Expander for brake

Abstract

The utility model provides an expander for a brake, and belongs to the technical field of braking. The problem that impurities enter a shell of an existing expander, and consequently the braking effect is affected is solved. The expander for the brake comprises a shell, a reset spring and a rod-shaped push rod, a roller is connected to the inner end of the push rod, an annular connecting cover is axially limited on the outer side of the push rod, a cylindrical sealing cylinder and a cylindrical spring seat are further arranged on the outer side of the push rod in a sleeving mode, and the opposite ends of the sealing cylinder and the spring seat are fixed and sealed. The end, facing the connecting cover, of the sealing cylinder is fixed to the push rod, the sealing cylinder can deform when the push rod moves in the axial direction, the outer side of the end, facing the rolling wheel, of the spring base is sleeved with and fixedly provided with an annular sealing ring, and the outer side of the sealing ring abuts against the inner wall of the shell to form sealing. The expander for the brake has the advantage of being good in braking effect.

Description

Technical Field

[0001] The utility model belongs to the technical field of brakes and relates to an expander for brakes. Background Art

[0002] The brake is a device that has the function of slowing down, stopping or keeping the moving parts in a stopped state. It is a mechanical part that stops or slows down the moving parts in the machine, commonly known as brakes or gates. The expander is an important component of the brake, which is used to withstand the force and push the iron shoe to move to achieve braking.

[0003] For example, the applicant designed a ratchet expander for a wedge-type brake and applied for a Chinese patent, and its application number is: 202022017040.0; the ratchet expander for a wedge-type brake includes a shell, a push rod device, and a piston device. The shell is provided with a channel hole passing through two opposite sides of the shell, and the shell is also provided with a vertical hole vertically passing through the center of the channel hole and the other side of the shell. A ratchet ejector pin is fixed on the shell, and the piston device is provided with two groups. The two groups of piston devices are mirror-symmetrical and can be movably arranged in the channel holes on both sides of the vertical hole, respectively. The push rod device can be movably arranged in the vertical hole. The piston device includes a piston, a ratchet, and an adjusting bolt assembly. The piston can be slidably arranged in the channel hole. One end of the piston is an inclined surface and contacts with the push rod device. The other end of the piston is provided with an inwardly recessed accommodating hole. The adjusting The whole bolt assembly comprises an adjusting bolt, an adjusting nut and an ejection section. One end of the adjusting bolt is provided with a thread and is arranged in the piston accommodating hole, and the other end is fixed to the ejection section. The adjusting nut is threadedly connected with the adjusting bolt and can move in the piston accommodating hole. The ratchet is sleeved on the adjusting bolt and is close to one end of the adjusting bolt extending into the piston accommodating hole. A coupling portion is provided on the side of the adjusting nut and engages with the ratchet teeth of the ratchet. A gap is provided between the end face of the end of the adjusting bolt extending into the piston accommodating hole and the bottom of the accommodating hole. A disc spring is provided in the gap. The outer edge of the disc spring is tightly attached to the side face of the ratchet, and the center of the disc spring is tightly attached to the bottom of the piston accommodating hole. The piston is provided with a long slot hole for accommodating a ratchet ejector pin to pass through. An inwardly recessed arc ejector pin groove is provided on the circumferential surface of the ratchet. The top of the ratchet ejector pin is tightly attached to the bottom of the arc ejector pin groove and can slide along the bottom of the arc ejector pin groove.

[0004] When the wedge brake is working with a ratchet expander, the push rod device moves inward, and the inclined surface on the piston acts on the inner ends of the two pistons at the same time, so that the two pistons move outward, pushing the two adjusting bolt assemblies outward, and the ejection section at the outer end of the adjusting bolt assembly pushes the brake shoe and the friction pair to move, thereby achieving braking.

[0005] However, in the ratchet expander for the wedge brake, there is a gap between the push rod assembly and the housing. When impurities enter the housing and fall between the inner end of the push rod assembly and the inclined surface of the piston, it will affect the synchronization of the outward force movement of the two pistons and the stability of the push rod pushing the piston to move, thereby affecting the braking effect. Utility Model Content

[0006] The utility model aims to solve the above problems existing in the prior art and proposes a brake expander, which solves the problem that impurities may enter the shell of the prior expander and affect the braking effect.

