Hub motor and vehicle

Abstract

The utility model provides a hub motor and a vehicle, the hub motor comprises a motor body and a speed reducing mechanism, the speed reducing mechanism comprises a first-stage speed reducing part and a second-stage speed reducing part which are in transmission connection, the first-stage speed reducing part is connected with the output end of the motor body, and the second-stage speed reducing part is connected with a hub. By arranging the first-stage speed reduction part and the second-stage speed reduction part, the torque output by the motor body can be effectively amplified. The first-stage speed reduction part is connected with the output end of the motor body, torque output by the motor is primarily amplified through the first-stage speed reduction part and then transmitted to the second-stage speed reduction part, the second-stage speed reduction part further increases the torque and then outputs the torque to the hub, and therefore the hub obtains larger torque, and the requirement of vehicle running for the torque is met. For vehicles with large loads such as electric commercial vehicles, large torque output helps the vehicles to better cope with working conditions such as heavy-load starting, climbing and high-speed running, the running efficiency and stability of the vehicles are improved, and the adaptability of the vehicles under complex road conditions is enhanced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electric machines, and particularly relates to a wheel hub motor and a vehicle. BACKGROUND

[0002] With the increasing global concern for environmental protection and energy sustainability, electric vehicles as a clean energy transportation tool are experiencing rapid development. In the technical architecture of electric vehicles, the power system is the core part. The wheel hub motor technology emerges as a new solution for electric vehicle power. The wheel hub motor directly integrates the motor in the wheel hub, omitting a large number of intermediate transmission components. Each wheel can be independently driven by the wheel hub motor, thereby realizing distributed driving, and the unique layout brings many significant advantages.

[0003] The existing wheel hub motor is usually of the outer rotor type, with the rotor outside and the stator inside. The rotor is usually connected with the wheel hub, and the stator is fixed on the axle or suspension structure through the motor shaft and other components. The output torque of the motor can directly act on the wheel hub to drive the wheel to rotate. Because the wheel hub motor of the outer rotor type usually does not set a speed reduction mechanism, it is difficult to provide the required torque for vehicle driving. CONTENT OF THE UTILITY MODEL

[0004] Therefore, the technical problem to be solved by the present application is to provide a wheel hub motor and a vehicle, which increases the speed reduction mechanism and thereby provides the required torque for vehicle driving.

[0005] In order to solve the above problems, the first aspect of the present application provides a wheel hub motor, comprising a motor body and a speed reduction mechanism, the speed reduction mechanism comprising a transmission connection of a first-stage speed reduction part and a second-stage speed reduction part, the first-stage speed reduction part being connected with an output end of the motor body, and the second-stage speed reduction part being connected with a wheel hub.

[0006] Optionally, the first-stage speed reduction part and the second-stage speed reduction part are planetary gear train speed reduction assemblies.

[0007] Optionally, the wheel hub motor comprises a central axle, the first-stage speed reduction part comprises a first-stage sun gear, a first-stage planet carrier and a plurality of first-stage planet gears, the first-stage sun gear being connected with the central axle, the central axle being in transmission connection with the motor body, the first-stage planet carrier comprising a first input end and a first output end, and the plurality of first-stage planet gears being arranged on the first input end, the second-stage speed reduction part comprising a second-stage sun gear, a second-stage planet carrier and a plurality of second-stage planet gears, the second-stage sun gear being connected with the first output end, the second-stage planet carrier comprising a second input end and a second output end, and the plurality of second-stage planet gears being arranged on the second input end, and the second output end being connected with the wheel hub.

[0008] Optionally, the wheel hub motor comprises a rotor, the first-stage reduction part comprises a first-stage ring gear, the first-stage ring gear is concentrically fitted with a housing of the rotor, and the first-stage planetary gear is engaged with the first-stage ring gear; the wheel hub motor comprises a stator, the second-stage reduction part comprises a second-stage ring gear, the second-stage ring gear is concentrically fitted with a housing of the stator, and the second-stage planetary gear is engaged with the second-stage ring gear.

[0009] Optionally, the wheel hub motor comprises a connecting disc, and the second output end is connected with a rim of the wheel hub through the connecting disc.

[0010] Optionally, the first-stage planetary gear is rotationally connected to the first-stage carrier through a first-stage planetary gear bearing, the second-stage planetary gear is rotationally connected to the second-stage carrier through a second-stage planetary gear bearing, a first-stage carrier bearing is arranged between the first-stage carrier and the central axle, a second-stage carrier bearing is arranged between the first-stage carrier and the second-stage carrier, the motor body comprises a sealing seat, the sealing seat is arranged opposite to the second-stage carrier, a first sealing structure is arranged between the sealing seat and the second-stage carrier, the motor body comprises a rotor support, the rotor support is connected to the housing of the rotor, a second sealing structure is arranged between the rotor support and the housing of the rotor, and a third sealing structure is arranged between the rotor support and the central axle.

