Hub electric drive system with built-in brake system

Abstract

The invention discloses a hub electric drive system with a built-in brake system, which comprises a stator shell, an inner rotor and a transmission shaft, and is characterized in that the stator shell comprises a front shell, an outer stator ring and a rear shell, and the inner rotor comprises a rotor bracket and a permanent magnet; the end, penetrating through the front shell, of the transmission shaft is connected with a connecting disc, the other end of the transmission shaft extends into the rear shell and is provided with a brake drum, and two brake shoes are installed in the brake drum. The corresponding ends of the two brake shoes are rotationally connected with the bottom face of the brake drum, and the other ends of the two brake shoes are connected through a linkage mechanism. A concave cavity is formed in the position, corresponding to the brake drum, of the rear shell, a driving mechanism is arranged in the concave cavity, and the driving mechanism is connected with the linkage mechanism. The brake mechanism is integrated in the electric drive system, so that the overall size can be greatly reduced, meanwhile, the brake mechanism can be sealed and cooled in an oil cooling mode, the heat dissipation problem is effectively solved, and the sealing problem is also solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new energy vehicle driving technology, and particularly relates to a wheel hub electric drive system with a built-in braking system. BACKGROUND

[0002] Wheel hub drive integration is to directly integrate a drive motor into a wheel hub, which is compact in structure, saves space, makes vehicle layout more flexible, and can increase the vehicle interior space or optimize the vehicle body design. At the same time, power is directly transmitted to the wheels, reducing energy loss and improving energy utilization, which helps to improve the vehicle's range; four-wheel independent drive can be realized, the speed and torque of each wheel can be precisely controlled, and the vehicle's acceleration, braking and turning performance can be improved, especially in complex road conditions; it is very suitable for new energy vehicles such as electric vehicles, simplifies the structure of the power system, and promotes the development of vehicle electrification. For the existing wheel hub electric drive system, the main braking scheme at present is to combine motor kinetic energy recovery and brake kinetic energy recovery to brake. However, the existing braking mechanism is mostly externally mounted during installation, so that the overall structure of the wheel hub electric drive system is large, and the vehicle layout is easily affected during assembly. At the same time, during braking, the braking mechanism generates a large amount of heat, which easily affects the braking performance. Moreover, the current installation structure of the braking mechanism cannot completely seal the motor, and the dust generated by the friction between the brake disc and the brake drum is easy to enter the motor, which affects the performance of the motor. SUMMARY

[0003] In view of the above problems in the prior art, the purpose of the present application is to solve the problems of large overall volume of the existing wheel hub electric drive system and braking mechanism, poor heat dissipation effect, unsealed motor, and easy influence on the motor and braking performance, and to provide a wheel hub electric drive system with a built-in braking system. By integrating the braking mechanism into the electric drive system, the overall volume can be greatly reduced, and the braking mechanism can be sealed and cooled by oil cooling, which effectively solves the problems of heat dissipation and sealing, thereby greatly improving the braking performance.

[0004] To solve the above technical problems, the technical scheme adopted by the present application is as follows: a wheel hub electric drive system with a built-in braking system, comprising a stator shell, an inner rotor and a transmission shaft, characterized in that: the stator shell comprises a front shell body, an outer stator ring and a rear shell body, one end of the transmission shaft penetrates through the front shell body; the inner rotor comprises a rotor support and a permanent magnet, and an installation support is arranged in the stator shell, the rotor support is rotatably installed on the outside of the installation support, a planetary reduction mechanism is arranged on the inside of the installation support, the rotor support is connected with the planetary reduction mechanism through a connecting frame, the planetary reduction mechanism is connected with the transmission shaft, and the inner rotor can drive the transmission shaft to rotate through the planetary reduction mechanism; The transmission shaft is connected with a connecting disc at one end penetrating the front shell, and extends into the rear shell and is formed with a brake drum, and two brake shoes are installed in the brake drum; wherein, one end of the two brake shoes corresponding to the brake drum is rotationally connected with the bottom surface of the brake drum, and the other end of the two brake shoes is connected through a linkage mechanism; the rear shell is formed with a recess at a position corresponding to the brake drum, the brake drum is located in the recess, and there is a gap between the side wall of the brake drum and the side wall of the recess; a driving mechanism is arranged in the recess, and the driving mechanism is connected with the linkage mechanism and can drive the two brake shoes to approach or separate through the linkage mechanism.

