Fixed brake wheel type dead-point-free brake device of oil pumping unit

Abstract

The utility model provides a fixed brake wheel type non-dead-point brake device of an oil pumping unit. The fixed brake wheel type non-dead-point brake device comprises a brake force arm rod and a rotary fluted disc which are fixed on a speed reducer of the oil pumping unit, the brake force arm rod is matched with the rotating fluted disc to achieve braking and comprises a brake force arm body, a movable clamping block and a limiting structure. An arc-shaped limiting sliding groove is formed in the brake force arm body. The first end of the brake force arm body is hinged to the operating rod, and the second end of the brake force arm body is rotatably connected to the pumping unit speed reducer. The movable clamping block is installed in the arc-shaped limiting sliding groove in a sliding mode. The limiting structure is installed in the arc-shaped limiting sliding groove and is in sliding connection with the movable clamping block. Therefore, the movable clamping block can automatically slide to the locking position where the movable clamping block and the rotary fluted disc are locked in the process of being clamped into the rotary fluted disc, rotation of the brake wheel is limited, braking is achieved, the stability and reliability of braking are kept, operation convenience and efficiency are improved, and the brake device is suitable for popularization and application. And the movable clamping block locks the rotary fluted disc in a self-adaptive manner, so that the braking can be accurately and reliably realized, and the operation safety is improved.

Description

Technical Field

[0001] This utility model relates to the field of petroleum machinery parts technology, and more specifically, to a fixed brake wheel type brake device for oil pumping units with no dead spot. Background Technology

[0002] The braking mechanism of an oil pumping unit typically consists of a brake wheel mounted on the input shaft of a reducer and brake shoes fixed to the reducer, connected by an operating mechanism to achieve braking and releasing, forming the main braking mechanism. For added safety, an auxiliary locking component is also provided. A simpler method is to install a hook on the reducer. When the main brake is engaged, the hook is directly engaged in the slot on the brake wheel. However, this method has a problem: after the brake is engaged, the first slot on the wheel may not be perfectly aligned with the hook's locking claw. The brake needs to be slightly loosened, and the brake wheel needs to be slightly rotated to engage the claw. Both engaging and disengaging the claw are done manually, which is complex and poses safety risks.

[0003] Therefore, it is necessary to provide a braking mechanism to solve the problems existing in the prior art. Utility Model Content

[0004] The main purpose of this utility model is to provide a fixed brake wheel type brake device for oil pumping units without dead spots, so as to at least solve the problem in the prior art that when the brake is stopped, the slot is not aligned with the hook claw, and manual release of the brake is required, which leads to complicated operation and potential safety risks.

[0005] To achieve the above objectives, this utility model provides a fixed brake wheel type brake device for an oil pumping unit with no dead spot, including a brake arm and a rotating gear disk fixed on the oil pumping unit reducer, the rotating gear disk being fixedly connected to the brake wheel; the brake arm cooperates with the rotating gear disk to achieve braking, the brake arm includes: a brake arm body, a movable locking block, and a limiting structure; the brake arm body has an arc-shaped limiting groove, the arc of the arc-shaped limiting groove matching the wheel edge arc of the rotating gear disk; the first end of the brake arm body is hinged to an operating rod, and the second end of the brake arm body is rotatably sleeved on the outer surface of a fixed pin fixedly installed on the oil pumping unit reducer; the movable locking block is slidably installed in the arc-shaped limiting groove along the extension direction of the arc-shaped limiting groove; the limiting structure is installed in the arc-shaped limiting groove and slidably connected to the movable locking block;

[0006] The movable locking block has an initial position that slides along the arc-shaped limiting groove and a locked position that moves to both sides; when the first end of the brake arm body moves toward the rotating gear disk to a preset position under the action of external force, the movable locking block and the rotating gear disk are locked together and driven to the locked position by the rotating gear disk; the limiting structure is used to limit the locked position of the movable locking block.

[0007] Optionally, the brake arm body includes an arm base and two sealing plates; the first end of the arm base is hinged to the operating lever, and the second end of the arm base is rotatably connected to the pumping unit reducer; the two sealing plates are symmetrically installed on both sides of the arm base and form an arc-shaped limiting groove with the arm base.