[0011] Optionally, a transmission ratio of the first-stage reduction part is 2.902, and a transmission ratio of the second-stage reduction part is 3.837.

[0012] Optionally, the motor body is an inner rotor permanent magnet synchronous motor.

[0013] Optionally, the wheel hub motor comprises a wheel hub body, the motor body and the reduction mechanism are connected to the wheel hub body, a cleaning brush head is arranged on the wheel hub body, one end of the cleaning brush head is fixed on the wheel hub body, so that the cleaning brush head can rotate with the wheel hub body, and the other end of the cleaning brush head extends to contact an outer wall of the motor body.

[0014] In a second aspect, the application provides a vehicle comprising the wheel hub motor as described above.

[0015] Advantages

[0016] The wheel hub motor and the vehicle provided in the embodiment of the utility model, through setting up the speed reduction mechanism, and making the first stage speed reduction part and the second stage speed reduction part of the speed reduction mechanism transmission connection, can effectively amplify the torque output by the motor body. The output end of the first stage speed reduction part is connected with the motor body, the torque output by the motor first passes through the first stage speed reduction part and is preliminarily amplified, and then is transmitted to the second stage speed reduction part, the second stage speed reduction part further increases the torque and then outputs the torque to the wheel hub, so that the wheel hub obtains greater torque, and the demand of torque for vehicle driving is met. For the electric commercial vehicle and other vehicles with large load, large torque output helps the vehicle to better cope with heavy load starting, climbing and high-speed driving and the like working conditions, improves the operation efficiency and stability of the vehicle, and enhances the adaptability of the vehicle under complex road conditions. BRIEF DESCRIPTION OF DRAWINGS

[0017] Fig. 1 It is a structural schematic view of the speed reduction mechanism of the embodiment of the utility model.

[0018] Fig. 2 It is a structural schematic view of the first stage speed reduction part of the embodiment of the utility model.

[0019] Fig. 3 It is a structural schematic view of the second stage speed reduction part of the embodiment of the utility model.

[0020] The signs are represented as:

[0021] 11, first stage sun gear; 12, first stage planet carrier; 13, first stage planet gear; 14, first stage ring gear;

[0022] 21, second stage sun gear; 22, second stage planet carrier; 23, second stage planet gear; 24, second stage ring gear;

[0023] 3, connecting disc;

[0024] 41, first stage planet gear bearing; 42, second stage planet gear bearing; 43, first stage planet carrier bearing; 44, second stage planet carrier bearing; 45, first steering bearing; 46, second steering bearing; 47, wheel hub bearing;

[0025] 51, sealing seat; 52, first sealing structure;

[0026] 61, rotor support; 62, second sealing structure;

[0027] 71, central axle; 72, third sealing structure; 73, input shaft. DETAILED DESCRIPTION

[0028] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0029] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly specified and limited.

[0030] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication between two elements inside. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0031] The preferred embodiments of the present application are described below in conjunction with the drawings, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0032] For reference Figs. 1 to 3 According to the first aspect of the embodiments of the present application, a wheel hub motor is provided, which comprises a motor body and a speed reduction mechanism, the speed reduction mechanism comprising a primary speed reduction part and a secondary speed reduction part connected in transmission, the primary speed reduction part being connected with the output end of the motor body, and the secondary speed reduction part being connected with the wheel hub.

[0033] The torque output by the motor body can be effectively amplified through the setting of the speed reduction mechanism and the transmission connection of the first speed reduction part and the second speed reduction part. The first speed reduction part is connected with the output end of the motor body, and the torque output by the motor is first amplified by the first speed reduction part, and then transmitted to the second speed reduction part. The second speed reduction part further increases the torque and then outputs it to the wheel hub, so that the wheel hub obtains greater torque, meeting the demand of vehicle driving for torque. For electric commercial vehicles and other vehicles with heavy load, large torque output helps the vehicle better cope with heavy load starting, climbing and high-speed driving conditions, improves the running efficiency and stability of the vehicle, and enhances the adaptability of the vehicle in complex road conditions.

[0034] The first speed reduction part is fixedly connected with the output end of the motor body, so that the output end of the motor body can drive the first speed reduction part to rotate. The first speed reduction part is in transmission connection with the second speed reduction part, so that the first speed reduction part drives the second speed reduction part to rotate. The second speed reduction part is fixedly connected with the wheel hub, so that the second speed reduction part can drive the wheel hub to rotate, realizing power output.

[0035] The transmission ratio of the first speed reduction part is different from the transmission ratio of the second speed reduction part.

[0036] The wheel hub motor comprises a shell, and the motor body and the speed reduction mechanism are arranged in the shell.

