel bearing positioning steps, and the planet wheel bearing positioning steps on the first planet carrier and the second planet carrier pass through the inner ring of the planet wheel bearing, and are used to support and fix the inner ring of the planet wheel bearing. A through hole is provided at the center position of the first planet carrier for the motor shaft to pass through.

[0014] Preferably, a positioning column groove is provided on the planetary gear positioning column, and an elastic clamp ring is provided on the positioning column groove. The elastic clamp ring is arranged outside the first planet carrier and the second planet carrier for fixing the positions of the first planet carrier and the second planet carrier.

[0015] Preferably, a rectangular groove is provided on the outer circle of the gear ring, and an L-shaped key is provided on the inner surface of the planetary reducer housing, and the rectangular groove cooperates with the L-shaped key to fix the axial position of the gear ring in the planetary reducer housing.

[0016] A method for using a heavy-load vehicle electric wheel structure, comprising: When a heavy-loaded vehicle is traveling, the wheel hub motor transmits the required driving torque to the sun gear through the motor shaft. The rotation of the sun gear drives the planetary gear to rotate, and the rotation of the planetary gear drives the ring gear to rotate. The rotation of the ring gear drives the planetary reducer housing to rotate, thereby transmitting power to the wheel rim. The rotation of the wheel rim drives the rotation of the brake drum. At this time, the brake drum does not generate any braking torque, and the internal driving part and braking part of the electric wheel of the heavy-loaded vehicle operate normally. When the heavy-loaded vehicle brakes, the brake wheel cylinder outputs the braking thrust, and the brake wheel cylinder outputs the braking thrust to the brake shoe, so that the brake shoe and the brake drum fit closely, generating friction, forcing the speed of the brake drum to decrease, and finally the speed of the wheel rim to decrease, achieving the purpose of decelerating the vehicle.

[0017] Compared with the prior art, the present invention has the following beneficial effects: the present invention provides an electric wheel structure for a heavy-duty vehicle, comprising a rim, a planetary reducer and a drum brake connected to the inner surface of the rim, a cavity arranged inside the drum brake, a hub motor installed in the cavity, the hub motor connected to the planetary reducer through a motor shaft, the hub motor, the drum brake and the planetary reducer are all installed in the rim, and the overall weight of the vehicle is reduced through an integrated design, the planetary reducer comprises a sun gear, a planetary gear, a gear ring and a planetary reducer housing connected in sequence, the sun gear is connected to the motor shaft, the planetary reducer housing is connected to the rim, a motor housing, a motor outer end cover and a motor inner end cover are arranged on the outer side of the hub motor, and both sides of the motor housing are respectively connected to the motor outer end cover and the motor inner end cover, the drum brake comprises a brake drum, a brake shoe and a brake wheel cylinder connected in sequence, the brake wheel cylinder is connected to the motor inner end cover, the brake drum is connected to the rim, and the motor housing is connected to the brake drum, the design and assembly process of independent components are reduced, thereby reducing the manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the overall structure of the electric wheel for a heavy-duty vehicle proposed by the present invention; Figure 2 This is a cross-sectional view of the overall structure of the electric wheel for a heavy-duty vehicle proposed by the present invention; Figure 3 This is a schematic diagram of the overall structure of the electric wheel hub motor for a heavy-duty vehicle proposed by the present invention; Figure 4 This is a schematic diagram of the inner end cover structure of the electric wheel hub motor of a heavy-duty vehicle proposed by the present invention; Figure 5 This is a schematic diagram of the outer end cover structure of the electric wheel hub motor of a heavy-duty vehicle proposed by the present invention; Figure 6 This is a schematic diagram of the internal structure of the electric wheel drum brake for heavy-duty vehicles proposed by the present invention; Figure 7 This is a schematic diagram of the brake wheel cylinder structure of the heavy-duty vehicle electric wheel drum brake proposed by the present invention; Figure 8 A schematic diagram of the brake drum and internal structure of the electric wheel drum brake for a heavy-duty vehicle proposed by the present invention; Fig. 9 This is a schematic diagram of the structure of the electric wheel planetary reducer for heavy-duty vehicles proposed by the present invention; Fig.10 This is a schematic diagram of the planet carrier structure of the electric wheel planetary reducer for heavy-duty vehicles proposed by the present invention; Fig.11 This is a schematic diagram of the housing structure of the electric wheel planetary reducer for heavy-duty vehicles proposed by the present invention; Fig.12 This is a schematic diagram of the rim structure of the electric wheel for heavy-duty vehicles proposed by the present invention; In the figure: 1. outer end cover of motor; 2. cylindrical roller bearing; 3. brake drum; 4. brake shoe; 5. rim; 6. planetary reducer housing; 7a. first planet carrier; 7b. second planet carrier; 8. planetary gear positioning column; 9. motor shaft; 10. sun gear; 11. planetary gear; 12. planetary gear bearing; 13. elastic retaining ring; 14. planetary reducer end cover; 15. gear ring; 16. inner end cover of motor; 17. brake wheel cylinder; 18. return spring; 19. motor housing; 20. motor stator; 21. brake shoe support block; 22. threaded hole of inner end cover of motor; 23. threaded hole of brake wheel cylinder; 24. friction lining; 25. H-key of brake wheel cylinder. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0022] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0023] like Figure 1 As shown, the present invention provides an electric wheel structure for a heavy-duty vehicle, comprising a rim 5, a planetary reducer and a drum brake are connected to the inner surface of the rim 5, a cavity is provided inside the drum brake, a hub motor is installed in the cavity, and the hub motor is connected to the planetary reducer through a motor shaft 9; The planetary reducer includes a sun gear 10, a planetary gear 11, a ring gear 15 and a planetary reducer housing 6 which are connected in sequence. The sun gear 10 is connected to the motor shaft 9, the planetary reducer housing 6 is connected to the rim 5, a motor housing 19, a motor outer end cover 1 and a motor inner end cover 16 are arranged on the outside of the hub motor, and the two sides of the motor housing 19 are respectively connected to the motor outer end cover 1 and the motor inner end cover 16. The drum brake includes a brake drum 3, a brake shoe 4 and a brake wheel cylinder 17 which are connected in sequence. The brake wheel cylinder 17 is connected to the motor inner end cover 16, the brake drum 3 is connected to the rim 5, and the motor housing 19 is connected to the brake drum 3.