[0005] Further, a support boss is arranged in the middle of the recess corresponding to the position of the transmission shaft, and the support boss is connected with the transmission shaft through a bearing; the driving mechanism is installed on the support boss, and the driving mechanism comprises an inner stator coil assembly and an outer rotor ring assembly, the inner stator coil assembly is sleeved on the support boss, and the outer rotor ring assembly is sleeved outside the inner stator coil assembly; a support boss is arranged in the inner cavity corresponding to the position of the outer rotor ring assembly, and the outer rotor ring assembly is connected with the support boss through a bearing.

[0006] Further, the linkage mechanism comprises a sleeve, and a set of threads are arranged on the inner side of the sleeve from both ends to the middle; two transmission members are arranged in the sleeve, and the two transmission members are connected with the two sets of threads on the inner side of the sleeve through cooperation; the two brake shoes are rotationally connected with the two transmission members respectively, the sleeve is rotated to move the two transmission members towards each other or away from each other; a plurality of protrusions are arranged on the outer side of the sleeve in the middle, and a helical tooth is arranged on the outer side of the rotor ring of the outer rotor ring assembly along the axial direction, the helical tooth is engaged with the protrusions to form a worm and gear mechanism.

[0007] Further, the mounting bracket comprises a rotor mounting ring close to the rear shell and a gear ring mounting ring close to the front shell, and separates the inner part of the stator shell into two parts, wherein the inner and outer diameters of the rotor mounting ring are smaller than the inner and outer diameters of the gear ring mounting ring; the rotor mounting bracket is located outside the gear ring mounting ring, and has a rotor mounting sleeve on the inner side, the rotor mounting sleeve is sleeved on the rotor mounting ring, and a double-row ball bearing is arranged between the rotor mounting sleeve and the rotor mounting ring; the gear ring is mounted on the inner side of the gear ring mounting ring and tightly fitted with the gear ring mounting ring; the two sides of the planet carrier are connected with the rotor mounting bracket and the front shell through a tapered roller bearing respectively.

[0008] Further, the stator housing is also provided with a cooling oil channel, the oil inlet of the cooling oil channel is located on the upper part of the outer stator ring near the side of the rear housing, the cooling oil channel extends to the front side of the front housing in the direction of the front housing, and then extends in the radial direction of the transmission shaft along the rear housing; the transmission shaft is provided with a cooling oil delivery channel, the delivery channel is arranged in the axial direction of the transmission shaft and extends into the rear housing through one end of the transmission shaft; the transmission shaft is provided with an oil hole corresponding to the position of the cooling oil channel, and the oil hole is in communication with the cooling oil channel; the lower part of the connection between the outer stator ring and the rear housing is formed with an oil storage cavity, the lower part of the recessed cavity of the rear housing is obliquely provided with an oil return channel, the oblique oil channel is in communication with the oil storage tank, and the oil return channel is in communication with the oil storage tank; the oil suction pump is arranged on the outer side of the lower part of the rotor housing corresponding to the position of the oil storage cavity, and the oil inlet of the oil suction pump is in communication with the oil storage cavity.

[0009] Further, the front housing is formed with an annular groove around the front housing corresponding to the position of the oil hole, the cooling oil channel is in communication with the annular groove, and an oil pool is formed.

[0010] Further, the end face of the open end of the brake drum is an inclined surface, and the inner side is inclined to the outer side; the side wall of the recessed cavity of the rear housing is provided with an oil blocking ring around the inner wall of the recessed cavity corresponding to the position of the side wall of the brake drum, and the oil blocking ring has a gap with the side wall of the brake drum.

[0011] Further, the mounting bracket is also provided with a oil distribution channel on the upper part, one end of the oil distribution channel is in communication with the cooling oil channel, and the other end extends to the position corresponding to the tapered roller bearing and then penetrates the mounting bracket.

[0012] Further, a screw hole is arranged on the lower side wall of the recessed cavity of the rear housing, and a magnetic bolt is arranged in the screw hole.

