Hydraulic cylinder capable of preventing piston rod from rotating
By setting a positioning rod structure with a groove in the hydraulic cylinder body to cooperate with the positioning column, the problems of high processing difficulty and high cost of existing hydraulic cylinders are solved, and stable guidance of the piston rod and simplified processing are achieved.
Patent Information
- Application Number
- CN202520268774.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-20
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2035-02-20
AI Technical Summary
Existing hydraulic cylinder structures for preventing piston rod rotation are difficult to manufacture and costly. They require guide grooves to be made on the inner wall of the cylinder and ribs to be set on the piston, as well as additional seals.
The cylinder body has a groove that mates with the positioning pin, and the positioning square rod is inserted and fixed by the positioning pin. The piston rod has a square guide hole that mates with the positioning square rod. The groove on the inner wall of the cylinder body and the piston rib are eliminated, simplifying the process and eliminating the need for seals.
It achieves stable guidance of the piston rod, preventing rotation, eliminating the need for additional machining of the cylinder and seals, simplifying the machining process and reducing costs.
Smart Images
Figure CN223621906U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of hydraulic cylinder technology, specifically to a hydraulic cylinder that prevents the piston rod from rotating. Background Technology
[0002] A hydraulic cylinder is a hydraulic actuator that converts hydraulic energy into mechanical energy, performing linear reciprocating motion (or oscillating motion). It has a simple structure and reliable operation. When used to achieve reciprocating motion, it eliminates the need for a speed reduction device, eliminates transmission backlash, and provides smooth movement. Therefore, it is widely used in the hydraulic systems of various machines.
[0003] Currently, hydraulic cylinders that prevent piston rod rotation generally have a guide groove on the inner wall of the cylinder, with a rib on one side of the piston to cooperate with the guide groove, and sometimes even require a specific seal. This structure is difficult to manufacture and costly. Therefore, there is an urgent need for an improved technology to solve this problem in the existing technology. Utility Model Content
[0004] The purpose of this utility model is to provide a hydraulic cylinder that prevents the piston rod from rotating. Compared with the traditional method of opening grooves on the inner wall of the cylinder and setting ribs on the piston for guidance, it does not require additional processing of the cylinder body and piston, nor does it require separate preparation of seals, making the processing simpler and solving the problems mentioned in the background art.
[0005] To achieve the above objectives, this utility model provides the following technical solution: a hydraulic cylinder for preventing piston rod rotation, comprising a cylinder body, an end cap, a piston rod, a piston, and a positioning rod. One end of the cylinder body is open and has an end cap bolted to it. One end of the piston rod passes through the end cap and is movably disposed within the cylinder body. A piston and a limiting nut are provided at the end of the piston rod located inside the cylinder body. The limiting nut presses against the piston end. The piston is movably disposed within the cylinder body. A first oil hole is provided on the side wall of the cylinder body near the end cap. Bosses are provided on both sides of the side wall of the cylinder body away from the end cap. Each of the bosses on both sides has a positioning pin hole. The boss located on the side of the first oil hole... The boss is also provided with a second oil hole. The first oil hole, the second oil hole, and the positioning pin hole all penetrate the side wall of the cylinder body. A groove is provided inside the cylinder body at the end away from the end cover. The second oil hole and the positioning pin hole are connected to the groove. A positioning post is provided in the cylinder body and located in the groove. One end of the positioning rod is inserted into the positioning post. Positioning holes are provided on both sides of the positioning rod near the positioning post. The positions of the positioning holes and the positioning pin holes correspond to each other and are engaged by the positioning pin. The positioning pin is threaded into the positioning pin hole and its end is inserted into the corresponding positioning hole. A square guide hole is provided inside the piston rod along the axial direction. The positioning rod is inserted into the square guide hole.
[0006] Preferably, the present invention provides a hydraulic cylinder for preventing piston rod rotation, wherein the outer wall of the positioning square rod is in close sliding contact with the inner wall of the square guide hole of the piston rod, and an oil drain groove is also provided on the upper surface of the positioning square rod along its length.
[0007] Preferably, the present invention provides a hydraulic cylinder for preventing piston rod rotation, wherein the outer surface of the piston is provided with a plurality of rubber rings along the circumferential direction, and the rubber rings cooperate with the inner wall of the cylinder.
[0008] Preferably, the hydraulic cylinder for preventing piston rod rotation provided by this utility model has a sealing fit between the end cover and the cylinder body, and between the end cover and the piston rod, through a sealing element.
[0009] Preferably, in the hydraulic cylinder provided by this utility model for preventing piston rod rotation, a sealing cap is also provided at the outer end of the end cover by bolts.
