Slidable brake disc system

• US 6,247,560 B1
• Filed: 04/30/1999
• Issued: 06/19/2001
• Est. Priority Date: 12/12/1996
• Status: Expired due to Term

• Current Assignee: BWI Company Limited SA (Shougang Corporation)
• Original Assignee: Federal-Mogul Technology Ltd. (Apollo Global Management, Inc.)
• Inventors: Bunker, Kenneth J.
• Primary Examiner(s): Schwartz, Christopher P.
• Application Number:
  US09/303,183
• Time in Patent Office: 781 Days
• Field of Search: 188/71.5, 188/73.38, 188/18.A, 188/218.L, 188/264.A, 188/264.AA, 192/70-7-
• US Class Current: 188/18.00A
• CPC Class Codes: B60G 2200/142 with a single lateral arm, e.g. MacPherson type
• CPC Class Codes: B60G 2204/129 Damper mount on wheel suspension or knuckle
• CPC Class Codes: B60G 2206/50 Constructional features of wheel supports or knuckles, e.g. steering knuckles, spindle attachments
• CPC Class Codes: B60T 1/065 employing disc B60T1/062 takes precedence
• CPC Class Codes: B60T 8/368 combined with other mechanical components, e.g. pump units, master cylinders
• CPC Class Codes: B60T 8/4266 having an electro-mechanically actuated expansion unit, e.g. solenoid, electric motor, piezo stack
• CPC Class Codes: F16D 2055/0008 Brake supports
• CPC Class Codes: F16D 2055/0062 Partly lined, i.e. braking surface extending over only a part of the disc circumference
• CPC Class Codes: F16D 2055/0091 Plural actuators arranged side by side on the same side of the rotor
• CPC Class Codes: F16D 2065/1316 radially segmented
• CPC Class Codes: F16D 2065/1348 resilient
• CPC Class Codes: F16D 2065/1368 with relative movement both radially and axially
• CPC Class Codes: F16D 2065/1384 to wheel hub
• CPC Class Codes: F16D 2065/1392 Connection elements
• CPC Class Codes: F16D 2065/1396 Ancillary resilient elements, e.g. anti-rattle or retraction springs
• CPC Class Codes: F16D 2121/20 using electromagnets
• CPC Class Codes: F16D 55/32 actuated by a fluid-pressure device arranged in or on the brake
• CPC Class Codes: F16D 55/36 Brakes with a plurality of rotating discs all lying side by side
• CPC Class Codes: F16D 55/40 actuated by a fluid-pressure device arranged in or one the brake
• CPC Class Codes: F16D 65/0977 Springs made from sheet metal
• CPC Class Codes: F16D 65/12 : Discs; Drums for disc brakes
• CPC Class Codes: F16D 65/123 : comprising an annular disc secured to a hub member; Discs characterised by means for mounting

Abstract

An axially, slidable brake disc system employs leaf springs between a hub of a suspension casting or knuckle to float the brake discs for axial sliding movement, while holding the discs against wobbling, and employs brake pads which are biased by springs to float on a stationary bridge so that the contact between the brake pads and discs is a light random contact thereby resulting in reduced residual torque drag and disc thickness variation. The rotating brake discs will shift axially, slightly from the braking position to the off-brake position with the brake pads urged by their spring forces to keep their pad faces parallel to and slightly spaced from adjacent brake disc surfaces to prevent corner engagement and localized rubbing contact thereby reducing pad wear, residual drag torque and disc thickness variation. The brake force applicator may be mounted at a 12:00 position and in an integral bore in the suspension knuckle to reduce the size, weight, and space envelope of the braking system. Less braking pressure is needed with two brake discs and four brake pads and the system will pass the AMS fade test.

