Integrated oil cooling hub speed reduction electric wheel

Abstract

The invention relates to an integrated oil cooling hub speed reduction electric wheel which comprises a motor, a planetary gear speed reducer and a bearing system which are arranged in the axial direction, and the planetary gear speed reducer is arranged in the motor and integrated with a brake. The bearing system comprises a rotor supporting bearing used for supporting a motor rotating system and a hub bearing used for supporting a wheel rotating system, the motor, the planetary gear reducer and the rotor supporting bearing are designed in an integrated oil cooling mode, and cavities where the motor, the planetary gear reducer and the rotor supporting bearing are located are communicated with one another. Cooling liquid cools and lubricates the motor, the planetary gear reducer and the rotor supporting bearing at the same time. Compared with the prior art, the electric wheel is compact in structure, the number of sealing pieces of the electric wheel can be reduced on the premise that the electric wheel has good structural rigidity, the axial size of an electric wheel assembly is reduced, and the electric wheel has the advantages of being good in cooling effect and easy to maintain.

Description

Technical Field

[0001] The invention relates to the technical field of hub electric wheels, and in particular to an integrated oil-cooled hub reduction electric wheel. Background Art

[0002] With the continuous development of new energy vehicle technology, the market's requirements for new energy vehicle performance and ride comfort are also increasing. In-wheel electric wheel is a distributed drive technology that arranges the drive motor inside the wheel. The whole vehicle can realize multiple drive forms such as front wheel hub electric wheel drive, rear wheel hub electric wheel drive and four-wheel hub electric wheel drive, which enhances the vehicle's handling stability. Compared with centralized drive electric vehicles, the in-wheel electric wheel drive solution eliminates transmission components such as clutch, gearbox, drive shaft, differential, and half shaft, saving a lot of vehicle chassis space. The chassis is flatter, which is conducive to the layout of the power battery pack and the design of the vehicle cabin. On the other hand, the in-wheel electric wheel drive system has a short transmission chain and has the advantage of high drive efficiency.

[0003] Since cars have many working conditions such as acceleration, climbing, and high-speed driving, when using a hub electric wheel direct drive, the drive motor is required to have the ability to output large torque at low speeds, resulting in the size and unsprung mass of such electric wheels being generally large. Therefore, in the structural design of the hub electric wheel, a reduction mechanism is usually required, such as the Chinese patent with publication number CN116572728A and the Chinese patent with publication number CN116238319A. However, both of these solutions arrange the reduction mechanism side by side with the motor stator and rotor, resulting in an increase in the axial size of the electric wheel. The Chinese patent with publication number CN116605042A arranges the first-stage reduction mechanism inside the motor rotor, optimizing the axial size of the electric wheel, but the following problems still exist: 1. The motor stator, bearings, and reducer do not share a cooling system, resulting in two dynamic seals being provided at the high-speed rotor bracket to prevent lubricating oil from leaking into the motor cavity. Therefore, the peak speed performance of the electric wheel is subject to the sealing performance of the dynamic seal, and the cost is increased;

[0004] 2. The bearings in the electric wheel are in series relationship on the transmission path of the wheel force, and their external shell does not transmit the multi-directional forces and moments exerted on the wheel, resulting in poor overall structural stiffness of the electric wheel. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide an integrated oil-cooled hub reduction electric wheel, which can reduce the number of seals of the electric wheel and reduce the axial size of the electric wheel assembly while ensuring the cooling effect.

[0006] The objectives of the present invention can be achieved through the following technical solutions: an integrated oil-cooled hub reduction electric wheel, comprising an axially arranged motor, a planetary gear reducer and a bearing system, the planetary gear reducer is arranged inside the motor and is integrated with a brake, the bearing system comprises a rotor support bearing for supporting the motor rotation system and a hub bearing for supporting the wheel rotation system, the motor, planetary gear reducer and rotor support bearing adopt an integrated oil cooling design, the cavities where the motor, planetary gear reducer and rotor support bearing are located are interconnected, and the motor, planetary gear reducer and rotor support bearing are cooled and lubricated by coolant at the same time.