[0010] Preferably, the present invention provides a hydraulic cylinder for preventing piston rod rotation, wherein the cylinder body has a first connecting hole at the end away from the end cover, and the piston rod has a second connecting hole at the end away from the piston.
[0011] Preferably, in the hydraulic cylinder for preventing piston rod rotation provided by this utility model, the positioning pin hole adopts a countersunk hole structure.
[0012] Compared with the prior art, the beneficial effects of this utility model are:
[0013] The cylinder body has a groove at the inner end with a positioning pin inside. One end of the positioning rod is inserted into the positioning pin, and positioning holes are opened on both sides of the positioning rod to correspond to the positioning pin holes on both sides of the cylinder body. The positioning holes and positioning pin holes can fix the position of the positioning rod through the cooperation of the positioning pins. The piston rod has a positioning hole to guide the positioning rod. When the piston drives the piston rod to move back and forth in the cylinder body, the positioning rod prevents the piston rod from rotating. Compared with the traditional method of opening grooves on the inner wall of the cylinder body and setting ribs on the piston for guidance, this structure does not require additional machining of the cylinder body and piston, and does not require separate preparation of seals, making the manufacturing process simpler. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the structure of this utility model;
[0015] Figure 2 For the appendix Figure 1 Schematic diagram of the angle transformation structure;
[0016] Figure 3 For the appendix Figure 1 Enlarged structural diagram of point A in the middle;
[0017] Figure 4 This is a schematic cross-sectional view of the present invention.
[0018] Figure 5 For the appendix Figure 4 Enlarged structural diagram of point B in the middle;
[0019] Figure 6 This is a schematic diagram of the positioning square rod structure;
[0020] Figure 7 For the appendix Figure 6 Enlarged structural diagram of point C in the middle;
[0021] Figure 8 This is a schematic diagram of the cross-sectional structure of the piston rod.
[0022] In the diagram: 1. Cylinder body; 2. End cap; 3. Piston rod; 4. Piston; 5. Positioning square rod; 6. Limiting nut; 7. First oil hole; 8. Boss; 9. Positioning pin hole; 10. Second oil hole; 11. Groove; 12. Positioning pin; 13. Positioning hole; 14. Square guide hole; 15. Oil drain groove; 16. Sealing cap; 17. First connecting hole; 18. Second connecting hole. Detailed Implementation
[0023] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0024] It should be noted that in the description of this utility model, the terms "inner", "outer", "upper", "lower", "both sides", "one end", "the other end", "left", "right", 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 utility model 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. Therefore, they should not be construed as limitations on this utility model.
[0025] Please see Figure 1-8This utility model provides a technical solution: a hydraulic cylinder for preventing piston rod rotation, comprising a cylinder body 1, an end cap 2, a piston rod 3, a piston 4, and a positioning rod 5. One end of the cylinder body 1 is open and is bolted to the end cap 2. One end of the piston rod 3 passes through the end cap 2 and is movably disposed within the cylinder body 1. The end cap 2 and the cylinder body 1, and the end cap 2 and the piston rod 3 are sealed together by seals to ensure the sealing performance of the end cap 2 and prevent oil leakage. A sealing cap 16 is also bolted to the outer end of the end cap 2 to further achieve the sealing performance between the end cap 2 and the piston rod 3. The piston rod 3, located inside the cylinder body 1, has a movable end cap 5. A piston 4 and a limiting nut 6 are provided. The limiting nut 6 is pressed against the end of the piston 4. The piston 4 is movably disposed inside the cylinder body 1. Several rubber rings are provided on the outer surface of the piston 4 along the circumferential direction. The rubber rings cooperate with the inner wall of the cylinder body 1 to ensure the sealing between the piston 4 and the inner wall of the cylinder body 1. A first oil hole 7 is provided on the side wall of the cylinder body 1 near the end cap 2. Bosses 8 are provided on both sides of the side wall of the cylinder body 1 away from the end cap 2. Each of the two bosses 8 has a positioning pin hole 9. The boss 8 located on the side of the first oil hole 7 also has a second oil hole 10. The first oil hole 7, the second oil hole 10, and the positioning pin hole 9 all penetrate the cylinder body 1. A groove 11 is provided on the side wall of the cylinder body 1, inside and away from the end cap 2. The second oil hole 10 and the positioning pin hole 9 are connected to the groove 11. A positioning pin 12 is provided in the cylinder body 1, located in the groove 11. One end of the positioning rod 5 is inserted into the positioning pin 12. Positioning holes 13 are provided on both sides of the positioning rod 5 near the positioning pin 12. The positions of the positioning holes 13 and the positioning pin holes 9 are corresponding and cooperate with the positioning pin. The positioning pin is threaded into the positioning pin hole 9 and its end is inserted into the corresponding positioning hole 13. The positioning pin hole 9 adopts a countersunk hole structure to ensure that the connection of the oil circuit is not affected when connecting the oil circuit. The piston rod 3 is located inside and along the axial direction. A square guide hole 14 is provided, and a positioning square rod 5 is inserted into the square guide hole 14. The outer wall of the positioning square rod 5 is in close sliding contact with the inner wall of the square guide hole 14 of the piston rod 3, thereby ensuring the stability between the piston rod 3 and the positioning square rod 5. An oil drain groove 15 is also provided on the upper surface of the positioning square rod 5 along the length direction to ensure that the hydraulic oil in the square guide hole 14 of the piston rod 3 can be smoothly discharged when the positioning square rod 5 and the piston rod 3 are guided and matched. A first connecting hole 17 is provided at the end of the cylinder body 1 away from the end cover 2, and a second connecting hole 18 is provided at the end of the piston rod 3 away from the piston 4, so as to connect with the two objects that need to be matched respectively.