Claims

1. A disc brake system comprising a knuckle, a hub being mounted for rotation on the knuckle about a central axis through the hub;

a plurality of brake discs each having an inner portion slidably mounted on the hub for sliding in a direction parallel to the central axis of the hub between a braking position and off-brake position;

a drive connection between the hub and the brake disc to rotate the disc with rotation of the hub and to decelerate the rotation of the hub when the disc is in the braking position;

braking pads including at least two slidable brake pads each having a friction pad surface for applying braking torque to opposite sides of the brake discs when in the braking torque position to decelerate the engaged brake discs and thereby the hub;

a stationary bridge support carried by the knuckle and mounting the slidable brake pad for travel between an off-brake position and the braking position;

an actuator for sliding the slidable brake pad and brake disc into the braking position;

a disc force applicator comprising biasing springs for applying radially directed biasing forces between the hub and the inner portion of each of the brake discs to cause friction between the hub and disc inner portion to retard their sliding axially relative to one another to position the brake discs in planes normal to the rotational, central axis;

an outer rim portion on the braking disc rotating while in the off-brake position and engaging the slidable brake pad'"'"'s friction surface to slide the pad from the braking position to an off-brake pad position;

as the slidable brake disc floating on the disc force applicator and slidable axially along the hub from a braking position to an off-braking position relative to the braking pads;

a brake pad force applicator exerting biasing forces on the slidable brake pads, to align their friction pad surfaces parallel to to the planes of the brake discs to reduce tilting of the brake pads on the stationary bridge support and its rubbing on the brake disc that would increase off-brake, residual torque; and

the biasing forces of the respective disc force and brake farce applicators being balanced with respect to one another to allow separation of the brake pads and brake discs and to maintain such separation at the off-brake position and to maintain the friction pads and brake discs in their respective parallel planes to reduce off-brake residual torque.

2. A disc brake system in accordance with claim 1 wherein the brake pad force applicator comprises at least one spring pushing on the brake pads in a direction substantially normal to the rotational axis of the brake disc and normal to the path of travel of the brake pads along the stationary support.

3. A disc brake system in accordance with claim 2 wherein;

the slidable brake pad comprises a slidable pad carrier mounted for sliding on the bridge and carrying frictional pad surfaces thereon; and

the spring is positioned over the brake pad carrier and forces the brake pad carrier downwardly against the bridge.

4. A disc brake system in accordance with claim 1 wherein two or more brake discs are slidably mounted on the hub;

a central slidable brake pad having opposed friction pads thereon is disposed between the twin brake discs and is slidably mounted on the stationary support; and

the force applicator comprises at least one spring to constrain the slidable brake pad and the central slidable brake pad and to assist in constraining the rims of the slidable twin disc brakes in their off-brake position.

5. A disc brake system in accordance with claim 4 wherein the brake pad force applicator comprises separate springs each engageable with the slidable friction pad and the central slidable friction pad.

6. A disc brake system in accordance with claim 1 wherein the brake pad force applicator comprises resilient means forcing the brake pads against the support to provide predetermined frictional forces therebetween sufficient to assist in positioning the outer rims of the brake discs in an axial direction and position on the hub.

7. A disc brake system in accordance with claim 1 wherein the force applicator comprises a hydraulic cylinder and a reciprocal hydraulic piston in the cylinder;

and

a compressible seal ring in the cylinder compressible by the piston movement and storing energy to provide a return force to retract the piston thereby permitting the brake pad to shift axially along its stationary support toward the cylinder during rotation of the brake disc in its off-brake position.

8. A disc brake system in accordance with claim 1 wherein the drive connection between the disc and hub comprises intermeshed teeth.

9. A disc brake in accordance with claim 1 wherein the brake pad force applicator is also operable, when the slidable brake pad is in its off-brake position, to prevent the slidable brake pad from contacting the disc by sliding axially on the stationary support.

10. A disc brake system in accordance with claim 1 wherein:

the disc expands at higher temperatures and tends to slide axially relative to the hub; and

the disc force applicator between the brake disc and hub comprises a spring applying friction forces for limiting the sliding of the expanded disc on the hub.

