GB1580752A

GB1580752A - Disc brake more particularly for motor vehicles

Info

Publication number: GB1580752A
Application number: GB1267277A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-03-25
Filing date: 1977-03-25
Publication date: 1980-12-03

Description

(54) DISC BRAKE, MORE PARTICULARLY FOR MOTOR VEHICLES (71) I, HERMANN KLAUE, a German citizen of Tour d'Ivoire 24e, Montreux, Switzerland, do hereby declare the invention for which I pray that a Patent may be granted to me and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to disc brakes for motor vehicles.

The object of the invention is to provide a disc brake more particularly for private motor vehicles, wherein heat received by a brake housing is dissipated to the air very rapidly and thermal and mechanical stressing of a hydraulic actuator is reduced, with no impairment of brake accessibility and ease of lining replacement.

According to the invention there is provided a disc brake for motor vehicles comprising a rotatable externally open, radially ribbed brake housing and a stationary brake carrier disposed over the brake housing, annular brake lining discs suspended on the brake carrier and fixed in the circumferential direction but freely movable axially, said brake housing being formed of two annular parts inter-connected only by way of radially inwardly projecting yoke-shaped extensions integral with each housing part, said extensions being circumferentially spaced to provide an opening between adjacent extensions, the brake housing being attachable to a wheel hub by means comprising screws which in a wheel and brake assembly, connect the yoke-shaped housing extensions to radially outwardly projecting extensions of the hub said yoke-shaped housing extensions being circumferentially spaced from bolts which attach the wheel to flange, of the hub and a hydraulic actuating device disposed between the brake lining discs, said device having two stepped rings, which act on the respective brake lining discs by way of axial extensions disposed on the same circle of action as the steps of the stepped rings.

The brake construction according to the invention ensures that cooling air flows uniformly around the brake housing.

Because the same is ventilated uniformly, heat stressing is uniformly distributed between the two parts of the brake housing. Air reaches the brake interior by way of the openings between the yoke-shaped housing extension members and can pass through the gaps bounded by the stepped rings, the axial extensions thereof and the brake discs to reach the outside, the air flow cooling the hydraulic actuating device. The axial extensions of the stepped rings, which extensions transmit pressure to the brake lining discs which are arranged at the places where the steps of the two stepped rings are located, transmit the brake-applying pressures over the same effective circle on both sides; consequently, a brake application does not produce any torque tending to twist the hydraulic actuating device.

In a motor vehicle wheel assembly incorporating a disc brake of the invention, the attachment of the yoke-shaped housing extension members is advantageously effected on radial extension members on the wheel hub which are axially offset with respect to the wheel-side face surface of the wheel hub flange. This feature further increases the open cross-section for cooling air.

According to another preferred feature of the invention, the step between the rings of the hydraulic actuating device is Z-shaped in cross section whereby the width, necessary for the wear path, of the inner cylindrical surface of the outer stepped ring associated with an inner sealing ring and the width, necessary for the wear path, of the outer cylindrical surface of the inner stepped ring associated with an outer sealing ring lie, when the brake is new, in the same axial region of the actuating device. This feature helps to reduce brake width and therefore weight.

Embodiments of the invention are shown in the accompanying drawings in which: Figure 1 is a longitudinal section of one embodiment of the invention for a driven front wheel taken along the line A-B of Figure 2; Figure 2 is a side elevation looking from the inside of the wheel in the upper one-half and is divided into two partial cross-sections taken along the lines C-D and E-F of Figure 1 in the lower one-half.

Figure 3 is an enlarged longitudinal section through one-half of the embodiment of Figure 1; Figure 3a is a plan view of that portion of the embodiment of Figure 3 marked "Z".

Figure 4 is a partial longitudinal section of a second embodiment of the invention; and Figure 5 is an enlarged fragmentary view taken along the line G-H of Figure 4.

Referring to Figures 1 to 3 of the drawings, there can be seen a wheel 1 and a stationary combined wheel carrier and brake carrier 2; for the latter purpose the carrier 2 has two extensions 2. A two-part radially ribbed rotatable brake housing 31, 32 carried by hub 4 and connected thereto as later described, carrier 2 being disposed over the brake housing. Hub 4 is mounted in carrier 2 on a double-row ball-bearing 6. Wheel 1 is connected to ring flange part 41 of hub 4 by wheel bolts 7. The brake housing parts 31, 32 are provided with radially inwardly projecting yoke-shaped extensions 33, 34 which are circumferentially spaced from each other and from bolts 7 to provide an opening between adjacent extensions and the hub is provided with radially outwardly projecting extensions 42. For the sake of ventilation the brake housing parts are interconnected only by way of the yoke-shaped extensions by screws 5 which also engage the extensions 42 to connect the brake housing to the hub.

