braking device

Abstract

The application provides a brake device for a wheel hub drive assembly of a vehicle to brake a rotating part of the wheel hub drive assembly, which comprises a housing for being fixed to a frame of the vehicle, the rotating part being rotatable relative to the housing; an inner sleeve (P0) in a sleeve shape and for being fixedly connected with the rotating part; a brake disc (10) sleeved on the inner sleeve (P0), the brake disc (10) being unable to rotate relative to the inner sleeve (P0) but being able to reciprocate relative to the inner sleeve (P0) in an axial direction (A) of the inner sleeve (P0); and a friction disc (20) being connected with the housing in a manner of being unable to rotate relative to the housing and being able to reciprocate relative to the brake disc (10) in the axial direction (A) to selectively engage and disengage with the brake disc (10). The brake device according to the application is compact in structure, large in braking torque and good in heat dissipation performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of brakes, and in particular to a brake device for a wheel hub drive assembly of a vehicle. BACKGROUND

[0002] Wheel hub drive technology is a kind of drive technology for electric drive vehicles. Figure 1 A possible wheel hub drive system is shown in which the motor E and the brake B are both integrated on the inner circumferential side of the wheel hub, the rotor of the motor E transmits torque to the sun gear of the planetary gear set PG through the rotor support, and the planet carrier of the planetary gear set PG transmits torque to the wheel hub. The brake B transmits braking torque to the sun gear (or rotor support), thereby achieving braking of the wheel hub drive system.

[0003] Common brakes include drum brakes and disc brakes, for example.

[0004] Figure 2 is a schematic diagram of a partial structure of a drum brake, the actuator of the drum brake achieving braking by engaging the friction lining L with the inner circumferential wall of the brake drum (not shown). Since the actuator of the drum brake and the friction lining L are both accommodated in the inner cavity of the brake drum, this makes the heat dissipation performance of the drum brake poor. Especially in the case of continuous braking, the heat generated by friction cannot be dissipated in time, causing the temperature of the friction lining to rise and the friction lining to age easily, and the braking efficiency to decrease.

[0005] Figure 3 is a schematic diagram of a disc brake, the disc brake achieving braking by moving the caliper C in the axial direction to clamp the brake disc P. The components that drive the caliper C to move occupy a large space, for example, the caliper C usually needs to be driven by double hydraulic cylinders; and the friction lining mounted on the caliper C also needs to have a large enough surface area to achieve good braking effect, which makes the overall size of the disc brake large and the braking torque not high. SUMMARY

[0006] The present application aims to overcome or at least alleviate the deficiencies of the prior art, and provides a brake device.

[0007] The present application provides a brake device for a wheel hub drive assembly of a vehicle to achieve braking of a rotating component of the wheel hub drive assembly, the brake device comprising:

[0008] a housing for being fixed to a frame of the vehicle, the rotating component being rotatable relative to the housing;

[0009] an inner sleeve in the form of a sleeve and for being fixedly connected with the rotating component;

[0010] A brake disc is sleeved on the inner sleeve, the brake disc and the inner sleeve cannot rotate relative to each other but can reciprocate relative to the inner sleeve in the axial direction of the inner sleeve;

[0011] A friction disc is connected with the housing and cannot rotate relative to the housing and can reciprocate relative to the brake disc in the axial direction to selectively engage and disengage with the brake disc.

[0012] In at least one embodiment, the friction disc includes a first friction disc and a second friction disc located on two opposite sides of the brake disc in the axial direction,

[0013] The first friction disc can move relative to the housing in the axial direction, and the second friction disc cannot move relative to the housing in the axial direction,

[0014] In the axial direction, the first friction disc can be driven to move towards the brake disc and push the brake disc to move towards the second friction disc, so that the brake disc is frictionally engaged with the first friction disc and the second friction disc.

[0015] In at least one embodiment, the brake device further includes a spring, which applies a force to the brake disc in the axial direction towards the first friction disc when the brake disc is engaged with the second friction disc.

[0016] In at least one embodiment, the brake device further includes an annular support fixed to the housing,

[0017] The first friction disc is splined to the support, and the second friction disc is fixedly connected to the support.