[0024] This electric wheel structure integrates the wheel hub motor, drum brake and planetary reducer, and adopts a new combination integrated design method. Specifically, the brake base plate of the drum brake is integrated with the inner end cover 16 of the motor, the brake wheel cylinder 17 of the drum brake is fixed on the inner end cover 16 of the motor by screws, the wheel hub motor runs through the cavity of the drum brake, and the axial and radial positions of the brake shoe 4 are determined by the brake wheel cylinder H-shaped keys 25 at both ends of the brake wheel cylinder 17 and the brake shoe support block 21 on the outer side of the wheel hub motor housing 19; the outer side of the motor housing 19 is sleeved with a cylindrical roller bearing 2, and the outer ring of the cylindrical roller bearing 2 is tightly fitted with the inner surface of the brake drum 3 of the drum brake, and the axial position and radial position of the wheel hub motor in the drum brake cavity are fixed by the cylindrical roller bearing 2. The outer end cover 1 of the motor is provided with upper and lower support arms, and the wheel hub motor is fixed to the axle of the vehicle by the support arms. The motor shaft 9 cooperates with the keyway of the sun gear 10 through the shaft end spline to realize power transmission. The motor inner end cover 16 is connected with a planetary gear positioning column 8, and the first planetary carrier 7a and the second planetary carrier 7b are connected with the planetary gear positioning column 8 in parallel. The positions of the first planetary carrier 7a and the second planetary carrier 7b are fixed on the planetary gear positioning column 8 on the outer side of the motor inner end cover 16 through an elastic clamp ring 13; the torque output by the hub motor is transmitted to the ring gear 15 through the sun gear 10 and the planetary gear 11, and the ring gear 15 is connected to the planetary reducer end cover 14 through a rectangular keyway, and the planetary reducer housing 6 is fixedly connected to the rim 5 through screws. This design successfully solves the technical problem of the difficulty of arranging drum brakes, hub motors and planetary reducers in the rim 5 at the same time when designing the integrated design of the electric wheel of a heavy-duty vehicle, and at the same time, ensures the driving force and braking force required by the heavy-duty vehicle.