A hydraulic actuator comprising a radially inner stepped ring 81 and an outer stepped ring 82 has a step 83 on which the hydraulic pressure acts. The hydraulic actuator is sealed by two sealing rings 84, 85 which also ensure infinitely variable adjustment of the brake discs as the linings wear. The stepped rings act on the annular brake lining discs 9, 10, by way of axial extensions 86, s7, disposed on the same circle of action as the step 83. The annular brake discs 9, 10 are so suspended on the brake carrier arms 2 as to be fixed in the circumferential direction but free to move axially.

Between the extensions 86 and 87 there are openings 8s, 89 through which cooling air supplied to the brake as the wheel rotates can pass to reach the back surfaces of the annular brake discs. When the wheel rotates, the side walls of the extensions 33, 34 act as fan blades. Arrows 11 - 13 (see Figure 3) indicate the fan effect of the inside parts of the brake. The cooling air also flows around the radial ribs of the brake housing parts in the direction indicated by arrows 14, 15.

Figures 4 and 5 show an embodiment having an actuator with a Z-shaped step. Figure 4 is a view in longitudinal section of the top half of the brake of a private motor vehicle.

Figure 5 is a partial cylinder section, marked G - H in Figure 4, through the brake. For the sake of clarity, the securing of the brake housing described with reference to the embodiment shown in Figures 1 to 3 has been omitted from Figure 4.

In Figures 4 and 5 a two-part brake housing 27, 28 is secured to the hub by means of extensions (not shown) and, on brake carrier arms (not shown) which extend around the brake housing, so carries the two annular brake discs 16, 17 that the same are peripherally stationary but free to move axially, the two annular brake discs 16, 17 having a friction lining 18, 19. Disposed therebetween and mounted on the brake carrier is a stepped-ring actuator embodied by the two stepped rings 20, 21.

A ring seal 22 disposed in the outer stepped ring 20 and a ring seal 23 disposed in the radially inner stepped ring 21 provide sealing tightness and adjustment for wear. In the event of a brake movement in which because of wear the normal clearance movement determined by the construction of the seal cross-section and effected by a change of shape is exceeded, the seals 22, 23 move on the cylinder surface 201 of the outer stepped ring and on the cylindrical surface 21, of the inner stepped ring. In this case as in the example shown in Figures 1 to 3, if the wear movement is to be adequate the lengths of the latter cylinder surfaces must be at least twice the wearing thickness of a brake lining.

The surfaces 2Oi, 211 are disposed concentrically of one another and in the same width region of the brake. This is the reason for the step 24 being Z-shaped. So that the step 24 may have a Z-shape, each stepped ring has a respective extension 202, 212 which engages in a corresponding recess in the other stepped ring.

The two stepped rings transmit their axial forces by way of extensions 203, 213 which are disposed opposite one another and near the step 24. Protection against dirt is provided by two boots or the like 25, 26 which interconnect the two stepped rings associated with a single actuator.

WHAT I CLAIM IS: 1. A disc brake for motor vehicles comprising a rotatable externally open, radially ribbed brake housing and a stationary brake carrier disposed over the brake housing, annular brake lining discs suspended on the brake carrier and fixed in the circumferential direction but freely movable axially, said