[0007] Further, the wheel hub bearing is fixedly connected to the housing system, the housing system includes an electric wheel housing, an electric wheel end cover, a bearing end cover and a wheel hub bearing seat, an oil cooler and an oil pump are installed on the electric wheel housing, a filter is provided at the bottom of the electric wheel housing, and an oil channel and a nozzle are processed in the electric wheel housing, wherein the oil channel is connected to each nozzle and the oil outlet of the oil pump, and the nozzle is aligned with the stator winding of the motor;

[0008] The electric wheel end cover is processed with an oil groove and an oil channel, and the oil groove is used to collect and guide the circulation of coolant;

[0009] The bearing end cover is provided with a sealing pipe joint for leading out the wiring harness of the rotary transformer;

[0010] The wheel hub bearing seat is fixedly connected to the electric wheel end cover by screws, and the electric wheel end cover is fixedly connected to the electric wheel housing by screws, so as to transfer the wheel load received by the wheel hub bearing to the vehicle body.

[0011] Furthermore, the rotor support bearing includes a deep groove ball bearing and a needle roller bearing, and the deep groove ball bearing is installed in the motor housing, and its inner and outer rings are completely positioned to fix the axial position of the motor rotating system relative to the housing system;

[0012] The needle roller bearing is arranged between the planet carrier and the sun gear of the planetary gear reducer and is completely floating in the axial direction, so as to enhance the structural rigidity of the motor rotating system.

[0013] Furthermore, the housing system is provided with a first sub-cavity, a second sub-cavity and a third sub-cavity which are interconnected. The first sub-cavity is used to accommodate the motor, the second cavity is used to accommodate the planetary gear reducer and the needle bearing, and the third cavity is used to accommodate the deep groove ball bearing.

[0014] Furthermore, the circulation process of the coolant includes: after the coolant is cooled by the oil cooler, it flows into the oil circuit inside the electric wheel housing under the action of the pressure in the pipeline, and is sprayed onto the winding of the stator through the nozzle. Part of the coolant flows into the second sub-cavity through the oil groove and the oil channel to cool and lubricate the planetary gear reducer and the needle roller bearing, and then flows out from the oil channel at the bottom of the second sub-cavity and enters the first sub-cavity again. The remaining coolant flows into the third sub-cavity to lubricate the deep groove ball bearing. The coolant at the bottom of the first sub-cavity is drawn into the filter under the action of pressure, flows into the oil pump after filtration, and then flows into the oil cooler under the action of the oil pump for cooling.

[0015] Furthermore, the motor rotation system is composed of a rotor, a rotor support and a sun gear, and the rotor support plays a role in transmitting torque between the rotor and the sun gear.

[0016] Furthermore, the wheel rotation system consists of a rim, a brake drum and an axle, the axle is fixedly connected to the rim and the brake drum by multiple bolts evenly distributed on the circumference of the flange, the hub bearing is mounted on the axle, and the wheel load exerted on the rim is transmitted to the housing system through the hub bearing by the axle; the axle is mounted on the planetary carrier, and the torque is transmitted to the planetary carrier through a spline fit.

[0017] Furthermore, the torque transmission process includes: the motor generates driving torque after three-phase electricity is supplied, the torque is transmitted from the rotor to the rotor bracket through key matching, and then transmitted to the sun gear through spline matching, the sun gear transmits the torque to the planetary gear through gear transmission, and the planetary gear rotates while driving the planetary carrier to revolve around the sun gear, reducing the speed and increasing the torque, the planetary carrier transmits the torque to the axle through spline matching, and the axle transmits the driving torque to the rim through multiple bolts.

[0018] Furthermore, a brake shoe assembly is fixedly mounted on the electric wheel end cover, and the brake shoe assembly is located in a cavity between the rim and the electric wheel housing.

[0019] Furthermore, a dynamic seal is provided at the joint between the planetary carrier output shaft and the electric wheel end cover, and static seals are provided between the electric wheel housing and the bearing end cover and between the electric wheel housing and the electric wheel end cover.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] The present invention arranges the planetary gear reducer inside the motor and integrates a brake, and adopts an integrated oil cooling design for the motor, the planetary gear reducer and the rotor support bearing, that is, the cavities where the motor, the planetary gear reducer and the rotor support bearing are located are interconnected, and the motor, the planetary gear reducer and the rotor support bearing are cooled and lubricated by the coolant at the same time. Thus, a compact hub reduction electric wheel is realized, which has the advantages of a small number of seals, a small axial size, a good cooling effect and easy maintenance.

[0022] In the present invention, the rotor support bearing includes a deep groove ball bearing and a needle roller bearing, wherein the deep groove ball bearing is installed in the motor housing, and its inner and outer rings are completely positioned to fix the axial position of the motor rotating system relative to the housing system; the needle roller bearing is arranged between the planetary carrier and the sun gear of the planetary gear reducer, and is completely floating in the axial direction to enhance the structural rigidity of the motor rotating system. The motor rotating system is supported by the deep groove ball bearing and the needle roller bearing, which has better overall structural rigidity than the cantilever beam structure supported by single-row or double-row deep groove ball bearings commonly used in the prior art.

