CN113353187A

CN113353187A - Brake device

Info

Publication number: CN113353187A
Application number: CN202010153755.0A
Authority: CN
Inventors: 康嘉瑞; 吴少雄
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2020-03-07
Filing date: 2020-03-07
Publication date: 2021-09-07

Abstract

The present invention relates to a brake device. The brake device is used for being installed on a wheel of a vehicle and comprises a pressure plate assembly, a friction disc assembly and a driving mechanism, wherein the pressure plate assembly is used for being connected with a wheel shaft of the wheel in a torsion-resistant mode, and the friction disc assembly is used for being fixedly connected with a wheel rim of the wheel; the pressure plate assembly comprises a first pressure plate and a second pressure plate, the friction disc assembly comprises a first friction disc and a second friction disc, the first pressure plate and the second pressure plate are installed between the first friction disc and the second friction disc in the axial direction, the driving mechanism can drive the first pressure plate and the second pressure plate to move axially simultaneously and abut against the first friction disc and the second friction disc respectively, and when the braking device is installed on a wheel, the pressure plate assembly and the friction disc assembly are located on the same side of the wheel rim in the axial direction. The braking device of the invention can reduce the abrasion and noise of the bearing.

Description

Brake device

Technical Field

The invention relates to the technical field of vehicles. In particular, the present invention relates to a braking device for mounting on a wheel.

Background

Brake devices are important components on a variety of vehicles. In the case of two-wheeled vehicles such as bicycles and motorcycles, the brake device is generally mounted directly on the wheel. Currently, some electric bicycles employ a Center Brake Cylinder (CBC). The centering type brake cylinder is coaxially arranged on one side of the wheel and fixed on the wheel shaft. When a rider presses a brake, the hydraulic mechanism of the brake cylinder drives the pressure plate against a friction disc fixed to the rim, thereby generating a frictional force between the pressure plate and the friction disc to force the wheel to decelerate.

In the prior art brake device shown in fig. 1, the hydraulic mechanism has an annular piston and a hydraulic chamber arranged coaxially with the wheel, the piston being axially displaced under the influence of hydraulic pressure so as to push the pressure plate against the friction disc. The axial pressure acts directly on the friction disc and the rim and is transmitted to the bearing outer ring of the wheel. The bearings supporting the wheel will also be subjected to axial forces. Because the outer ring of the bearing is connected with the rim in an anti-torsion manner, and the inner ring is connected with the wheel shaft in an anti-torsion manner, the outer ring and the inner ring can generate relative displacement in the axial direction through the axial force exerted on the outer ring by the rim, so that noise is caused, the bearing is abraded, and the service life of the bearing is finally shortened. For small vehicles, the axial forces are not too great and therefore do not cause significant wear on the wheel bearings. For vehicles with larger wheel sizes or higher rotational speeds, a correspondingly higher axial pressure is required to brake the vehicle, but this makes the wheel bearings susceptible to wear and noise. The bearings supporting the wheel are not designed to withstand axial forces, but are required to withstand greater axial forces (perhaps up to 10000N in some cases) at higher braking torques and higher decelerations.

In order to solve the above problems, some new double-cylinder brake devices have appeared. The novel design is improved on the basis of the existing middle-type brake cylinder, and two hydraulic mechanisms and two pairs of friction pairs are oppositely arranged on two sides of a wheel. The axial forces generated by the two hydraulic mechanisms act on the rim in opposite directions from the two sides of the rim, and therefore cancel each other out, thereby avoiding the influence on the bearing. However, this design requires two sets of brake devices to be mounted on either side or the same side of the wheel, and is therefore inconvenient and costly.

Disclosure of Invention

The invention is therefore based on the object of providing a brake device which reduces wear and noise.

