DE20014539U1 - Brake with combined emergency release and adjustment / readjustment device - Google Patents

Description

235 G87

Brake with combined emergency release and adjustment/re-adjustment
contraption

The invention relates to a brake according to the preamble of claim 1.

Spring-operated brakes, preferably solid disc brakes, are used in particular on vehicles such as wheel loaders. Such brakes serve as additional service brakes and parking brakes. If no hydraulic or pneumatic pressure is built up in the parking piston pressure chamber, the brake disc arrangement is mechanically compressed by the springs of the spring accumulator, the parking piston and the operating piston attached to it and thus brought into the operating position. In order to release the brake, however, pressure must build up in the parking piston pressure chamber in order to move the parking piston and thus also the operating piston in the opposite direction, which requires the engine to be running.

If the engine fails due to a defect, the brakes are in braking mode. To tow the vehicle, the brakes must therefore be released mechanically. This is done using an emergency release device in the form of several, for example three, pressure pins that are screwed axially into the brake housing, which push the locking piston back so that the operating piston is also retracted into its release position and the brake discs are released.

The disadvantage of this known emergency release device is that screwing in the pressure pins is time-consuming and very cumbersome, since the pressure pins are arranged in places that are difficult to reach.

Furthermore, adjustment or readjustment devices for brakes are known with which the play of the brake disc arrangement can be adjusted in the axial direction and readjusted as wear increases.

The invention is based on the object of creating a brake with an emergency release and adjustment/readjustment device that is as simple as possible in design and handling.

5 This object is achieved according to the invention by the features of claim 1. Advantageous embodiments are described in the further claims.

The brake according to the invention has an emergency release and adjustment/re-adjustment device for the brake disc arrangement.

A brake system with two ramp rings arranged axially one behind the other, which have inclined ramp surfaces on their opposite side surfaces, is provided. One of the ramp rings is rotatably mounted in the brake housing. The opposite ramp surfaces are arranged and operatively connected to one another in such a way that a rotation of the rotatable ramp ring is coupled with an axial displacement of the other ramp ring that can be transmitted to the brake disk arrangement.

Due to the arrangement according to the invention, the rotation of the rotating ramp ring leads to an axial displacement of the other ramp ring, which rests on the brake disc arrangement and determines its axial play. If the rotating ramp ring is rotated in such a way that the opposite ramp surfaces engage with each other as much as possible, so that the two ramp rings lie close together, the brake disc arrangement receives maximum axial play, through which the brake disc arrangement can be brought into the non-braking state even if the motor 0 fails. If, on the other hand, the rotating ramp ring is rotated in the opposite direction, i.e. in the spreading direction, the other ramp ring increasingly shifts in the other axial direction, i.e. in the direction of the brake disc arrangement. This narrows its axial play. The device according to the invention can therefore also be used as an adjustment device for the initial adjustment of the axial play of the brake disc arrangement and as an adjustment device for later adjustment of this axial play, 0 if this is necessary due to operational wear

becomes necessary.

A particular advantage here is that the emergency release and setting/adjustment device can be operated very quickly and easily, since only adjustment means need to be provided which cause the rotating ramp ring to rotate in one direction or the other. Furthermore, this creates a combined emergency release and setting/adjustment device which is inexpensive to manufacture and requires little installation space in the brake housing. Another advantage is the uniform loading of the brake disc arrangement over its entire circumference by the axially displaceable ramp ring.

According to an advantageous embodiment, the rotational position of the rotatable ramp ring can be changed by means of two adjusting elements in the form of two adjusting screws, which can be screwed into the housing from opposite sides and act on a radially projecting extension O of the rotatable ramp ring.

A relatively simple implementation of the device according to the invention is achieved if the emergency release and setting/adjustment device is arranged on the other side of the brake disc arrangement than the operating piston. In this case, the brake disc arrangement is located between the operating piston and the axially displaceable ramp ring. The axial play of the brake disc arrangement is thus directly and immediately influenced by an axial displacement of the ramp ring.