[0007] The purpose of the utility model can be achieved through the following technical solutions:

[0008] The cam is an axially movable member which is configured to move relative to the outer wall of the housing, the cam being configured to move relative to the outer wall of the housing and being capable of moving relative to the outer wall of the housing.

[0009] In the expander for the brake, a sealing cylinder and a spring seat are arranged between the outer side of the push rod and the inner wall of the housing, and a seal is formed between the sealing cylinder, the push rod and the spring seat, and a seal is formed between the spring seat and the inner wall of the housing, so that the gap between the push rod and the housing is blocked, effectively preventing impurities from entering the housing and affecting the braking effect. The sealing cylinder can be partially made of rubber material, so that when the push rod moves axially inward relative to the housing, the sealing cylinder can move with the push rod under the condition of being compressed and deformed, thereby ensuring the sealing performance during the movement of the push rod.

[0010] In the above-mentioned expander for brakes, the inner wall of the housing has a protruding boss, and the end of the spring seat facing the roller abuts against the boss. The boss is used to position the spring seat to ensure the sealing effect between the sealing ring outside the spring seat and the housing.

[0011] In the above-mentioned expander for brakes, the number of the bosses is two and they are arranged on the two opposite side walls in the housing, the two sides of the end of the spring seat facing the roller are respectively against the two bosses, and the inner end of the push rod passes between the two bosses. The two bosses support the spring seat, and the support and positioning effect is better. The inner end of the push rod passes through the gap between the two bosses, ensuring the normal operation of the push rod.

[0012] In the above-mentioned expander for brakes, the end of the spring seat facing the roller has a bending portion with a U-shaped cross section and the opening of the bending portion faces the above-mentioned connection cover, the end of the reset spring facing the roller extends from the opening of the bending portion into the bending portion and abuts against the bending portion, the end of the bending portion close to the inner wall of the shell is bent toward the inner wall of the shell to form a circular ring-shaped limiting portion, a circular ring is fixed to the outside of the bending portion, and the sealing ring is arranged between the ring and the limiting portion. The U-shaped bending portion can not only strengthen the strength of the end of the spring seat, but also better position and guide the end of the reset spring, and the setting of the limiting portion and the ring is used to fix the sealing ring to prevent the sealing ring from slipping and ensure the sealing performance.

[0013] In the above-mentioned expander for brake, the outer wall of the push rod has a recessed annular groove, and the end of the sealing cylinder facing the connection cover is inserted into the groove. The sealing cylinder and the push rod are fixed by the groove, which is convenient for installation.

[0014] In the above-mentioned expander for brakes, the sealing cylinder includes a deformation part in the shape of a cone cylinder and a connection part 1 and a connection part 2 both in the shape of a circular ring. The deformation part is made of rubber material. The connection part 1 and the connection part 2 are respectively located at the two ends of the deformation part and fixed to the deformation part. The connection part 1 is inserted into the above-mentioned slot, and the connection part 2 is located in the spring seat and fixed to the spring seat. The sealing cylinder is divided into three parts. The deformation part in the middle section is made of rubber material, so that the sealing cylinder can be deformed accordingly when the push rod moves, and the connection part 1 and the connection part 2 can be made of hard plastic or metal material to ensure the stability of the connection.

[0015] In the above-mentioned expander for brakes, a circular ring is fixed to the outer side of the outer end of the push rod, and the connection cover abuts against the ring under the elastic force of the return spring. By means of the arrangement of the ring and the return spring, the connection cover is axially limited to the outer side of the push rod and will not fall out from the outer end of the push rod, and also provides a support point for the end of the return spring.

[0016] Compared with the prior art, in the expander for the brake, a sealing cylinder and a spring seat are arranged between the outer side of the push rod and the inner wall of the shell, a seal is formed between the sealing cylinder, the push rod and the spring seat, and a seal is formed between the spring seat and the inner wall of the shell, so that the gap between the push rod and the shell is blocked, effectively preventing impurities from entering the shell and affecting the braking effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the cross-sectional structure of the expander for the brake.

[0018] Figure 2 It is a schematic cross-sectional structure diagram of the expander for the brake from another perspective.