[0023] The present invention bears and transmits wheel loads through the housing system, so that the bearing structure has a larger diameter and has a higher bending section coefficient compared to the common center shaft bearing structure in the prior art. At the same time, the elimination of the center shaft saves the center space of the electric wheel, reduces the minimum number of teeth required for the sun gear in the planetary gear reducer, and is conducive to the design of a planetary gear reducer with a small volume and a large reduction ratio, thereby reducing the volume and mass of the hub reduction electric wheel. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the external overall structure of the present invention;

[0025] Figure 2 It is an exploded view of the overall structure of the present invention;

[0026] Figure 3 It is a schematic diagram of the hub reduction electric wheel cavity in the present invention;

[0027] Figure 4 It is a schematic diagram of the structure of the hub-reduced electric wheel motor in the present invention;

[0028] Figure 5 It is a schematic diagram of the structure of the hub portion of the hub-reduced electric wheel in the present invention;

[0029] Figure 6 It is a schematic diagram of the arrangement of the wheel speed sensor of the hub-reduced electric wheel in the present invention;

[0030] Figure 7 This is a schematic diagram of the integrated design of the hub bearing in the present invention;

[0031] Figure 8 Schematic diagram of the arrangement of the hub reduction electric wheel external parts in the present invention

[0032] Description of the markings in the figure: 1. Rim;

[0033] 2. Brake; 201. Brake drum; 202. Brake shoe assembly; 203. Brake mounting screw; 204. Cable-type parking mechanism;

[0034] 3. Wheel speed sensor; 301. Magnetic ring; 302. Probe; 303. Probe fixing screw;

[0035] 4. Transmission parts; 401. Rotor bracket; 402. Snap ring; 403. Rim bolt; 404. Axle gasket; 405. Axle nut; 406. Protective shell; 407. Axle;

[0036] 5. Motor; 501. stator; 502. rotor; 503. aluminum gasket;

[0037] 6. Planetary gear reducer; 601. Oil plug; 602. Planet carrier; 603. Sun gear; 604. Planet gear; 605. Ring gear; 606. Rotor nut; 607. Rotary retaining spring;

[0038] 7. Resolver; 701. Resolver rotor; 702. Resolver stator;

[0039] 8. Electrical interface; 801, low voltage interface; 802, high voltage interface;

[0040] 9. Oil cooling system; 901. Bearing end cover pipe joint; 902. Filter; 903. Oil cooler; 904. Oil pump;

[0041] 10. Seals; 1001. Exposed skeleton type lip seal ring; 1002. Electric wheel end cover seal gasket; 1003. Bearing end cover seal gasket;

[0042] 11. Bearing system; 1101. Needle roller bearing; 1102. Deep groove ball bearing; 1103. Wheel hub bearing;

[0043] 12. Housing system; 1201. Housing screws; 1202. Electric wheel housing; 1203. Electric wheel end cover; 1204. Gear ring retaining spring; 1205. Sealing ring; 1206. Electric wheel bolt; 1207. Bearing end cover screws; 1208. Bearing end cover; 1209. Steel sleeve; 1210. Rotary screw; 1211. Hub bearing seat screws; 1212. Hub bearing seat; 1213. Hub bearing retaining spring; 1214. Hub bearing nut; 1215. Locking washer; 1216. Hub bearing washer; 1217. Exhaust plug;

[0044] A, first sub-cavity; B, second sub-cavity; C, third sub-cavity. DETAILED DESCRIPTION

[0045] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] Example

[0047] like Figure 1 and Figure 2 As shown, an integrated oil-cooled hub reduction electric wheel includes a rim 1, a brake 2, a wheel speed sensor 3, a transmission part 4, a motor 5, a planetary gear reducer 6, a rotary transformer 7, an electrical interface 8, an oil cooling system 9, a seal 10, a bearing system 11, and a housing system 12.

[0048] The motor 5 is composed of a stator 501 and a rotor 502. The motor 5 is an inner rotor permanent magnet synchronous motor. The stator 501 is fixedly connected to the housing system 12, and the rotor 502 is fixedly connected to the rotor bracket 401. The motor 5 is cooled by oil.

[0049] The planetary gear reducer 6 is an NGW type planetary transmission mechanism, which consists of a sun gear 603, a planetary gear 604, a planet carrier 602 and a ring gear 605; the sun gear 603 and the sun gear shaft are designed as an integrated whole, and the sun gear (shaft) is installed in the center hole of the rotor bracket 401 and is fixedly connected to the rotor bracket 401; the ring gear 605 is fixedly connected to the housing system 12; the planetary gear reducer 6 is nested as a whole inside the motor 5.