[0018] In at least one embodiment, the brake device further includes a first retaining ring, the support includes a spline barrel and a connecting ring,

[0019] The connecting ring includes a main body and a plurality of insertion portions, the main body is annular and connected with the housing, and the insertion portions are arranged on the inner circumferential side of the main body,

[0020] The inner circumferential wall of the spline barrel is formed with a spline structure to cooperate with the first friction disc, and one end of the spline barrel is formed with an insertion opening to cooperate with the insertion portion to prevent the spline barrel from rotating relative to the connecting ring,

[0021] The spline barrel is embedded in the inner circumferential wall of the main body to be positioned in the radial direction of the main body,

[0022] The first blocking ring is embedded in the inner periphery of the spline sleeve, and at the insertion port, the spline sleeve and the first blocking ring are respectively located on both sides of the insertion portion in the axial direction, so that the spline sleeve is positioned relative to the connecting ring in the axial direction.

[0023] In at least one embodiment, the friction disc comprises a plurality of trays and pads, each of the trays is annular, and one or more pads are mounted on each of the trays, and the pads are arranged towards the brake disc.

[0024] In at least one embodiment, the inner sleeve is splined coupled with the brake disc.

[0025] In at least one embodiment, a plurality of radial heat dissipation channels are formed on the brake disc.

[0026] In at least one embodiment, the brake device further comprises an actuator, which is reciprocable in the axial direction to engage or disengage the friction disc with the brake disc.

[0027] In at least one embodiment, the actuator comprises an annular push ring and a plurality of push rods connected to the push ring,

[0028] The plurality of push rods are distributed along the circumferential direction of the push ring, and the push rods are reciprocable in the axial direction under the influence of fluid pressure.

[0029] The brake device according to the present application has compact structure, large braking torque, and good heat dissipation performance. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a schematic view of a possible hub drive device.

[0031] Figure 2 is a schematic view of a partial structure of a drum brake.

[0032] Figure 3 is a schematic view of a partial structure of a disc brake.

[0033] Figure 4 is a sectional view of a brake device according to a first embodiment of the present application.

[0034] Figure 5 is a partial enlarged view of Figure 4

[0035] Figure 6 is an exploded schematic view of a partial structure of a brake device according to a first embodiment of the present application.

[0036] Figure 7 ​is a schematic view of a spring of a brake device according to the first embodiment of the present application.

[0037] Figure 8 is a schematic view of a partial structure of a brake device according to the first embodiment of the present application, viewed in the axial direction.

[0038] Figure 9 is a sectional view of a brake device according to the second embodiment of the present application.

[0039] Explanation of Reference Numerals:

[0040] E motor; B brake; PG planetary gear set; L brake pad; C brake caliper; P brake disc;

[0041] S support shaft; PI sun gear;

[0042] PO inner sleeve; P01 outer spline; HI inner housing; H2 housing cover; H2a stepped portion; Bt screw;

[0043] 10 brake disc; 11 inner ring; 12 outer ring; 101 heat dissipation passage; 102 inner spline;

[0044] 20 friction disc; 21 first friction disc; 22 second friction disc; 201 tray; 202 pad;

[0045] 30 bracket; 31 spline barrel; 31a, 301 tube portion; 31b, 303 inner folded portion; 31ai inner region; 31ao outer region; 311 insertion port; 312 heat dissipation hole; 313 first stop ring groove; 32 connection ring; 321 main body; 322 insertion portion; 302 connection ring portion;

[0046] 40 actuator; 41 push ring; 41a folded edge; 42 push rod; 42a stop edge; 421 front end;

[0047] 50 spring; 61 first stop ring; 62 second stop ring;

[0048] A1 first direction; A2 second direction; A axial direction; R radial direction. DETAILED DESCRIPTION

[0049] Exemplary embodiments of the present application will be described below with reference to the accompanying drawings. It should be understood that the specific description is only for teaching those skilled in the art how to implement the present application, and is not intended to exhaust all possible ways of the present application, nor to limit the scope of the present application.

[0050] Reference Signs Figures 4 to 9 A brake device according to the present application will be described below. Hereinafter, unless specifically described, reference will be made to Figures 4 to 6 , A denotes an axial direction of the brake device, and R denotes a radial direction of the brake device.

[0051] The brake device according to the present application is used in a hub drive assembly, which can brake a rotating component (for example, a rotor of an electric motor and a sun gear of a planetary gear set) of the hub drive assembly.