[0008] Optionally, multiple identical tooth grooves are formed between each adjacent tooth of the rotating toothed disc, and the movable locking block includes a guide block and a locking tooth; the guide block is installed in the arc-shaped limiting slide groove, and the edge of the arc-shaped top surface of the guide block fits against the inner arc-shaped surface of the arc-shaped limiting slide groove; the locking tooth is disposed on the bottom surface of the guide block, and the outer dimensions of the locking tooth match the shape of the tooth groove, and the locking tooth is used to engage in the tooth groove under the drive of the guide block.

[0009] Optionally, the guide block has a strip groove inside, the curvature of which matches the curvature of the wheel edge of the rotating gear disk; the limiting structure includes a limiting pin, the two ends of which are fixed to the two sets of the sealing plates, and the limiting pin passes through the strip groove. The limiting pin is used to restrict the guide block from moving to the locking position in the arc-shaped limiting groove.

[0010] Optionally, the brake lever further includes an elastic structure, which connects the brake lever body and the movable locking block respectively; the elastic structure is used to reset the movable locking block to the initial position.

[0011] Optionally, the elastic structure includes two sets of compression springs, with each set of compression springs having its two ends fixedly installed on an inner sidewall of the arc-shaped limiting slide groove and the sidewall of the movable block, respectively; wherein, when the brake is released, the force of the two sets of compression springs causes the movable block to return to the initial position.

[0012] Optionally, a first slot is formed on the inner sidewalls of both sides of the arc-shaped limiting slide groove, and two sets of compression springs are arranged in the arc-shaped limiting slide groove and correspondingly arranged on both sides of the movable block. A second slot is formed on the sidewalls of the movable block opposite to the first slot. The two ends of each set of compression springs are respectively fixedly installed in one of the first slots and one of the corresponding second slots.

[0013] Optionally, the two ends of the strip groove are arcs that precisely match the surface of the limiting pin; the width of the strip groove precisely matches the diameter of the limiting pin.

[0014] This utility model discloses a fixed brake wheel type brake device for an oil pumping unit with no dead spot, comprising a brake arm and a rotating gear disk fixedly connected to the reducer of the oil pumping unit. The rotating gear disk is fixedly connected to the brake wheel. The brake arm cooperates with the rotating gear disk to achieve braking. The brake arm includes a brake arm body, a movable locking block, and a limiting structure. An arc-shaped limiting groove is formed on the brake arm body, and the arc of the arc-shaped limiting groove matches the arc of the wheel edge of the rotating gear disk. The first end of the brake arm body is hinged to an operating rod, and the second end of the brake arm body is rotatably connected to... It is connected to the pumping unit reducer; the movable locking block is slidably installed in the arc-shaped limiting groove along the extension direction of the arc-shaped limiting groove; the limiting structure is installed in the arc-shaped limiting groove and slidably connected to the movable locking block; wherein, the movable locking block has an initial position for sliding along the arc-shaped limiting groove and a locked position for moving to both sides; when the first end of the brake arm body moves towards the rotating gear disk to the preset position under the action of external force, the movable locking block and the rotating gear disk are locked together and driven to the locked position by the rotating gear disk; the limiting structure is used to limit the locked position of the movable locking block. Thus, the movable locking block can automatically slide to the locked position with the rotating gear disk during the process of locking into the rotating gear disk, so that at any rotation position of the rotating gear disk, the movable locking block can be locked into the rotating gear disk, thereby limiting the rotation of the brake wheel, realizing braking, and maintaining the stability and reliability of the brake, improving the convenience and efficiency of operation, and the movable locking block adaptively locks the rotating gear disk to ensure that the braking can be realized accurately and reliably, improving operational safety. Attached Figure Description

[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0016] Figure 1 This is a schematic diagram of a fixed brake wheel type dead-point braking device for an oil pumping unit, which is an optional embodiment of this utility model;

[0017] Figure 2 This is a schematic diagram of an optional brake lever according to an embodiment of the present utility model.