[0013] Further, the knuckle arm is integrated on the rear housing.

[0014] Compared with the prior art, the present application has the following advantages: 1. In the scheme, the inner rotor and the planetary reduction mechanism are distributed in an inner-outer staggered manner, which can greatly reduce the axial length of the entire wheel hub motor, thereby reducing the space occupied by the entire system and facilitating the layout and design of the entire vehicle.

[0015] 2. The EMB brake system is directly built in the wheel hub drive, and the structure of the EMB brake system is more compact and miniaturized, thereby greatly reducing the structure of the entire electric drive system, facilitating assembly and use, and the entire EMB brake system is enclosed in the stator housing, thereby effectively solving the problem of dust and water prevention.

[0016] 3. The cooling oil channel is arranged on the stator shell, and the cooling oil is delivered to the inside of the EMB brake system through the delivery channel on the transmission shaft, so that the heat generated in the working process of the EMB brake system can be dissipated by oil cooling, and the support bearing can be lubricated, thereby ensuring the stability of the working of the EMB brake system.

[0017] 4. The magnetic bolt is arranged on the lower side plate of the inner cavity of the rear shell, when the EMB brake system works and generates dust, the cooling oil can flow through the brake drum and the brake shoe to take away the dust when the EMB brake system is loosened; and the centrifugal force is generated when the brake drum rotates with the transmission shaft to throw the dust to the concave cavity side wall; since the oil blocking ring is arranged on the concave cavity side wall, the oil cannot enter the front shell body, but can only flow down to the lower part of the concave cavity, since the magnetic bolt is arranged on the lower side wall of the concave cavity, the magnetic dust can be collected by the magnetic bolt, thereby avoiding affecting the EMB brake system; and then the oil flows back to the oil storage pool through the oil return channel.

[0018] 5. The EMB brake adopts an outer rotor motor drive; the inner stator coil assembly is installed on the support boss of the rear shell, the rotor ring is rotatably installed on the support boss of the rear shell through the bearing, and the spiral teeth are arranged on the rotor ring, and the convex teeth are arranged on the sleeve, which cooperate with the spiral teeth to form a worm and gear mechanism, so that the motor rotation can drive the brake shoe to separate to realize braking or folding, and the brake is released; thereby the number of components can be reduced, and the structure is compact. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present application.

[0020] Figure 2 It is Figure 1 It is a sectional view along A-A direction.

[0021] In the figure: 1-transmission shaft, 21-front shell body, 22-outer stator ring, 23-rear shell body, 24-support boss, 25-support boss, 31-rotor support, 32-permanent magnet, 33-rotor installation sleeve, 4-installation support, 51-tooth ring, 52-planetary gear, 53-planetary carrier, 54-sun gear, 6-connection frame, 7-connection disc, 81-brake drum, 82-brake shoe, 91-inner stator coil assembly, 92-outer rotor ring assembly, 93-spiral teeth, 101-sleeve, 102-transmission part, 103-convex teeth, 20-double row ball bearing, 30-tapered roller bearing, 40-cooling oil channel, 50-delivery channel, 60-oil hole, 70-oil storage cavity, 80-annular groove, 90-oil blocking ring, 100-magnetic bolt, 110-steering arm. DETAILED DESCRIPTION

[0022] The present application will be further described below in conjunction with the drawings and examples.