[0050] The bearing system 11 is composed of a deep groove ball bearing 1102, a wheel hub bearing 1103 and a needle roller bearing 1101; the deep groove ball bearing 1102 and the needle roller bearing 1101 constitute a rotor support bearing, and jointly support the motor rotating system composed of the rotor 502, the rotor bracket 401 and the sun gear 603; the deep groove ball bearing 1102 is installed in the housing of the motor 5, and its inner and outer rings are completely positioned to fix the axial position of the motor rotating system relative to the housing system 12; the needle roller bearing 1101 is arranged between the planetary carrier 602 and the sun gear 603, and is completely floating in the axial direction to enhance the structural rigidity of the motor rotating system; the wheel hub bearing 1103 is fixedly connected to the housing system 12 to support the wheel rotating system composed of the rim 1, the brake drum 201 and the wheel axle 407; in this embodiment, the deep groove ball bearing 1102 and the needle roller bearing 1101 are lubricated by oil bath, and the wheel hub bearing 1103 is lubricated by grease.

[0051] The transmission member 4 includes a rotor bracket 402 and an axle 407; the rotor bracket 401 plays a role in transmitting torque between the rotor 502 and the sun gear 603; the axle 407 is a transmission shaft with a flange feature, which is fixed to the rim 1 and the brake drum 201 through a plurality of bolts evenly distributed on the circumference of the flange, and the hub bearing 1103 is mounted on the axle 407, so that the axle 407 can transmit the axial force and radial force exerted on the wheel (rim 1) to the housing system 12 through the hub bearing 1103; the axle 407 is mounted on the planet carrier 602, and the torque is transmitted between the axle 407 and the planet carrier 602 through a spline fit.

[0052] The housing system 12 includes an electric wheel housing 1202, an electric wheel end cover 1203, a bearing end cover 1208 and a hub bearing seat 1212. The housing system 12 forms three sub-cavities inside the electric wheel, such as Figure 3 As shown, A is the first sub-cavity (used to accommodate the motor 5), B is the second sub-cavity (used to accommodate the planetary gear reducer 6 and the needle roller bearing 1101), and C is the third sub-cavity (used to accommodate the deep groove ball bearing 1102). The three sub-cavities are interconnected, and the coolant can flow between the sub-cavities through the oil channels and the gaps between the shells, thereby realizing integrated oil cooling of the parts in the cavity. Oil passages and nozzles are machined inside the electric wheel housing 1202, and the oil passages are connected to the nozzles and the oil outlet of the oil pump 904, and the nozzles are aligned with the stator windings of the motor; oil grooves and oil passages are machined inside the electric wheel end cover 1203, and the oil grooves are used to collect the coolant in the first sub-cavity A, and the oil passages guide the collected coolant to the second sub-cavity B; a sealing pipe joint is provided on the bearing end cover 1208, which is used to lead out the wiring harness of the rotary transformer 7; the hub bearing seat 1212 is fixedly connected to the electric wheel end cover 1203 by screws, and the load on the hub bearing 1103 is transferred to the electric wheel end cover 1203.

[0053] The seal 10 includes a dynamic seal and two static seals. The dynamic seal is arranged at the joint between the output shaft of the planetary carrier 602 and the electric wheel end cover 1203; the two static seals are arranged between the electric wheel housing 1202 and the bearing end cover 1208, and between the electric wheel housing 1202 and the electric wheel end cover 1203, respectively.

[0054] The oil cooling system 9 at least includes an oil cooler 903, a filter 902, an oil pump 904 and a coolant; the oil cooler 903 and the oil pump 904 are fixedly mounted on the electric wheel housing 1202; the filter 904 is arranged at the bottom of the electric wheel housing 1202, and its filter screen is exposed in the first sub-cavity A; the coolant must have both cooling and lubrication functions.

[0055] The brake 2 is a drum brake, including a brake drum 201 (rotating part, rotating with the wheel) and a brake shoe assembly 202 (stationary part), wherein the brake shoe assembly 202 is fixedly mounted on the electric wheel end cover 1203 .

[0056] The resolver 7 is composed of a resolver rotor (i.e., resolver rotor 701) and a resolver stator (i.e., resolver stator 702). The resolver rotor 701 is fixedly connected to the sun gear 603, and the resolver stator 702 is fixedly installed in the bearing end cover 1208 to measure the angular change of the motor rotating system relative to the housing system 12.

