CN221374305U - Automatic adjusting arm for brake clearance - Google Patents

Abstract

The utility model discloses an automatic brake clearance adjusting arm. The brake device comprises a shell, a worm wheel, a worm and a direction limiting piece, wherein one end of the shell is linked with a brake cam shaft through an internal spline of the worm wheel, and the other end of the shell is connected with a connecting sleeve through a pin shaft; one end of the coupling sleeve is connected with the brake push rod, the other end of the coupling sleeve is connected with the sliding block and the ratchet wheel through the connecting rod, the ratchet wheel is connected with the worm in a matched manner through the internal spline, and the ratchet wheel is meshed with the pawl on the shell; the direction limiting piece acts on the worm, and the worm capable of rotating unidirectionally drives the worm wheel and the brake cam shaft to rotate, so that a brake clearance tends to be reduced. According to the utility model, the relative rotation of the ratchet wheel and the pawl is utilized to drive the worm and the worm wheel to rotate by corresponding angles, so that the automatic adjustment of the braking gap is realized; the special direction limiting piece is arranged for the worm, so that the worm can only rotate unidirectionally, the worm is prevented from reversing due to external interference, the worm and the worm wheel are ensured to enable a braking gap to tend to be smaller, and therefore the stability and reliability of the braking gap automatic adjusting arm and the whole braking system are improved.

Description

Automatic adjusting arm for brake clearance

Technical Field

The utility model relates to the technical field of brake devices, in particular to an automatic brake clearance adjusting arm.

Background

The brake friction pair is one of main wear parts in the running process of the motor vehicle, and the reserved standard gap between the friction surfaces is increased due to the abrasion of the brake friction working surfaces along with the increase of the use frequency and the extension of the use time. Moreover, the gap between the brake friction pairs of the wheels of the same vehicle, which is increased by abrasion, is not completely uniform due to the influence of various factors. If the increased braking clearance is not adjusted in time, hidden danger is caused to driving safety. In the existing motor vehicle equipment, particularly in large-scale transportation vehicles, an automatic brake clearance adjusting arm has become the mainstream instead of manual adjustment.

Patent document CN1369655A (2002.9.18) discloses an automatic adjusting arm for braking clearance, which comprises a shell and an internal worm gear-worm transmission pair, wherein one end of the adjusting arm is linked with a braking cam shaft through a worm gear internal spline, and the other end of the adjusting arm is connected with a connecting sleeve through a pin shaft. One end of the connecting sleeve is connected with the brake pneumatic push rod, the other end of the connecting sleeve is connected with the sliding block and the ratchet wheel through the connecting rod, the ratchet wheel is connected with the worm in a matched mode through the internal spline, and the ratchet wheel is meshed with the pawl arranged on the shell. When the adjusting arm is reset, the relative rotation of the ratchet wheel and the pawl is utilized to drive the worm and the worm wheel to rotate by corresponding angles, and the idle clearance caused by abrasion between the braking friction pair is overcome, so that the automatic adjustment of the braking clearance is realized, and the adjusting arm is suitable for various motor vehicle braking devices.

The worm wheel-worm drive pair is one of the main components of the adjusting arm, but the worm can reversely rotate under certain working conditions when the worm is found in operation, and correspondingly the worm wheel can be driven to rotate, so that the adjustment of the braking gap is inaccurate or invalid, and the braking system cannot work normally under severe conditions, thereby causing potential safety hazards.

For the above reasons, there is a need for an improvement in the existing brake clearance automatic adjustment arm to increase its stability and reliability.

Disclosure of utility model

In order to enable the brake clearance automatic adjusting arm and a brake system to stably and reliably operate, the utility model provides the brake clearance automatic adjusting arm.

The technical scheme adopted by the utility model is as follows: the utility model provides a brake clearance automatic adjustment arm, includes casing, worm wheel and worm, casing one end is passed through the internal spline of worm wheel links with the brake camshaft, the other end of casing is with round pin axle coupling cover, the one end of coupling cover is associative with brake push rod, and the other end is with connecting rod connection slider and ratchet, the ratchet with the internal spline with the worm cooperation is connected, just the ratchet with pawl meshing on the casing still includes the limit to the piece, the limit is acted on the worm, unidirectional rotation the worm drives worm wheel with the brake camshaft is rotatory for the brake clearance tends to diminish.