[0019] In the figure, 1, housing; 1a, boss; 2, return spring; 3, push rod; 3a, slot; 4, roller; 5, connecting cover; 6, sealing cylinder; 6a, deformation part; 6b, connecting part 1; 6c, connecting part 2; 7, spring seat; 7a, bending part; 7b, limiting part; 8, sealing ring; 9, retaining ring; 10, retaining ring. DETAILED DESCRIPTION

[0020] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0021] like Figure 1 As shown, the expander for the brake comprises a housing 1, a push rod assembly, a piston, an adjusting bolt assembly and a sheath. The shape of the housing 1, the location of the push rod assembly, the specific structures of the sheath, the piston and the adjusting assembly, and the working principle of the entire expander are the same as those of the applicant's prior application in the background technology, and are not described in detail. Here, the sheath is a structure for protecting the push rod 3 when the product is sold, and needs to be removed when it is actually used.

[0022] The specific structure of the push rod assembly is described below in the orientation shown in the accompanying drawings.

[0023] The push rod assembly includes a return spring 2 and a rod-shaped push rod 3. The inner end, i.e., the lower end, of the push rod 3 extends into the housing 1 and the lower end of the push rod 3 is rotatably connected to two rollers 4. The two rollers 4 are used to cooperate with the inclined surfaces of the two pistons to achieve linkage.

[0024] A circular ring 10 is fixed to the outer side of the upper end of the push rod 3, and a circular connecting cover 5 and the above-mentioned return spring 2 are sleeved on the outer side of the push rod 3. The upper end of the return spring 2 abuts against the lower side of the connecting cover 5, so that the upper side of the connecting cover 5 abuts against the lower side of the ring 10, and the push rod 3 cannot be detached from the upper end of the push rod 3, thereby achieving axial limitation on the push rod 3.

[0025] A sealing cylinder 6 and a spring seat 7 both in cylindrical shape are sleeved on the outside of the push rod 3 . The sealing cylinder 6 and the spring seat 7 are both arranged between the connecting cover 5 and the roller 4 , and the sealing cylinder 6 is located above the spring seat 7 .

[0026] The sealing cylinder 6 comprises a deformation part 6a in the shape of a cone cylinder, and a connecting part 1 6b and a connecting part 2 6c in the shape of an annular ring. The deformation part 6a is made of rubber material. The connecting part 1 6b and the connecting part 2 6c are respectively located at the two ends of the deformation part 6a and fixed to the deformation part 6a. The connecting part 1 6b and the connecting part 2 6c are made of metal material. The outer wall of the push rod 3 has a recessed groove 3a in the shape of an annular ring. The connecting part 1 6b located at the upper end of the sealing cylinder 6 is inserted into the groove 3a. The diameter of the connecting part 2 6c located at the lower end of the sealing cylinder 6 is larger than that of the connecting part 1 6b. The connecting part 2 6c is passed into the upper end of the spring seat 7 and is interference fit with the spring seat 7. If necessary, it can be fixed by welding.

[0027] like Figure 2 As shown, the inner wall of the shell 1 has two protruding bosses 1a, which are arranged on two opposite side walls of the shell 1. The two sides of one end of the spring seat 7 facing the roller 4 are respectively against the two bosses 1a, and the inner end of the push rod 3 passes between the two bosses 1a.

[0028] The end of the spring seat 7 facing the roller 4 is bent outward and upward to form a U-shaped bending portion 7a, and the opening of the bending portion 7a is arranged upward, and the lower end of the return spring 2 extends into the bending portion 7a and abuts against the inner bottom of the bending portion 7a. The upper end of the bending portion 7a close to the inner wall of the housing 1 is bent toward the inner wall of the housing 1 to form a circular ring-shaped limiting portion 7b, and the outer side of the bending portion 7a is interference-fitted with a circular ring 9, and a sealing groove is formed between the upper end of the ring 9 and the lower side of the limiting portion 7b, and a circular ring 8 is arranged in the sealing groove, and the diameter of the sealing ring 8 is greater than the depth of the sealing groove, and the sealing ring 8 forms a seal between the inner wall of the housing 1 and the spring seat 7.

[0029] When the brake expander is in use, the outer end of the push rod 3 moves downward under the force of the driving member such as the cylinder, the spring seat 7 rests on the boss 1a and remains motionless, the connecting cover 5 moves downward with the push rod 3 and compresses the reset spring 2, the connecting part 1 6b of the sealing tube 6 moves downward with the push rod 3, the connecting part 2 6c remains motionless, and the deformation part 6a is compressed and deformed. The two rollers 4 act on the inclined surfaces of the pistons on both sides as the push rod 3 moves downward, pushing the two pistons and the corresponding adjustment bolt assembly to move outward, pushing the brake shoe and the friction pair to act to achieve braking.