[0037] The first speed reduction part and the second speed reduction part are planetary gear train reduction assemblies.

[0038] By setting the first speed reduction part and the second speed reduction part as planetary gear train reduction assemblies, the structure of the first speed reduction part and the second speed reduction part is more compact, the overall volume of the speed reduction mechanism can be effectively reduced, the layout of the wheel hub motor in the wheel hub is more reasonable, the utilization rate of the internal space of the wheel hub is improved, more space is left for other parts of the vehicle, and the overall vehicle structure design is optimized.

[0039] The gears of the planetary gear train reduction assembly are closely meshed, the transmission efficiency is high, the energy loss in the power transmission process is reduced, the energy output by the motor is more effectively transmitted to the wheel hub to drive the vehicle to run, and the energy utilization efficiency is improved. For electric vehicles, the vehicle range can be extended.

[0040] Specifically, the hub motor includes a center shaft 71, a first-stage reduction part including a first-stage sun gear 11, a first-stage planet carrier 12 and a plurality of first-stage planet gears 13, the first-stage sun gear 11 is connected with the center shaft 71, the center shaft 71 is in driving connection with the motor body, the first-stage planet carrier 12 includes a first input end and a first output end, the plurality of first-stage planet gears 13 are arranged on the first input end, a second-stage reduction part including a second-stage sun gear 21, a second-stage planet carrier 22 and a plurality of second-stage planet gears 23, the second-stage sun gear 21 is connected with the first output end, the second-stage planet carrier 22 includes a second input end and a second output end, the plurality of second-stage planet gears 23 are arranged on the second input end, and the second output end is connected with the hub.

[0041] By connecting the first-stage sun gear 11 of the first-stage reduction part with the center shaft 71 and drivingly connecting the center shaft 71 with the motor body, the power output by the motor can be rapidly and accurately transmitted to the first-stage planet gears 13. The first input end of the first-stage planet carrier 12 is connected with the first-stage planet gears 13, and the first output end is connected with the second-stage sun gear 21 of the second-stage reduction part, so that the power is smoothly transferred between the two-stage reduction parts. The second input end of the second-stage planet carrier 22 is connected with the second-stage planet gears 23, and the second output end is connected with the hub, so as to ensure that the power after two-stage reduction is efficiently transmitted to the hub to drive the wheel to rotate, the whole power transmission path is clear and direct, the energy loss is reduced, and the transmission efficiency is improved.

[0042] The center shaft 71 is fixedly sleeved with an input shaft 73, and the input shaft 73 is arranged on the outer circumferential side of the center shaft 71, and the input shaft is in driving connection with the motor body.

[0043] The plurality of first-stage planet gears 13 are evenly distributed on the first input end of the first-stage planet carrier 12 and meshed with the first-stage sun gear 11, so as to effectively convert the high-speed rotating power of the first-stage sun gear 11 into a rotating speed and a torque suitable for input of the second-stage reduction part. The plurality of second-stage planet gears 23 are matched with the second-stage sun gear 21 on the second input end of the second-stage planet carrier 22, further optimizing power conversion, so that the torque and the rotating speed finally output to the hub meet the vehicle driving requirements, the advantages of the planetary gear train reduction assembly can be fully played, and the power performance of the vehicle is improved.

[0044] Specifically, the first input end of the primary planetary carrier 12 includes a plurality of mounting positions, and the mounting positions of the primary planetary carrier 12 are arranged one by one with the primary planetary gears 13. The mounting positions of the primary planetary carrier 12 are uniformly arranged along the circumference of the primary sun gear 11 with the primary planetary gears 13. The first output end of the primary planetary carrier 12 is one, and the second sun gear 21 is fixedly connected with the first output end, so that the second sun gear 21 rotates synchronously with the primary planetary carrier 12. The second input end of the secondary planetary carrier 22 includes a plurality of mounting positions, and the mounting positions of the secondary planetary carrier 22 are arranged one by one with the secondary planetary gears 23. The mounting positions of the secondary planetary carrier 22 are uniformly arranged along the circumference of the second sun gear 21 with the secondary planetary gears 23. The second output end of the secondary planetary carrier 22 is connected with the wheel hub, so that the wheel hub rotates synchronously with the secondary planetary carrier 22.

[0045] The wheel hub motor includes a rotor, the primary reduction part includes a primary ring gear 14, the primary ring gear 14 is centered with the shell of the rotor, and the primary planetary gears 13 are engaged with the primary ring gear 14. The wheel hub motor includes a stator, the secondary reduction part includes a secondary ring gear 24, the secondary ring gear 24 is centered with the shell of the stator, and the secondary planetary gears 23 are engaged with the secondary ring gear 24.