[0023] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0024] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In the description of the present application, it should be explained that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present application is usually placed, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the indicated device or element 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. In addition, the terms "first", "second", "third" and the like are only used for differentiation in description, and cannot be understood as indicating or implying relative importance. In addition, the terms "horizontal", "vertical" and the like do not mean that the parts must be absolutely horizontal or vertical, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined. In the description of the present application, it should also be explained that, unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or detachably connected, or integrally connected; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0025] Embodiment: see Figure 1 , Figure 2The application discloses a wheel hub motor system with built-in brake system, which comprises a stator shell, an inner rotor and a transmission shaft 1. The stator shell comprises a front shell 21, an outer stator ring 22 and a rear shell 23 connected in sequence, and one end of the transmission shaft 1 penetrates through the front shell 21; an outer stator coil is arranged on the inner side of the outer stator ring 22, and the conductive lead of the outer stator coil is led out after penetrating through the outer stator ring 22 or the rear shell 23, so that the assembly and connection are facilitated. The inner rotor comprises a rotor support 31 and a permanent magnet 32, and an installation support 4 is arranged in the stator shell, and the rotor support 31 is rotatably installed on the outer side of the installation support 4. In the scheme, the stator shell and the inner rotor are combined to form an axial flux motor, and output power is provided. A planetary reduction mechanism is arranged on the inner side of the installation support, the rotor support 31 is connected with the planetary reduction mechanism through a connecting frame 6, the planetary reduction mechanism is connected with the transmission shaft 1, and the inner rotor can drive the transmission shaft 1 to rotate through the planetary reduction mechanism. Specifically, the planetary reduction mechanism comprises a gear ring 51, a planetary gear 52, a planetary carrier 53 and a sun gear 54. The sun gear 54 is provided with an axle hole, is sleeved on a rotating shaft through the axle hole and is in gap cooperation with the rotating shaft. The rotor support 31 is connected with the sun gear 54 through the connecting frame 6 and can drive the sun gear 54 to rotate. A plurality of planetary shafts are arranged on the planetary carrier 53, the planetary gear 52 is sleeved on the planetary shafts, the gear ring 51 is sleeved on the outer side of the planetary gear 52, and the planetary gear 52 is in meshing cooperation with the sun gear 54 and the gear ring 51. The planetary carrier 53 is sleeved on the transmission shaft 1 and is connected with the transmission shaft 1 through a spline, so that the transmission shaft 1 can be synchronously driven to rotate. In this way, the inner rotor can transmit power to the transmission shaft 1 through the planetary reduction mechanism, so that the rotating distance of the transmission shaft 1 can be increased.

[0026] In the embodiment, the mounting bracket 4 comprises a rotor mounting ring close to the rear housing 23 and a gear ring 51 mounting ring close to the front housing 21, and separates the stator housing into two parts, as an optimization, the rotor mounting ring and the gear ring 51 mounting ring are connected by a taper ring. The inner and outer diameters of the rotor mounting ring are smaller than those of the gear ring 51 mounting ring. The rotor support 31 is located outside the gear ring 51 mounting ring, and has a rotor mounting sleeve 33 on the inner side, the outer side of the section of the rotor mounting sleeve 33 is U-shaped, the permanent magnet 32 is mounted in the U-shaped groove, specifically, the permanent magnet 32 is mounted on the two side walls of the U-shaped groove, and the inner side of the stator coil extends into the U-shaped groove. The rotor mounting sleeve 33 is sleeved on the rotor mounting ring, and a double-row ball bearing 20 is arranged between the rotor mounting sleeve 33 and the rotor mounting ring; the inner rotor is supported by the double-row ball bearing 20, which can effectively improve the bearing capacity, resist deflection, and eliminate the adverse effects of the inner rotor during movement. The gear ring 51 is mounted on the inner side of the gear ring 51 mounting ring and tightly fitted with the gear ring 51 mounting ring; the two sides of the planet carrier 53 are also connected with the rotor mounting bracket and the front housing 21 through a tapered roller bearing 30. In the assembly process, the outer ring of the connecting bracket 6 is fixedly connected with the rotor mounting sleeve 33; a connecting sleeve is arranged on the side of the sun gear 54 connected with the connecting bracket 6, the inner ring of the rotor mounting sleeve 33 is sleeved on the connecting sleeve and connected with the connecting sleeve through a spline.

[0027] The transmission shaft 1 is connected with a connecting disc 7 at one end penetrating the front housing 21, and the other end extends into the rear housing 23 and is formed with a brake drum 81, two brake shoes 82 are mounted in the brake drum 81. One end of the two brake shoes 82 corresponding to the brake drum 81 is rotatably connected with the bottom surface of the brake drum 81, and the other end of the two brake shoes 82 is connected through a linkage mechanism. The rear housing 23 is formed with a recess corresponding to the position of the brake drum 81, the brake drum 81 is located in the recess, and there is a gap between the side wall of the brake drum 81 and the side wall of the recess. A driving mechanism is arranged in the recess, the driving mechanism is connected with the linkage mechanism and can drive the two brake shoes 82 to approach or separate through the linkage mechanism.