[0018] Figure label:

[0019] 10. Brake lever; 11. Brake lever body; 111. Lever base; 112. Sealing plate; 12. Movable locking block; 121. Guide block; 122. Locking tooth; 13. Limiting structure; 131. Limiting pin; 14. Elastic structure; 141. Compression spring; 20. Rotating gear plate; 30. Fixed pin. Detailed Implementation

[0020] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] like Figure 1 As shown, a fixed brake wheel type brake device for an oil pumping unit includes a brake arm 10 and a rotating gear 20 fixed on the oil pumping unit reducer. The rotating gear 20 is fixedly connected to the brake wheel. The brake arm 10 cooperates with the rotating gear 20 to achieve braking. The brake arm 10 includes a brake arm body 11, a movable locking block 12, and a limiting structure 13. An arc-shaped limiting groove is provided on the brake arm body 11, and the arc of the arc-shaped limiting groove matches the arc of the wheel edge of the rotating gear 20. The first end of the brake arm body 11 is hinged to an operating rod, and the second end of the brake arm body 11 is rotatably sleeved on the outer surface of a fixed pin (30) fixedly installed on the oil pumping unit reducer. The movable locking block 12 is slidably installed in the arc-shaped limiting groove along the extension direction of the arc-shaped limiting groove. The limiting structure 13 is installed in the arc-shaped limiting groove and slidably connected to the movable locking block 12.

[0022] The movable locking block 12 has an initial position for sliding along the arc-shaped limiting groove and a locking position for moving to both sides; when the first end of the brake arm body 11 moves toward the rotating gear 20 to a preset position under the action of external force, the movable locking block 12 and the rotating gear 20 are locked together and driven to the locking position by the rotating gear 20; the limiting structure 13 is used to limit the locking position of the movable locking block 12.

[0023] Specifically, the rotating gear disk 20 is fixedly connected to the brake wheel of the pumping unit via positioning bolts, allowing the braking force acting on the rotating gear disk 20 to be directly transmitted to the brake wheel. That is, when the rotating gear disk is restricted from rotating, the brake wheel stops rotating, causing the pumping unit to brake and stop working. When the movable locking block 12 is not in contact with the rotating gear disk 20, the movable locking block 12 is always in the set position of the arc-shaped limiting groove, which is the initial position. The arc-shaped limiting groove allows the movable locking block 12 to move only along the arc of the groove, thus enabling a smoother match with the wheel edge of the rotating gear disk 20. The first end of the brake arm body 11 is hinged to the operating lever on the pumping unit. A fixed pin 30 is fixedly installed on the pumping unit reducer. The second end of the brake arm body 11 is rotatably sleeved on the outer surface of the fixed pin 30. When the force of the operating lever acts on the first end of the brake arm body 11, it causes the second end of the brake arm body 11 to rotate around the fixed pin 30.

[0024] When the movable locking block 12 contacts and is subjected to force with the rotating gear disk 20, the movable locking block 12 moves until it is locked to the rotating gear disk 20. At this time, the position of the movable locking block 12 is the locked position. The movable locking block 12 can move in different directions according to the rotation position of the rotating gear disk 20, so there are two locking positions. The initial position is located between the two locking positions, and sometimes the initial position is the same as the locking position.

[0025] In this application, an arc-shaped limiting groove is formed on the brake arm body 11. The curvature of the arc-shaped limiting groove matches the wheel edge of the rotating gear disk 20. The movable locking block 12 is slidably installed along the arc-shaped limiting groove, that is, the movable locking block 12 slides around the wheel edge of the rotating gear disk 20 during the process of locking with the rotating gear disk 20. A limiting structure 13 is installed inside the arc-shaped limiting groove, which restricts the sliding position of the movable locking block 12 within the arc-shaped limiting groove. When the first end operating lever of the brake arm body 11 moves towards the rotating gear disk 20 to a preset position under the force applied, the movable locking block 12 slides within the arc-shaped limiting groove with the center of the rotating gear disk 20 as the center, under the restriction of the limiting structure 13, and then locks into the rotating gear disk 20. Because the movable locking block 12 can slide to a locked position with the rotating gear 20 during engagement, it can engage and lock with the rotating gear 20 at any rotational position, thus restricting the rotation of the brake wheel, achieving braking, and maintaining the stability and reliability of the brake. The operator does not need to perform tedious manual fine-tuning before braking; braking can be achieved with simple operation, greatly improving the convenience and efficiency of operation. Furthermore, the self-adaptive locking of the rotating gear 20 by the movable locking block 12 ensures accurate and reliable braking regardless of the position of the rotating gear 20, reducing the risk of brake failure due to improper operation and improving operational safety.

