阅读说明：本技术 用于轮内驱动总成的鼓式制动器 (Drum brake for in-wheel drive assembly ) 是由 王荣偲 于 2020-06-22 设计创作，主要内容包括：本发明提供一种用于轮内驱动总成的鼓式制动器,其包括制动鼓(10)、制动执行器和制动衬片(20),所述制动鼓(10)呈筒形并具有中空的内腔,所述制动执行器设置于所述内腔,所述制动执行器包括制动执行片(30),所述制动执行片(30)能在所述径向(R)上移动以靠近或远离所述制动鼓(10)的周壁,所述制动衬片(20)安装于所述制动执行片(30),所述制动鼓(10)的轴向上的端壁具有在所述轴向(A)上贯通的轴向通气区(F1),所述轴向通气区(F1)能使空气轴向地穿过所述内腔以利于所述鼓式制动器散热。根据本发明的鼓式制动器结构简单、散热效果好。(The invention provides a drum brake for an in-wheel drive assembly, which comprises a brake drum (10), a brake actuator and a brake lining (20), wherein the brake drum (10) is cylindrical and provided with a hollow inner cavity, the brake actuator is arranged in the inner cavity, the brake actuator comprises a brake actuating sheet (30), the brake actuating sheet (30) can move in the radial direction (R) to be close to or far away from the peripheral wall of the brake drum (10), the brake lining (20) is mounted on the brake actuating sheet (30), the axial end wall of the brake drum (10) is provided with an axial ventilation area (F1) penetrating in the axial direction (A), and the axial ventilation area (F1) can enable air to axially pass through the inner cavity to facilitate heat dissipation of the drum brake. The drum brake has the advantages of simple structure and good heat dissipation effect.)

1. A drum brake for an in-wheel drive assembly having a radial direction (R), an axial direction (A) and a circumferential direction and comprising a brake drum (10), a brake actuator and a brake lining (20), the brake drum (10) being cylindrical and having a hollow interior, the brake actuator being provided in the interior, the brake actuator comprising a brake actuating plate (30), the brake actuating plate (30) being movable in the radial direction (R) to be close to or away from a circumferential wall of the brake drum (10), the brake lining (20) being mounted to the brake actuating plate (30), wherein,

the axial end wall of the brake drum (10) has an axial ventilation zone (F1) passing through in the axial direction (A), the axial ventilation zone (F1) enabling air to pass axially through the inner cavity to facilitate heat dissipation of the drum brake.

2. The drum brake according to claim 1, characterized in that said axial ventilation zone (F1) has a plurality of first blades (F10), said first blades (F10) being non-parallel to a plane perpendicular to said axial direction (a), so that said first blades (F10) can force air axially through said inner cavity during the following rotation of said brake drum (10).

3. A drum brake according to claim 1, characterized in that the peripheral wall of the brake drum (10) has a radial venting zone (F2) passing through in the radial direction (R), said radial venting zone (F2) enabling air to flow radially into or out of the inner cavity.

4. A drum brake according to claim 3, in which the radial ventilation zone (F2) has a plurality of second blades (F20), the second blades (F20) being angled with respect to the circumferential wall of the brake drum (10) so that the second blades (F20) can cause air to flow radially into or out of the internal cavity during rotation with the brake drum (10).

5. A drum brake according to any one of claims 1 to 4, characterized in that the brake drum (10) comprises a cylindrical drum shell (11) and a disc-shaped drum cover (12),

the shell (11) includes a shell end wall (111) located at an end of the brake drum (10) in the axial direction (A) and a shell peripheral wall (112) surrounding the shell end wall (111),

the drum cover (12) is connected to an axial opening of the drum peripheral wall (112) away from the drum end wall (111).

6. A drum brake according to claim 3 or 4, characterized in that the region of said brake actuation plate (30) adjacent to said radial venting zone (F2) in said axial direction (A) and in said circumferential direction is provided with a plurality of venting holes (31) passing through in said radial direction (R), said venting holes (31) being at least partially unobstructed by said brake lining (20).

7. A drum brake according to claim 6, in which said radial venting zone (F2) is located in a central region of said peripheral wall in said axial direction (A), said venting hole (31) is located in a central region of said brake actuation plate (30) in said axial direction (A),

the brake lining (20) on each brake actuating plate (30) comprises two sub-linings, namely a first lining (21) and a second lining (22), wherein the first lining (21) and the second lining (22) are arranged at intervals in the axial direction (A).