[0057] In addition, in this embodiment, the planetary gear reducer 6 is a helical gear planetary gear reducer; the outer ring of the hub bearing 1103 and the hub bearing seat 1212 are integrated into a design, and half of the inner ring of the hub bearing 1103 and the wheel axle 407 are integrated into a design; the oil cooler 903 is installed on the electric wheel housing 1202 facing the direction of the vehicle's forward movement to enhance the heat dissipation performance.

[0058] Specifically, Figure 4 As shown, the stator 501 is fixed in the motor wheel housing 1202 by interference fit. The rotor 502 is mounted on the rotor bracket 401, and key slots are machined on the mating surfaces of the two, and flat key transmission is adopted. Aluminum gaskets 503 are attached to the end surfaces of both sides of the rotor 502, which are used to adjust the dynamic balance of the rotor and prevent magnetic leakage. The retaining ring 402 and the rotor bracket 401 are interference fit to fix the axial position of the rotor 502 and the aluminum gasket 503 relative to the rotor bracket 401.

[0059] The rotor bracket 401 is designed with a central through hole, in which the sun gear 603 is installed, and a spline transmission is adopted between the two. In this embodiment, the spline is an involute spline; a light hole and a light axis of the same diameter are respectively processed on the central through hole and the right end shaft of the sun gear 603, which play a centering role. A deep groove ball bearing 1102 is also installed on the rotor bracket 401, and the inner ring and outer ring of the deep groove ball bearing 1102 are both completely positioned, and its axial displacement is respectively limited by the shaft shoulder of the rotor bracket 401, the rotor nut 606, the hole wall of the electric wheel housing 1202 and the bearing end cover 1208. The electric wheel housing 1202 in this embodiment is made of aluminum alloy, so the outer ring of the deep groove ball bearing 1101 must be installed with a steel sleeve 1209, and the two are installed together in the bearing hole of the electric wheel housing 1202.

[0060] The bearing end cover 1208 is mounted on the electric wheel housing 1202 by means of a plurality of bearing end cover screws 1207, and a static seal bearing end cover sealing gasket 1003 is arranged between the bearing end cover 1208 and the electric wheel housing 1202. The resolver stator 702 is mounted in the bearing end cover 1208 by means of resolver screws 1210, and the resolver rotor 701 is mounted on the sun gear 603, and its axial position relative to the sun gear 603 is fixed by means of resolver retaining rings 607. A bearing end cover pipe joint 901 is also mounted on the bearing end cover 1208, and is used to lead out the wiring harness of the resolver 7.

[0061] The planetary gear reducer 6 is arranged inside the motor 5 (i.e., the rotor bracket 401). The ring gear 605 is fixed in the electric wheel end cover 1203 through a spline fit with the ring gear retaining spring 1204. Three planetary gears 604 are installed on the planetary carrier 602, and the planetary gears 604 and the planetary carrier 602 are in a revolving pair fit. A central through hole is machined in the output shaft of the planetary carrier 602 as a refueling channel, and a needle bearing 1101 is installed between the central through hole and the left end shaft of the sun gear 603. The needle bearing 1101 is completely floating in its axial direction, and an oil plug 601 is installed at the refueling channel port to prevent coolant leakage. A sealing ring 1205 is also installed on the output shaft of the planetary carrier 602, and the two are in an interference fit. The sealing ring 1205 cooperates with the exposed skeleton-type lip seal ring 1001 installed on the electric wheel end cover 1203 to achieve dynamic sealing.

[0062] The electric wheel housing 1202 is connected to the electric wheel end cover 1203 by a plurality of housing screws 1201, and a static sealing electric wheel end cover sealing gasket 1002 is arranged between the joint surfaces of the two. The electric wheel housing 1202 is machined with oil passages and nozzles, and the oil passages are connected to the nozzles and the outlet of the oil pump 904, and the nozzles are aligned with the windings at both ends of the motor stator 501. The electric wheel end cover 1203 is machined with oil grooves and oil passages, and the oil grooves are used to collect the coolant in the motor sub-cavity A, and the oil passages guide the collected coolant to the planetary gear reducer sub-cavity B. There is a gap between the rotor bracket 401 and the electric wheel housing 1202, so that the coolant can flow from the motor sub-cavity A to the deep groove ball bearing sub-cavity C. A filter 902 is installed at the bottom of the electric wheel housing 1202, and the filter screen of the filter 902 is exposed in the motor sub-cavity A. A plurality of electric wheel bolts 1206 are pre-embedded in the electric wheel housing 1202 for fixing the connection between the hub reduction electric wheel and the axle or steering knuckle.