[0026] In one possible implementation, the brake lever body 11 includes a lever base 111 and two sealing plates 112; the first end of the lever base 111 is hinged to the operating lever, and the second end of the lever base 111 is rotatably connected to the pumping unit reducer; the two sealing plates 112 are symmetrically installed on both sides of the lever base 111 and form an arc-shaped limiting groove between them and the lever base 111.

[0027] Specifically, the brake arm body 11 consists of an arm base 111 and two sealing plates 112, simplifying the manufacturing process. Furthermore, the movable locking block 12 can be more easily installed in the arc-shaped limiting groove. During installation, one sealing plate 112 is installed first, then the movable locking block 12 is placed into the arc-shaped limiting groove, and then the other sealing plate 112 is installed, thus confining the movable locking block 12 within the arc-shaped limiting groove. Additionally, if any of the arm base 111 or the two sealing plates 112 is damaged or requires repair, it can be replaced or repaired individually, reducing maintenance costs and complexity.

[0028] In one possible implementation, multiple identical tooth grooves are formed between each adjacent tooth of the rotating toothed disk 20. The movable locking block 12 includes a guide block 121 and a locking tooth 122. The guide block 121 is installed in the arc-shaped limiting slide groove, and the edge of the arc-shaped top surface of the guide block 121 fits against the inner arc-shaped surface of the arc-shaped limiting slide groove. The locking tooth 122 is disposed on the bottom surface of the guide block 121, and the outer dimensions of the locking tooth 122 match the shape of the tooth groove. The locking tooth 122 is used to be locked into the tooth groove under the drive of the guide block 121.

[0029] Specifically, such as Figure 2 As shown, the guide block 121 is located within the arc-shaped limiting groove. The edge of the arc-shaped top surface of the guide block 121 fits against the inner arc-shaped surface of the arc-shaped limiting groove, allowing the guide block 121 to slide along the inner arc-shaped surface of the arc-shaped limiting groove. The locking tooth 122 is fixed to the bottom surface of the guide block 121 and located outside the arc-shaped limiting groove. When the guide block 121 slides along the inner arc-shaped surface of the arc-shaped limiting groove, it drives the locking tooth 122 to move along the same path. Multiple teeth are evenly distributed on the outer circumference of the rotating gear disk 20, with each adjacent tooth forming a tooth groove; that is, the wheel edge of the rotating gear disk 20 forms multiple tooth grooves. The outer dimensions of the locking tooth 122 match the tooth grooves. When the outer shape of the locking tooth 122 completely matches the tooth groove, the locking tooth 122 is locked in place with the tooth groove. The guide block 121 and the locking tooth 122 are integrally cast.

[0030] In one possible implementation, the guide block 121 has a strip-shaped groove inside, the curvature of which matches the curvature of the wheel edge of the rotating gear disk 20; the limiting structure 13 includes a limiting pin 131, the two ends of which are fixed to two sets of sealing plates 112, and the limiting pin 131 is located in the strip-shaped groove. The limiting pin 131 is used to restrict the guide block 121 from moving to the locked position in the arc-shaped limiting groove.

[0031] Specifically, the limiting pin 131 is on both sets of sealing plates 112, and the limiting pin 131 passes through the strip-shaped groove. The limiting pin 131 restricts the guide block 121 within the arc-shaped limiting groove, and through the cooperation of the limiting pin 131 and the strip-shaped groove, the longest sliding distance of the guide block 121 within the arc-shaped limiting groove is the length of the strip-shaped groove, thus restricting the guide block 121 from moving to the locked position within the arc-shaped limiting groove. At the same time, it also restricts the guide block 121 from moving from the locked position to the initial position.

[0032] In one possible implementation, the brake lever 10 further includes an elastic structure 14, which is connected to the brake lever body 11 and the movable locking block 12 respectively; the elastic structure 14 is used to reset the movable locking block 12 to the initial position.