8. A drum brake according to any one of claims 1 to 4, characterized in that the inner cavity of the brake drum (10) is provided with two brake actuators which can perform a braking action simultaneously or not.

9. The drum brake of claim 8, wherein the two brake actuators are a primary brake actuator and a secondary brake actuator,

when the temperature of the brake drum (10) is less than a critical temperature, the braking action of the drum brake is performed only by the main brake actuator;

when the temperature of the brake drum (10) is greater than or equal to the threshold temperature, the secondary brake actuator participates in the braking action of the drum brake.

10. The drum brake of claim 9, wherein the surface area of the brake actuating plate of the primary brake actuator is greater than the surface area of the brake actuating plate of the secondary brake actuator, and the surface area of the brake lining provided to the primary brake actuator is greater than the surface area of the brake lining provided to the secondary brake actuator.

Technical Field

The present invention relates to the field of brakes, In particular drum brakes for In-wheel drive assemblies (IWDs) of vehicles.

Background

For in-wheel drive assemblies (also called hub drive assemblies) of vehicles, reference may be made, for example, to chinese patent publication CN105691102A, in which the brakes of the wheels are integrated in the hub drive. Drum brakes typically include a brake drum, brake pads, and a brake actuator. The brake drum being rotatable relative to the brake lining when the brake drum is not performing a braking action; when the brake actuator performs a braking action, the brake pads are pushed by the brake actuator into contact with the brake drum, thereby braking the hub under the influence of friction.

Because the drum brake is arranged in the shell of the in-wheel drive assembly, the space where the brake is located is relatively closed and limited in size, the mutual friction between the brake lining and the brake drum generates larger heat, and the volume of the brake drum is limited and the mass of the brake drum is smaller, so that the brake drum is easy to generate larger temperature rise in the braking process, and further the temperature rise of the brake and even the temperature rise of the whole in-wheel drive assembly is brought. The above-mentioned temperature increase not only adversely affects the safety of the brake system, but may also lead to failure of, for example, seals in the in-wheel drive assembly and other undesirable consequences.

Disclosure of Invention

The present invention aims to overcome or at least alleviate the above-mentioned deficiencies of the prior art and to provide a drum brake for an in-wheel drive assembly which effectively solves the problem of excessive temperature when the drum brake is braking.

The present invention provides a drum brake for an in-wheel drive assembly, having radial, axial and circumferential directions and comprising a brake drum having a cylindrical shape and a hollow inner cavity, a brake actuator provided in the inner cavity, the brake actuator including a brake actuating plate movable in the radial direction so as to be close to or away from a circumferential wall of the brake drum, and a brake lining mounted to the brake actuating plate, wherein,

the axial end wall of the brake drum has an axial ventilation zone running through in the axial direction, the axial ventilation zone enabling air to pass axially through the inner cavity to facilitate heat dissipation of the drum brake.

In at least one embodiment, the axial ventilation zone has a plurality of first blades that are non-parallel to a plane perpendicular to the axial direction such that the first blades urge air axially through the internal cavity during rotation with the brake drum.

In at least one embodiment, the circumferential wall of the brake drum has a radial ventilation zone running through in the radial direction, which enables air to flow radially into or out of the inner cavity.

In at least one embodiment, the radial ventilation zone has a plurality of second blades that are angled with respect to the circumferential wall of the brake drum such that the second blades urge air radially into or out of the internal cavity during rotation with the brake drum.

In at least one embodiment, the brake drum includes a cylindrical shell and a disc-shaped drum cover,

the shell includes a shell end wall located at an end of the brake drum in the axial direction and a shell peripheral wall surrounding the shell end wall,

the drum cover is connected to an axial opening of the drum peripheral wall remote from the drum end wall.

In at least one embodiment, a region of the brake actuation plate adjacent to the radial ventilation zone in the axial direction and the circumferential direction is provided with a plurality of ventilation holes penetrating in the radial direction, the ventilation holes being at least partially unobstructed by the brake lining.

In at least one embodiment, the radial ventilation zone is located at a central region of the peripheral wall in the axial direction, the ventilation hole is located at a central region of the brake actuation plate in the axial direction,

the brake lining on each of the brake actuation plates includes two sub-linings, a first lining and a second lining, respectively, which are disposed at a distance in the axial direction.