The above-mentioned technical problem is solved by a brake device according to the present invention. The braking device is intended to be mounted on a wheel of a vehicle, in particular a two-wheeled vehicle. The brake device includes a pressure plate assembly, a friction disc assembly and a drive mechanism. The pressure plate assembly is used for being connected with an axle of a wheel in a torsion-proof mode, the friction disc assembly is used for being fixedly connected with a rim of the wheel, and the rim of the wheel is rotatably supported on the axle. The pressure plate assembly comprises a first pressure plate and a second pressure plate, the friction disc assembly comprises a first friction disc and a second friction disc, and the first pressure plate and the first friction disc, and the second pressure plate and the second friction disc respectively form a friction pair. The first pressure plate and the second pressure plate are mounted between the first friction disc and the second friction disc in the axial direction, and the driving mechanism can drive the first pressure plate and the second pressure plate to move in opposite directions in the axial direction simultaneously to abut against the first friction disc and the second friction disc respectively. When the brake device is mounted on a wheel, the pressure plate assembly and the friction disc assembly are located on the same side of the rim in the axial direction.

Because the pressure plate assembly is arranged between the two friction disks, the pressure plates in the two friction pairs axially press the friction disks in opposite directions, and therefore, when the vehicle brakes, the axial forces applied to the two friction disks which are jointly fixed on the wheel rim are mutually offset. This means that the axial force of the drive mechanism driving the platen assembly is not significantly transmitted to the rim, nor is the bearing supporting the rim subjected to significant axial loads, thereby reducing wear and noise on the bearing and extending the useful life of the bearing. In addition, because two sets of friction pairs are arranged on the same side of the rim, the two sets of friction pairs can be integrated together, and two pressure plates can be driven simultaneously by the same driving mechanism, so that the number of parts can be reduced, and the compactness of the structure can be improved. In this case, the brake device may preferably further comprise a housing for fixed connection to the rim, the first and second friction discs being fixed in the housing, respectively.

According to a preferred embodiment of the present invention, the pressure plate assembly and the friction disc assembly may be arranged coaxially with the axle, respectively, when the brake apparatus is mounted on the wheel. At the moment, the pressure plate and the friction disc are both in circular ring structures, so that pressure which is uniformly distributed around the wheel shaft can be generated, a large uniform friction force can be generated between the pressure plate and the friction disc, and stable braking of a vehicle is facilitated.

According to another preferred embodiment of the invention, a drive mechanism may be mounted axially between the first and second pressure plates to simultaneously drive both pressure plates axially towards both sides to abut the respective friction discs. Preferably, the drive mechanism may be a hydraulic drive mechanism comprising a cylinder having an axially extending cavity, a first piston and a second piston, respectively, axially slidably mounted in the cavity and axially abutting the first and second pressure plates, respectively. Further preferably, the drive mechanism may comprise a hydraulic chamber formed in the cavity between the first piston and the second piston. The two pressing plates are under the action of the liquid pressure in the same hydraulic cavity, so that the driving mechanism can drive the two pressing plates to move axially at the same time.

According to another preferred embodiment of the present invention, the cylinder may have an inlet hole penetrating the cylinder and communicating with the hydraulic pressure chamber at an axially middle portion of the cylinder. When hydraulic fluid is supplied from the inlet hole to the hydraulic chamber, the hydraulic pressure in the hydraulic chamber increases, thereby pushing the two pressure plates to move toward the corresponding friction disks on both sides.

According to another preferred embodiment of the present invention, the cylinder body may further include an outer ring and an inner ring fixedly connected to each other, the outer ring being coaxially mounted on a radially outer side of the inner ring, the inner ring being adapted to be fixed on a radially outer side of the wheel shaft, the cavity of the cylinder body being formed radially between the outer ring and the inner ring. Therefore, the drive mechanism is also formed as an annular structure arranged coaxially with the rim, so that the platen can be smoothly urged to move in the axial direction.

According to a further preferred embodiment of the invention, the first pressure plate and the second pressure plate can each be mounted in a rotationally fixed manner radially outside the inner ring and in turn be rotationally fixed to the wheel axle via the inner ring, while the outer ring is situated axially between the first pressure plate and the second pressure plate.