[0030] After the braking is completed, the downward push force disappears, and the push rod 3 moves upward and resets under the elastic force of the reset spring 2. Similarly, the deformation portion 6a also returns to the initial state.

[0031] During this working process, the cooperation of the sealing tube 6, the spring seat 7 and the sealing ring 8 always maintains the seal between the outer side of the push rod 3 and the inner wall of the housing 1, which can effectively prevent impurities from entering the housing 1 and affecting the braking effect.

[0032] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A brake expander, comprising a housing (1), a return spring (2) and a rod-shaped push rod (3), wherein the inner end of the push rod (3) extends into the housing (1) and the inner end of the push rod (3) is rotatably connected to a roller (4), the outer end of the push rod (3) is axially limited by a circular connecting cover (5), the return spring (2) is sleeved on the outer side of the push rod (3) and one end of the return spring (2) is in contact with the connecting cover (5), characterized in that: The outer side of the push rod (3) is also sleeved with a sealing cylinder (6) and a spring seat (7) both in the shape of a cylinder. The sealing cylinder (6) and the spring seat (7) are both arranged between the connecting cover (5) and the roller (4), and the sealing cylinder (6) is closer to the connecting cover (5) than the spring seat (7). The ends of the sealing cylinder (6) and the spring seat (7) facing each other are fixed to each other and form a seal. The end of the sealing cylinder (6) facing the connecting cover (5) is fixed to the push rod (3), and the sealing cylinder (6) can be deformed when the push rod (3) moves axially. The outer side of the end of the spring seat (7) facing the roller (4) is sleeved and fixed with a circular sealing ring (8), and the outer side of the sealing ring (8) abuts against the inner wall of the housing (1) to form a seal. The other end of the return spring (2) abuts against the spring seat (7).

2. A brake expander according to claim 1, characterized in that: The inner wall of the housing (1) has a protruding boss (1a), and one end of the spring seat (7) facing the roller (4) abuts against the boss (1a).

3. A brake expander according to claim 2, characterized in that: The number of the bosses (1a) is two and they are arranged on two opposite side walls of the housing (1); the two sides of one end of the spring seat (7) facing the roller (4) are respectively in contact with the two bosses (1a); the inner end of the push rod (3) passes between the two bosses (1a).

4. A brake expander according to claim 1, 2 or 3, characterized in that: The end of the spring seat (7) facing the roller (4) has a bending portion (7a) with a U-shaped cross section, and the opening of the bending portion (7a) faces the above-mentioned connection cover (5); the end of the return spring (2) facing the roller (4) extends from the opening of the bending portion (7a) into the bending portion (7a) and abuts against the bending portion (7a); the end of the bending portion (7a) close to the inner wall of the shell (1) is bent toward the inner wall of the shell (1) to form a circular ring-shaped limiting portion (7b); a circular ring-shaped retaining ring (9) is fixed to the outer side of the bending portion (7a); and the sealing ring (8) is arranged between the retaining ring (9) and the limiting portion (7b).

5. A brake expander according to claim 1, 2 or 3, characterized in that: The outer wall of the push rod (3) has a recessed circular groove (3a), and one end of the sealing cylinder (6) facing the connecting cover (5) is inserted into the groove (3a).

6. A brake expander according to claim 5, characterized in that: The sealing cylinder (6) comprises a conical deformation portion (6a) and a connecting portion 1 (6b) and a connecting portion 2 (6c) both in the shape of an annular ring. The deformation portion (6a) is made of rubber material. The connecting portion 1 (6b) and the connecting portion 2 (6c) are respectively located at two ends of the deformation portion (6a) and are fixed to the deformation portion (6a). The connecting portion 1 (6b) is inserted into the above-mentioned slot (3a), and the connecting portion 2 (6c) is located in the spring seat (7) and is fixed to the spring seat (7).

7. A brake expander according to claim 1, 2 or 3, characterized in that: A circular ring (10) is fixed to the outer side of the outer end of the push rod (3), and the connecting cover (5) is pressed against the ring (10) under the elastic force of the return spring (2).

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