In at least one embodiment, the interior cavity of the brake drum is provided with two of the brake actuators, which are capable of performing braking actions simultaneously or not.

In at least one embodiment, the two brake actuators are a primary brake actuator and a secondary brake actuator,

when the temperature of the brake drum is less than a critical temperature, the braking action of the drum brake is performed only by the main brake actuator;

when the temperature of the brake drum is greater than or equal to the threshold temperature, the secondary brake actuator participates in the braking action of the drum brake.

In at least one embodiment, the surface area of the brake actuating pad of the primary brake actuator is greater than the surface area of the brake actuating pad of the secondary brake actuator, and the surface area of the brake lining provided to the primary brake actuator is greater than the surface area of the brake lining provided to the secondary brake actuator.

The drum brake for the in-wheel drive assembly is simple in structure and good in heat dissipation effect.

Drawings

Fig. 1 is a schematic perspective view of a drum brake according to an embodiment of the present invention.

Fig. 2 is a sectional view in the axial direction of fig. 1.

Fig. 3 is a side view of fig. 1.

Fig. 4 is a front view of fig. 1.

Fig. 5 is a rear view of fig. 1.

Description of reference numerals:

10, braking the drum; 11 a drum body; 111 a drum end wall; 112 a shell peripheral wall; 12, a drum cover;

f10 a first fan blade; f20 second fan blade; f1 axial ventilation zone; f2 radial ventilation zone;

20 a brake lining; 21 a first liner; 22 a second liner;

30 brake actuation pads; 31 a vent hole; 40, screws; 50 a main shaft; and 60, connecting a screw with the rotating shaft.

Detailed Description

Exemplary embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the detailed description is intended only to teach one skilled in the art how to practice the invention, and is not intended to be exhaustive or to limit the scope of the invention.

With reference to fig. 1 to 5, a detailed structure of a drum brake for an in-wheel drive assembly according to the present invention will be described. Hereinafter, referring to fig. 2, a indicates the axial direction of the drum brake, the axial direction a coinciding with the axial direction of the main shaft 50, R indicates the radial direction of the drum brake, and the radial direction R coinciding with the radial direction of the main shaft 50, unless otherwise specified.

The drum brake according to the present invention may be used, for example, in an in-wheel drive assembly of a vehicle, which may be arranged between a main shaft 50 and a hub for controlling the rotation of the hub relative to the main shaft 50 (see fig. 2, the main shaft does not rotate relative to the frame).

A drum brake according to the present invention includes a brake drum 10, a brake lining 20, and a brake actuator. The brake drum 10 is connected in a rotationally fixed (non-rotatable manner) to a shaft (not shown) which drives the hub in rotation. The brake actuator is connected in a rotationally fixed manner with respect to the spindle 50 (or with respect to the vehicle frame), and the brake lining 20 is arranged on the outer circumference of the brake actuator.

It is worth noting that the spindle and the frame are not shown in the drawings. Referring to fig. 2, a rotating shaft may be fitted around the outer periphery of the main shaft 50, for example, and the rotating shaft receives torque transmitted from a transmission gear, and the brake drum 10 may be non-rotatably coupled to the rotating shaft by a rotating shaft coupling screw 60, for example. The brake actuator is accommodated in the inner cavity of the brake drum 10, and the brake actuator is fixed by, for example: in the first mode, the brake actuator is connected to the spindle 50 in a rotationally fixed manner; in the second mode, the brake actuator is sleeved on the outer periphery of the main shaft 50 and is connected with a bracket (not shown, for example, an annular gap for the bracket to pass through can be reserved between the inner peripheral edge of the drum cover 12 shown in fig. 2 and the main shaft 50) passing through the brake drum 10 along the axial direction a in a torsion-proof manner, and the bracket passes through the brake drum 10 and is fixed on the vehicle frame.

The brake drum 10 includes a drum shell 11 having a cylindrical shape and a drum cover 12 having a disk shape. The shell 11 includes a shell end wall 111 at an end in the axial direction a and a shell peripheral wall 112 connected to an outer peripheral edge of the shell end wall 111. The radially inner side of the drum end wall 111 has an opening for the spindle 50 to pass through. The drum cover 12 can be attached to an opening of the drum peripheral wall 112 by, for example, screws 40, so that the drum end wall 111 and the drum cover 12 serve as two axial end walls of the brake drum 10, respectively. The radially inner side of the drum cover 12 has an opening for passing the spindle 50 therethrough.