Advantageously, the operating piston is coupled to the locking piston via at least one, preferably two or three tension springs, which are arranged inside the pistons. This allows a very compact design of the brake to be achieved.

A uniform transmission of the spring force to the locking piston is achieved if the spring accumulator consists of several, preferably three, compression springs distributed evenly over the circumference, in particular in the form of disc spring packages.

The invention is explained in more detail below using the drawings as examples. In particular: 15

Figure 1 : a front view of the inventive

Brake,

Figure 2 : a sectional view of the brake of

0 Figure 1 along the line II-II of Figure

1,

Figure 3 : a side view of the brake of Figure 1

in the area of an adjusting screw,
25

Figure 4 : a section along the line IV-IV of

Figure 3,

Figure 5 : a perspective view of the two

0 the ramp rings, and

Figure 6 : the rotating ramp ring of Figure 5 in

Unique selling point.

As can be seen from Figure 2, the brake according to the invention has a four-part housing 1 with a housing end part 2, a first housing middle part 3, a second housing middle part 4 and a housing cover 5. The central cavity within the housing end part 2 and the housing middle parts 3, 4 is stepped in diameter and contains an emergency release and setting/adjustment device 6, a brake disk arrangement 7, an operating piston 8 and a locking piston 9, which are arranged one behind the other in this order in the axial direction.

The brake disc arrangement 7 consists of several, in the present case five, intermediate discs 10 which are held in the middle part of the housing 3 in a rotationally fixed but axially displaceable manner, between which lining discs 11 are arranged. These lining discs 11 are seated in a rotationally fixed but axially displaceable manner on a drive flange 12 which is connected to a vehicle axle (not shown) via an internal toothing 13. The rotationally fixed but axially displaceable mounting of the intermediate discs 10 on the middle part of the housing 3 is achieved via an internal toothing running in the axial direction and provided on the middle part of the housing 3 and a correspondingly complementary external toothing on the intermediate discs 10. The rotationally fixed, axially displaceable mounting of the lining discs 11 on the drive flange 12 is achieved via a 0 provided on the drive flange 12 and running in the axial direction.

external toothing, into which a corresponding complementary internal toothing of the lining disks 11 engages. The braking process is brought about by axially pushing the intermediate disks 10 and lining disks 11 together. To release the brake, the axial pressure on both sides on the brake disk arrangement 7 is removed, as will be described in more detail later.

The operating piston 8 and the locking piston 9 are arranged so that they can move axially in the central cavity of the second housing middle part 4 and are pulled together by means of several tension springs 14 which are arranged inside the operating piston 8 and locking piston 9, i.e. in tension spring receiving spaces 15, 16 which are aligned with one another. Due to the sectional line shown in Figure 1, only one of these tension springs 14 is visible in Figure 2. However, three of these tension springs 14 are expediently arranged evenly distributed over the circumference of the brake. The tension springs 14 are suspended in retaining tabs 17, 18 of the operating piston 8 and locking piston 9.

Operating piston 8 and locking piston 9 are arranged on the side of the brake disk arrangement 7 that faces the housing cover 5. In the position shown in Figure 2, in which the parking brake is actuated, the operating piston 8 rests with its end face 19 directly on the brake disk arrangement 7, i.e. on the outermost intermediate disk 10. The opposite end face 20 of the operating piston 8 rests directly on the locking piston 9 in the position shown in Figure 2.

The locking piston 9 rests with its end face remote from the operating piston 8 on a pressure ring 21 which is preloaded axially in the direction of the brake disk arrangement 7 by three disc spring assemblies 22 arranged regularly in the circumferential direction of the housing cover 5. The disc spring assemblies 22 are seated in corresponding recesses 2 3 in the housing cover 5 and, like the pressure ring 21, are guided axially displaceably on a central bearing pin 24. The bearing pins 24 are fastened to the bearing cover 5 with their outer end and have a stop collar 2 5 on their opposite end facing the locking piston 9, which engages behind the pressure ring 21, limits its axial movement in the direction of the brake disk arrangement 7 and prevents it from falling off the bearing pin 24 in the axial direction when the housing cover 5 is dismantled.

