Single-acting spring-return type fork actuator
By using guide rings and self-lubricating angular contact guide bearings in the spring-return type shift fork mechanism, the problems of wear and jamming caused by lateral forces are solved, improving the stability and lifespan of the mechanism.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- KOSO CONTROL ENG (WUXI) CO LTD
- Filing Date
- 2025-10-29
- Publication Date
- 2026-06-09
AI Technical Summary
In practical applications, existing spring-return type shift fork mechanisms suffer from non-pure axial loads due to working condition disturbances, resulting in lateral forces, accelerated wear, shortened fatigue life, and impact on reset accuracy and mechanism stability.
It adopts a guide ring and a matching spring seat, and uses a self-lubricating angular contact guide bearing at the end of the tie rod, which can withstand radial and axial loads, self-adjust to reduce lateral forces and prevent jamming.
It effectively reduces the lateral force of the spring, improves the service life of the return spring and the operational stability of the mechanism, prevents jamming, and ensures the smoothness and accuracy of the reset action.
Smart Images
Figure CN121139682B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a shift fork actuator, and more particularly to a single-acting spring-return type shift fork actuator. Background Technology
[0002] In fields such as automated equipment, construction machinery, and fluid control equipment, the spring-return type shift fork mechanism, as the core actuator for achieving automatic reset of reciprocating motion, is widely used in various scenarios requiring precise reversing and reciprocating drive. Its core function is to use a pneumatic actuator to provide driving force to complete the mechanism's active movement, and then rely on the elastic deformation of the return spring to store and release energy, thereby pushing the shift fork to reset, ultimately ensuring the continuity and reliability of the entire mechanism's reciprocating motion. The core components of this mechanism include the return spring, the shift fork, and the pneumatic actuator. Among these, the return spring, as the key component for achieving the automatic reset function, directly determines the reset accuracy, response speed, and service life of the spring-return type shift fork mechanism.
[0003] Under ideal operating conditions, the return spring must meet two key requirements: first, the installation must be absolutely perfect, meaning the mounting surface must be flat, the mounting hole and the spring axis must be completely coaxial, and the assembly and positioning of the shift fork and the spring must be without deviation; second, the force must be purely axial, meaning the direction of the pneumatic actuator's output force must be completely coincident with the spring axis, without any off-center load interference. Under this ideal state, the return spring generates only axial reaction force along the axis during compression, with no lateral force component. The force transmission path is precise and efficient, ensuring the smoothness and accuracy of the shift fork's reset action and avoiding problems such as jamming or offset during reset.
[0004] However, in practical engineering applications, due to the influence of working conditions, the output force of the pneumatic actuator may be unbalanced, the shift fork may oscillate slightly during the movement of the mechanism, and external environmental vibrations and other factors may cause the return spring to bear non-pure axial loads, thereby inducing lateral forces.
[0005] The presence of lateral force has a series of negative impacts on the operation of spring-returning shift fork mechanisms: on the one hand, lateral force accelerates the wear of the return spring, significantly shortening its fatigue life and increasing the risk of spring breakage and failure; on the other hand, lateral force acts on the shift fork and related transmission components, causing shift fork jamming, delayed reset action, or reset accuracy deviation, and even generating abnormal noises. In severe cases, it can lead to premature failure of the entire spring-returning shift fork mechanism, affecting the normal operation of downstream equipment. Therefore, how to reduce or eliminate the lateral force generated during the compression of the return spring and improve the force transmission stability and service life of the return spring has become a key technical requirement to ensure the long-term stable operation of the spring-returning shift fork mechanism, and also provides an important technical direction for optimizing the structural design, manufacturing process, and assembly method of the return spring. Summary of the Invention
[0006] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a single-acting spring-return type shift fork actuator. This single-acting spring-return type shift fork actuator uses a guide ring and a matching spring seat to avoid or reduce the lateral force of the spring, and further uses a self-lubricating angular contact guide bearing at the end of the pull rod, which can withstand radial load, axial load, or loads that exist simultaneously in the radial and axial directions. When the spring seat is slightly tilted by the lateral force of the return spring, it can achieve self-adjustment, and the pull rod can move back and forth normally in the guide sleeve, preventing jamming.
[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:
[0008] A single-acting spring-return type shift fork actuator includes a spring pack, an intermediate shift fork cylinder body, and a cylinder body arranged sequentially; the three are sealed together.