[0025] The wheel hub motor is installed in the cavity formed by the drum brake as the driving force source of the electric wheel. The wheel hub motor is composed of a motor outer end cover 1, a motor inner end cover 16, a motor housing 19 and a motor shaft 9. The motor inner end cover 16 and the motor outer end cover 1 are fixedly connected to the motor housing 19 by screws; the motor outer end cover 1 is provided with two support arms, which are used to connect the wheel hub motor to the axle of the vehicle, and two reinforcing ribs are provided at the end of the support arm to improve the bearing capacity of the support arm. The motor outer end cover 1 is also provided with a positioning shoulder for fixing the inner ring of the cylindrical roller bearing 2. At the same time, the positioning shoulder strengthens the bearing capacity of the motor outer end cover 1; the outer side of the motor inner end cover 16 is provided with a planetary gear positioning column 8; the motor housing 19 is provided with six ear plates on the side close to the motor inner end cover 16, and the six ear plates are fixedly connected to the motor inner end cover 16 by screws. Brake shoe support blocks 21 are provided on both the upper and lower sides of the outer side of the motor housing 19 close to the motor inner end cover 16, which are used to support and fix the axial position of the brake shoe 4 on the surface of the motor housing 19; a shaft shoulder is provided on the side of the motor housing 19 close to the motor outer end cover 1, and the shaft shoulder fixes the inner ring of the cylindrical roller bearing 2 together with the positioning shoulder on the motor outer end cover 1.

[0026] The drum brake is used to provide the torque required by the electric wheel. The drum brake consists of two left and right brake shoes 4, friction linings 24, return springs 18, brake drums 3, and upper and lower brake wheel cylinders 17. The brake wheel cylinder 17 is fixedly connected to the inner end cover 16 of the motor by screws, and the axial position of the brake shoe 4 is determined by fixing the position of the brake wheel cylinder 17. At the same time, the axial position and radial position of the left and right brake shoes 4 are fixed by the support blocks outside the motor housing 19; the return spring 18 is installed at both ends of the brake shoe 4, and the installation position is kept at a certain distance from the wheel hub motor and the brake wheel cylinder 17 to avoid friction loss; one side of the brake drum 3 is fixedly connected to the rim 5 and the planetary reducer housing 6 by screws, and the other side of the brake drum 3 is provided with an L-shaped positioning shoulder for fixing the axial position of the cylindrical roller bearing 2, and the inner side of the brake drum 3 is tightly fitted with the outer ring of the cylindrical roller bearing 2. Among them, the inner ring of the cylindrical roller bearing 2 is fixed, and the outer ring rotates with the brake drum 3. At the same time, six reinforcing ribs are arranged on the outer side of the brake drum 3 to improve the anti-deformation and radial bearing capacity of the brake drum 3 .

[0027] The planetary reducer is used to convert the high speed and low torque output by the wheel hub motor into low speed and high torque output to the wheel rim 5. The planetary reducer is composed of a sun gear 10, a planetary gear 11, a planet carrier, a gear ring 15, a planetary reducer housing 6 and a planetary reducer end cover 14. A spline keyway is provided inside the sun gear 10 to cooperate with the spline on the motor shaft 9; the outer teeth of the planetary gear 11 mesh with the outer teeth of the sun gear 10, and the rotation of the sun gear 10 drives the planetary gear 11 to rotate around its own axis. The planet carrier includes a first planet carrier 7a and a second planet carrier 7b, a planetary gear bearing 12 is connected between the first planet carrier 7a and the second planet carrier 7b, the planetary gear 11 is interference fit with the planetary gear bearing 12, and the first planet carrier 7a and the second planet carrier 7b are both provided with planetary gear bearing positioning steps, the planetary gear bearing positioning steps on the first planet carrier 7a and the second planet carrier 7b pass through the inner ring of the planetary gear bearing 12, and are used to support and fix the inner ring of the planetary gear bearing 12, and the outer ring of the planetary gear bearing 12 rotates with the planetary gear 11; the inner teeth of the ring gear 15 are meshed with the outer teeth of the planetary gear 11 for power transmission, and the outer circle of the ring gear 15 is provided with a rectangular groove for matching with the L-shaped key provided on the inner circle surface of the planetary reducer housing 6, so that the torque on the ring gear 15 is output to the planetary reducer housing 6, and the L-shaped key and the planetary reducer end cover 14 jointly determine the axial position of the ring gear 15 in the planetary reducer housing 6. The planetary reducer end cover 14 is fixedly connected to the planetary reducer housing 6 by screws, and a positioning cylinder is provided on the inner surface of the planetary reducer end cover 14 for fixing the axial position of the ring gear 15 .