[0052] The brake device comprises a rotating assembly and a non-rotating assembly. The rotating assembly is connected to the rotating component in a non-rotatable manner (i.e., cannot rotate relative to the rotating component), and the non-rotating assembly does not rotate with the rotating component. The non-rotating assembly can move relative to the rotating assembly in the axial direction A, so that the rotating assembly and the non-rotating assembly can be engaged and disengaged. When the rotating assembly and the non-rotating assembly are engaged, the hub drive system is in a braking state.

[0053] (First embodiment)

[0054] Firstly, refer to Figures 4 to 8 The brake device according to the first embodiment of the present application is introduced.

[0055] Refer to Figure 4 In the present embodiment, the sun gear P1 of the planetary gear set of the hub drive system is sleeved on the support shaft S, and the sun gear P1 can rotate relative to the support shaft S under the drive of the rotor of the electric motor, and further transmit torque to the hub (for example, refer to the connection mode of the planetary gear set PG and the hub in Figure 1 , and the carrier is connected to the hub in a non-rotatable manner). The support shaft S is fixed relative to the housing H of the brake device (or relative to the frame of the vehicle).

[0056] The housing H comprises an inner housing H1 and a housing cover H2. The inner housing H1 is substantially cylindrical, and the housing cover H2 is installed at the end of the inner housing H1. The rotating assembly is accommodated in the inner cavity of the housing, and the non-rotating assembly is partially located in the inner cavity of the housing and is limited by the housing.

[0057] The annular edge of the inner periphery of the housing cover H2 is stepped in the axial direction A, and the stepped portion H2a limits the push rod 42 introduced below.

[0058] The rotating assembly of the brake device comprises an inner sleeve P0, a brake disc 10, a spring 50, and a second retaining ring 62.

[0059] The inner sleeve P0 is sleeved on the outer periphery of the support shaft S and is connected to the sun gear P1 in a non-rotatable manner. At least part of the outer periphery of the inner sleeve P0 in the axial direction A is provided with external splines P01.

[0060] The brake disc 10 is annular and is sleeved on the outer periphery of the inner sleeve P0. The inner periphery of the brake disc 10 has internal splines 102 (also refer to Figure 6 ), which cooperate with the external splines P01, so that the brake disc 10 can move in the axial direction A relative to the inner sleeve P0, but cannot rotate in the circumferential direction.

[0061] The Figure 4The left side of the brake disc 10 in the axial direction A is defined as the first side, and the right side of the brake disc 10 in the axial direction A is defined as the second side.

[0062] In order to limit the movement range of the brake disc 10 in the axial direction A and to separate the brake disc 10 from the friction disc 20 to be described below, a spring 50 is arranged on the first side of the brake disc 10 in the axial direction A. In addition, in order to limit the movement range of the brake disc 10 on the second side, a second stop ring 62 is arranged on the second side of the brake disc 10 in the axial direction A.

[0063] The outer circumferential portion of the inner sleeve P0 is provided with two recessed annular grooves, i.e. a spring groove for at least partially embedding the spring 50 and a second stop ring groove for partially embedding the second stop ring 62.

[0064] In the present embodiment, the spring 50 is a ring-shaped wave spring (see also Figure 7 ).

[0065] The Figure 4 axial direction A to the left is defined as the first direction A1, and the direction opposite to the first direction A1 is the second direction A2.

[0066] When the brake disc 10 is not in contact with the non-rotating component, i.e. the brake device is not in the braking state, the brake disc 10 is in the initial position, and at this time the spring 50 abuts against the axial end surface of the brake disc 10. When the brake disc 10 is pushed by the non-rotating component to move in the first direction A1 away from the initial position, the spring 50 is compressed in the axial direction A to exert a pressing force on the brake disc 10 in the second direction A2, which enables the spring 50 to push the brake disc 10 back to the initial position when the non-rotating component removes the pressure on the brake disc 10.

[0067] Referring to Figure 5 and Figure 6 , the brake disc 10 comprises an inner ring 11 located at the inner circumferential portion and an outer ring 12 located at the outer circumferential portion. In the axial direction A, the thickness of the outer ring 12 is greater than the thickness of the inner ring 11, and the outer ring 12 is used to contact the pad of the non-rotating component. The inner ring 11 is thin and light, so that the brake disc 10 has a small moment of inertia; the outer ring 12 is thick and heavy, so that the part of the brake disc 10 that implements braking friction has a large heat capacity. Preferably, on the second side of the brake disc 10, the outer ring 12 protrudes from the inner ring 11 in the axial direction A, which makes the inner circumferential portion of the outer ring 12 form a space for partially accommodating the actuator 40 to be described below, and the brake device structure is compact.