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. weight. Embodiments of the invention are shown in the accompanying drawings in which: Figure 1 is a longitudinal section of one embodiment of the invention for a driven front wheel taken along the line A-B of Figure 2; Figure 2 is a side elevation looking from the inside of the wheel in the upper one-half and is divided into two partial cross-sections taken along the lines C-D and E-F of Figure 1 in the lower one-half. Figure 3 is an enlarged longitudinal section through one-half of the embodiment of Figure 1; Figure 3a is a plan view of that portion of the embodiment of Figure 3 marked "Z". Figure 4 is a partial longitudinal section of a second embodiment of the invention; and Figure 5 is an enlarged fragmentary view taken along the line G-H of Figure 4. Referring to Figures 1 to 3 of the drawings, there can be seen a wheel 1 and a stationary combined wheel carrier and brake carrier 2; for the latter purpose the carrier 2 has two extensions 2. A two-part radially ribbed rotatable brake housing 31, 32 carried by hub 4 and connected thereto as later described, carrier 2 being disposed over the brake housing. Hub 4 is mounted in carrier 2 on a double-row ball-bearing 6. Wheel 1 is connected to ring flange part 41 of hub 4 by wheel bolts 7. The brake housing parts 31, 32 are provided with radially inwardly projecting yoke-shaped extensions 33, 34 which are circumferentially spaced from each other and from bolts 7 to provide an opening between adjacent extensions and the hub is provided with radially outwardly projecting extensions 42. For the sake of ventilation the brake housing parts are interconnected only by way of the yoke-shaped extensions by screws 5 which also engage the extensions 42 to connect the brake housing to the hub. A hydraulic actuator comprising a radially inner stepped ring 81 and an outer stepped ring 82 has a step 83 on which the hydraulic pressure acts. The hydraulic actuator is sealed by two sealing rings 84, 85 which also ensure infinitely variable adjustment of the brake discs as the linings wear. The stepped rings act on the annular brake lining discs 9, 10, by way of axial extensions 86, s7, disposed on the same circle of action as the step 83. The annular brake discs 9, 10 are so suspended on the brake carrier arms 2 as to be fixed in the circumferential direction but free to move axially. Between the extensions 86 and 87 there are openings 8s, 89 through which cooling air supplied to the brake as the wheel rotates can pass to reach the back surfaces of the annular brake discs. When the wheel rotates, the side walls of the extensions 33, 34 act as fan blades. Arrows 11 - 13 (see Figure 3) indicate the fan effect of the inside parts of the brake. The cooling air also flows around the radial ribs of the brake housing parts in the direction indicated by arrows 14, 15. Figures 4 and 5 show an embodiment having an actuator with a Z-shaped step. Figure 4 is a view in longitudinal section of the top half of the brake of a private motor vehicle. Figure 5 is a partial cylinder section, marked G - H in Figure 4, through the brake. For the sake of clarity, the securing of the brake housing described with reference to the embodiment shown in Figures 1 to 3 has been omitted from Figure 4. In Figures 4 and 5 a two-part brake housing 27, 28 is secured to the hub by means of extensions (not shown) and, on brake carrier arms (not shown) which extend around the brake housing, so carries the two annular brake discs 16, 17 that the same are peripherally stationary but free to move axially, the two annular brake discs 16, 17 having a friction lining 18, 19. Disposed therebetween and mounted on the brake carrier is a stepped-ring actuator embodied by the two stepped rings 20, 21. A ring seal 22 disposed in the outer stepped ring 20 and a ring seal 23 disposed in the radially inner stepped ring 21 provide sealing tightness and adjustment for wear. In the event of a brake movement in which because of wear the normal clearance movement determined by the construction of the seal cross-section and effected by a change of shape is exceeded, the seals 22, 23 move on the cylinder surface 201 of the outer stepped ring and on the cylindrical surface 21, of the inner stepped ring. In this case as in the example shown in Figures 1 to 3, if the wear movement is to be adequate the lengths of the latter cylinder surfaces must be at least twice the wearing thickness of a brake lining. The surfaces 2Oi, 211 are disposed concentrically of one another and in the same width region of the brake. This is the reason for the step 24 being Z-shaped. So that the step 24 may have a Z-shape, each stepped ring has a respective extension 202, 212 which engages in a corresponding recess in the other stepped ring. The two stepped rings transmit their axial forces by way of extensions 203, 213 which are disposed opposite one another and near the step 24. Protection against dirt is provided by two boots or the like 25, 26 which interconnect the two stepped rings associated with a single actuator. WHAT I CLAIM IS:

1. A disc brake for motor vehicles comprising a rotatable externally open, radially ribbed brake housing and a stationary brake carrier disposed over the brake housing, annular brake lining discs suspended on the brake carrier and fixed in the circumferential direction but freely movable axially, said

brake housing being formed of two annular parts interconnected only by way of radially inwardly projecting yoke-shaped extensions integral with each housing part, said extensions being circumferentially spaced to provide an opening between adjacent extensions, the brake housing being attachable to a wheel hub by means comprising screws which in a wheel and brake assembly, connect the yoke-shaped housing extensions radially outwardly projecting extensions of the hub said yoke-shaped housing extensions being circumferentially spaced from bolts which attach the wheel to flange of the hub, and a hydraulic actuating device disposed between the brake lining discs, said device having two stepped rings, which act on the respective brake lining discs by way of axial extensions disposed on the same circle of action as the steps of the stepped rings.

2. A disc brake according to Claim 1 wherein the step between the rings of the hydraulic actuating device is Z-shaped in cross-section whereby the width necessary for the wear path, of the inner cylindrical surface of the outer stepped ring associated with an inner sealing ring and the width, necessary for the wear path, of the outer cylindrical surface of the inner stepped ring associated with an outer sealing ring lie, when the brake is new, in the same axial region of the actuating device.

3. A disc brake substantially as herein described with reference to, and as shown in Figures 1 to 3 or Figures 4 and 5 of the accompanying drawings.

4. A wheel assembly for a motor vehicle incorporating a disc brake as claimed in any one of the preceding claims.