[0046] The primary planetary gears 13 are engaged with the primary ring gear 14, which provides support for the primary planetary gears 13, so that the primary planetary gears 13 can maintain engagement with the primary sun gear 11 and rotate stably. The secondary planetary gears 23 are engaged with the secondary ring gear 24, which provides support for the secondary planetary gears 23, so that the secondary planetary gears 23 can maintain engagement with the secondary sun gear 21 and rotate stably.

[0047] The primary ring gear 14 is located on the side of the primary planetary gears 13 away from the primary sun gear 11, and the secondary ring gear 24 is located on the side of the secondary planetary gears 23 away from the secondary sun gear 21. That is, the primary planetary gears 13 are located between the primary ring gear 14 and the primary sun gear 11 and are engaged with the primary ring gear 14 and the primary sun gear 11 respectively. The secondary planetary gears 23 are located between the secondary ring gear 24 and the secondary sun gear 21 and are engaged with the secondary ring gear 24 and the secondary sun gear 21 respectively.

[0048] By centering the primary ring gear 14 with the rotor shell and centering the secondary ring gear 24 with the stator shell, an accurate positioning reference is provided for the engagement of the primary planetary gears 13 with the primary ring gear 14 and the secondary planetary gears 23 with the secondary ring gear 24. It can ensure that the gears at all levels maintain good engagement state during motor operation, the tooth surface contact is uniform, the uneven wear, impact and noise caused by gear deflection or misalignment are reduced, the precision and stability of gear transmission are improved, and the power transmission is more stable and continuous.

[0049] The center axle 71, the first sun gear 11, the first ring gear 14, the second sun gear 21, the second ring gear 24 and the wheel hub are coaxially arranged.

[0050] The wheel hub motor comprises a connecting disc 3, and the second output end is connected with the rim of the wheel hub through the connecting disc 3.

[0051] By arranging the connecting disc 3, the power after two-stage reduction can be accurately and stably transmitted from the second output end of the second planetary carrier 22 to the rim of the wheel hub, ensuring the continuity and effectiveness of power transmission, so that the wheel hub can obtain sufficient torque to drive the vehicle to run, and the power performance and operation reliability of the vehicle are improved.

[0052] The connecting disc 3 can enhance the connection rigidity between the second planetary carrier 22 and the wheel hub rim, reduce the energy loss and power interruption risk caused by loose or deformation connection during power transmission, can bear larger torque and shear force, ensure that the connection between the motor and the wheel hub is always stable under conditions such as acceleration, deceleration, climbing, driving on bumpy road, etc., maintain the stability of power transmission, and improve the handling performance and driving safety of the vehicle.

[0053] The connecting disc 3 is in the form of a disc, one side of the connecting disc 3 is fixedly connected with the second output end, and the other side is fixedly connected with the rim of the wheel hub.

[0054] The connecting disc 3 is coaxially arranged with the center axle 71.

[0055] The first planetary gear 13 is rotatably connected to the first planetary carrier 12 through a first planetary gear 13 bearing. The second planetary gear 23 is rotatably connected to the second planetary carrier 22 through a second planetary gear 23 bearing. A first planetary carrier 12 bearing is arranged between the first planetary carrier 12 and the center axle 71. A second planetary carrier 22 bearing is arranged between the first planetary carrier 12 and the second planetary carrier 22.

[0056] The first planetary gear 13 is connected to the first planetary carrier 12 through the first planetary gear 13 bearing, and the second planetary gear 23 is connected to the second planetary carrier 22 through the second planetary gear 23 bearing, so that the planetary gears can freely rotate on the corresponding planetary carriers, and at the same time, can revolve around the corresponding sun gears with the corresponding planetary carriers. By arranging the bearing, the frictional resistance between the planetary gears and the planetary carriers can be effectively reduced, the smoothness of the planetary gear movement during power transmission is ensured, the transmission efficiency is improved, the energy loss is reduced, the motor can more efficiently convert electrical energy into mechanical energy output to the wheel hub, and drive the vehicle to run.

[0057] The inner ring of the first planetary gear 13 bearing is connected to the first planetary gear 13, and the outer ring is connected to the first planetary carrier 12. The inner ring of the second planetary gear 23 bearing is connected to the second planetary gear 23, and the outer ring is connected to the second planetary carrier 22.

[0058] The inner ring of the bearing of the first planetary carrier 12 is connected to the center axle 71, and the outer ring is connected to the first planetary carrier 12.

[0059] The inner ring of the bearing of the second planetary carrier 22 is connected to the first planetary carrier 12, and the outer ring is connected to the second planetary carrier 22.

[0060] The speed reduction mechanism further comprises a first steering bearing and a second steering bearing, which are arranged on the side of the first sun gear 11 away from the second sun gear 21, and are sleeved on the center axle 71 and arranged in sequence along the axial direction of the center axle 71.