[0009] A first pull rod through hole is provided at the center of the end wall of the spring pack near the middle shift fork cylinder, and a spring seat is provided at the center of the other end wall away from the middle shift fork cylinder. The spring seat moves back and forth along the inner wall of the spring pack.
[0010] A second pull rod through hole is provided at the center of the end wall of the spring seat near the first pull rod through hole;
[0011] One end of the lever is located inside the spring seat, and the other end is connected to the shift fork mechanism; the end located inside the spring seat has an integrally formed stepped protrusion.
[0012] A self-lubricating angular contact guide bearing and a spacer are fitted between the second tie rod through hole and the stepped protrusion, and the tie rod is installed with a gap between it and the second tie rod through hole.
[0013] Furthermore, the guide bearing and the valve seat form a self-lubricating angular contact guide bearing; the self-lubricating angular contact guide bearing is fitted and assembled in close contact with the inner end wall of the spring pack; the spacer is annular, with one end fitted and assembled in close contact with the self-lubricating angular contact guide bearing, and the other end fitted and assembled in close contact with the stepped protrusion.
[0014] Furthermore, the guide bearing is gradually widened, from the small end face to the large end face, forming an inner spherical ring, and the outer ring surface of the valve seat is coated with a composite material.
[0015] Furthermore, a guide ring is provided on the connection surface between the end wall of the spring seat away from the first pull rod through hole and the inner wall of the spring pack.
[0016] Furthermore, the return spring is sleeved along the outer periphery of the spring seat, and is sandwiched between the end wall of the spring seat away from the first pull rod through hole and the end wall of the spring pack near the middle shift fork cylinder.
[0017] Furthermore, a guide sleeve is installed inside the first tie rod through hole.
[0018] Furthermore, both the first pull rod through hole and the second pull rod through hole are located on the central axis of the spring pack.
[0019] Furthermore, a piston is assembled inside the cylinder, and a piston rod is installed at the center of the piston. The piston rod drives the piston to reciprocate along the central axis of the cylinder; the end of the piston rod away from the piston is connected to the cylinder body of the intermediate shift fork.
[0020] Furthermore, the intermediate shift fork cylinder is equipped with a guide rod, a coupling element, and a shift fork element;
[0021] The lower part of the coupling element is connected to the shift fork element, and the shift fork element drives the coupling element to swing back and forth along the central axis of the spring pack.
[0022] The upper part of the coupling component has an oil-free bearing, which is sleeved on the guide rod; the lower two ends of the coupling component have ports.
[0023] Furthermore, the central axis of the cylinder, the central axis of the spring pack, and the central axis of the return spring coincide.
[0024] The present invention has the following beneficial effects:
[0025] 1. While using a guide ring and a matching spring seat to avoid or reduce the lateral force of the spring, this application further incorporates a self-lubricating angular contact guide bearing and a spacer block sandwiched between the second tie rod through hole and the stepped protrusion. The self-lubricating angular contact guide bearing can withstand radial loads, axial loads, or loads that exist simultaneously in both the radial and axial directions. When the spring seat tilts slightly due to the lateral force of the return spring, the addition of the self-lubricating angular contact guide bearing allows for self-adjustment, enabling the tie rod to move normally back and forth within the guide sleeve and preventing jamming.
[0026] 2. The guide bearing and valve seat form a self-lubricating angular contact guide bearing; the guide bearing is gradually widening from the small end face to the large end face and forming an inner ring spherical surface, and the outer ring surface of the valve seat is coated with composite material. The self-lubricating angular contact guide bearing can produce a self-lubricating effect during operation. Attached Figure Description
[0027] Figure 1 This is a schematic diagram of the structure of a single-acting spring-return type shift fork actuator according to the present invention.
[0028] Figure 2 This is a schematic diagram of the structure of the spring pack of the present invention.
[0029] Figure 3 This is the present invention. Figure 2 A magnified view of a portion of the image.
[0030] Among them are:
[0031] 1. Spring pack; 11. First pull rod through hole; 12. Spring seat; 13. Return spring; 14. Second pull rod through hole; 15. Pull rod; 16. Guide ring; 17. Spacer block; 18. Self-lubricating angular contact guide bearing; 181. Guide bearing; 182. Valve seat; 19. Stepped protrusion.
[0032] 21. Center shift fork cylinder body; 22. Guide rod; 23. Coupling component; 24. Oil-free bearing; 25. Shift fork component.
[0033] 3. Cylinder body; 31. Piston; 32. Piston rod. Detailed Implementation
[0034] The present invention will now be described in further detail with reference to the accompanying drawings and specific preferred embodiments.