[0028] An inner flange is provided at the middle of the inner surface of the rim 5 , and the rim 5 is fixedly connected to the brake drum 3 of the drum brake and the planetary reducer housing 6 by means of the inner flange.

[0029] The brake wheel cylinder 17 is composed of a cylinder body and a connecting column. An ear plate is provided on the lower surface of the connecting column. The ear plate is fixedly connected to the inner end cover 16 of the motor by screws, thereby fixing the position of the brake wheel cylinder 17.

[0030] Among them, brake wheel cylinder H-shaped keys 25 are provided at both ends of the brake wheel cylinder 17. The brake wheel cylinder H-shaped key 25 is used to clamp the brake shoe 4 and fix the axial position of the brake shoe 4. At the same time, the brake wheel cylinder H-shaped key 25 ensures that the brake wheel cylinder 17 stably outputs the required braking force.

[0031] A support block is provided in the middle of the motor housing 19 , and the support block is used to fix the axial and radial positions of the brake shoe 4 ; the position of the brake shoe 4 is determined by the support block and the brake wheel cylinder H-shaped key 25 provided at both ends of the brake wheel cylinder 17 .

[0032] Among them, the return spring 18 in the drum brake is distributed on both sides of the brake shoe 4 and away from the brake wheel cylinder 17 and the motor housing 19. The return spring 18 is used to make the brake shoe 4 fit tightly with the support block and the brake wheel cylinder H-shaped key 25 of the brake wheel cylinder 17 when the brake shoe 4 is not subjected to the thrust generated by the brake wheel cylinder 17, thereby fixing the radial and axial positions of the brake shoe 4 in the drum brake.

[0033] An outer flange is provided at one end of the brake drum 3, and the outer flange is fixedly connected to the inner flange provided on the inner surface of the rim 5 by screws; the other end of the brake drum 3 is an L-shaped positioning shoulder, and the positioning shoulder is used to fix the outer ring of the cylindrical roller bearing 2 on the brake drum 3 so that the outer ring of the cylindrical roller bearing 2 fits tightly with the brake drum 3; six reinforcing ribs are provided on the outer side of the brake drum 3 to increase the deformation resistance and radial load-bearing capacity of the brake drum 3.

[0034] Two upper and lower support arms are provided on the outside of the motor outer end cover 1, and two reinforcing ribs are provided at the end of each support arm; a positioning shoulder for fixing the inner ring of the cylindrical roller bearing 2 is provided on the motor outer end cover 1, and the positioning shoulder not only works together with the shaft shoulder on the motor housing 19 to fix the inner ring of the cylindrical roller bearing 2, but also strengthens the radial load-bearing capacity of the motor outer end cover 1.

[0035] A planetary gear positioning column 8 is disposed outside the motor inner end cover 16 , and two positioning column grooves are disposed on the planetary gear positioning column 8 . The positioning column grooves are used to place elastic clamps 13 to fix the relative position of the planet carrier on the positioning column.

[0036] The planetary reducer includes a first planet carrier 7a and a second planet carrier 7b, which interact with each other to fix the planetary gear 11 and the planetary gear bearing 12; three positioning steps are provided on the first planet carrier 7a and the second planet carrier 7b, each positioning step fixes a planetary gear 11 and a planetary gear bearing 12, and the positioning steps on the first planet carrier 7a and the second planet carrier 7b are opposite to each other, supporting and fixing the planetary gear bearing 12, so that the inner ring of the planetary gear bearing 12 remains stationary and the outer ring rotates; the planetary gear 11 has an interference fit with the outer ring of the planetary gear bearing 12 through its inner circle, thereby realizing the rotation of the planetary gear 11 around its own axis.

[0037] An inner flange is provided at one end of the planetary reducer housing 6, which is used to be fixedly connected to the inner flange provided on the inner surface of the rim 5 and the inner flange provided at one end of the brake drum 3 by screws; a positioning shoulder is provided at the other end of the planetary reducer housing 6, and the axial position of the planetary reducer housing 6 relative to the rim 5 is fixed by the positioning shoulder; an L-shaped key is provided on the inner surface of the planetary reducer housing 6, and the L-shaped key is used to cooperate with the rectangular groove provided on the outer circular surface of the ring gear 15; at the same time, the L-shaped key cooperates with the flange on the inner side of the planetary reducer end cover 14 to jointly fix the axial position of the ring gear 15 in the planetary reducer housing 6.