[0068] Preferably, a plurality of radially-through and circumferentially-distributed heat dissipation channels 101 are formed on the outer ring 12 to facilitate heat dissipation of the outer ring 12. More preferably, the heat dissipation channels 101 are arranged at an angle with respect to the radial direction R, and the openings of the heat dissipation channels 101 on the inner circumferential side of the outer ring 12 are closer to the first side in the axial direction A than the openings on the outer circumferential side of the outer ring 12, and the two openings are circumferentially staggered by a certain angle, which makes it easier for air to flow through the heat dissipation channels 101 in a centrifugal manner during rotation of the brake disc 10.

[0069] The non-rotating components of the brake device include the friction disc 20, the bracket 30, the actuator 40 and the first blocking ring 61.

[0070] The friction disc 20 is connected with the housing in a non-rotatable manner through the bracket 30, and the friction disc 20 is capable of reciprocating in the axial direction A relative to the brake disc 10 to achieve engagement and disengagement with the brake disc 10.

[0071] With reference to Figure 5 and Figure 6 , the bracket 30 includes a spline barrel 31 and a connecting ring 32.

[0072] The connecting ring 32 is used to connect the spline barrel 31 and the housing. The connecting ring 32 includes an annular main body 321 and a plurality of circumferentially-spaced insertion portions 322 on the inner circumferential side of the main body 321, and the plurality of insertion portions 322 form a toothed structure on the inner circumferential portion of the connecting ring 32. The main body 321 is fixed to the housing by, for example, screws Bt. Preferably, the outer circumferential portion of the connecting ring 32 is clamped between the inner housing H1 and the housing cover H2.

[0073] The spline barrel 31 includes a tubular pipe portion 31a extending in the axial direction A and an inner folded portion 31b at one end of the pipe portion 31a, the inner folded portion 31b being on the inner circumferential side of the pipe portion 31a and perpendicular to the axial direction A.

[0074] The pipe portion 31a provides internal splines for the friction disc 20. Specifically, the pipe portion 31a includes alternately arranged strip-shaped inner regions 31ai and outer regions 31ao of different radial dimensions. The inner diameter of the inner regions 31ai is smaller than the inner diameter of the outer regions 31ao, and in this embodiment, the outer diameter of the inner regions 31ai is smaller than the outer diameter of the outer regions 31ao. The spline barrel 31 is formed by, for example, a stamping process. The alternately arranged inner regions 31ai and outer regions 31ao make the inner circumferential wall and the outer circumferential wall of the pipe portion 31a form toothed structures, and the toothed structure of the inner circumferential wall provides internal splines for the friction disc 20.

[0075] The end of the tube portion 31a distal to the inner fold portion 31b forms a plurality of insertion openings 311 that can cooperate with the insertion portion 322 of the connecting ring 32. The outer diameter of the tube portion 31a is substantially equal to the inner diameter of the main body 321. Thus, by aligning the insertion portion 322 and the insertion openings 311 in the circumferential direction and bringing the spline barrel 31 and the connecting ring 32 close to each other in the axial direction A, the spline barrel 31 can be fitted into the inner periphery of the main body 321 (the spline barrel 31 is positioned in the radial direction R), and the insertion portion 322 is inserted into the insertion openings 311 (the spline barrel 31 is positioned in the circumferential direction and at one end in the axial direction A, i.e., the movement of the spline barrel 31 to the second side in the axial direction is limited by the insertion portion 322).

[0076] The insertion portion 322 also plays a role in radially positioning the push ring 41 of the actuator 40 described below.

[0077] The inner periphery of the tube portion 31a also fits a first stop ring 61, which can position the spline barrel 31 at the other end in the axial direction A; or in other words, the bottom of the insertion openings 311 and the first stop ring 61 respectively sandwich the insertion portion 322 on both sides in the axial direction A of the insertion portion 322, so that the spline barrel 31 cannot move in the axial direction A relative to the connecting ring 32 (see also Figure 8 ).