11. A disc brake system in accordance with claim 1 wherein the residual, off-load torque allows the brake discs to cool quickly to less than 20 degrees above an ambient temperature in the range of 10°

to 20°

C. due to residual, off-brake torque.

12. A disc brake system in accordance with claim 1 wherein:

the stationary support has a machined, supporting surface thereon; and

the brake pad comprises a slidable carrier mounted on the stationary support and having machined slide surface thereon in sliding frictional contact with the machined, supporting surface on the stationary support; and

the brake pad force applicator comprises a leaf spring positioned over the slidable carrier and pushing the carrier'"'"'s machined slide surface against the stationary machined supporting surface to prevent tilting of the slidable carrier on the stationary support during the off-brake condition.

13. A disc brake system comprising a hub being mounted for rotation about a central axis through the hub;

at least one brake disc having an inner portion slidably mounted on the hub for sliding in a direction parallel to the central axis of the hub between a braking position and off-brake position;

a drive connection between the hub and the brake disc to rotate the disc with rotation of the hub and to decelerate the rotation of the hub when the disc is in the braking position;

braking pads arranged on opposite sides of the disc and each having a friction pad surface for applying braking torque to the disc when in a braking position thereof, the braking pads including a slidable brake pad and a stationary brake pad which is fixed relative to the hub;

a stationary support mounting the slidable brake pad for travel between an off-brake position and the braking position;

an actuator operable to slide the slidable brake pad and disc into a braking condition, the actuator also being operable to create sufficient clearance to allow the slidable brake pad and disc to slide into an off-brake condition;

a disc force applicator applying a radially directed force between the hub and the inner portion of the brake disc to cause friction between the hub and disc inner portion to retard their sliding axially relative to one another;

an outer, flat rim portion on the braking disc rotating while in the off-brake position and engaging the slidable brake pad'"'"'s friction surface to slide the pad from the braking position to an off-brake pad position;

the slidable brake disc floating on the disc force applicator and slidable axially along the hub from a braking position to an off-braking position relative to the braking pads;

a plurality of radially inwardly projecting teeth on the inner portion of the brake disc;

a plurality of grooves on the inner portion of the hub to receive the teeth of the brake disc;

inclined flanking sides on the teeth and on the hub grooves providing marked lines of contact between opposite sides of the teeth and the engaged flanking side of the hub groove thereby providing a marked tooth drive connection between the hub and the brake disc;

projecting arcuate portions on the hub substantially larger in circumferential extent than the brake disc teeth arcuate grooves on the inner portion of the brake disc with the grooves on the inner portion of the brake disc being substantially larger circumferentially than the grooves on the hub;

flat leaf springs each having a central portion laid tangentially on a central portion of an arcuate large hub projection; and

outer bent ends on each leaf spring bent by the arcuate large groove to provide spaced points of contact at which the bent spring exerts biasing forces to center the flat brake disc on the hub and to hold the flat brake disc in a plane normal to the rotational axis of the hub to reduce DTV and residual wear.

14. A disc brake system in accordance with claim 13 wherein the disc force applicator forces the pads against the stationary support with force sufficient to prevent tilting of the slidable pad on the stationary support from causing contact between the slidable pad and the disc.

15. A brake disc system in accordance with claim 13 wherein the engaged flanking sides of the teeth function as meshed gear teeth having plastic deformation at their engaged surfaces to reduce corrosion thereof.

16. A brake disc system in accordance with claim 13 wherein only four teeth are on the brake disc inner portion and only four springs are floating the brake disc on the hub between the brake disc and hub.

17. A brake disc system in accordance with claim 13 comprising:

a second brake disc mounted on the hub having the same construction as the other brake disc; and

the flat leaf spring extending in axial direction of the hub to be positioned under both of the brake discs.