[0033] Specifically, the elastic structure 14 connects the brake arm body 11 and the movable locking block 12, enabling the movable locking block 12 to automatically reset. When the brake is released, the movable locking block 12 moves away from its position engaged with the tooth groove of the rotating gear disc 20, and the elastic structure 14 provides a restoring force, automatically pulling the movable locking block 12 back to its initial position. This improves the stability and reliability of the braking system and simplifies the operation process. Furthermore, the automatic reset of the movable locking block 12 under the action of the elastic structure 14 reduces manual operation and improves safety.

[0034] In one possible implementation, the elastic structure 14 includes two sets of compression springs 141. The two sets of compression springs 141 are disposed in the arc-shaped limiting slide groove and are correspondingly disposed on both sides of the movable block 12. The two ends of each set of compression springs 141 are respectively fixedly installed on one inner side wall of the arc-shaped limiting slide groove and the side wall of the movable block 12.

[0035] When the brake is released, the force of the two sets of compression springs 141 causes the movable block 12 to return to its initial position.

[0036] Specifically, a set of compression springs 141 are provided on each side of the movable latch 12. The compression springs 141 have a defined restoring force and direction, ensuring that the movable latch 12 quickly and accurately returns to its initial position after the brake is released. Furthermore, the elasticity and restoring force of the compression springs 141 can be adjusted according to actual needs to adapt to different operational requirements. In addition, compared to other complex elastic structures, compression springs are relatively inexpensive and easy to procure and install. This helps reduce the overall cost of the braking system, resulting in a high cost-performance ratio.

[0037] In one possible implementation, the inner sidewalls of both sides of the arc-shaped limiting slide are provided with first slots, and the sidewalls of the movable block 12 opposite to the first slots are provided with second slots; the two ends of each set of compression springs 141 are respectively fixedly installed in a first slot and a corresponding second slot.

[0038] Specifically, the inner wall of the arc-shaped limiting slide groove has a first slot for mounting one end of a compression spring 141, and the side wall of the movable block 12 corresponding to the first slot has a second slot for mounting the other end of the compression spring 141. The first and second slots provide a clear mounting position for the compression spring 141, ensuring that both ends of the compression spring 141 can be stably fixed to the brake arm body 11 and the movable block 12, preventing the compression spring 141 from loosening or misaligning during installation, and ensuring the normal operation and long-term reliability of the compression spring. In addition, the first and second slots not only provide a mounting position for the compression spring, but also enhance the structural stability between the brake arm body 11 and the movable block 12, preventing the movable block from shaking or shifting during force application, thereby improving the overall stability and safety of the braking system.

[0039] In one possible implementation, the two ends of the strip groove are arcs that precisely match the surface of the limiting pin 131; the width of the strip groove precisely matches the diameter of the limiting pin 131.

[0040] Specifically, the precise matching of the width of the strip groove with the diameter of the limiting pin 131 reduces the wobbling or offset of the movable block 12 during movement, improving the overall accuracy and reliability of the braking system. When the movable block 12 slides to contact the limiting pin 131 within the strip groove, the arc of the end face of the strip groove precisely matches the outer surface of the limiting pin 131, further enhancing stability.

[0041] When the oil extraction requires braking: The operating lever is manipulated, which then generates a mechanical linkage, moving the first end of the brake arm 11 towards the rotating gear 20 until the preset braking position is reached. The interaction between the movable block 12 and the rotating gear 20 is rapid and precise. The movable block 12 is tightly engaged in the preset slot of the rotating gear 20 and is steadily driven from its initial position to the locked position by the mechanical structure of the rotating gear 20. This process ensures that the rotating gear 20 is completely locked and cannot rotate.

[0042] When the brake needs to be released during oil extraction: The operating lever is operated in the opposite direction to the braking direction, causing the first end of the brake arm 11 to gradually move away from the previously reached preset braking position, thus releasing the braking pressure on the rotating gear 20. As the operating lever continues to be operated in the opposite direction, the locking state between the movable block 12 and the rotating gear 20 gradually weakens until the movable block 12 is completely disengaged from the teeth of the rotating gear 20, at which point the locking state of the rotating gear 20 is released. Once the movable block 12 is completely disengaged from the rotating gear 20, the reset mechanism is immediately activated, and the movable block 12 quickly returns to its initial position from the locked position, preparing for the next braking operation.