[0038] Another embodiment of the present invention provides a heavy-duty vehicle electric wheel structure, such as Figure 1-Figure 12 As shown, it includes a hub motor, a drum brake, a planetary reducer and a wheel rim 5. The hub motor includes a motor outer end cover 1, a motor housing 19, a motor stator 20 and a motor shaft 9, etc.; the drum brake includes a brake drum 3, a brake shoe 4, a brake wheel cylinder 17 and a return spring 18; the planetary reducer includes a sun gear 10, a planetary gear 11, a gear ring 15, a planetary reducer housing 6, a first planetary carrier 7a, a second planetary carrier 7b, an elastic retaining ring 13, a planetary wheel bearing 12 and a planetary reducer end cover 14.

[0039] The hub motor is installed in the wheel rim 5, as shown in FIG. Figure 1 , Figure 2 As shown, the wheel hub motor is arranged on the left half of the wheel rim 5 and is located in the cavity formed by the brake drum 3 and the brake shoe 4 of the drum brake.

[0040] like Figure 3 As shown, the motor outer end cover 1 of the hub motor is fixedly connected to the motor housing 19 by six screws. A shaft shoulder is provided in the middle of the motor housing 19 to locate the axial position of the cylindrical roller bearing 2 on the motor housing 19. Two symmetrical brake shoe support blocks 21 are provided on the motor housing 19 near the motor inner end cover 16 to support and fix the radial and axial positions of the brake shoe. The motor inner end cover 16 is provided with a brake wheel cylinder threaded hole 23 and a motor inner end cover threaded hole 22. The brake wheel cylinder 17 is fixedly connected to the motor inner end cover 16 through the brake wheel cylinder threaded hole 23. The motor inner end cover 16 is fixedly connected to the six mounting ears on the motor housing 19 through the motor inner end cover threaded holes 22. Figure 4 As shown, three planetary gear positioning columns 8 are provided on the right side of the inner end cover 16 of the motor, and two positioning column grooves are provided on the planetary gear positioning columns 8 for placing elastic clamping rings 13, and the axial position of the planetary carrier 7 on the planetary gear positioning columns 8 is fixed by the elastic clamping rings 13; a spline is provided at the end of the motor shaft 9 for cooperating with the keyway inside the sun gear 10 to realize power transmission.

[0041] like Figure 5 As shown, in this embodiment, two support arms are provided on the outer end cover 1 of the motor, and the support arms are used to connect the heavy-load vehicle electric wheel with the vehicle axle, so as to transfer the weight of the vehicle body and the force of the vehicle body to the heavy-load vehicle electric wheel; two reinforcing ribs are provided at the end of each of the two support arms, which are used to improve the bearing capacity of the support arms, and a positioning shoulder is provided on the right side of the support arm, which is used to fix the inner ring of the cylindrical roller bearing 2, and also strengthens the bearing capacity of the outer end cover 1 of the motor, effectively avoiding deformation, rupture or other structural failure of the outer end cover 1 of the motor due to excessive load, thereby ensuring the safe operation of the heavy-load vehicle electric wheel proposed in the present invention and extending its service life.

[0042] like Figure 1 , Figure 2 , Figure 6 and Figure 8 As shown, the drum brake is integrally arranged around the motor housing 19 and is located inside the rim 5; the brake base plate required in the drum brake is replaced by the motor inner end cover 16, and the brake drum 3 in the drum brake is fixedly connected to the rim 5 by six screws and rotates with the rim 5.

[0043] like Figure 6 As shown, the internal structure of the brake drum 3 of the drum brake consists of two upper and lower brake wheel cylinders 17, two left and right brake shoes 4, friction linings 24 and return springs 18. Figure 7 As shown, the ear plate provided on the brake wheel cylinder 17 is fixedly connected to the inner end cover 16 of the motor by screws, and the brake wheel cylinder 17 is provided with a brake wheel cylinder H-shaped key 25 at both ends, and the brake wheel cylinder H-shaped key 25 cooperates with the grooves provided at both ends of the brake shoe 4 to fix the axial and radial positions of the brake shoe 4. At the same time, the brake shoe 4 cooperates with the groove provided on the brake shoe support block 21 to further fix the axial and radial positions of the brake shoe 4, ensuring that the required braking force output by the brake wheel cylinder 17 is safer and more stable.