[0028] In the implementation, the middle part of the concave cavity is provided with a support boss 24 corresponding to the position of the transmission shaft 1, and the support boss 24 is connected with the transmission shaft 1 through a bearing. Specifically, the support boss 24 is provided with an outer connecting ring at one end close to the transmission shaft 1, the transmission shaft 1 is provided with an inner connecting ring at one end close to the support boss 24, and the bearing is arranged between the outer connecting ring and the inner connecting ring and connects the support boss 24 with the transmission shaft 1. The driving mechanism is mounted on the support boss 24 and includes an inner stator coil assembly 91 and an outer rotor ring assembly 92, forming an outer rotor motor. The inner stator coil assembly 91 is sleeved on the support boss 24, and the outer rotor ring assembly 92 is sleeved outside the inner stator coil assembly 91. The inner stator coil assembly 91 includes an inner stator ring and an inner stator coil, and the conductive lead of the inner stator coil extends out of the rear shell 23 after penetrating through the support boss 24, so as to facilitate wiring and power supply. The outer rotor ring assembly 92 includes a rotor ring and a permanent magnet 32 embedded in the inner side of the rotor ring. A support convex ring 25 is arranged at the position corresponding to the rotor ring in the inner cavity, and the outer side of the rotor ring is connected with the inner side of the support convex ring 25 through a bearing.

[0029] The linkage mechanism includes a sleeve 101, and a set of threads are arranged on the inner side of the sleeve 101 from both ends to the middle part. Two transmission members 102 are arranged in the sleeve 101, and the two transmission members 102 are connected with the two sets of threads on the inner side of the sleeve 101 through cooperation. Two brake shoes 82 are rotatably connected with the two connecting members, and rotating the sleeve 101 can make the two connecting members move towards each other or in opposite directions. A convex tooth 103 is arranged around the middle part of the outer side of the sleeve 101, and a helical tooth 93 is arranged on the outer side of the rotor ring along the axial direction. The helical tooth 93 is meshed with the convex tooth 103, forming a worm and gear mechanism.

[0030] In the implementation process, a cooling oil channel 40 is further arranged on the stator housing, an oil inlet of the cooling oil channel 40 is located on one side of the upper portion of the outer stator ring 22 close to the rear housing 23, the cooling oil channel 40 extends to the front side of the front housing 21 in the front housing 21 direction and then extends to the transmission shaft 1 direction along the radial direction of the front housing 21. In the implementation process, the outer stator coil is fixedly connected with the outer stator housing through a coil mounting ring, an arc-shaped groove is arranged on the outer side of the coil mounting ring, two ends of the arc-shaped groove extend from the upper portion of the coil mounting support 4 to the lower portion of the coil mounting support 4 respectively, the arc-shaped groove cooperates with the outer stator ring 22 to form an arc-shaped oil channel, and the oil channel is in communication with the cooling oil channel 40, and a plurality of spray holes are distributed on the groove bottom of the arc-shaped groove. A backflow hole is arranged on the lower portion of the coil mounting ring, and the backflow hole is located between the two ends of the arc-shaped groove. A cooling oil delivery channel 50 is arranged on the transmission shaft 1, the delivery channel 50 is arranged along the axial direction of the transmission shaft 1 and extends into one end of the rear housing 23 through the transmission shaft 1. An oil hole 60 is arranged on the transmission shaft 1 corresponding to the position of the cooling oil channel 40, and the oil hole 60 is in communication with the cooling oil channel 40. The front housing 21 is formed with an annular groove 80 around the front housing 21 corresponding to the position of the oil hole 60, the cooling oil channel 40 is in communication with the annular groove 80 to form an oil pool, and the oil hole 60 is in communication with the annular groove 80. In order to improve the sealing of the entire electric drive system, a sealing ring is further arranged between the front housing 21 and the transmission shaft 1, and the sealing ring is located on the front side of the annular groove 80. The end face of the open end of the brake drum 81 is an inclined surface, and the inner side of the open end of the brake drum 81 is inclined to the outer side (that is, the inner diameter of the open end of the brake drum 81 gradually increases); as an optimization, the inclination angle of the inner side of the open end of the brake drum 81 to the outer side is 45°; in this way, during the rotation of the brake drum 81, the cooling oil entering the brake drum 81 can be thrown out along the edge of the open end of the brake drum 81, thereby avoiding the cooling oil flowing along the outer side of the brake drum 81 and entering the drive motor. On the side wall of the recessed cavity of the rear housing 23, an oil blocking ring 90 is arranged around the inner wall of the recessed cavity corresponding to the position of the side wall of the brake drum 81, the oil blocking ring 90 is located on the side wall of the recessed cavity close to the outer stator ring 22, and has a gap between the oil blocking ring 90 and the side wall of the brake drum 81. A distribution channel is further arranged on the upper portion of the mounting support 4, one end of the distribution channel is in communication with the cooling oil channel 40, the other end of the distribution channel extends to the position corresponding to the conical roller bearing 30 and then penetrates the mounting support 4. A screw hole is arranged on the lower side wall of the recessed cavity of the rear housing 23, the screw hole is in communication with the recessed cavity, and a magnetic bolt 100 is arranged in the screw hole in a matched mode.