Preferably, the direction limiting member adopts a one-way bearing or a one-way clutch.

Preferably, be equipped with between the outside one end of worm with the casing is equipped with as the oil seal circle of limit to the piece, the oil seal circle includes elasticity, concentric setting and integrated structure's lip circle and holding ring, the center formation of lip circle with worm complex toper shaft hole, the inner wall in toper shaft hole evenly has arranged a plurality of first limit to the sand grip, first limit is followed to the sand grip the axis in toper shaft hole extends and has rotation angle, first limit to the direction of rotation of sand grip with the direction of rotation of worm is unanimous.

Preferably, the lip ring forms a boss along the axial direction, a plurality of second limit to sand grip is evenly arranged to the terminal surface of boss, the second limit is to sand grip by the outside radial extension of boss, and have with first limit is to sand grip direction unanimous rotation angle, the second limit is to sand grip with the step face of worm supports tightly.

Preferably, a clamping spring is arranged between one end of the outer side of the worm and the shell, and the boss penetrates through an inner hole of the clamping spring to be abutted against the step surface of the worm.

Preferably, the oil seal ring further comprises a metal framework, the metal framework is provided with an end wall with holes and an annular wall, the end wall is fixed on the outer end face of the joint part of the lip ring and the support ring, and the annular wall is wrapped on the outer peripheral wall of the support ring.

Preferably, the end of the annular wall is provided with a flanging towards the axle center, and the flanging is embedded and fixed in the supporting ring.

Preferably, the worm wheel is assembled in a turbine hole of the shell, cover plates with holes are arranged at two ends of the turbine hole, a sealing piece is arranged between the worm wheel and the cover plates, and the sealing piece is supported between the end face of the worm wheel and the inner wall face of the cover plates.

Preferably, the inner wall of the cover plate is provided with a sealing ring groove facing the worm wheel, and the sealing element is installed in the sealing ring groove.

Preferably, the cover plate is of a cap-shaped structure with holes, and is provided with an outer edge part and a convex plug-in part, the end face of the plug-in part forms the inner wall surface, and the plug-in part is in plug-in fit with the turbine holes.

The utility model has the following beneficial effects: according to the utility model, the relative rotation of the ratchet wheel and the pawl is utilized to drive the worm and the worm wheel to rotate by corresponding angles, so that the automatic adjustment of the braking gap is realized; the special direction limiting piece is arranged for the worm, so that the worm can only rotate unidirectionally, the worm is prevented from reversing due to external interference, the worm and the worm wheel are ensured to enable a braking gap to tend to be smaller, and therefore the stability and reliability of the braking gap automatic adjusting arm and the whole braking system are improved.

Drawings

Fig. 1 is a perspective view of an embodiment of the present utility model.

Fig. 2 is a cross-sectional view of an embodiment of the present utility model.

Fig. 3 is an assembly diagram of a worm, an oil seal ring and a clamp spring in an embodiment of the utility model.

Fig. 4 is a perspective view of an oil seal in an embodiment of the utility model.

Fig. 5 is a cross-sectional view of an oil seal in an embodiment of the utility model.

Wherein:

a housing 1;

a worm wheel 2;

a worm 3;

A pin 4;

A coupling sleeve 5;

a connecting rod 6;

a slider 7;

a ratchet wheel 8;

a pawl 9;

The oil seal ring 10, the lip ring 1001, the support ring 1002, the conical shaft hole 1003, the first direction limiting convex strip 1004, the boss 1005, the second direction limiting convex strip 1006, the metal framework 1007, the end wall 1008, the annular wall 1009 and the flanging 1010;

and a clamp spring 11.

Detailed Description

The utility model will be further described with reference to examples and drawings.