[0044] like Figure 8 As shown, the brake drum 3 is provided with six reinforcing ribs and six threaded holes, and the six threaded holes are used to be fixedly connected to the rim 5 by screws; the inner ring of the cylindrical roller bearing 2 is fixed together by the positioning shoulder provided on the outer end cover 1 of the motor and the shaft shoulder provided on the motor housing 19, so that the inner ring of the cylindrical roller bearing 2 is fixed and the outer ring rotates; the cylindrical roller bearing 2 is used to transfer the force and torque borne by the support arm of the outer end cover 1 of the motor to the brake drum 3, and the brake drum 3 is then transferred to the surface of the rim 5; at the same time, the six reinforcing ribs provided on the surface of the brake drum 3 can ensure that the brake drum 3 has greater anti-deformation and load-bearing capacity in the radial direction.

[0045] The planetary reducer is driven by the sun gear 10, the planetary gears 11 are fixed, and the ring gear 15 rotates. The planetary reducer is arranged as a whole in the right half of the inside of the rim 5, as shown in FIG. Figure 1 , Figure 2 As shown, the planetary reducer housing 6 is fixedly connected to the rim 5 and the brake drum 3 by screws, so that the torque output by the hub motor is transmitted to the rim 5 through the planetary reducer to reduce the torque and increase the torque, thereby realizing the electric wheel driving heavy-load vehicle movement described in the present invention.

[0046] like Fig. 9 As shown, the interior of the planetary reduction housing is composed of a ring gear 15, a planetary gear 11, a first planetary carrier 7a, a second planetary carrier 7b, a planetary gear positioning column 8 and an elastic clamping ring 13. Figure 2 and Fig. 9As shown, the difference between the first planet carrier 7a and the second planet carrier 7b is that: there is a through hole in the middle of the first planet carrier 7a, and the motor shaft 9 passes through the through hole in the middle of the first planet carrier 7a, so that the torque output by the hub motor is transmitted to the sun gear 10, and the rotation of the sun gear 10 drives the planetary gear 11 to rotate around its own axis. At the same time, the rotation of the planetary gear 11 drives the rotation of the ring gear 15, and the ring gear 15 is connected to the planetary reducer housing 6 through a keyway. Finally, the ring gear 15 drives the planetary reducer housing 6 to rotate, and the planetary reducer housing 6 drives the wheel rim 5 to rotate, so that the vehicle can run normally.

[0047] like Fig.10 As shown, three planetary wheel bearing positioning steps are provided on the first planetary carrier 7a, and the planetary wheel bearing positioning steps support and fix the inner ring of the planetary wheel bearing 12, determine the axial position of the planetary wheel bearing 12 between the two planetary carriers, and the planetary wheel 11 and the planetary wheel bearing 12 are interference fit, thereby fixing the axial position of the planetary wheel 11; Figure 4 The planetary gear positioning column 8 shown is provided with two positioning column grooves, which cooperate with two elastic collars 13 to determine the relative positions of the first planet carrier 7 a and the second planet carrier 7 b on the planetary gear positioning column 8 .

[0048] like Fig.11 As shown, the inner surface of the planetary reducer housing 6 is provided with an L-shaped rectangular key for cooperating with the rectangular groove provided on the outer circle of the gear ring 15; the gear ring 15 fits tightly with the left side of the L-shaped rectangular key. Figure 2 As shown, the planetary reducer end cover 14 is tightly fitted with the right side of the ring gear 15 , and the two together determine the relative position of the ring gear 15 in the planetary reducer housing 6 .

[0049] The working principle of a heavy-duty vehicle electric wheel structure of the present invention is introduced below.