According to another preferred embodiment of the present invention, the braking device may further include a return spring axially connected between the first pressure plate and the second pressure plate. When hydraulic fluid in the hydraulic driving mechanism is discharged, the extrusion force generated by the driving mechanism to the two pressure plates and pushed towards the two axial sides is reduced, and the reset spring pulls the pressure plates on the two sides to move towards each other through the elastic force of the reset spring to be far away from the corresponding friction disc, so that the braking is released.

Drawings

The invention is further described below with reference to the accompanying drawings. Identical reference numbers in the figures denote functionally identical elements. Wherein:

fig. 1 shows a schematic view of a braking device according to the prior art when mounted on a wheel; and

fig. 2 shows a schematic view of a brake apparatus according to an embodiment of the present invention when mounted on a wheel.

Detailed Description

Hereinafter, a specific embodiment of the braking apparatus according to the present invention will be described with reference to the accompanying drawings. The following detailed description and drawings are included to illustrate the principles of the invention, which is not to be limited to the preferred embodiments described, but is to be defined by the appended claims.

According to an embodiment of the present invention, there is provided a brake apparatus for a vehicle, which is suitable for various vehicles, particularly two-wheeled vehicles, such as bicycles, motorcycles, electric scooters, and the like. Fig. 2 shows a schematic view of a brake apparatus according to an embodiment of the present invention when mounted on a wheel.

As shown, the rim 10 of the wheel is rotatably supported on the axle 20, for example by two bearings 30. The brake device is coaxially mounted on the radial outer side of the wheel shaft 20 on one axial side of the rim 10. The brake apparatus includes a pressure plate assembly 40, a friction disc assembly 50, a drive mechanism 60, and a housing 70.

The housing 70 comprises an annular housing plate 71 and a housing cover 72 which are bolted to each other and to the rim 10. The other components of the brake are mounted within the housing 70. The pressure plate assembly 40 comprises a first pressure plate 41 and a second pressure plate 42, both of which have identical annular configurations and are each arranged coaxially with the rim 10. The friction disc assembly 50 comprises a first friction disc 51 and a second friction disc 52, each also having substantially the same annular configuration and each arranged coaxially with the rim 10. The first friction disk 51 is fixed to the housing plate 71, and the second friction disk 52 is fixed to the housing cover 72. The two pressure plates of the pressure plate assembly 40 are axially located between the two friction disks, with the first pressure plate 41 being axially closer to the first friction disk 51 and the second pressure plate 42 being axially closer to the second friction disk 52. The first pressure plate 41 and the first friction disk 51, and the second pressure plate 42 and the second friction disk 52 may form a friction pair, respectively.

The drive mechanism 60 is installed between the axial directions of the two pressure plates. The drive mechanism 60 is a hydraulic drive mechanism including a cylinder block, a first piston 63, and a second piston 64, which are coaxially arranged. Wherein the cylinder body is constituted by an inner ring 61 and an outer ring 62 fixedly connected (preferably integrally formed) to each other, the inner ring 61 being fixed on the radially outer side of the wheel shaft 20, the outer ring 62 being coaxially arranged on the radially outer side of the inner ring 61, an annular cavity being formed between the outer ring 62 and the inner ring 61. The inner race 61 and the outer race 62 are connected to each other at an axially intermediate portion, preferably an axially central point, by radially extending connecting plates or ribs, thereby forming one body. The connecting plate or the connecting rib divides the cavity into two parts in the axial direction, and the two parts can be communicated with each other through the pore passages on the connecting plate or the gaps between the connecting ribs. Annular first and

second pistons

63 and 64 are mounted in the cavity on either axial side of the connecting plate or rib, respectively, and are each able to slide axially in the cavity. The first piston 63 and the second piston 64 have identical shapes and dimensions and are arranged symmetrically about the axial midpoint of the cavity, forming an annular hydraulic chamber 67 between them. Although the hydraulic chamber 67 is divided into two parts in the axial direction by the connecting plate or the connecting rib, the two parts are communicated with each other and thus have the same hydraulic pressure, and can be regarded as the same hydraulic chamber. The first and