[0031] The lower part of the connection between the outer stator ring 22 and the rear housing 23 is formed with an oil storage cavity 70. In practice, the oil storage cavity 70 is formed by the part corresponding to the position between the outer stator ring 22 and the two ends of the arc-shaped groove and the downward recess of the lower part of the rear housing 23, so that the return flow hole is connected with the oil storage cavity 70. An oil return channel is obliquely arranged at the lower part of the recess of the rear housing 23, and the oblique oil channel connects the recess with the oil storage tank. An oil suction pump is arranged on the outer side of the lower part of the rotor housing corresponding to the position of the oil storage cavity 70, and the oil inlet of the oil suction pump is connected with the oil storage cavity 70.

[0032] In practice, the knuckle arm 110 is integrated on the rear housing 23; the integration degree of the entire wheel hub motor drive system is further improved to improve the assembly convenience.

[0033] In the working process of the scheme, after the outer stator coil of the axial flux motor is powered, the inner rotor of the axial flux motor starts to rotate and drives the sun gear 54 of the planetary reducer mechanism to rotate through the connecting frame 6, and the sun gear 54 drives the planetary gear 52 to rotate around the gear ring 51, and in the process of the planetary gear rotating around the gear ring 51, the planetary shaft drives the planetary carrier 53 to rotate through the planetary shaft, and the planetary carrier 53 is connected with the transmission shaft 1 through the spline, so as to drive the transmission shaft 1 to rotate and output torque. In the above transmission process, the torque of the axial flux motor is reduced through the planetary reducer and then transmitted to the transmission shaft 1, so as to increase the torque.

[0034] When braking is needed, the inner stator coil (forward) of the driving mechanism in the brake drum 81 is powered, and after the inner stator coil is powered, the rotor ring is driven to rotate, and since the outer side of the rotor ring is provided with a spiral tooth 93, and the spiral tooth 93 cooperates with the convex tooth 103 outside the sleeve 101 to form a worm and gear mechanism, the sleeve 101 can be driven to rotate through the rotor ring; in the process of rotating the sleeve 101, the two connecting pieces are moved in opposite directions, so as to push the two brake shoes 82 to move towards the brake drum 81, until they are pressed on the brake drum 81, and the brake is realized. When the brake is released, the inner stator coil (reverse) of the driving mechanism in the brake drum 81 is powered, and the whole working process is opposite to the above process, until the brake shoes 82 are separated from the brake drum 81, and the two connecting pieces are reset.