[0061] The speed reduction mechanism further comprises a hub bearing, which is arranged on the side of the second sun gear 21 away from the first sun gear 11, and is sleeved on the center axle 71 and located between the center axle 71 and the second planetary carrier 22.

[0062] The motor body comprises a sealing seat 51, which is arranged opposite to the second planetary carrier 22, and a first sealing structure 52 is arranged between the sealing seat 51 and the second planetary carrier 22. The motor body comprises a rotor support 61, which is connected to the shell of the rotor, and a second sealing structure 62 is arranged between the rotor support 61 and the shell of the rotor. A third sealing structure 72 is arranged between the rotor support 61 and the center axle 71.

[0063] The first sealing structure 52 between the sealing seat 51 and the second planetary carrier 22 can effectively prevent external pollutants such as dust, sand, and water vapor from entering the motor from the gap between the second planetary carrier 22 and the sealing seat 51. The second sealing structure 62 between the rotor support 61 and the rotor shell and the third sealing structure 72 between the rotor support 61 and the center axle 71 work together to provide reliable sealing protection for the rotor and the center axle 71. During vehicle driving, the environment near the wheels is relatively harsh, especially when driving on unpaved roads, dust and water vapor are easy to enter the hub motor. Good sealing performance can prevent these pollutants from entering the key components such as gears and bearings inside the motor, avoid the problems of accelerated wear of components, lubrication failure, short circuit, etc. caused by impurities entering, prolong the service life of the components, and ensure the normal operation of the motor.

[0064] The sealing seat 51 is arranged at the end of the motor body close to the rim, and the sealing seat 51 and the second planetary carrier 22 are arranged opposite along the radial direction of the second planetary carrier 22, the first sealing structure 52 is an oil seal, the first sealing structure 52 is annular, and is arranged on the inner circumferential side of the sealing seat 51 and the outer circumferential side of the second planetary carrier 22, and the first sealing structure 52 is squeezed between the sealing seat 51 and the second planetary carrier 22.

[0065] The rotor housing is arranged in the rotor support 61, and a part of the rotor housing is arranged opposite to the rotor support 61 in the radial direction of the rotor. The second sealing structure 62 is an oil seal, is annular, and is arranged on the inner circumferential side of the rotor support 61 and the outer circumferential side of the rotor housing. The second sealing structure 62 is pressed between the rotor housing and the rotor support 61.

[0066] The rotor support 61 is sleeved on the outer circumferential side of the central axle 71, and the third sealing structure 72 is annular and arranged between the rotor support 61 and the central axle 71.

[0067] The transmission ratio of the first-stage reduction part is 2.902, and the transmission ratio of the second-stage reduction part is 3.837.

[0068] By reasonably designing the transmission ratio, the vehicle can provide appropriate torque output under different working conditions, so that the vehicle can stably run in the case of starting, accelerating, climbing and the like requiring large torque, and the power performance of the vehicle is improved.

[0069] The motor body is an inner rotor permanent magnet synchronous motor.

[0070] Specifically, in an embodiment, the motor rotor core has an outer diameter of 272 mm, an inner diameter of 132 mm, a magnet thickness of 6.94 mm, and a magnet width of 27.7 mm. The motor stator core has an outer diameter of 500 mm and an inner diameter of 273 mm. The tooth part has a slot depth of 75.8 mm, a slot opening width of 12 mm, a slot width of 75.9 mm, a tooth shoe angle of 15 degrees, a tooth thickness of 6.73 mm, and a top corner radius of 5.56 mm. The motor stator winding adopts star connection, is driven by a sine wave, and adopts an upper and lower overlapping method for coil wiring. The slot insulation thickness is 1.11 mm, the coil layer insulation thickness is 1.11 mm, the slot wedge thickness is 2.22 mm, the coil filling factor is 40%, the winding factor is 93.3%, the motor adopts a water cooling mode, and the shell thickness is 22.2 mm.

[0071] The hub motor comprises a hub body, a motor body and a reduction mechanism connected with the hub body. The hub body is provided with a cleaning brush head. One end of the cleaning brush head is fixed on the hub body, so that the cleaning brush head can rotate with the hub body. The other end of the cleaning brush head extends to contact the outer wall of the motor body.

[0072] By arranging the cleaning brush head on the hub body, the cleaning brush head can clean dust and soil on the outer wall of the motor body during rotation of the hub body, so as to ensure that the outer wall of the motor body is clean, and the heat dissipation efficiency of the motor body is ensured, thereby avoiding overload of the motor body due to excessive heat.

[0073] In a second aspect of the embodiment, a vehicle is provided, comprising the hub motor as described above.

[0074] Embodiment

[0075] 1. Design input parameters.

[0076] 1.1 Design load.