18. A disc brake system comprising a hub being mounted for rotation about a central axis through the hub;

at least one brake disc having an inner portion slidably mounted on the hub for sliding in a direction parallel to the central axis of the hub between a braking position and off-brake position;

a drive connection between the hub and the brake disc to rotate the disc with rotation of the hub and to decelerate the rotation of the hub when the disc is in the braking position;

braking pads arranged an opposite side of the disc and each having a friction pad surface for applying braking torque to the disc when in a braking position thereof, the braking pads including a slidable brake pad and a stationary brake pad which is fixed relative to the hub;

a stationary support mounting the slidable brake pad for travel between an off-brake position and the braking position;

an actuator operable to slide the slidable brake pad and disc into a braking condition, the actuator also being operable to create sufficient clearance to allow the slidable brake pad and disc to slide into an off-brake condition;

a disc force applicator applying a radially directed force between the hub and the inner portion of the brake disc to cause friction between the hub and disc inner portion to retard their sliding axially relative to one another;

an outer rim portion on the braking disc rotating while in the off-brake position and engaging the slidable brake pad'"'"'s friction surface to slide the pad from the braking position to an off-brake pad position;

the slidable brake disc floating on the disc force applicator and slidable axially along the hub from a braking position to an off-braking position relative to the braking pads;

a brake pad force applicator acting on the slidable brake pad wherein the forces applied to the disc by the disc force applicator and to the slidable brake pad by the brake pad force applicator are balanced so that the system can move from its braking condition to its off-brake condition by the action of separation forces between the disc and the braking pads, the disc sliding axially on the hub by a first distance to thereby separate itself from the stationary brake; and

the slidable brake pad sliding on the stationary support by a second distance, which is greater than said first distance, to thereby separate itself from the disc, the forces applied by the applicators in the off-brake condition being sufficient to prevent axial sliding of the disc causing contact with either braking pad, and to prevent axial sliding of the slidable pad from causing contact between the disc and the slidable pad; and

first and second discs;

a central slidable pad;

the forces being applied to the discs by the disc force applicator and to the slidable brake pads by the brake pad force applicator are balanced so that the system can move from its braking condition to its off-brake condition by the action of separation forces between the discs and the braking pads, the first disc sliding axially on the hub by a first distance to thereby separate itself from the stationary brake pad, the central slidable brake pad assembly sliding on the stationary support by a second distance, which is greater than said first distance, to thereby separate itself from the first disc, the second disc sliding axially on the hub by a third distance, which is greater than said second distance, to thereby separate itself from the central slidable brake pad, and the other slidable brake pad sliding on the stationary support by a fourth distance, which is greater than said third distance, to thereby separate itself from the second disc, the forces applied by the applicators in the off-brake condition being sufficient to prevent axial sliding of the discs causing contact of either disc with any of the braking pads, and to prevent axial sliding of the slidable pads from causing contact between either disc and either slidable pad.

19. A disc brake system in accordance with claim 18 wherein:

the pad force applicator comprises at least one leaf spring pushing the sliding brake pads against the stationary support; and

the disc force applicator comprises at least one leaf spring disposed between the hub and the slidable brake discs.

20. A disc brake system in accordance with claim 19 wherein:

the leaf spring of the pad force applicator comprises separate leaf springs pushing against the respective slidable brake pads; and

the disc force applicator comprises a separate leaf spring disposed between each of the first and second brake discs.

21. A disc brake system comprising a hub being mounted for rotation about a central axis through the hub;

first and second brake discs each having an inner portion slidably mounted on the hub for sliding in a direction parallel to the central axis of the hub between a braking position and off-brake position;

a drive connection between the hub and the brake discs to rotate the discs with rotation of the hub and to decelerate the rotation of the hub when the discs are in the braking position;

braking pads each having a friction pad surface for applying braking torque to the disc when in a braking position thereof, the braking pads including a slidable brake pad, a central slidable brake pad between the first and second brake discs, and a stationary brake pad which is fixed relation to the hub;

a stationary support mounting the slidable brake pads for travel between an off-brake position and the braking position;

an actuator for sliding the slidable brake pads and brake discs into the braking position;

a disc force applicator applying a radially directed force between the hub and the inner portion of the brake disc to cause friction between the hub and disc inner portion to retard their sliding axially relative to one another;