[0035] In addition, in the present scheme, the entire (EMB) braking system is located in the recess of the rear housing 23, thereby forming a completely sealed structure. In order to achieve cooling of the braking system, a cooling oil channel 40 is provided on the stator housing and cooperates with the oil suction pump to circulate cooling oil to cool and lubricate the stator coil, the braking system, and the bearings inside the stator housing, etc. In use, the oil inlet of the cooling oil channel 40 and the oil outlet of the oil suction pump are respectively connected to the cooling oil tank of the vehicle. During operation, the oil suction pump is started, and the cooling oil enters from the oil inlet of the cooling oil channel 40 under the action of the oil suction pump, one way through the cooling oil channel 40 and then enters the arc-shaped oil channel, and sprays and cools the stator coil, the other way through the cooling oil channel 40 and the annular groove 80 and the oil hole 60, and then enters the delivery channel 50 of the transmission shaft 1, and then is output from the end of the transmission shaft 1, and then flows through the bearing between the transmission shaft 1 and the support boss 24, and then enters the brake drum 81; since the brake drum 81 always rotates with the transmission shaft 1, the cooling oil entering the brake drum 81 flows along the inner wall of the brake drum 81 under the action of centrifugal force, and flows from the surface of the brake shoe 82 and / or the gap between the brake shoe 82 and the brake drum 81, thereby taking away the heat generated between the brake shoe 82 and the brake drum 81, and achieving cooling. After the cooling oil continuously enters the brake drum 81, the cooling oil flows into the recess of the rear housing 23 from the open side of the brake drum 81 during the rotation of the brake drum 81; wherein the end face of the open end of the brake drum 81 is a bevel, so that the cooling oil entering the brake drum 81 is thrown out along the edge of the open end of the brake drum 81, and directly falls on the side wall of the rear housing 23, thereby only flowing along the side wall of the rear housing 23 and the groove side wall. Since the recess side wall is provided with an oil baffle 90, and the oil baffle 90 is close to the outer stator ring 22, the cooling oil is blocked, avoiding the cooling oil entering the outer stator ring 22, ensuring the cooling oil flowing down along the side wall of the recess to the oil storage cavity 70, and finally being sucked away by the oil suction pump. At the same time, the cooling oil also flows to the surface of the tapered roller bearing 30 through the oil distribution channel, lubricates and cools the tapered roller bearing 30, and then flows into the outer stator ring 22, and finally flows into the oil storage cavity 70.

[0036] During braking, metal powder and the like will be generated by the friction between the brake shoe 82 and the brake drum 81, for this reason, a magnetic bolt 100 is arranged at the lower part of the recess, so that the generated powder is attracted by the magnetic bolt 100 and concentrated at the lower part of the recess, and finally enters the oil storage cavity 70 and is sucked away by the oil suction pump, thereby effectively preventing the dust from being long-term free in the braking system or entering the outer stator ring 22, to further improve the working stability of the braking system and the electric drive system. In order to facilitate cleaning of the metal powder, a filter is further arranged between the oil suction pump and the oil storage cavity 70 during implementation, thereby improving the working stability and service life of the oil suction pump, etc.

[0037] Finally, it needs to be explained that the above examples are only used to illustrate the technical solutions of the present application but not to limit the technical solutions, and those of ordinary skill in the art should understand that the technical solutions of the present application are modified or equivalently replaced without departing from the purpose and scope of the technical solutions, which should be covered in the scope of claims of the present application.

Claims

1. An in-wheel motor drive system with a built-in brake system, comprising a stator housing, an inner rotor and a transmission shaft, characterized in that: The stator housing comprises a front shell, an outer stator ring and a rear shell, one end of the transmission shaft penetrates the front shell; the inner rotor comprises a rotor support and a permanent magnet, an installation support is arranged in the stator housing, the rotor support is rotatably installed outside the installation support, a planetary reduction mechanism is arranged inside the installation support, the rotor support is connected with the planetary reduction mechanism through a connecting frame, the planetary reduction mechanism is connected with the transmission shaft, and the inner rotor can drive the transmission shaft to rotate through the planetary reduction mechanism; One end of the transmission shaft penetrating the front shell is connected with a connecting disc, the other end extends into the rear shell and is formed with a brake drum, two brake shoes are installed in the brake drum; wherein, one end of the two brake shoes corresponding to the brake drum is rotatably connected with the bottom surface of the brake drum, the other end of the two brake shoes is connected through a linkage mechanism; the rear shell is formed with a recess at a position corresponding to the brake drum, the brake drum is located in the recess, and there is a gap between the side wall of the brake drum and the side wall of the recess; a driving mechanism is arranged in the recess, the driving mechanism is connected with the linkage mechanism and can drive the two brake shoes to move close to each other or separate through the linkage mechanism.