[0063] like Figure 5 and Figure 6As shown, the hub bearing 1103 is installed in the hub bearing seat 1212, and the hub bearing retaining ring 1213 plays an axial limiting role on the outer ring of the hub bearing 1103. The inner ring of the hub bearing 1103 is installed on the axle 407, and the hub bearing nut 1214, the locking washer 1215 and the hub bearing gasket 1216 play an axial limiting and gap adjustment role on the hub bearing 1103. The hub bearing seat 1212 is fixed to the electric wheel end cover 1203 by a plurality of hub bearing seat screws 1211. Preferably, a through hole is machined on the flange surface of the axle 407, so that the installation tool can install or remove the hub bearing seat screws 1211 through the through hole. The axle 407 and the planet carrier 602 are splined, and the relative position between the two is fixed by the axle gasket 404 and the axle nut 405. The protective shell 406 prevents dust and water vapor from corroding the axle nut 405 and the planet carrier 407. Preferably, the spline is an involute spline. The brake 2 is arranged in the cavity between the rim 1 and the electric wheel end cover 1203. The rim 1 and the brake drum 201 are fixed to the axle 407 by a plurality of rim bolts 403 and nuts. The brake shoe assembly 202 is mounted on the end face of the electric wheel end cover 1203 by a plurality of brake mounting screws 203. The brake 2 is a traditional drum brake and does not require customized development. The cable-type parking mechanism 204 is mounted on the electric wheel housing 1202. When parking, the cable-type parking mechanism 204 uses the cable to make the brake shoe close to the brake drum to maintain the braking force.

[0064] The magnetic ring 301 is interference-fitted on the flange of the wheel shaft 407 and rotates with the wheel shaft 407. A groove for arranging the probe 302 is designed on the motor wheel end cover 1203, and the probe fixing screw 303 fixes the probe 302 on the motor wheel end cover 1203.

[0065] like Figure 7 As shown, in a preferred embodiment, the outer ring of the hub bearing 1103 and the hub bearing seat 1212 are designed as an integrated whole, the left inner ring of the hub bearing 1103 and the wheel axle 407 are designed as an integrated whole, and the hub bearing nut 1214, the locking washer 1215 and the hub bearing washer 1216 play an axial limiting and clearance adjustment role on the right inner ring of the hub bearing 1103.

[0066] like Figure 8As shown, an exhaust plug 1217 is installed on the top of the electric wheel housing 1202, and the exhaust plug 1217 is connected to the motor sub-cavity A. A low-pressure interface 801 is installed on the end face of the electric wheel housing 1202, and the high-pressure interface 802 is arranged on the outer circumferential surface of the electric wheel housing 1202. The oil pump 904 is installed at the bottom of the electric wheel housing 1202, and the installation position should be as close to the filter 902 as possible. The arrangement position of the oil cooler 903 is slightly higher than the oil pump 904, and is located on the windward side of the hub reduction electric wheel when the vehicle is moving forward. The filter 902 and the oil pump 904, and the oil pump 904 and the oil cooler 903 are interconnected through the oil circuit inside the electric wheel housing 1202.

[0067] In the above-mentioned hub reduction electric wheel, the circulation process of the coolant when its oil cooling system is working is as follows: after the coolant is cooled by the oil cooler 903, it flows into the oil circuit inside the electric wheel housing 1202 under the action of the pressure in the pipeline, and is sprayed onto the winding of the stator 501 through the nozzle. Part of the coolant flows into the second sub-cavity B through the oil groove and the oil channel to cool and lubricate the planetary gear reducer 6 and the needle bearing 1101, and then flows out from the oil channel at the bottom of the second sub-cavity B and enters the first sub-cavity A again. The remaining coolant flows along the inner wall of the electric wheel housing 1202 and the wall of the rotor bracket 401 to the third sub-cavity C to lubricate the deep groove ball bearing 1102. The coolant at the bottom of the first cavity A is drawn into the filter 902 under the action of pressure, flows into the oil pump 904 after filtration, and then flows into the oil cooler 903 under the action of the oil pump 904 for cooling.

[0068] In the above-mentioned hub reduction electric wheel, the transmission path of its driving torque is: the motor 5 generates driving torque after the three-phase electricity is supplied, and the driving torque is transmitted from the rotor 502 to the rotor bracket 401 through the key fit, and then transmitted to the sun gear 603 through the spline fit. The sun gear 603 transmits the driving torque to the planetary gear 604 through the gear transmission. The planetary gear 604 generates rotation and drives the planetary carrier 602 to revolve around the sun gear 603, reducing the rotation speed and increasing the torque. The planetary carrier 602 transmits the torque to the axle 407 through the spline fit, and the axle 407 transmits the driving torque to the rim 1 through multiple rim bolts 403.