In the embodiment, as shown in fig. 1-5, the automatic brake clearance adjusting arm comprises a shell 1, a worm wheel 2 and a worm 3, wherein one end of the shell 1 is linked with a brake cam shaft through an internal spline of the worm wheel 2, the other end of the shell 1 is connected with a connecting sleeve 5 through a pin shaft 4, one end of the connecting sleeve 5 is connected with a brake push rod, the other end of the connecting sleeve is connected with a sliding block 7 and a ratchet wheel 8 through a connecting rod 6, the ratchet wheel 8 is connected with the worm 3 in a matched manner through an internal spline, the ratchet wheel 8 is meshed with a pawl 9 on the shell 1, the automatic brake clearance adjusting arm further comprises a direction limiting piece, the direction limiting piece acts on the worm 3, and the worm 3 which rotates unidirectionally drives the worm wheel 2 and the brake cam shaft to rotate, so that the brake clearance tends to be reduced. The adjusting principle of the embodiment is consistent with that of the patent document CN1369655A, namely, the relative rotation of the ratchet wheel 8 and the pawl 9 is utilized to drive the worm 3 and the worm wheel 2 to rotate by corresponding angles, the backlash gap caused by abrasion between the braking friction pair is overcome, and the automatic adjustment of the braking gap is realized. In this embodiment, a special direction limiting member is specifically configured for the worm 3, so that the worm 3 can only rotate in one direction, that is, the worm wheel 2 rotates anticlockwise in fig. 2, so that the worm 3 is prevented from reversing due to external interference, the worm 3 and the worm wheel 2 are ensured to enable the brake gap to tend to be smaller, and the stability and reliability of the brake gap automatic adjusting arm and the whole brake system are improved.

In the embodiment, as shown in fig. 2 and 3, an oil seal ring 10 serving as a limiting member is arranged between one end of the outer side of the worm 3 and the housing 1, the oil seal ring 10 comprises a lip ring 1001 and a support ring 1002 which are arranged elastically and concentrically and are integrally formed, a conical shaft hole 1003 matched with the worm 3 is formed in the center of the lip ring 1001, a plurality of first limiting raised strips 1004 are uniformly arranged on the inner wall of the conical shaft hole 1003, the first limiting raised strips 1004 extend along the axis of the conical shaft hole 1003 and have a rotation angle, and the rotation direction of the first limiting raised strips 1004 is consistent with that of the worm 3. In this embodiment, by providing the first direction-limiting protruding strips 1004 with a rotation angle on the inner wall of the tapered shaft hole 1003, the resistance of the worm 3 against the reverse rotation of the first direction-limiting protruding strips 1004 is improved, and only the worm 3 is allowed to rotate along the rotation direction of the first direction-limiting protruding strips 1004, thereby realizing the dual functions of sealing and rotation direction limiting, and having good performance when applied to low-pressure sealing occasions. Compared with common one-way bearings or devices such as one-way clutches, the oil seal ring 10 of the embodiment has the advantages of simple and compact structure, and the original adjusting arm is not required to be changed, and only the novel oil seal ring 10 is required to be directly replaced, so that the oil seal ring 10 is simple in implementation, low in cost and obvious in effect.

In the embodiment, as shown in fig. 2 to 5, a boss 1005 is formed on the lip ring 1001 along the axial direction, a jump ring 11 is arranged between one end of the outer side of the worm 3 and the housing 1, and the boss 1005 passes through an inner hole of the jump ring 11 to contact with a step surface of the worm 3. A plurality of second direction limiting raised strips 1006 are uniformly arranged on the end surface of the boss 1005, the second direction limiting raised strips 1006 radially extend outwards from the boss 1005, and have a rotation angle consistent with the direction of the first direction limiting raised strips 1004, and the second direction limiting raised strips 1006 are abutted against the step surface of the worm 3. The oil seal 10 of the present embodiment is further provided with a second direction-limiting protrusion 1006 for contacting the step surface of the worm 3, and also has a function of rotation direction limitation, and the second direction-limiting protrusion 1006 cooperates with the first direction-limiting protrusion 1004 to function, thereby better achieving the purpose of rotation direction limitation.

In an embodiment, the rotation angle of the first direction-limiting convex strips 1004 and the second direction-limiting convex strips 1006 is 30-60 °, and the width is 0.2-0.6 mm. The lengths of the first direction limiting raised strips 1004 and the second direction limiting raised strips 1006 are determined according to the model of the product, and certain space is reserved at two ends, so that the whole positions of the conical shaft hole 1003 and the boss 1005 are not occupied, and the sealing effect is not influenced. Generally speaking, the greater the number and the greater the width of the first direction-limiting raised strips 1004 and the second direction-limiting raised strips 1006, the greater the reverse resistance, but the smaller the number and the narrower the width of the first direction-limiting raised strips 1004 and the second direction-limiting raised strips 1006, the better the sealing effect, so that proper parameters need to be selected according to the actual working conditions, and a balance is achieved between the two requirements, so as to meet the requirements of the safe production of equipment.