[0043] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A fixed brake wheel type brake device for an oil pumping unit, comprising a brake lever (10) and a rotating gear disc (20) fixed on the reducer of the oil pumping unit, characterized in that, The rotating gear disc (20) is fixedly connected to the brake wheel; the brake lever (10) cooperates with the rotating gear disc (20) to achieve braking, and the brake lever (10) includes: The brake arm body (11) has an arc-shaped limiting groove, the arc of which matches the wheel edge arc of the rotating gear disc (20); the first end of the brake arm body (11) is hinged to the operating rod, and the second end of the brake arm body (11) is rotatably sleeved on the outer surface of the fixed pin (30) fixedly installed on the pump reducer; The movable card block (12) is slidably installed in the arc-shaped limiting slide groove along the extension direction of the arc-shaped limiting slide groove; The limiting structure (13) is installed in the arc-shaped limiting groove and is slidably connected to the movable card block (12); The movable locking block (12) has an initial position for sliding along the arc-shaped limiting groove and a locking position for moving to both sides; when the first end of the brake arm body (11) moves toward the rotating gear disk (20) to a preset position under the action of external force, the movable locking block (12) and the rotating gear disk (20) are locked together and driven to the locking position by the rotating gear disk (20); the limiting structure (13) is used to limit the locking position of the movable locking block (12).

2. The fixed brake wheel type brake device for an oil pumping unit with no dead spot as described in claim 1, characterized in that, The brake arm body (11) includes: A lever arm base (111) has a first end hinged to the operating rod and a second end rotatably connected to the pumping unit reducer. Two sealing plates (112) are symmetrically installed on both sides of the lever arm base (111), forming the arc-shaped limiting groove between them and the lever arm base (111).

3. The fixed brake wheel type brake device for an oil pumping unit with no dead spot as described in claim 2, characterized in that, The rotating toothed disc (20) forms multiple identical tooth grooves between each adjacent tooth, and the movable locking block (12) includes: Guide block (121), the guide block (121) is installed in the arc-shaped limiting slide groove, and the edge of the arc-shaped top surface of the guide block (121) is in contact with the inner arc-shaped surface of the arc-shaped limiting slide groove; A locking tooth (122) is disposed on the bottom surface of the guide block (121). The outer dimensions of the locking tooth (122) match the shape of the tooth groove. The locking tooth (122) is used to engage in the tooth groove under the action of the guide block (121).

4. A fixed brake wheel type brake device for an oil pumping unit with no dead spot as described in claim 3, characterized in that, The guide block (121) has a strip-shaped groove inside, and the curvature of the strip-shaped groove matches the wheel edge curvature of the rotating gear disk (20); the limiting structure (13) includes: A limiting pin (131) is fixedly installed at both ends on two sets of sealing plates (112), and the limiting pin (131) passes through the strip groove. The limiting pin (131) is used to restrict the guide block (121) from moving to the locking position in the arc-shaped limiting groove.

5. A fixed brake wheel type brake device for an oil pumping unit with no dead spot as described in claim 3, characterized in that, The brake lever (10) also includes: An elastic structure (14) is provided, which connects the brake arm body (11) and the movable locking block (12) respectively; the elastic structure (14) is used to reset the movable locking block (12) to the initial position.

6. A fixed brake wheel type brake device for an oil pumping unit with no dead spot as described in claim 5, characterized in that, The elastic structure (14) includes: Two sets of compression springs (141) are provided in the arc-shaped limiting slide groove and are correspondingly provided on both sides of the movable block (12). The two ends of each set of compression springs (141) are respectively fixedly installed on one inner side wall of the arc-shaped limiting slide groove and the side wall of the movable block (12). When the brake is released, the force of the two sets of compression springs (141) causes the movable block (12) to return to the initial position.

7. A fixed brake wheel type brake device for an oil pumping unit with no dead spot as described in claim 6, characterized in that, The inner sidewalls of both sides of the arc-shaped limiting slide groove are provided with first slots, and the sidewalls of the movable block (12) opposite to the first slots are provided with second slots; the two ends of each set of compression springs (141) are respectively fixedly installed in one of the first slots and one of the corresponding second slots.

8. A fixed brake wheel type brake device for an oil pumping unit with no dead spot as described in claim 4, characterized in that, The two ends of the strip groove are arcs that precisely match the surface of the limiting pin (131); the width of the strip groove precisely matches the diameter of the limiting pin (131).

Images