[0069] In the above-mentioned hub-reduced electric wheel, the transmission path of the wheel load is as follows: the rim 1 transmits the wheel load to the axle 407 via the rim bolt 403, and then transmits the wheel load to the hub bearing seat 1212 via the hub bearing 1103; the hub bearing seat 1212 transmits the wheel load to the electric wheel end cover 1203 via the stop structure and the hub bearing seat screw 1211, and then transmits the wheel load to the electric wheel housing 1202 via the stop structure and the housing screw 1201; the electric wheel housing 1202 transmits the wheel load to the vehicle body via the electric wheel bolt 1206.

[0070] In summary, this scheme designs a new hub-reduced electric wheel configuration, which can realize integrated oil cooling of the motor, reducer and rotor support bearing. It can reduce the number of seals of the electric wheel and the axial size of the electric wheel assembly while ensuring that the electric wheel has good structural rigidity. The cavities where the above components are located are interconnected through pipeline design, thereby having the advantages of good cooling effect and easy maintenance.

[0071] This solution nests the planetary gear reducer inside the motor, fully utilizing the internal space of the motor and reducing the axial size of the hub reduction electric wheel assembly; the motor, planetary gear reducer and rotor support bearing are integrated with oil cooling, fewer seals are required in the housing system, the risk of coolant leakage is low, and the production and maintenance costs of the electric wheel assembly are reduced; the cavities where the motor, planetary gear reducer and rotor support bearing are located are interconnected, resulting in a good cooling effect, and the total volume of the cavity is increased, so it is not easy for an oil-gas mixture to be generated in the cavity.

[0072] In this solution, the motor rotating system is supported by a deep groove ball bearing and a needle roller bearing, and the inner and outer rings of the deep groove ball bearing are completely positioned. Compared with the cantilever beam structure supported by a single-row or double-row deep groove ball bearing commonly used in the prior art, the overall structural rigidity of the motor rotating system in the present invention is better;

[0073] In this solution, the installation and disassembly of the wheel hub bearing, wheel hub bearing seat, wheel axle and brake do not involve the motor and its housing, which is beneficial to the maintenance and repair of the electric wheel assembly; the oil cooler, filter and oil pump are all integrated in the electric wheel, reducing the number of interfaces between the electric wheel and the vehicle chassis, and the electric wheel has a higher degree of modularity; in addition, the brake integrated in the electric wheel assembly is a traditional drum brake with a long wear life and low development cost.

Claims

1. An integrated oil-cooled hub reduction electric wheel, characterized in that: The invention comprises an axially arranged motor (5), a planetary gear reducer (6) and a bearing system (11), wherein the planetary gear reducer (6) is arranged inside the motor (5) and is integrated with a brake (2), and the bearing system (11) comprises a rotor support bearing for supporting the rotation system of the motor (5) and a wheel hub bearing (1103) for supporting the rotation system of the wheel, wherein the motor (5), the planetary gear reducer (6) and the rotor support bearing adopt an integrated oil cooling design, wherein the cavities where the motor (5), the planetary gear reducer (6) and the rotor support bearing are located are interconnected, and the motor (5), the planetary gear reducer (6) and the rotor support bearing are cooled and lubricated by a coolant at the same time.

2. The integrated oil-cooled hub reduction electric wheel according to claim 1, characterized in that: The wheel hub bearing (1103) is fixedly connected to the housing system (12); the housing system (12) comprises an electric wheel housing (1202), an electric wheel end cover (1203), a bearing end cover (1208) and a wheel hub bearing seat (1212); an oil cooler (903) and an oil pump (904) are installed on the electric wheel housing (1202); a filter (902) is arranged at the bottom of the electric wheel housing (1202); an oil channel and a nozzle are machined inside the electric wheel housing (1202); the oil channel is connected to each nozzle and an oil outlet of the oil pump (904); the nozzle is aligned with the stator (501) winding of the motor (5); An oil groove and an oil channel are machined inside the electric wheel end cover (1203), and the oil groove is used to collect and guide the circulation of coolant; The bearing end cover (1208) is provided with a sealing pipe joint for leading out the wiring harness of the rotary transformer; The housing system (12) bears and transmits wheel loads, the wheel hub bearing seat (1212) is fixedly connected to the electric wheel end cover (1203) by screws, and the electric wheel end cover (1203) is fixedly connected to the electric wheel housing (1202) by screws, so as to transmit the wheel load received by the wheel hub bearing (1103) to the vehicle body.