2. The electric wheel drive system with built-in brake system according to claim 1, characterized in that: A support boss is arranged at a position corresponding to the transmission shaft in the middle of the recess, the support boss is connected with the transmission shaft through a bearing; the driving mechanism is installed on the support boss and comprises an inner stator coil assembly and an outer rotor ring assembly, the inner stator coil assembly is sleeved on the support boss, and the outer rotor ring assembly is sleeved outside the inner stator coil assembly; a support convex ring is arranged at a position corresponding to the outer rotor ring assembly in the inner cavity, and the outer rotor ring assembly is connected with the support convex ring through a bearing.

3. The in-wheel motor drive system with a built-in brake system according to claim 2, characterized in that: The linkage mechanism comprises a sleeve, a set of threads are arranged inside the sleeve from both ends to the middle; two transmission members are arranged in the sleeve, the two transmission members are connected with the two sets of threads on the inner side of the sleeve in a matched mode, the two brake shoes are rotatably connected with the two connecting members, the sleeve is rotated to move the two connecting members towards each other or away from each other; a plurality of protruding teeth are arranged on the outer side of the sleeve in the middle, a helical tooth is arranged on the outer side of the rotor ring of the outer rotor ring assembly in the axial direction, the helical tooth is meshed with the protruding teeth to form a worm and gear mechanism.

4. The electric wheel drive system with built-in brake system according to claim 1, characterized in that: The installation support comprises a rotor installation ring close to the rear shell and a gear ring installation ring close to the front shell, and separates the inner part of the stator housing into two parts, wherein the inner diameter and the outer diameter of the rotor installation ring are smaller than those of the gear ring installation ring; the rotor support is located outside the gear ring installation ring, and has a rotor installation sleeve on the inner side, the rotor installation sleeve is sleeved on the rotor installation ring, and a double-row ball bearing is arranged between the rotor installation sleeve and the rotor installation ring; the gear ring is installed on the inner side of the gear ring installation ring and is tightly matched with the gear ring installation ring; the two sides of the planet carrier are connected with the rotor installation frame and the front shell through a tapered roller bearing respectively.

5. The electric wheel drive system with built-in brake system according to claim 1, characterized in that: The cooling oil channel has an oil inlet located at the upper part of the outer stator ring and close to one side of the rear housing, extends to the front side of the front housing in the direction of the front housing, and then extends in the radial direction of the front housing to the direction of the transmission shaft; the transmission shaft is provided with a cooling oil delivery channel arranged in the axial direction of the transmission shaft and extending through the transmission shaft to the end of the rear housing; the transmission shaft is provided with an oil hole corresponding to the position of the cooling oil channel and connected with the cooling oil channel through the oil hole; the lower part of the connection between the outer stator ring and the rear housing is formed with an oil storage cavity, the lower part of the recess of the rear housing is obliquely provided with a return oil channel, the oblique oil channel connects the recess with the oil storage tank, and the oil suction pump is arranged on the outer side of the lower part of the rotor housing and corresponds to the position of the oil storage cavity.

6. The in-wheel motor drive system with a built-in brake system according to claim 5, characterized in that: The front housing is provided with an annular groove around the front housing corresponding to the position of the oil hole, the cooling oil channel is connected with the annular groove, and an oil pool is formed.

7. The in-wheel motor drive system with a built-in brake system according to claim 5, characterized in that: The end face of the open end of the brake drum is an inclined surface, and the inner side is inclined to the outer side; the recess of the rear housing is provided with an oil blocking ring around the inner wall of the recess corresponding to the position of the side wall of the brake drum, and the oil blocking ring has a gap with the side wall of the brake drum.

8. The in-wheel motor drive system with a built-in brake system according to claim 5, characterized in that: The mounting bracket is further provided with a distribution channel at the upper part, one end of the distribution channel is connected with the cooling oil channel, the other end extends to the corresponding position of the tapered roller bearing and then penetrates the mounting bracket.

9. The in-wheel motor drive system with a built-in brake system according to claim 5, characterized in that: The recess of the rear housing is provided with a screw hole, and a magnetic bolt is matched in the screw hole.

10. The in-wheel motor drive system with a built-in brake system according to claim 1, characterized in that: The rear housing is integrated with a knuckle arm.

Images