an outer rim portion on each braking disc rotating while in the off-brake position and engaging the slidable brake pad'"'"'s friction surface to slide the pad from the braking position to an off-brake pad position;

the slidable brake disc being movable axially along the hub from a braking position to an off-braking position relative to the braking pads; and

a brake pad force applicator acting on the slidable brake pads wherein the forces applied to the discs by the disc force applicator and to the slidable brake pads by the brake pad force applicator are balanced so that the system can move from its braking condition to its off-brake condition by the action of separation forces between the discs and the braking pads, the first disc sliding axially on the hub by a first distance to thereby separate itself from the stationary brake pad, the central slidable brake pad assembly sliding on the stationary support by a second distance, which is greater than said first distance, to thereby separate itself from the first disc, the second disc sliding axially on the hub by a third distance, which is greater than said second distance, to thereby separate itself from the central slidable brake pad assembly, and the other slidable brake pad sliding on the stationary support by a fourth distance, which is greater than said third distance, to thereby separate itself from the second disc, the forces applied by the applicators in the off-brake condition being sufficient to prevent axial sliding of the discs causing contact of either disc with any of the braking pads, and to prevent axial sliding of the slidable pads from causing contact between either disc and either slidable pad.

22. A disc brake system in accordance with claim 21 wherein:

slide supporting surfaces are provided on the stationary support;

the slidable brake pads have pad carriers carrying the pad friction surfaces thereon;

spaced friction slide surfaces are provided on the pad carriers; and

the pad force applicator comprises at least one leaf spring attached to the stationary support and pushing the friction slide surfaces against the slide supporting surfaces on the stationary support.

23. A disc brake system in accordance with claim 22 wherein a plurality of leaf springs are positioned between the hub and the inner portion of each brake disc to increase friction between the engaged surfaces of the drive connection of the hub and disc.

24. A vehicle braking and suspension system comprising:

a vehicle suspension having a suspension member;

a wheel adapted to be carried by the vehicle suspension member;

a disc brake and wheel support assembly having a supporting suspension member in the form of a cast metal, knuckle;

a rotatable hub mounted on a portion of the knuckle for rotation about a central rotational axis through the hub and carrying the wheel for rotation about the rotational axis;

a brake actuator for the disc brake mounted on an upper portion of the knuckle and having a cylinder machined and integral with the cast knuckle;

a stationary rigid bridge secured to an upper position of the knuckle and having slidable surfaces thereon;

a plurality of flat brake discs slidably mounted on the hub for braking the hub and wheel;

a force applicator mounted between the hubs and an inner portion of the brake discs for biasing the flat brake disc into planes normal to the central rotational axis and to permit sliding of the brake discs in an axial direction;

an outer, fixed brake pad mounted on an outer end of the stationary bridge for engaging side of the brake disc;

slidable brake pads mounted on the slidable surfaces of the stationary bridge and slidable by the brake actuator to engage a friction surface thereon with sides of the brake discs and to slide the brake discs axially along to the hub from an off-brake, residual torque position to a on-brake position in which the braking pads are engaging opposite sides of the brake discs to brake the discs, hub and wheel; and

a brake pad force applicator carried on the stationary bridge applying a biasing force greater than a force necessary to prevent rattling to the slidable brake pads to hold the brake pads in planes parallel to the planes of the slidable brake disc and at positions separated from the brake discs at the off-braking position.

25. A vehicle braking system in accordance with claim 24 wherein the brake pad force applicator comprises a resilient spring member mounted on the stationary bridge.

26. A vehicle braking system in accordance with claim 24 wherein sliding surfaces on the stationary bridge have sliding frictional engagement with sliding surfaces on the brake disc;

and

the brake pad force applicator comprises a resilient spring member mounted to overlie the brake pad and to apply a predetermined spring force to the brake pad to increase substantially the friction beyond that needed to prevent rattling of the brake pad on the bridge.