The disc spring assemblies 22 thus represent a spring accumulator, also called a spring force accumulator, which permanently exerts a preload force on the pressure ring 21 and thus on the locking piston 9 and operating piston 8 in the direction of the brake disc arrangement 7.

As can be seen from Figure 2, the locking piston 9 has an outwardly projecting, circumferential radial shoulder 26. Between this radial shoulder 26 and the second housing middle part 4, a sealed axial free space is provided, which is created by an annular groove in the second housing middle part 4. This free space is connected to a compressed oil or compressed air source and

thus forms a locking piston pressure chamber 27. If the locking piston pressure chamber 27 is filled with oil or compressed air to release the brake, the locking piston 9 is moved in the direction of the disc spring assemblies 24, i.e. in the direction of the housing cover 5, whereby the disc spring assemblies 24 are compressed. The operating piston 8 is thereby pulled in the same direction by means of the tension springs 14, whereby the brake is released.

If, however, no pressure is built up in the locking piston pressure chamber 27, for example because the engine and thus the pump are not running, an emergency braking is mechanically effected by the locking piston 9 being pushed to the left by the disc spring packages 24 and the locking piston pressure chamber 27 being minimized. Since the locking piston 9 rests against the operating piston 8, in this state the operating piston 8 is also pushed by the locking piston 9 in the direction of the brake disc arrangement so that it compresses the brake disc arrangement 7 and produces a braking effect 0.

If the engine is running and pressure has built up in the locking piston pressure chamber 27 so that the locking piston 9 is moved to the right into its brake release position, braking can still be carried out by building up pressure in an operating piston pressure chamber 28 by supplying pressurized oil or compressed air. The operating piston pressure chamber 28 is located between a radially outwardly projecting radial shoulder 29 of the operating piston 8 and a corresponding radially inwardly projecting shoulder of the second

Housing middle part 4. Such a pressurization in the operating piston pressure chamber 2 8 causes the operating piston 8 to move to the left, although the locking piston 9 remains in the right position due to its pressurization. In this state, the operating piston 8 and the locking piston 9 separate from each other, whereby the tension springs 14 are pulled apart.

The emergency release and setting/adjustment device 6, which is located on the other side of the brake disc arrangement 7, serves on the one hand to be able to release the brake in the event of an engine failure and on the other hand to initially set and subsequently readjust the axial play of the intermediate discs 10 and pad discs 11.

The emergency release and setting/adjustment device 6 essentially consists of two ramp rings 31, 32 arranged axially one behind the other and concentrically to one another, which are shown in more detail in Figures 5 and 6. The ramp rings 31, 32 are accommodated in a central cavity 33 of the housing end part 2. The outer ramp ring 31 is rotatably mounted in an annular groove 34 of the housing end part 2 and is axially supported outwards. This annular groove 34 is located in a radial shoulder 35 of the housing end part 2 that projects radially inwards.

The inner ramp ring 32 is mounted in a rotationally fixed but axially displaceable manner by means of axial cylindrical pins 36, which are fixed in the first housing middle part 3 and protrude into the cavity 33. The ramp ring 32 lies with its

the front surface facing the brake disk arrangement 7 directly on the outermost intermediate disk 10 of the brake disk arrangement 7. As can also be seen from Figure 5, the axially displaceable ramp ring 32 has a plurality, in the present case eighteen, inclined ramp surfaces 37 on its front surface facing the rotatable ramp ring 31. The inclined ramp surfaces 37 are arranged circumferentially and are arranged in a sawtooth-like manner. The ramp surfaces 37 thus have elevations 38 projecting in the axial direction or depressions 39 recessed in the axial direction. The length of all ramp surfaces 37 in the circumferential direction is the same.

The rotatable ramp ring 31 has, on its end face facing the axially displaceable ramp ring 32, inclined ramp surfaces 40 that are complementary to the ramp surfaces 37. In the present exemplary embodiment, the rotatable ramp ring 31 also has eighteen ramp surfaces 40 of the same design, so that a number of elevations 41 projecting in the axial direction or depressions 42 receding in the axial direction corresponding to 0 is obtained.