The brake actuator includes a brake actuating plate 30, the brake actuating plate 30 having an arcuate shape and being disposed radially inward of the brake drum 10, and a length of the brake actuating plate 30 in the axial direction a is slightly smaller than a length of the drum body peripheral wall 112 in the axial direction a. In the present embodiment, one brake actuator is provided inside one brake drum 10, and one brake actuator includes two brake actuation pieces 30, and the two brake actuation pieces 30 are spaced apart in the circumferential direction. The brake actuating plate 30 can controllably reciprocate a small distance in the radial direction R to approach or separate from the drum peripheral wall 112.

The brake lining 20 is attached to the outer peripheral surface of the brake actuating piece 30. When the drum brake is in a non-braking state, the brake actuating plate 30 is located at an initial position where the brake lining 20 is not in contact with the brake drum 10; when the drum brake performs a braking action, the brake actuation piece 30 moves radially outward of the initial position until the brake lining 20 contacts the drum body peripheral wall 112 of the brake drum 10, the brake lining 20 provides damping so as to gradually decelerate the brake drum 10, and the braking force of the brake actuation piece 30 applied to the drum body peripheral wall 112 by the brake lining 20 can be adjusted.

To facilitate heat dissipation of the brake drum 10, both the drum end wall 111 and the drum cover 12 have openings therethrough in the axial direction a, thereby forming an axial ventilation area F1 (see fig. 4) in the drum end wall 111 and an axial ventilation area F1 (see fig. 5) in the drum cover 12, respectively.

Preferably, the axial ventilation zone F1 has a plurality of first blades F10, the first blades F10 being non-parallel to the plane perpendicular to the axial direction a. Thus, as the brake drum 10 rotates about the spindle 50, the first fan blades F10 agitate the air during rotation to cause an airflow to pass axially through the brake drum 10. For example, referring to FIG. 2, the hollow arrows schematically illustrate one instance of airflow through the brake drum 10. When the vehicle moves forward, the brake drum 10 rotates forward, which drives the first fan blades F10 to rotate forward, so that the air flow flows into the inner cavity of the brake drum 10 from the outside of the brake drum 10 through the axial ventilation area F1 located on the drum cover 12 in the axial direction a, and the air flow entering the inner cavity of the brake drum 10 further flows out of the brake drum 10 through the axial ventilation area F1 located on the drum body end wall 111. When the vehicle moves backwards, the brake drum 10 rotates reversely, the first fan blades F10 are driven to rotate reversely, the air flow flows into the brake drum 10 from the axial ventilation area F1 on the drum body end wall 111 in the axial direction a, and flows out of the brake drum 10 from the axial ventilation area F1 on the drum cover 12; of course, as known to those skilled in the art, the vehicle is usually at a lower speed when backing up, and the amount of heat generated by braking is also smaller, so that the specific design of the first blade F10 does not need to consider heat dissipation during braking when backing up.

Preferably, the drum peripheral wall 112 has an opening penetrating in the radial direction R, so that a radial ventilation zone F2 arranged in the circumferential direction is formed on the drum peripheral wall 112.

Preferably, the radial ventilation zone F2 has a plurality of second blades F20, the second blades F20 forming an angle with the peripheral wall of the drum peripheral wall 112. Thus, as the brake drum 10 rotates about the spindle 50, the second fan blades F20 agitate the air during rotation to cause an airflow radially through the brake drum 10. For example, referring to FIG. 2, when the vehicle is moving forward, the brake drum 10 rotates in a forward direction, which causes the second fan blades F20 to rotate in a forward direction, causing air located in the interior cavity of the brake drum 10 to flow out of the brake drum 10.

Since the inner peripheral side of the drum body peripheral wall 112 is provided with the brake actuation piece 30, in order to reduce the obstruction of the airflow passing radially through the drum body peripheral wall 112 by the brake actuation piece 30, it is preferable to provide a plurality of vent holes 31 arranged in the circumferential direction on the brake actuation piece 30. The vent hole 31 is located in the vicinity of the radial vent region F2 in both the circumferential direction and the axial direction, and the vent hole 31 is at least partially unobstructed by the brake lining 20.