[0077] The hub motor design load spectrum is used to calculate the bending / contact fatigue strength of each stage of gear and bearing life, and the hub motor design load spectrum is shown in Table 1. The maximum torque and braking torque are used to design and check the static strength of the gear, the static strength of the bearing, the static strength of the spline, the strength of the bolt and the strength of each structure.

[0078] Table 1

[0079]

[0080] In this embodiment, the maximum torque condition: the maximum output torque of the wheel end is 13000Nm, the maximum input torque of the motor is 1181Nm, and the braking torque is 31000Nm.

[0081] 1.2 Gearbox performance requirements.

[0082] According to the performance requirements of the vehicle, the performance of the gearbox should meet the requirements of each index in Table 2.

[0083] Table 2

[0084]

[0085] 2. Hub motor reduction mechanism transmission ratio distribution and gear parameter determination.

[0086] 2.1 Transmission ratio and load distribution of each stage.

[0087] The transmission ratio is distributed according to the minimum volume as the target, and the speed ratio of each stage of gear in the gearbox is distributed according to the equal contact strength. The transmission ratio distribution result is shown in Table 3.

[0088] Table 3 Gearbox performance requirements

[0089]

[0090] 2.2 Gear parameters.

[0091] According to the speed ratio of each stage of gear, the gear strength is ensured as the basis, the sliding rate is controlled within 3.0, the end face coincidence degree and the axial coincidence degree are close to integer, the law of tooth width coefficient is greater than 0.4 as the target, and each stage of gear parameter is designed. The gear parameters of each stage of gear in the gearbox are shown in Table 4.

[0092] Table 4

[0093]

[0094] 2.3 Gear strength calculation.

[0095] Gear strength calculation is calculated according to the method specified in ISO6336 standard, and each load coefficient is valued according to the general valuation method of the industry. The load coefficient values of each gear are shown in Table 5.

[0096] Table 5

[0097]

[0098] According to the commonly used gear materials and heat treatment methods of automobiles, the material and heat treatment method of the gear are selected. The material properties and heat treatment method of the gear are shown in Table 6.

[0099] Table 6

[0100]

[0101] Based on the load spectrum, maximum torque condition and braking torque condition of the above processing, the gear bending fatigue strength, contact fatigue strength, bending static strength and contact static strength are calculated according to the method specified in ISO6336 standard. The calculation results are shown in Table 7 and Table 8.

[0102] Table 7

[0103]

[0104] Table 8

[0105]

[0106] 2.4 Gear gluing strength calculation.

[0107] The gluing strength of the gear is calculated according to the integral method of ISO13989-2. The calculation conditions are shown in Table 9, the calculation is related to the parameters of the lubricating oil, and the gluing calculation results are shown in Table 11.

[0108] Table 9

[0109]

[0110] Table 10

[0111]

[0112] Table 11

[0113]

[0114] 3. Bearing scheme design and calculation of hub motor gear box.

[0115] 3.1 Bearing selection.

[0116] According to the structural arrangement of the gear box and the force characteristics of the bearing, the type of the bearing is selected, and the size of the bearing is selected according to the working condition of the gear box. The rationality of the bearing selection is checked through the calculation of the bearing life, static strength and rolling body stress. The bearing type is shown in Table 12.

[0117] Table 12

[0118]

[0119] 3.2 Bearing life calculation.

[0120] The bearing life calculation is calculated according to the ISO16281 standard. The reference damage rate is less than 300% in the ISO16281 amendment. The calculation results of the bearing damage rate are shown in Table 13.

[0121] Table 13

[0122]

[0123] 3.3 Bearing static strength and rolling body stress calculation results.

[0124] According to the ISO76 standard, the bearing static strength is checked. The static strength safety factor of the bearing should be greater than 1.2. According to the loading condition of the rolling body, the rolling body stress of the bearing is analyzed. The maximum rolling body stress of the ball bearing should be less than 3500MPa, and the maximum rolling body stress of the roller bearing should be less than 3800MPa. The calculation results of the bearing static strength and rolling body stress are shown in Table 14.

[0125] Table 14

[0126]

[0127] 4. Shaft strength calculation.

[0128] The shaft strength calculation is calculated according to the DIN743 standard. According to the specification requirements, under the extreme load working condition, the shaft static safety factor is 1.1, and under the fatigue load, the shaft fatigue safety factor is 1.2. In addition, in order to be conservative, the shaft surface roughness is taken as Rz=12.5, and the step round angle is taken as R=0.5. The shaft material is shown in Table 15, and the calculation results of the shaft strength are shown in Table 16.

[0129] Table 15

[0130]

[0131] Table 16

[0132]

[0133] 5. Structure design.

[0134] 5.1 Structure principle.