[0078] Specifically, the inner zone 31ai is provided with a first stop ring groove 313 extending in the circumferential direction and penetrating in the radial direction R, and the first stop ring 61 is at least partially fitted in the first stop ring groove 313. Since each inner zone 31ai has an outer zone 31ao with a larger radial dimension on both sides in the circumferential direction, the outer zone 31ao plays a role in radially limiting the first stop ring 61.

[0079] In the above manner, the spline barrel 31 is ingeniously and conveniently fixed on the connecting ring 32.

[0080] Preferably, the tube portion 31a is provided with a heat dissipation hole 312 penetrating in the radial direction R, and the axial position of the heat dissipation hole 312 at least partially coincides with the axial position of the opening of the heat dissipation passage 101 on the outer periphery of the outer ring 12 when the brake disc 10 and the friction disc 20 are engaged, so that the airflow through the heat dissipation passage 101 can further flow to the outer periphery side of the spline barrel 31 during braking. Preferably, the heat dissipation hole 312 is provided in the inner zone 31ai.

[0081] The friction disc 20 has two, and the friction disc 20 is arranged on the inner periphery of the tube portion 31a of the spline barrel 31, the first friction disc 21 is arranged on the second side of the brake disc 10, and the first friction disc 21 can reciprocate relative to the spline barrel 31 in the axial direction A; the second friction disc 22 is arranged on the first side of the brake disc 10, and the second friction disc 22 is fixed to the spline barrel 31.

[0082] The friction disc 20 includes a tray 201 and a pad 202. The tray 201 is annular and has external splines for mating with internal splines of the spline cylinder 31, and the tray 201 is used to fix the pad 202. A single annular pad 202 can be provided on one tray 201, or a plurality of pads 202 can be provided on one tray 201 in a circumferential direction. In the present embodiment, two arc-shaped pads 202 are provided on each tray 201. The pad 202 is provided on a surface of the tray 201 facing the brake disc 10.

[0083] The tray 201 of the second friction disc 22 is fixedly connected to the inner fold 31b, for example, by screws or bolts. The tray 201 of the first friction disc 21 is spline-coupled to the tube 31a.

[0084] Referring to Figure 4 , the actuator 40 includes a push ring 41 and a push rod 42.

[0085] The push ring 41 is annular, and an inner circumferential portion of the push ring 41 is connected to the push rod 42, and an outer circumferential portion of the push ring 41 can abut against the tray 201 of the first friction disc 21.

[0086] Preferably, the inner circumferential portion of the push ring 41 protrudes in the first direction A1 in the axial direction A, and the protruding inner circumferential portion partially extends into the inner circumferential side of the outer ring 12. The outer circumferential portion of the push ring 41 forms an annular flange 41a extending in the axial direction A, and the flange 41a abuts against the inner circumferential side of the insertion portion 322, so that the push ring 41 can be positioned in the radial direction R with the assistance of the connecting ring 32 (see also Figure 8 ).

[0087] The push rod 42 is substantially rod-shaped, and the push rod 42 can be driven by hydraulic pressure to reciprocate in the axial direction A, thereby pushing the push ring 41 to reciprocate in the axial direction A.

[0088] The push rod 42 is partially accommodated in the inner cavity of the housing, and a substantially middle portion of the push rod 42 in the axial direction A forms a flange 42a protruding to the radial outer side, and the flange 42a is limited by the step portion H2a on the housing cover H2 and cannot move to the outer side of the housing cover H2. Figure 4 In the present embodiment, a portion of the push rod 42 to the left of the flange 42a is a front portion 421 of the push rod 42, and the front portion 421 is completely accommodated in the inner cavity of the housing, and the front portion 421 is partially accommodated in the inner circumferential portion of the outer ring 12.

[0089] In the present embodiment, there are two push rods 42, and the two push rods 42 are arranged at an interval of 180° in the circumferential direction. The hydraulic control pipes of the two push rods 42 are connected, for example, the hydraulic chambers inside the two push rods 42 are connected by a steel pipe, so as to ensure that the two push rods 42 move synchronously and are subjected to equal hydraulic driving forces.

[0090] The braking method of the brake device will be described below.

[0091] In the process of switching the brake device from the non-braking state to the braking state, the push rod 42 pushes the push ring 41 to move in the first direction Al, the push ring 41 contacts the first friction disc 21 and pushes the first friction disc 21 to move in the first direction Al, then the first friction disc 21 contacts the brake disc 10 and further pushes the brake disc 10 to move in the first direction Al until the first friction disc 21, the brake disc 10 and the second friction disc 22 are tightly engaged together, and the rotation speed of the brake disc 10 is reduced or even gradually stopped. At this time, the spring 50 applies a force in the second direction A2 to the brake disc 10, and obviously, the force in the second direction A2 generated by the spring 50 is smaller than the force in the first direction Al generated by the push rod 42.