In an embodiment, as shown in fig. 5, the oil seal ring 10 further includes a metal skeleton 1007, where the metal skeleton 1007 has an end wall 1008 with a hole and an annular wall 1009, the end wall 1008 is fixed on an outer end surface of a connection portion between the lip ring 1001 and the support ring 1002, and the annular wall 1009 wraps around an outer peripheral wall of the support ring 1002. The end of the annular wall 1009 is provided with a flange 1010 facing the axle center, and the flange 1010 is embedded and fixed in the support ring 1002. The oil seal ring 10 of the embodiment adopts nitrile rubber with the hardness of 70-75 Shore A as a main sealing material, has good sealing performance, better wear resistance and moderate elasticity, can adapt to the movement of the worm 3 under different working conditions, and can still maintain effective sealing particularly under the condition that the first limit convex strip 1004 and the second limit convex strip 1006 exist. The metal skeleton 7 is made of Q235 or Q195 material, and the surface is subjected to scale treatment. The metal armature 1007 is structurally supported in the oil seal 10 by a number of functions such as providing structural support, resisting deformation and distortion, transmitting axial loads, guiding and positioning, corrosion and wear resistance, and the like.

It is apparent that the above examples of the present utility model are merely illustrative of the present utility model and are not limiting of the embodiments of the present utility model. Other obvious variations or modifications which are extended by the spirit of the present utility model are within the scope of the present utility model.

Claims (7)

1. The utility model provides a brake clearance automatic adjustment arm, includes casing (1), worm wheel (2) and worm (3), casing (1) one end is passed through the internal spline of worm wheel (2) links with the brake camshaft, the other end of casing (1) is with round pin axle (4) hookup coupling cover (5), the one end of coupling cover (5) is associative with the brake push rod, and the other end is with connecting rod (6) connection slider (7) and ratchet (8), ratchet (8) with the internal spline with worm (3) cooperation is connected, just ratchet (8) with pawl (9) meshing on casing (1), its characterized in that still includes the limit to the piece effect on worm (3), unidirectional rotation worm (3) drive worm wheel (2) with the brake camshaft is rotatory for the brake clearance tends to diminish.

2. The automatic brake slack adjustment arm of claim 1, wherein the direction limiter is a one-way bearing or a one-way clutch.

3. The automatic brake clearance adjusting arm according to claim 1, wherein an oil seal ring (10) serving as the direction limiting member is arranged between one end of the outer side of the worm (3) and the housing (1), the oil seal ring (10) comprises a lip ring (1001) and a support ring (1002) which are elastic, concentrically arranged and integrally structured, a conical shaft hole (1003) matched with the worm (3) is formed in the center of the lip ring (1001), a plurality of first direction limiting raised strips (1004) are uniformly arranged on the inner wall of the conical shaft hole (1003), the first direction limiting raised strips (1004) extend along the axis of the conical shaft hole (1003) and have a rotation angle, and the rotation direction of the first direction limiting raised strips (1004) is consistent with the rotation direction of the worm (3).

4. The automatic brake clearance adjusting arm according to claim 3, wherein the lip ring (1001) forms a boss (1005) along an axial direction, a plurality of second direction limiting raised ribs (1006) are uniformly arranged on an end surface of the boss (1005), the second direction limiting raised ribs (1006) radially extend outwards from the boss (1005) and have a rotation angle consistent with a direction of the first direction limiting raised ribs (1004), and the second direction limiting raised ribs (1006) are abutted against a step surface of the worm (3).

5. The automatic brake clearance adjusting arm according to claim 4, wherein a clamp spring (11) is arranged between one end of the outer side of the worm (3) and the housing (1), and the boss (1005) passes through an inner hole of the clamp spring (11) to be abutted against a step surface of the worm (3).

6. The automatic brake clearance adjustment arm according to claim 3, 4 or 5, wherein the oil seal ring (10) further comprises a metal skeleton (1007), the metal skeleton (1007) has an end wall (1008) with holes and an annular wall (1009), the end wall (1008) is fixed on the outer end surface of the connection part of the lip ring (1001) and the support ring (1002), and the annular wall (1009) is wrapped on the outer peripheral wall of the support ring (1002).

7. The automatic brake clearance adjustment arm according to claim 6, characterized in that the end of the annular wall (1009) is provided with a flange (1010) facing the axle center, said flange (1010) being embedded and fixed in the support ring (1002).