[0135] The speed reduction mechanism adopts two-stage NGW planetary transmission. The motor output torque is amplified by the speed reduction mechanism and then output to the rim. The motor rotor is connected to the first sun gear as the input, and the rim is connected to the second planetary carrier as the output. The first planetary carrier is connected to the second sun gear through the spline. The first ring gear is centered with the rotor housing, and the second ring gear is centered with the stator housing. The load of the wheel hub is transmitted to the intermediate axle through the second planetary carrier bearing.

[0136] 5.2 First-stage speed reduction part.

[0137] The first-stage speed reduction part can also be called the first-stage planetary gear train. It is composed of a first-stage planetary carrier, a first-stage planetary gear, a planetary gear bearing (K28x40x25), a first-stage planetary gear spacer, a tapered bearing (33216), a second-stage sun gear, and a snap ring, etc. The first-stage planetary carrier adopts a cantilever design and is formed by an integral forging. The planetary carrier is supported by a tapered bearing. The first-stage planetary gear train contains four planetary gears. The planetary gears are supported on the cantilever shaft of the planetary carrier by needle bearings. The two ends are in contact with copper pads to increase wear resistance and are axially limited by a snap ring. The second-stage sun gear is connected to the first-stage planetary carrier by a spline and is limited by a snap ring.

[0138] 5.3 Second-stage speed reduction part.

[0139] The second-stage speed reduction part can also be called the second-stage planetary gear train. It is composed of a second-stage planetary carrier, a second-stage planetary gear, a planetary gear bearing (K35x45x20), a second-stage planetary gear spacer, a tapered bearing (33216, 32932), a second-stage planetary pin shaft, and a snap ring, etc. The second-stage planetary carrier adopts a double-arm support design and is formed by an integral casting. The planetary carrier is supported by two tapered bearings. The second-stage planetary gear train contains five planetary gears. The planetary gears are supported on the planetary pin shaft by needle bearings. The two ends are in contact with copper pads to increase wear resistance. The planetary pin shaft is axially limited by a snap ring.

[0140] 5.4 Ring gear structure design.

[0141] The first-stage ring gear is centered with the motor rotor housing and is fixed on the rotor housing by 16 M8 bolts. The second-stage ring gear is centered with the motor stator housing and is fixed on the stator housing by 30 M8 bolts.

[0142] 5.5 Other structure design.

[0143] Connecting plate is the structure connecting the secondary planetary carrier and the wheel rim. The inner ring is connected with the secondary planetary carrier through 8 M24 bolts, and the outer ring is connected with the wheel rim through 9 M27 bolts. The oil seal cover is used to support the sealing oil seal at the end of the secondary planetary carrier, and is centered by the stopper and connected to the motor stator housing by bolts; the rotor housing is used to support the primary gear ring, and is sealed with the gear box according to the motor; the motor rotor is supported by two ball bearings (6018).

[0144] 5.6 Sealing design.

[0145] There are three sealing designs, the first sealing structure is the oil seal arranged between the secondary planetary carrier and the sealing seat. The second sealing structure is the seal arranged between the motor rotor housing and the rotor support. The third sealing structure is the seal arranged between the motor rotor support and the axle.

[0146] 6. Hub motor gear box connecting piece checking calculation.

[0147] 6.1 Spline parameter design and calculation.

[0148] According to the arrangement position of the spline and the size of the torque borne, the parameters of the spline are designed, and the design parameters of the spline are shown in Table 17.

[0149] Table 17

[0150]

[0151] According to ANSI B92, the strength of each level of spline is checked, the outer spline tooth root shear safety factor, the outer spline pitch circle shear safety factor, the outer spline tooth side pressure stress safety factor, and the inner spline tensile stress safety factor are all greater than 1, and the spline strength checking results are shown in Table 18.

[0152] Table 18

[0153]

[0154] 6.2 Bolt design and calculation.

[0155] According to the structural characteristics of the hub motor reduction mechanism, the arrangement mode of the bolt is selected, according to the characteristics and size of the load on the connecting surface, the size and number of the bolt are designed, the carrying capacity of the bolt is calculated according to VDI2230 standard, according to the specification requirements, the slip safety factor of the bolt and pin is greater than 1 under the maximum limit torque working condition, the bolt with complex stress is calculated by the finite element method, the bolt connection scheme calculation under the maximum torque working condition is shown in Table 19, and the bolt connection scheme calculation under the braking torque working condition is shown in Table 20.

[0156] Table 19

[0157]

[0158] Table 20

[0159]

[0160] 7. Structural component strength analysis.

[0161] 7.1 Primary planetary carrier finite element analysis.

[0162] According to the maximum torque of the gearbox and the braking torque of the gearbox, the strength of the primary planetary carrier is analyzed according to the simulation software.