[0050] When the heavy-loaded vehicle is running, the wheel hub motor transmits the required driving torque to the sun gear 10 through the motor shaft 9. The rotation of the sun gear 10 drives the planetary gear 11 to rotate. The rotation of the planetary gear 11 drives the ring gear 15 to rotate. The rotation of the ring gear 15 drives the planetary reducer housing 6 to rotate. The planetary reducer housing 6 finally drives the rim 5 to rotate, realizing power transmission. The rotation of the rim 5 drives the rotation of the brake drum 3, but the brake drum 3 does not generate any braking torque at this time. Therefore, the internal driving part and the braking part of the heavy-loaded vehicle electric wheel operate normally. When the heavy-loaded vehicle brakes, the brake wheel cylinder 17 outputs the required braking thrust. The brake wheel cylinder H-shaped keys 25 at both ends of the brake wheel cylinder 17 output the braking thrust smoothly to the brake shoe 4, so that the friction lining 24 on the surface of the brake shoe 4 fits tightly with the brake drum 3, generating friction, forcing the speed of the brake drum 3 to decrease, and finally the speed of the rim 5 to decrease, thereby achieving the purpose of decelerating the heavy-loaded vehicle.

[0051] Secondly, the internal stress condition of the electric wheel structure of a heavy-duty vehicle of the present invention is analyzed.

[0052] The wheel rim 5 is subjected to forces in three directions, horizontal, vertical and longitudinal, from the ground. The forces in these three directions are sequentially transmitted through the brake drum 3, the cylindrical roller bearing 2, the motor housing 19, and the upper and lower support arms of the motor outer end cover 1. Finally, the motor outer end cover 1 transmits the force from the ground to the axle of the heavy-loaded vehicle through the upper and lower support arms.

[0053] Finally, the installation method of the electric wheel structure of a heavy-duty vehicle of the present invention is introduced.

[0054] The installation method of the heavy-duty vehicle electric wheel described in the present invention is divided into two parts: the first part is the installation of the wheel hub motor and the drum brake. First, the motor housing 19 of the wheel hub motor is installed with the motor inner end cover 16. Secondly, the brake wheel cylinder 17 is installed on the motor inner end cover 16 by screws, and the two brake shoes 4 are installed in the grooves of the brake shoe support block 21 provided on the surface of the motor housing 19. At the same time, the grooves at both ends of the brake shoe 4 are matched with the brake wheel cylinder H-shaped keys 25 at both ends of the brake wheel cylinder 17, and the reset spring 18 is installed. The cylindrical roller bearing 2 is tightly fitted with the shoulder on the surface of the motor housing 19. Finally, the brake drum 3 is installed, so that the left side and inner surface of the brake drum 3 are tightly fitted with the left side and outer ring of the cylindrical roller bearing 2, and the motor outer end cover 1 is installed. The hub motor, drum brake and rim 5 are connected by screws; the second part is the installation of the planetary reducer. First, install the first planetary carrier 7a and the elastic retaining ring 13 on the planetary gear positioning column 8, then install the sun gear 10, three planetary gear bearings 12, planetary gears 11, and ring gear 15 in sequence, install the second planetary carrier 7b and another elastic retaining ring 13, and finally install the planetary reducer housing 6, rim 5, brake drum 3 and planetary reducer end cover 14.

Claims

1. A heavy-duty vehicle electric wheel structure, characterized in that: It comprises a wheel rim (5), the inner surface of which is connected to a planetary reducer and a drum brake, the drum brake is provided with a cavity inside, a wheel hub motor is installed in the cavity, and the wheel hub motor is connected to the planetary reducer via a motor shaft (9); The planetary reducer comprises a sun gear (10), a planetary gear (11), a ring gear (15) and a planetary reducer housing (6) which are connected in sequence; the sun gear (10) is connected to a motor shaft (9); the planetary reducer housing (6) is connected to a wheel rim (5); a motor housing (19), a motor outer end cover (1) and a motor inner end cover (16) are arranged on the outside of the wheel hub motor; two sides of the motor housing (19) are respectively connected to the motor outer end cover (1) and the motor inner end cover (16); the drum brake comprises a brake drum (3), a brake shoe (4) and a brake wheel cylinder (17) which are connected in sequence; the brake wheel cylinder (17) is connected to the motor inner end cover (16); the brake drum (3) is connected to the wheel rim (5); and the motor housing (19) is connected to the brake drum (3).

2. The electric wheel structure for a heavy-duty vehicle according to claim 1, characterized in that: The motor outer end cover (1) is provided with a support arm, the support arm is connected to the axle of the vehicle, and a reinforcing rib is provided at the end of the support arm.