The ramp rings 31, 32 are, as can be seen from Figure 5, arranged in such a way that the ramp surfaces 37, 40 abut one another. In a certain rotational position of the rotatable ramp ring 31, the elevations 38, 41 are located exactly opposite the depressions 39, 42 of the other ramp ring 32, so that the axially displaceable ramp ring 32, 0, viewed in the axial direction, is very close to the rotatable ramp ring 32, 0.

penring 31. If, however, the rotatable ramp ring 31 is rotated from this position relative to the axially displaceable ramp ring 32, the axially displaceable ramp ring 32 is pushed away from the rotatable ramp ring 31 in the axial direction, since the elevations 38 of one ramp ring increasingly lie opposite the elevations 41 of the other ramp ring. The axial position of the ramp ring 32 within the housing 1 thus depends on the rotational position of the rotatable ramp ring 31. If the ramp ring 32 is moved to the right, the axial play of the brake disk arrangement 7 decreases, while this axial play increases when the ramp ring 32 is moved to the left.

In order to be able to rotate the rotatable ramp ring 31, as can be seen from Figures 4 to 6, it has a single radial projection 43 protruding beyond its outer circumference. A force in the circumferential direction of the ramp ring 31 can be exerted on this radial projection 43 by means of two adjusting screws 44, 45. The adjusting screws 44, 45 are arranged on opposite sides of the radial projection 43 in alignment with one another so that they can exert a compressive force on the radial projection 43 from both sides. As can be seen from Figure 4, the adjusting screws 44, 45 are inserted into corresponding holes 46, 47 in the housing end part 2. These are through holes which extend from the outside of the housing end part 2 to the cavity 33 and each have a threaded section 48. The adjusting screws 44, 45 can therefore be operated from the outside of the housing 1, i.e. into the

Screwed into or unscrewed from the housing end part 2.

In the position shown in Figure 4, the two adjusting screws 44, 45 press on the radial projection 43 from opposite sides, whereby the pivot bearings of the ramp ring 31 are securely fixed. To change the rotational position of the ramp ring 31, first one of the two adjusting screws 44, 45 is unscrewed, whereby a free space is created between the radial projection 43 and the unscrewed adjusting screw 44, 45. The other adjusting screw is then screwed into the housing end part 2 until the desired rotational position of the ramp ring 31 is reached. To fix the ramp ring 31 in a rotationally fixed manner, the adjusting screw that was initially unscrewed is now screwed back in until the radial projection 43 is firmly clamped between the two adjusting screws 44, 45.

0 As can easily be seen, the emergency release and setting/adjustment device 6 according to the invention can be used in a simple manner to adjust the axial play of the brake disk arrangement 7. The individual parts are expediently designed in such a way that the desired axial play is achieved during brake production when the opposite ramp surfaces 37, 4 0 of the ramp rings 31, 32 overlap approximately halfway, as shown approximately in Figure 5, so that the axial ring 31 can be rotated in both circumferential directions. If it is necessary to adjust the axial play of the brake disk after a longer period of operation,

To reduce the width of the ramp arrangement 7 again, the ramp ring 31 is rotated in the circumferential direction by screwing in the adjusting screw 44, so that the overlap area of the opposite ramp surfaces 37, 40 is reduced and the ramp ring 32 is displaced to the right.

If, however, it is necessary, for example in the event of a motor failure, to release the brake which has been mechanically brought into the braking position by the disc spring assemblies 22, the ramp ring 31 is rotated in the opposite circumferential direction by screwing in the adjusting screw 45, whereby the degree of overlap of the ramp surfaces 37, 40 increases and the other ramp ring 32 approaches the ramp ring 31. The possible axial displacement of the ramp ring 32 in the direction of the rotatable ramp ring 31 is in any case greater than that of the pressure ring 21, on which the disc spring assemblies 22 act, or than that of the locking piston 9 or operating piston 8 in the direction of the brake disk arrangement 7, i.e. to the left in Figure 2. This ensures that a sufficiently large axial clearance is created to ensure that the brake is released with a corresponding axial movement of the ramp ring 32 to the left.