second pistons

63 and 64 are respectively provided with annular first and

second seals

65 and 66 at respective opposite ends thereof to prevent the hydraulic fluid in the hydraulic chamber 67 from leaking through the pistons. The first seal 65 and the second seal 66 also have identical shapes and dimensions. An inlet hole 68 is formed in the inner ring 61. The liquid inlet hole 68 extends from the end of the inner ring 61 facing away from the rim 10 to an axially intermediate portion, preferably an axially midpoint, of the outer peripheral surface of the inner ring 61 so as to communicate with the hydraulic pressure chamber 67. The opposite ends of the first and

second pistons

63, 64 may extend partially out of the cavity and abut axially against the first and

second pressure plates

41, 42 respectively, thereby urging the pressure plates towards the respective friction discs as the pistons slide axially outwardly in the cavity.

A plurality of return springs 80 are mounted between the two pressure plates. These return springs 80 may be in the form of coil springs, and each return spring 80 is axially connected between the first pressure plate 41 and the second pressure plate 42, and both axial ends thereof are fixed to the pressure plates on both sides, respectively. These return springs 80 are evenly distributed radially outward of the outer race 62 in the circumferential direction. In the mounted state, the return spring 80 is in a stretched state, and generates an elastic force that tends to bring the first presser plate 41 and the second presser plate 42 closer to each other.

Hydraulic fluid may enter and exit the hydraulic chamber 67 through the inlet openings 68, depending on the rider's control of the brakes. When the rider is not pressing the brake, no hydraulic fluid flows into the hydraulic chamber 67 through the inlet holes 68. At this time, the hydraulic pressure generated in the hydraulic pressure chamber 67 is small, and the first pressure plate 41 and the second pressure plate 42 are held at positions close to each other by the tensile force of the return spring 80, thereby being away from the first friction disk 51 and the second friction disk 52 on both sides, respectively. Therefore, the friction pairs on both sides are not engaged, the rim 10 can rotate freely relative to the wheel axle 20, and the vehicle can run normally. When the rider pushes the brake, hydraulic fluid may be injected into the hydraulic chamber 67 through the fluid inlet hole 68, so that the hydraulic pressure in the hydraulic chamber 67 is increased. At this time, the hydraulic fluid in the hydraulic chamber 67 generates substantially equal axial pressure to the two piston assemblies on both sides, so that the first pressure plate 41 and the second pressure plate 42 are moved toward the opposite axial ends against the pulling force of the return spring 80 simultaneously under the pushing of the pistons until abutting with the corresponding first friction disk 51 and the second friction disk 52. Under the action of the hydraulic pressure, the first pressure plate 41 and the first friction disk 51 and the second pressure plate 42 and the second friction disk 52 are respectively and tightly combined together to form two pairs of friction pairs, so that a friction action is generated between the wheel axle 20 and the shell 70 and further between the wheel axle 20 and the rim 10, the kinetic energy is converted into internal energy, the kinetic energy of the vehicle is reduced, and the vehicle is braked. When the vehicle brakes, the driving mechanism 60 drives the two pressure plates to opposite sides simultaneously, so that the axial pressure applied to the friction plates on the two sides is opposite in direction and approximately equal in magnitude, and the two friction plates are fixed on the rim 10 through the housing 70, so that the axial engaging force generated by the driving mechanism 60 on the braking mechanism is cancelled out on the housing 70, and no obvious axial force is transmitted to the rim 10. This allows the bearings 30 supporting the rim 10 to be subjected to no significant axial loads, thereby avoiding wear and noise in the bearings 30 and extending the useful life of the bearings 30.