In the present embodiment, the radial ventilation zone F2 is located at an axially intermediate position of the drum peripheral wall 112; the vent hole 31 is located at the axial middle position of the brake actuation plate 30; the brake lining 20 on each brake actuation plate 30 includes two sub-linings, a first lining 21 and a second lining 22, respectively, the first lining 21 and the second lining 22 being spaced apart in the axial direction a to avoid obscuring the radial ventilation zone F2 and the ventilation hole 31.

The above-described positions of the radial ventilation areas F2, the ventilation holes 31, the first lining 21, and the second lining 22 are set so that the drum brake as a whole is substantially symmetrical in the axial direction a, which also results in a better balance of the drum brake.

It should be understood that the radial ventilation areas F2 and the ventilation holes 31 may not be provided in the axial middle of the drum brake, for example, one radial ventilation area F2 may be provided at each of the axial ends of the drum peripheral wall 112, and the brake actuation piece 30 may be arranged in the axial middle area of the drum brake together with the brake lining 20 without obstructing the radial ventilation areas F2 at both ends. Of course, the present invention is not limited to the number and the arrangement positions of the radial ventilation areas F2, the ventilation holes 31, and the brake pads 20.

In another possible embodiment, two brake actuators are provided inside one brake drum 10. The two brake actuators are arranged next to each other in the axial direction a, for example. The two brake actuators can be independently controlled, and when the drum brake applies the brake, the two brake actuators can simultaneously execute the brake action, or only one of the two brake actuators can be selected to execute the brake action. The specific selection of which brake actuator is used to perform the braking operation can be determined according to the heating condition of the brake drum 10.

For example, one of the two brake actuators is a primary brake actuator and the other is a secondary brake actuator. Acquiring the real-time temperature of the brake drum 10, and executing a braking action by the main brake actuator and not executing a braking action by the auxiliary brake actuator when the temperature of the brake drum 10 is less than a set critical temperature; when the temperature of the brake drum 10 is greater than or equal to the threshold temperature, the sub-brake actuator performs a braking action, and at this time, the main brake actuator may reduce the braking force (reduce the force with which the brake actuator pushes the brake lining radially), or the main brake actuator may perform a braking action intermittently, or the main brake actuator does not perform a braking action.

Preferably, the surface area of the brake actuation plate of the main brake actuator is greater than the surface area of the brake actuation plate of the auxiliary brake actuator, and the surface area of the brake lining provided to the main brake actuator is greater than the surface area of the brake lining provided to the auxiliary brake actuator.

The invention has at least one of the following advantages:

(i) the brake drum 10 according to the present invention has an axial venting area F1 to facilitate heat dissipation. And more preferably, the axial ventilation zone F1 has first fan blades F10, the first fan blades F10 agitate the air during rotation of the brake drum 10 to facilitate airflow axially through the brake drum 10 to promote heat dissipation.

(ii) The brake drum 10 according to the present invention has a radial ventilation zone F2 to facilitate heat dissipation. And more preferably, the radial ventilation zone F2 has second fan blades F20, the second fan blades F20 agitate the air during rotation of the brake drum 10 to facilitate airflow radially through the brake drum 10 to promote heat dissipation.

(iii) The brake drum 10 comprises a drum body 11 and a drum cover 12, the drum cover 12 not only increases the mass of the brake drum 10 so that the brake drum 10 can absorb more heat and cannot be heated too fast, but also makes the brake drum 10 more symmetrical in the axial direction A so that the brake drum 10 has better balance in the rotating process.

(iv) A drum brake according to the present invention may have two brake actuators, the brake actuator currently performing the braking action being selected according to the temperature of the brake drum 10, which is advantageous for controlling the temperature rise of the brake drum 10.

(v) In comparison with drum brakes of the prior art, the drum brake according to the invention can have a suitably enlarged axial dimension, i.e. the parts of the drum brake have a suitably enlarged axial dimension: the increase in the axial dimension of the brake drum 10 allows the brake drum 10 to have a greater mass to absorb more heat; the increase in the axial dimension of the brake lining provides a larger friction braking area, a larger area of friction heating and a more distributed heat generation by friction.

Of course, the present invention is not limited to the above-described embodiments, and those skilled in the art can make various modifications to the above-described embodiments of the present invention without departing from the scope of the present invention under the teaching of the present invention.