3. The electric wheel structure for a heavy-duty vehicle according to claim 1, characterized in that: The motor housing (19) is connected to the brake drum (3) via a cylindrical roller bearing (2); positioning shoulders are provided on the motor housing (19) and the motor outer end cover (1); the positioning shoulders of the motor housing (19) and the motor outer end cover (1) fix the inner ring of the cylindrical roller bearing (2); and the outer ring of the cylindrical roller bearing (2) rotates with the brake drum (3).

4. The electric wheel structure for a heavy-duty vehicle according to claim 1, characterized in that: An ear plate is provided on one side of the motor housing (19) close to the motor inner end cover (16), and the ear plate is fixedly connected to the motor inner end cover (16) by screws. Brake shoe support blocks (21) are provided on both upper and lower sides of the outer side of the motor housing (19) close to the motor inner end cover (16), for supporting and fixing the axial position of the brake shoe (4) on the surface of the motor housing (19).

5. The electric wheel structure for a heavy-duty vehicle according to claim 1, characterized in that: The two ends of the brake wheel cylinder (17) are provided with brake wheel cylinder H-shaped keys (25), and the two ends of the brake shoe (4) are provided with grooves. The brake wheel cylinder H-shaped keys (25) cooperate with the grooves on the brake shoe (4) to fix the axial and radial positions of the brake shoe (4). A return spring (18) is installed on one side of the grooves at both ends of the brake shoe (4), and the return spring (18) is close to the center of the brake shoe (4). A friction lining (24) is provided between the brake shoe (4) and the inner surface of the brake drum (3).

6. The electric wheel structure for a heavy-duty vehicle according to claim 1, characterized in that: A planetary gear positioning column (8) is connected to the inner end cover (16) of the motor, a first planet carrier (7a) and a second planet carrier (7b) arranged in parallel are connected to the planetary gear positioning column (8), a planetary wheel bearing (12) is connected between the first planet carrier (7a) and the second planet carrier (7b), and the planetary wheel bearing (12) is connected to the planetary wheel (11).

7. The electric wheel structure for a heavy-duty vehicle according to claim 6, characterized in that: The first planet carrier (7a) and the second planet carrier (7b) are both provided with planetary wheel bearing positioning steps, the planetary wheel bearing positioning steps on the first planet carrier (7a) and the second planet carrier (7b) pass through the inner ring of the planetary wheel bearing (12) and are used to support and fix the inner ring of the planetary wheel bearing (12), and a through hole is provided at the center position of the first planet carrier (7a) for the motor shaft (9) to pass through.

8. The electric wheel structure for a heavy-duty vehicle according to claim 6, characterized in that: The planetary gear positioning column (8) is provided with a positioning column groove, the positioning column groove is provided with an elastic clamping ring (13), and the elastic clamping ring (13) is arranged outside the first planet carrier (7a) and the second planet carrier (7b).

9. The electric wheel structure for a heavy-duty vehicle according to claim 1, characterized in that: A rectangular groove is provided on the outer circle of the gear ring (15), and an L-shaped key is provided on the inner surface of the planetary reducer housing (6).

10. A method for using a heavy-duty vehicle electric wheel structure, characterized in that: A heavy-duty vehicle electric wheel structure according to any one of claims 1 to 9, comprising: When the heavy-loaded vehicle is traveling, the wheel hub motor transmits the required driving torque to the sun gear (10) through the motor shaft (9). The rotation of the sun gear (10) drives the planetary gear (11) to rotate. The rotation of the planetary gear (11) drives the ring gear (15) to rotate. The rotation of the ring gear (15) drives the planetary reducer housing (6) to rotate, thereby transmitting power to the wheel rim (5). The rotation of the wheel rim (5) drives the rotation of the brake drum (3). At this time, the brake drum (3) does not generate any braking torque, and the internal driving part and the braking part of the heavy-loaded vehicle electric wheel operate normally. When the heavy-loaded vehicle brakes, the brake wheel cylinder (17) outputs the braking thrust. The brake wheel cylinder (17) outputs the braking thrust to the brake shoe (4), so that the brake shoe (4) and the brake drum (3) are closely fitted, generating friction, forcing the rotation speed of the brake drum (3) to decrease, and finally causing the rotation speed of the wheel rim (5) to decrease, thereby achieving the purpose of decelerating the heavy-loaded vehicle.

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