[0035] In the description of this invention, it should be understood that the terms "left side," "right side," "upper part," "lower part," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. "First," "second," etc., do not indicate the importance of the components, and therefore should not be construed as a limitation of this invention. The specific dimensions used in this embodiment are only for illustrating the technical solution and do not limit the scope of protection of this invention.
[0036] like Figure 1-3 As shown, a single-acting spring-return type shift fork actuator includes a spring pack 1, an intermediate shift fork cylinder 2, and a cylinder body 3 arranged in sequence; the three are sealed together.
[0037] A first pull rod through hole 11 is provided at the center of the end wall of the spring pack 1 near the center of the middle shift fork cylinder 2, and a spring seat 12 is provided at the center of the other end wall away from the middle shift fork cylinder 2. The spring seat 12 moves back and forth along the inner wall of the spring pack 1.
[0038] Furthermore, in order to ensure the stability of the spring seat reciprocating within the spring pack and to reduce the lateral force of the spring, a guide ring 16 is provided on the connection surface between the end wall of the spring seat 12 away from the first pull rod through hole 11 and the inner wall of the spring pack 1. The spring seat 12 can reciprocate stably within the inner wall of the spring pack 1 through the guide ring 16, while simultaneously reducing the lateral force of the spring.
[0039] Furthermore, the return spring 13 is sleeved along the outer periphery of the spring seat 12, and is sandwiched between the end wall of the spring seat 12 away from the first pull rod through hole 11 and the end wall of the spring pack 1 near the middle shift fork cylinder 2.
[0040] A second pull rod through hole 14 is provided at the center of one end wall of the spring seat 12 near the first pull rod through hole 11; for example Figure 1 As shown, the first pull rod through hole 11 and the second pull rod through hole 14 are both located on the central axis of the spring pack 1.
[0041] Furthermore, a guide sleeve is installed inside the first tie rod through hole 11.
[0042] One end of the pull rod 15 is located inside the spring seat 12, and the other end is connected to the shift fork mechanism; the end located inside the spring seat 12 has an integrally formed stepped protrusion 19.
[0043] Furthermore, such as Figure 2-3 As shown, a self-lubricating angular contact guide bearing 18 and a spacer block 17 are sandwiched between the second tie rod through hole 14 and the stepped protrusion 19, and the tie rod 15 is installed with a gap between it and the second tie rod through hole 14.
[0044] During assembly, the end of the pull rod 15 with the integrally formed stepped protrusion 19 is first fitted with a spacer 17, and then fitted with a self-lubricating angular contact guide bearing 18. The other end (free end) of the pull rod 15 passes sequentially through the inner cavity of the spring seat 12 through the second pull rod through hole 14 and the first pull rod through hole 11 until it extends into the structure connecting to the shift fork. Thus, the self-lubricating angular contact guide bearing 18 and the spacer 17 are sandwiched and assembled between the second pull rod through hole 14 and the stepped protrusion 19. Figure 2-3 As shown, the self-lubricating angular contact guide bearing 18 is attached to the second tie rod through hole 14 on one side and to the spacer block 17 on the other side; the spacer block 17 is attached to the self-lubricating angular contact guide bearing 18 on one side and to the stepped protrusion 19 on the other side.
[0045] Furthermore, the self-lubricating angular contact guide bearing 18 includes a guide bearing 181 and a valve seat 182, which together form the self-lubricating angular contact guide bearing 18.
[0046] Furthermore, the self-lubricating angular contact guide bearing 18 is fitted and assembled to the inner end wall of the spring pack 1; the spacer block 17 is annular, with the self-lubricating angular contact guide bearing 18 fitted and assembled to one end, and the other end fitted and assembled to the stepped protrusion 19.
[0047] Furthermore, such as Figure 3 As shown, the guide bearing 181 is gradually widening from the small end face to the large end face and forming an inner ring spherical surface. The outer ring surface of the valve seat is coated with a composite material. The self-lubricating angular contact guide bearing can produce a self-lubricating effect during operation.
[0048] Further, optionally, PTEE textile is pasted onto the outer ring surface of the valve seat.
[0049] While employing a guide ring and a matching spring seat to avoid or reduce the lateral force of the spring, this application further incorporates a self-lubricating angular contact guide bearing 18 and a spacer block 17 sandwiched between the second tie rod through hole 14 and the stepped protrusion 19. The self-lubricating angular contact guide bearing can withstand radial loads, axial loads, or loads occurring simultaneously in both radial and axial directions. When the spring seat tilts slightly due to the lateral force of the return spring, the addition of the self-lubricating angular contact guide bearing allows for self-adjustment, enabling the tie rod to move normally back and forth within the guide sleeve and preventing jamming.