[0163] The maximum Mises stress of the primary planetary carrier appears at the root of the pin shaft under the maximum torque condition, which is 355.9 MPa, and the maximum Mises stress of the primary planetary carrier appears at the root of the pin shaft under the braking torque condition, which is 764.1 MPa. The planetary carrier material is 40Cr, the material yield strength is 785 MPa, and the planetary carrier meets the strength requirement.

[0164] 7.2 Secondary planetary carrier finite element analysis.

[0165] According to the maximum torque of the gearbox and the braking torque of the gearbox, the strength of the secondary planetary carrier is analyzed according to the simulation software.

[0166] The maximum Mises stress of the secondary planetary carrier appears at the edge of the planetary carrier and the pin shaft under the maximum torque condition, which is less than 400 MPa, and the maximum Mises stress of the primary planetary carrier appears at the edge of the planetary carrier and the pin shaft under the braking torque condition, which is less than 500 MPa. The planetary carrier material is 40Cr, the material yield strength is 785 MPa, and the planetary carrier meets the strength requirement.

[0167] It is easy for those skilled in the art to understand that the above-mentioned advantageous modes can be freely combined and superimposed without conflict.

[0168] The above is only a preferred embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above is only a preferred embodiment of the present application, and it should be pointed out that, for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and modifications can be made, which should be regarded as the protection scope of the present application.

Claims

1. A wheel hub motor, characterized by, The hub motor comprises a motor body and a speed reduction mechanism, the speed reduction mechanism comprises a primary speed reduction part and a secondary speed reduction part connected in transmission, the primary speed reduction part is connected with an output end of the motor body, and the secondary speed reduction part is connected with a wheel hub; The primary speed reduction part and the secondary speed reduction part are planetary gear train speed reduction assemblies; The hub motor comprises a central axle (71), the primary speed reduction part comprises a primary sun gear (11), a primary planet carrier (12) and a plurality of primary planet gears (13), the primary sun gear (11) is connected with the central axle (71), the central axle (71) is connected with the motor body in transmission, the primary planet carrier (12) comprises a first input end and a first output end, a plurality of the primary planet gears (13) are arranged on the first input end, the secondary speed reduction part comprises a secondary sun gear (21), a secondary planet carrier (22) and a plurality of secondary planet gears (23), the secondary sun gear (21) is connected with the first output end, the secondary planet carrier (22) comprises a second input end and a second output end, a plurality of the secondary planet gears (23) are arranged on the second input end, and the second output end is connected with the wheel hub.

2. The wheel hub motor according to claim 1, characterized in that The hub motor comprises a rotor, the primary speed reduction part comprises a primary ring gear (14), the primary ring gear (14) is centered with a shell of the rotor, and the primary planet gears (13) are engaged with the primary ring gear (14). The hub motor comprises a stator, the secondary speed reduction part comprises a secondary ring gear (24), the secondary ring gear (24) is centered with a shell of the stator, and the secondary planet gears (23) are engaged with the secondary ring gear (24).

3. The wheel hub motor according to claim 1, characterized in that, The hub motor comprises a connecting disc (3), and the second output end is connected with a rim of the wheel hub through the connecting disc (3).

4. The wheel hub motor of claim 1, wherein, The primary planet gears (13) are rotatably connected to the primary planet carrier (12) through primary planet gear (13) bearings; The secondary planet gears (23) are rotatably connected to the secondary planet carrier (22) through secondary planet gear (23) bearings; A primary planet carrier (12) bearing is arranged between the primary planet carrier (12) and the central axle (71); A secondary planet carrier (22) bearing is arranged between the primary planet carrier (12) and the secondary planet carrier (22); The motor body comprises a sealing seat (51), the sealing seat (51) is arranged opposite to the secondary planet carrier (22), and a first sealing structure (52) is arranged between the sealing seat (51) and the secondary planet carrier (22); The motor body comprises a rotor support (61), the rotor support (61) is connected with a shell of the rotor, and a second sealing structure (62) is arranged between the rotor support (61) and the shell of the rotor; A third sealing structure (72) is arranged between the rotor support (61) and the central axle (71).

5. The in-wheel motor according to claim 1, characterized by The transmission ratio of the primary speed reduction part is 2.902, and the transmission ratio of the secondary speed reduction part is 3.

837.

6. The in-wheel motor according to claim 1, characterized by The motor body is an internal rotor permanent magnet synchronous motor.

7. The in-wheel motor according to claim 1, characterized by The wheel hub motor comprises a wheel hub body, the motor body and the speed reduction mechanism are connected with the wheel hub body; A cleaning brush head is arranged on the wheel hub body, one end of the cleaning brush head is fixed on the wheel hub body so that the cleaning brush head can rotate with the wheel hub body, and the other end of the cleaning brush head extends to contact the outer wall of the motor body.

8. A vehicle characterized by comprising: The wheel hub motor as claimed in any one of claims 1-7.

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