27. A vehicle braking system in accordance with claim 24 wherein the brake actuator for the disc brake comprises the integral hydraulic cylinder having a piston for forcing the slidable brake pad into the braking position;

a compressible seal ring between the cylinder and piston exerts a return force on the piston when the braking fluid pressure is relieved at the no-load braking position; and

the hydraulic cylinder being mounted at an upper vertical position on the suspension member.

28. A vehicle braking system in accordance with claim 24 wherein:

a central brake pad carrier having opposed friction pads is slidably mounted on the stationary bridge to engage facing sides of the respective brake discs; and

the force applicator holding the central pad carrier in an off-brake, residual torque position relative to the rotating brake discs.

29. A vehicle braking system in accordance with claim 25 wherein intermeshed splines are formed on the brake disc and the hub to provide a positive drive connection therebetween;

and

the force applicator for the brake disc comprises spring members positioned between the hub and the brake disc to apply frictional forces to resist free sliding of the brake disc on the hub as the brake disc is heated and expands and thereafter contracts when cooled.

30. A vehicle braking system in accordance with claim 24 wherein the two brake discs cool to less than 20°

C. above ambient temperature when the ambient temperature is in the range of 10°

C. to 20°

C.

31. A vehicle braking system in accordance with claim 24 wherein the rotating brake disc and the brake pads and the brake pad force applicators position the brake discs for randomly engaging the brake pads at different locations, thereby preventing wear due to engagement at the same spot on the disc during each revolution as would cause disc thickness variation.

32. A method of disc braking employing inner and outer, annular brake discs mounted on a rotatable hub for rotation about a rotational axis and biased by springs to be in planes normal to the rotational axis and mounted for axial sliding on the hub and having a fixed caliper bridge with four brake pad having frictional surfaces thereon for engaging opposite sides of the brake discs, springs exerting forces on the brake pads to maintain the frictional pad surfaces in planes parallel to the planes of the brake discs and at positions spaced from the brake discs at an off-brake position, said method comprising;

applying an actuating force on the slidable brake pads to slide them along the bridge to a braking position to engage rims of the annular discs with the four pad frictional surfaces to generate braking forces to decelerate the discs;

pushing the brake discs by the slidable brake pads along the hub to engage an outer side of an outer brake disc with a stationary brake pad on the fixed bridge at the braking position;

relieving the actuating force after braking;

exerting forces by the rotating brake discs on the slidable brake pads to overcome predetermined spring forces holding the slidable brake pads against sliding to shift the brake pads to off-brake positions;

exerting first spring forces between each of the brake discs and hub to assist in locating the brake discs on the hub at off-brake positions;

exerting second spring forces between the slidable brake pads and the fixed bridge to hold the brake pad friction surfaces in planes parallel to the planes of the brake discs; and

balancing the first and second spring forces so that separation forces generated by the rotational brake discs engaging the brake pads results in the brake discs sliding on the hub to separate themselves from the brake pads and to constrain the brake pads to be in positions spaced from the brake discs and in their parallel planes to limit engagement between the rotating brake discs and the brake pads at their respective off-brake positions to only random engagement therebetween to minimize disc thickness variation due to rubbing and to minimize off-brake, residual torque between the discs and brake pads.

33. A method in accordance with claim 32 including the providing of the disc brake on a vehicle suspension;

and

driving the vehicle through the AMS test and maintaining the temperature of the brake discs below 650°

C.

34. A method in accordance with claim 33 including the step of maintaining the brake disc temperature below 600°

C.

35. A method in accordance with claim 32 actuating the brake pads from a position above the rotational axis through the hub and in a vertical plane at a substantial 12:

00 o'"'"'clock position.

36. A method in accordance with claim 32 wherein the applying of the actuating force on the slidable brake pads comprises moving a hydraulically operated piston to force at least two slidable brake pads and at least two slidable brake discs to shift to the braking position.

37. A method in accordance with claim 32 including holding the brake pads against tilting on the supporting bridge to prevent localized rubbing and resultant disc thickness variation while the braking system is experiencing vibration and vehicle inertial forces.