5 To limit the displacement path of the pressure ring 21 in the direction of the brake disc arrangement 7, the pressure ring 21 has through holes 49 for the bearing bolts 24, which have a smaller diameter than the stop collar 25. The stop collar 25 can thus be used to limit the axial displacement path of the pressure ring 21 in the direction of the brake disc arrangement 7.

arrangement 7.

The housing 1 is sealed to the drive flange 12 by means of a radial shaft seal 50 and a lamellar seal 51, which are mounted in the housing cover 5. To replace the radial shaft seal 50, the housing cover 5 only needs to be unscrewed using six hexagon socket screws 52, which are shown in Figure 1. The other parts of the housing 1 do not need to be dismantled for this purpose.

Claims (11)

1. Brake with - a brake housing ( 1 ), - an operating piston ( 8 ) slidably mounted within the brake housing ( 1 ), - a brake disc arrangement ( 7 ) which can be acted upon by the operating piston ( 8 ), - a locking piston ( 9 ) which is slidably mounted within the brake housing ( 1 ) and is in operative connection with the operating piston ( 8 ), - a spring accumulator operatively connected to the locking piston ( 9 ), characterized by an emergency release and setting/adjustment device ( 6 ) for the brake disc arrangement ( 7 ) with two ramp rings ( 31 , 32 ) arranged axially one behind the other, which have inclined ramp surfaces ( 37 , 40 ) on their opposite side surfaces, wherein one ( 31 ) of the ramp rings ( 31 , 32 ) is rotatably mounted in the brake housing ( 1 ) and the opposite ramp surfaces ( 37 , 40 ) are arranged and operatively connected to one another in such a way that a rotation of the rotatable ramp ring ( 31 ) is coupled to an axial displacement of the other ramp ring ( 32 ) which can be transmitted to the brake disc arrangement ( 7 ). 2. Brake according to claim 1, characterized in that the two ramp rings ( 31 , 32 ) are arranged concentrically to each other. 3. Brake according to claim 1 or 2, characterized in that the inclined ramp surfaces ( 37 , 40 ) consist of a plurality of ramp surfaces regularly distributed over the circumference of the ramp rings ( 31 , 32 ) and arranged in a sawtooth-like pattern. 4. Brake according to one of the preceding claims, characterized in that the rotational position of the rotatable ramp ring ( 31 ) can be changed by means of at least one adjusting element which extends from the ramp ring ( 31 ) through a housing opening. 5. Brake according to claim 4, characterized in that the rotational position of the rotatable ramp ring ( 31 ) can be changed by means of two adjusting elements in the form of two adjusting screws ( 44 , 45 ) which can be screwed into the housing ( 1 ) from opposite sides and act on a radial projection ( 43 ) of the rotatable ramp ring ( 31 ). 6. Brake according to one of the preceding claims, characterized in that the emergency release and adjustment/readjustment device ( 6 ) is arranged on the other side of the brake disc arrangement ( 7 ) than the operating piston ( 8 ). 7. Brake according to one of the preceding claims, characterized in that the rotatable ramp ring ( 31 ) is supported with its rear side on the housing ( 1 ) and the other ramp ring ( 32 ) is arranged adjacent to the brake disc arrangement ( 7 ). 8. Brake according to one of the preceding claims, characterized in that the operating piston ( 8 ) is coupled to the locking piston ( 9 ) via at least one tension spring ( 14 ) which is arranged in the interior of the pistons ( 8 , 9 ). 9. Brake according to one of the preceding claims, characterized in that the spring accumulator consists of several disc spring assemblies ( 22 ) regularly distributed over the circumference. 10. Brake according to one of the preceding claims, characterized in that the spring accumulator is mounted in the housing cover ( 5 ). 11. Brake according to claim 10, characterized in that a radial shaft sealing ring ( 50 ) for sealing the housing ( 1 ) with respect to a drive flange ( 12 ) is mounted in the housing cover ( 5 ).