Although possible embodiments have been described by way of example in the above description, it should be understood that numerous embodiment variations exist, still by way of combination of all technical features and embodiments that are known and that are obvious to a person skilled in the art. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. From the foregoing description, one of ordinary skill in the art will more particularly provide a technical guide to convert at least one exemplary embodiment, wherein various changes may be made, particularly in matters of function and structure of the components described, without departing from the scope of the following claims.

List of reference numerals

10 wheel rim

20 wheel axle

30 bearing

40 platen assembly

41 first pressing plate

42 second pressure plate

50 friction disc assembly

51 first friction disk

52 second friction disk

60 drive mechanism

61 inner ring

62 outer ring

63 first piston

64 second piston

65 first seal

66 second seal

67 hydraulic chamber

68 liquid inlet hole

70 casing

71 casing plate

72 casing cover

80 return spring

Claims

1. A brake device for mounting on a wheel of a vehicle, the brake device comprising a pressure plate assembly (40), a friction disc assembly (50) and a drive mechanism (60), the pressure plate assembly (40) being for non-rotatable connection with an axle (20) of the wheel, the friction disc assembly (50) being for fixed connection with a rim (10) of the wheel,

it is characterized in that the preparation method is characterized in that,

the pressure plate assembly (40) comprises a first pressure plate (41) and a second pressure plate (42), the friction plate assembly (50) comprises a first friction disc (51) and a second friction disc (52), the first pressure plate (41) and the second pressure plate (42) are installed between the first friction disc (51) and the second friction disc (52) in the axial direction, the driving mechanism (60) can drive the first pressure plate (41) and the second pressure plate (42) to move in opposite directions in the axial direction to abut against the first friction disc (51) and the second friction disc (52) respectively, and when the braking device is installed on the wheel, the pressure plate assembly (40) and the friction plate assembly (50) are located on the same side of the wheel rim (10) in the axial direction.

2. A braking device according to claim 1, characterized in that the pressure plate assembly (40) and the friction disc assembly (50) are each arranged coaxially with the wheel axle (20) when the braking device is mounted on the wheel.

3. A braking device according to claim 2, characterized in that the drive mechanism (60) is mounted axially between the first pressure plate (41) and the second pressure plate (42).

4. A braking device according to claim 3, characterized in that the drive mechanism (60) is a hydraulic drive mechanism comprising a cylinder having an axially extending cavity, a first piston (63) and a second piston (64), the first piston (63) and the second piston (64) being axially slidably mounted in the cavity and axially abutting the first pressure plate (41) and the second pressure plate (42), respectively.

5. A braking arrangement according to claim 4, characterised in that the drive mechanism (60) comprises a hydraulic chamber (67), the hydraulic chamber (67) being formed in the cavity between the first piston (63) and the second piston (64).

6. A braking apparatus in accordance with claim 5, characterized in that the cylinder has an inlet opening (68), which inlet opening (68) extends through the cylinder and communicates with the hydraulic chamber (67) in the axial middle of the cylinder.

7. A braking device according to claim 6, characterised in that the cylinder comprises an outer ring (62) and an inner ring (61) fixedly connected to each other, the outer ring (62) being mounted coaxially on the radially outer side of the inner ring (61), the inner ring (61) being intended to be fixed on the radially outer side of the wheel axle (20), the cavity being formed radially between the outer ring (62) and the inner ring (61).

8. Brake apparatus according to claim 7, wherein the first pressure plate (41) and the second pressure plate (42) are each mounted in a rotationally fixed manner radially outside the inner ring (61), the outer ring (62) being located axially between the first pressure plate (41) and the second pressure plate (42).

9. A braking device according to claim 4, characterized in that it further comprises a return spring (80), said return spring (80) being axially connected between said first pressure plate (41) and said second pressure plate (42).

10. A braking device according to any one of claims 1 to 9, characterised in that the braking device comprises a housing (70) for fixed connection with the rim (10), the first and second friction discs (51, 52) being fixed respectively in the housing (70).