38. A vehicle, front wheel braking assembly comprising:

a suspension support casting;

a rotatable hub journaled in the suspension support casting for rotation about a substantially horizontal axis of rotation;

inner and outer slidable brake discs slidably mounted on the hub and each having an outer rim portion and an inner portion having an interconnection with the hub to rotate with the hub;

force applicator exerting a biasing force between the hub and the inner portion of the brake discs to align the discs to rotate in planes substantially normal to the axis of rotation and to constrain the brake discs separated from the brake pads at an off-brake position except for random engagement therebetween;

a fixed, rigid bridge on the suspension supporting casting having slidable support surfaces thereon and having a distal end;

a fixed brake pad mounted on the distal end of the fixed bridge to engage an outer face of the outer slidable brake disc;

a central brake pad carrier carrying a pair of opposed brake pad surfaces to engage facing sides of the inner and outer brake discs mounted on the slidable support surfaces of the fixed bridge;

an inner brake pad carrier having an inner brake pad surface mounted on the slidable surfaces of the fixed bridge;

a force applicator exerting a biasing force on the brake pad carriers to position the brake pad surfaces thereon in planes parallel to the planes of the rims of the brake discs and to constrain the brake pad carriers from shifting along the fixed bridge when in an off-brake position;

an integral, hub support portion of the suspension support casting mounting the hub and attached wheel for rotation about the rotational axis;

a substantially vertical bore in the suspension support casting to receive a ball joint to permit the suspension support casting to turn about an axis therein;

an integral connecting portion on the suspension support casting for connection to a steering system to turn the suspension support casting about a swivel axis; and

an integral actuator bore in a top portion of the suspension support casting located above the rotational axis and in a vertical, substantially 12;

00 o'"'"'clock position with the bridge and brake pad carriers also being at the substantially 12;

00 o'"'"'clock position for engaging the upper outer rim portions of the slidable discs.

39. A vertical braking assembly in accordance with claim 38 wherein the integral actuator bore comprises a hydraulic cylinder bore;

and

a piston is mounted in the integral hydraulic cylinder bore.

40. A vehicle braking assembly in accordance with claim 38 wherein a brake-by-wire actuator is mounted in the integral actuator bore.

41. A vehicle braking assembly in accordance with claim 38 wherein the integral support casting comprises a connecting portion for connection to a McPherson strut so that the integral suspension casting can pivot about an axis of the strut.

42. A disc brake system comprising a hub being mounted for rotation about a central axis through the hub;

at least one brake disc having an inner portion slidably mounted on the hub for sliding in a direction parallel to the central axis of the hub between a braking position and off-brake position;

a drive connection between the hub and the brake disc to rotate the disc with rotation of the hub and to decelerate the rotation of the hub when the disc is in the braking position;

braking pads including at least one slidable brake pad each having a friction pad surface for applying braking torque to opposite sides of the brake disc when in the braking torque position to decelerate the engaged brake disc and thereby the hub;

a stationary support mounting the slidable brake pad for travel between an off-brake position and the braking position;

an actuator for sliding the slidable brake pad and brake disc into the braking position;

a disc force applicator applying a radially directed force between the hub and the inner portion of the brake disc to cause friction between the hub and disc inner portion to retard their sliding axially relative to one another;

an outer rim portion on the braking disc rotating while in the off-brake position and engaging the slidable brake pad'"'"'s friction surface to slide the pad from the braking position to an off-brake pad position;

the slidable brake disc floating on the disc force applicator and slidable axially along the hub from a braking position to an off-braking position relative to the braking pads;

a brake pad force applicator acting on the slidable brake pad, when in its off-brake position, to constrain the friction pad surface engaging the brake disc to reduce tilting of the brake pad on the stationary support and its rubbing on the brake disc that would increase off-brake, residual torque; and

the teeth on the brake disc being provided With stress relief fillets at the junctures of the teeth to the remainder of the brake disc.