3. The integrated oil-cooled hub reduction electric wheel according to claim 2, characterized in that: The rotor support bearing comprises a deep groove ball bearing (1102) and a needle roller bearing (1101), wherein the deep groove ball bearing (1102) is installed in the housing of the motor (5), and its inner and outer rings are completely positioned to fix the axial position of the rotating system of the motor (5) relative to the housing system (12); The needle roller bearing (1101) is arranged between the planet carrier (602) and the sun gear (603) of the planetary gear reducer (6) and is completely floating in the axial direction, so as to enhance the structural rigidity of the rotating system of the motor (5).

4. The integrated oil-cooled hub reduction electric wheel according to claim 3, characterized in that: The housing system (12) is provided with a first sub-cavity (A), a second sub-cavity (B) and a third sub-cavity (C) which are interconnected; the first sub-cavity (A) is used to accommodate the motor (5); the second sub-cavity is used to accommodate the planetary gear reducer (6) and the needle roller bearing (1101); and the third sub-cavity is used to accommodate the deep groove ball bearing (1102).

5. The integrated oil-cooled hub reduction electric wheel according to claim 4, characterized in that: The circulation process of the coolant comprises: after the coolant is cooled by the oil cooler (903), it flows into the internal oil circuit of the electric wheel housing (1202) under the action of the pressure in the pipeline, and is sprayed onto the winding of the stator (501) through the nozzle; part of the coolant flows into the second sub-cavity (B) through the oil groove and the oil channel to cool and lubricate the planetary gear reducer (6) and the needle roller bearing (1101); then it flows out from the oil channel at the bottom of the second sub-cavity (B) and enters the first sub-cavity (A) again; the rest of the coolant flows into the third sub-cavity (C) to lubricate the deep groove ball bearing (1102); the coolant at the bottom of the first sub-cavity (A) is drawn into the filter (902) under the action of pressure, flows into the oil pump (904) after being filtered, and then flows into the oil cooler (903) under the action of the oil pump (904) to be cooled.

6. The integrated oil-cooled hub reduction electric wheel according to claim 3, characterized in that: The rotating system of the motor (5) is composed of a rotor (502), a rotor support (401) and a sun gear (603), and the rotor support (401) plays a role in transmitting torque between the rotor (502) and the sun gear (603).

7. The integrated oil-cooled hub reduction electric wheel according to claim 6, characterized in that: The wheel rotation system is composed of a wheel rim (1), a brake drum (201) and a wheel axle (407); the wheel axle (407) is fixedly connected to the wheel rim (1) and the brake drum (201) by a plurality of bolts evenly distributed on the circumference of a flange; the wheel hub bearing (1103) is sleeved on the wheel axle (407); the wheel axle (407) is used to transmit the wheel load received by the wheel rim (1) to the housing system (12) through the wheel hub bearing (1103); the wheel axle (407) is sleeved on the planet carrier (602) and transmits torque to the planet carrier (602) through a spline fit.

8. The integrated oil-cooled hub reduction electric wheel according to claim 7, characterized in that: The torque transmission process includes: the motor (5) generates a driving torque after three-phase electricity is supplied, the torque is transmitted from the rotor (502) to the rotor bracket (401) through a key fit, and then transmitted to the sun gear (603) through a spline fit, the sun gear (603) transmits the torque to the planetary gear (604) through gear transmission, the planetary gear (604) generates self-rotation while driving the planetary carrier (602) to revolve around the sun gear (603), thereby reducing the rotation speed and increasing the torque, the planetary carrier (602) transmits the torque to the wheel shaft (407) through a spline fit, and the wheel shaft (407) transmits the driving torque to the wheel rim (1) through a plurality of bolts.

9. The integrated oil-cooled hub reduction electric wheel according to claim 7, characterized in that: A brake shoe assembly (202) is fixedly mounted on the electric wheel end cover (1203), and the brake shoe assembly (202) is located in a cavity between the wheel rim (1) and the electric wheel housing (1202).

10. The integrated oil-cooled hub reduction electric wheel according to claim 3, characterized in that: A dynamic seal is provided at the joint between the output shaft of the planetary carrier (602) and the electric wheel end cover (1203), and static seals are provided between the electric wheel housing (1202) and the bearing end cover (1208) and between the electric wheel housing (1202) and the electric wheel end cover (1203).

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