[0050] The following is in conjunction with the appendix Figure 1 Further detailed explanation of the center shift fork cylinder body and cylinder:
[0051] A piston 31 is installed inside the cylinder 3, and a piston rod 32 is installed at the center of the piston. The piston rod drives the piston to reciprocate along the central axis of the cylinder 3. The end of the piston rod away from the piston is connected to the intermediate shift fork cylinder 2.
[0052] Furthermore, the intermediate shift fork cylinder 2 is equipped with a guide rod 21, a coupling member 22, and a shift fork member 23;
[0053] The lower part of the coupling member 22 is connected to the shift fork member 23, and the shift fork member 23 can drive the coupling member to swing back and forth along the central axis of the spring pack 1.
[0054] The upper part of the coupling member 22 has an oilless bearing 221, which is sleeved on the guide rod 21; the lower two ends of the coupling member 22 have ports, and the piston rod 32 and the pull rod 15 are connected to the ports at the lower two ends respectively.
[0055] like Figure 1 As shown, when the shift fork drives the coupling to reciprocate left and right, the central axis of the cylinder 3, the central axis of the spring pack 1, and the central axis of the return spring coincide.
[0056] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0057] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all fall within the protection scope of the present invention.
Claims
1. A single-acting spring-return type shift fork actuator, characterized in that: It includes a spring pack, a middle shift fork cylinder body, and a cylinder body arranged in sequence; the three are sealed together. A first pull rod through hole is provided at the center of the end wall of the spring pack near the middle shift fork cylinder, and a spring seat is provided at the center of the other end wall away from the middle shift fork cylinder. The spring seat moves back and forth along the inner wall of the spring pack. A second pull rod through hole is provided at the center of the end wall of the spring seat near the first pull rod through hole; One end of the lever is located inside the spring seat, and the other end is connected to the shift fork mechanism; the end located inside the spring seat has an integrally formed stepped protrusion. A self-lubricating angular contact guide bearing and a spacer are sandwiched between the second tie rod through hole and the stepped protrusion, and the tie rod is installed with a gap between it and the second tie rod through hole. The guide bearing and the valve seat form a self-lubricating angular contact guide bearing; the self-lubricating angular contact guide bearing is fitted and assembled in close contact with the inner end wall of the spring pack; the spacer is annular, with one end fitted and assembled in close contact with the self-lubricating angular contact guide bearing, and the other end fitted and assembled in close contact with the stepped protrusion. The guide bearing is gradually widening from the small end face to the large end face, forming an inner spherical ring. The outer ring surface of the valve seat is coated with a composite material.
2. The single-acting spring-return type shift fork actuator according to claim 1, characterized in that: A guide ring is provided on the connection surface between the end wall of the spring seat away from the first pull rod through hole and the inner wall of the spring pack.
3. The single-acting spring-return type shift fork actuator according to claim 1, characterized in that: The return spring is sleeved along the outer periphery of the spring seat, and is sandwiched between the end wall of the spring seat away from the first pull rod through hole and the end wall of the spring pack near the middle shift fork cylinder.
4. The single-acting spring-return type shift fork actuator according to claim 1, characterized in that: A guide sleeve is installed inside the first tie rod through hole.
5. The single-acting spring-return type shift fork actuator according to claim 1, characterized in that: Both the first and second pull rod through holes are located on the central axis of the spring pack.
6. The single-acting spring-return type shift fork actuator according to claim 1, characterized in that: A piston is installed inside the cylinder, and a piston rod is installed at the center of the piston. The piston rod drives the piston to reciprocate along the central axis of the cylinder; the end of the piston rod away from the piston is connected to the cylinder body of the intermediate shift fork.
7. The single-acting spring-return type shift fork actuator according to claim 1, characterized in that: The middle shift fork cylinder is equipped with a guide rod, a coupling element, and a shift fork element; The lower part of the coupling element is connected to the shift fork element, and the shift fork element drives the coupling element to swing back and forth along the central axis of the spring pack. The upper part of the coupling component has an oil-free bearing, which is sleeved on the guide rod; the lower two ends of the coupling component have ports.
8. The single-acting spring-return type shift fork actuator according to claim 6 or 7, characterized in that: The central axis of the cylinder, the central axis of the spring pack, and the central axis of the return spring coincide.