[0092] In the process of switching the brake device from the braking state to the non-braking state, the push rod 42 moves in the second direction A2, then the pushing force transmitted to the first friction disc 21 through the push ring 41 is gradually reduced, and the clamping force of the first friction disc 21 and the second friction disc 22 to the brake disc 10 is gradually reduced. When the force in the second direction A2 applied to the brake disc 10 by the spring 50 is greater than the force in the first direction Al applied to the brake disc 10 by the first friction disc 21, the brake disc 10 moves in the second direction A2 until the initial position. It should be understood that in the case where the push rod 42 moves in the second direction A2 to the limit position, in the process of returning the brake disc 10 to the initial position, the first friction disc 21 and the push ring 41 are pushed by the brake disc 10 to move in the second direction A2, and finally the first friction disc 21 is separated from the brake disc 10.

[0093] (Second Embodiment)

[0094] Reference Figure 9 The brake device according to the second embodiment of the present application will be described. The same parts as those of the first embodiment will not be described.

[0095] In this embodiment, the bracket 30 is an integral single component which includes a tube portion 301, a connecting ring portion 302 and an inner folded portion 303. The tube portion 301 and the inner folded portion 303 are the same as the tube portion 31a and the inner folded portion 31b in the first embodiment, and the connecting ring portion 302 is directly connected to the tube portion 301 without the need of the insertion structure or the use of the retaining ring.

[0096] Referring to the positioning mode of the push ring 41 by the insertion portion 322 in the first embodiment, in this embodiment, a plurality of protrusions (not shown) protruding radially inward can be formed on the inner periphery of the tube portion 301 by, for example, stamping, and the protrusions abut against the outer periphery of the folded edge 41a to radially position the push ring 41. It should be understood that in the case where the push rod 42 is sufficient to position the push ring 41, the push ring 41 can not be positioned on the outer periphery side.

[0097] The present application has at least one of the following advantages:

[0098] (i) The brake device according to the present application is compact and has good heat dissipation performance.

[0099] (ii) The area of the lining 202 can be adjusted according to the needs of heat dissipation without changing the size of the push rod 42; compared with the traditional disc brake which needs to increase the size of the caliper to increase the area of the lining, the brake device according to the present application occupies less space and is flexible in design adjustment.

[0100] (iii) The front part 421 of the push rod 42 is accommodated in the inner cavity of the housing, saving the space of the outer cavity of the housing. According to the design needs of the braking torque, the number of push rods 42 can be appropriately increased.

[0101] (iv) There is a large gap between the friction surface of the friction component (the lining 202 and the brake disc 10) and the housing, and the temperature rise of the friction component has less effect on other surrounding components, especially the motor of the hub drive system which is not easily affected by the heat generated by braking.

[0102] (v) When the two sides of the brake disc 10 are provided with friction discs, not only the contact area between the brake disc 10 and the lining can be increased to increase the friction torque, but also the axial force on the brake disc 10 can be balanced, making the braking structure more stable.

[0103] (vi) The brake device according to the present application brakes the sun gear of the planetary gear set, and the hub of the hub drive assembly containing the brake device is torsionally connected to the carrier of the planetary gear set. Since the planetary gear set functions as a reducer in the hub drive assembly, the braking torque of the brake device is amplified when transmitted to the hub, and the braking efficiency is high.

[0104] Of course, the present application is not limited to the above-mentioned embodiments, and those skilled in the art can make various modifications to the above-mentioned embodiments of the present application under the guidance of the present application without departing from the scope of the present application. For example:

[0105] (i) The inner sleeve P0 can also be part of the sun gear P1 and formed integrally with the sun gear P1.

[0106] (ii) The present application does not limit the number of push rods 42, and the push rod 42 can have more than three, for example.

[0107] (iii) The spring 50 can also not be a wave spring, for example, the spring 50 can also be a disc spring (referred to as a disc spring), and the opening of the disc spring with gradually increasing diameter is arranged towards the brake disc 10, and when the brake disc 10 is in the initial position, the outer peripheral part of the disc spring abuts against the brake disc 10.

Claims

1. A braking device for a wheel hub drive assembly of a vehicle to brake rotating components of the wheel hub drive assembly, the braking device comprising: A housing for fixing to the vehicle frame, the rotating component being rotatable relative to the housing; The inner sleeve (P0) is sleeve-shaped and is used for fixed connection with the rotating component; Brake disc (10) is sleeved on the inner sleeve (P0). The brake disc (10) and the inner sleeve (P0) cannot rotate relative to each other, but can reciprocate relative to the inner sleeve (P0) in the axial direction (A) of the inner sleeve (P0). The friction disc (20) is connected to the housing in a non-rotatable manner and can reciprocate relative to the brake disc (10) in the axial direction (A) to selectively engage and disengage with the brake disc (10); Actuator (40); The brake disc (10) is characterized by having an inner ring (11) located on the inner periphery and an outer ring (12) located on the outer periphery. In the axial direction (A), the thickness of the outer ring (12) is greater than the thickness of the inner ring (11). The outer ring (12) protrudes from the inner ring (11) on one side of the brake disc (10) in the axial direction (A), thereby forming a space in the inner periphery of the outer ring (12) for partially accommodating the actuator (40).

2. The braking device according to claim 1, characterized in that, The friction disc (20) includes a first friction disc (21) and a second friction disc (22) located on two opposite sides of the brake disc (10) along the axial direction (A). The first friction disc (21) is movable relative to the housing in the axial direction (A), while the second friction disc (22) is not movable relative to the housing in the axial direction (A). In the axial direction (A), the first friction disc (21) can be driven to move toward the brake disc (10) and push the brake disc (10) toward the second friction disc (22), so that the brake disc (10) is in frictional engagement with both the first friction disc (21) and the second friction disc (22).

3. The braking device according to claim 2, characterized in that, The braking device also includes a spring (50) that, when the brake disc (10) is engaged with the second friction disc (22), applies a force to the brake disc (10) in the axial direction (A) toward the first friction disc (21).

4. The braking device according to claim 2, characterized in that, The braking device further includes an annular bracket (30), which is fixed to the housing. The first friction disc (21) is splinedly connected to the bracket (30), and the second friction disc (22) is fixedly connected to the bracket (30).

5. The braking device according to claim 4, characterized in that, The braking device further includes a first retaining ring (61), and the bracket (30) includes a splined cylinder (31) and a connecting ring (32). The connecting ring (32) includes a main body (321) and a plurality of insertion portions (322). The main body (321) is annular and connected to the housing. The insertion portions (322) are disposed on the inner circumferential side of the main body (321). A spline structure is formed on the inner peripheral wall of the spline cylinder (31) to cooperate with the first friction disc (21). One end of the spline cylinder (31) forms an insertion port (311) that cooperates with the insertion part (322) to prevent the spline cylinder (31) and the connecting ring (32) from rotating relative to each other. The splined tube (31) is embedded in the inner periphery of the body (321) to be positioned in the radial direction (R) of the body (321). The first retaining ring (61) is embedded in the inner circumference of the splined cylinder (31), and at the insertion port (311), the splined cylinder (31) and the first retaining ring (61) are respectively located on both sides of the axial direction (A) of the insertion part (322), so that the splined cylinder (31) is positioned relative to the connecting ring (32) in the axial direction (A).

6. The braking device according to claim 1, characterized in that, The friction disc (20) includes a tray (201) and a liner (202), the tray (201) being annular, and one or more liners (202) being mounted on one of the trays (201), the liners (202) being positioned toward the brake disc (10).

7. The braking device according to claim 1, characterized in that, The inner sleeve (P0) is splinedly connected to the brake disc (10).

8. The braking device according to claim 1, characterized in that, The brake disc (10) has multiple heat dissipation channels (101) that run radially (R).

9. The braking device according to any one of claims 1 to 8, characterized in that, The actuator (40) is capable of reciprocating along the axial direction (A) to engage or disengage the friction disc (20) from the brake disc (10).

10. The braking device according to claim 9, characterized in that, The actuator (40) includes an annular push ring (41) and a plurality of push rods (42) connected to the push ring (41). The plurality of push rods (42) are distributed circumferentially along the push ring (41), and the push rods (42) can reciprocate in the axial direction (A) under the influence of fluid pressure.

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