[0026] Assembly method and operating principle: First, insert the positioning square rod 5 into the cylinder body 1 and connect it to the positioning pin 12. Then, thread the positioning pin into the positioning pin hole 9 and insert the end of the positioning pin into the positioning hole 13 on the corresponding side of the positioning square rod 5. At this time, the positioning square rod 5 cannot rotate. The positioning pin and the positioning pin hole 9 are sealed by a sealing ring, wherein the positioning pin hole 9 adopts a countersunk hole structure. Next, pass the piston rod 3 through the sealing cover 16 and the end cover 2, and then fit the piston 4 onto the end of the piston rod 3 and press it with the limit nut 6 to make the piston 4 and piston rod 3 securely connected. Put the rubber ring around the piston 4 and insert the piston 4 into the cylinder body 1. At the same time, connect the square guide hole 14 of the piston rod 3 to the positioning square rod 5. Finally, connect the end cover 2 to the end of the cylinder body 1 with bolts, and connect the sealing cover 16 to the end cover 2 with bolts to complete the assembly. In use, the oil lines are connected to the first oil hole 7 and the second oil hole 10 respectively. Oil is supplied through the first oil hole 7, and the piston 4 drives the piston rod 3 to move backward. Oil is supplied through the second oil hole 10, and the piston 4 drives the piston rod 3 to move forward. This utility model has a reasonable structure. The inner end of the cylinder body 1 has a groove 11 and a positioning post 12 is set in the groove 11. One end of the positioning rod 5 is inserted into the positioning post 12. At the same time, positioning holes 13 are opened on both sides of the positioning rod 5 to correspond to the positioning pin holes 9 on both sides of the cylinder body 1. The positioning holes 13 and the positioning pin holes 9 can fix the position of the positioning rod 5 through the cooperation of the positioning pins. The piston rod 3 has a positioning square hole to guide the positioning rod 5. When the piston 4 drives the piston rod 3 to move back and forth in the cylinder body 1, the piston rod 3 cannot rotate through the cooperation of the positioning rod 5. Compared with the traditional method of opening the groove 11 on the inner wall of the cylinder body 1 and setting the piston 4 with the rib guide, this structure does not require additional processing of the cylinder body 1 and piston 4, and does not require separate preparation of sealing parts, making the processing simpler.
[0027] Any aspects of this utility model not described in detail are well-known technologies to those skilled in the art.
[0028] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although this utility model has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications and equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the claims of this utility model.
Claims
1. A hydraulic cylinder for preventing piston rod rotation, characterized in that: The cylinder includes a cylinder body (1), an end cap (2), a piston rod (3), a piston (4), and a positioning rod (5). One end of the cylinder body (1) is open and is bolted to the end cap (2). One end of the piston rod (3) passes through the end cap (2) and is movably disposed inside the cylinder body (1). The piston rod (3) is located inside the cylinder body (1) and is fitted with a piston (4) and a limiting nut (6). The limiting nut (6) is pressed against the end of the piston (4). The piston (4) is movably disposed inside the cylinder body (1). A first oil hole (7) is provided on the side wall of the cylinder body (1) near the end cap (2). Bosses (8) are provided on both sides of the side wall of the cylinder body (1) away from the end cap (2). Both sides of the bosses (8) are provided with positioning pin holes (9). The boss (8) located on the side of the first oil hole (7) is also provided with a second oil hole (10). (7) The second oil hole (10) and the positioning pin hole (9) both penetrate the side wall of the cylinder body (1). A groove (11) is provided inside the cylinder body (1) and away from the end cap (2). The second oil hole (10) and the positioning pin hole (9) are connected to the groove (11). A positioning post (12) is provided in the cylinder body (1) and located in the groove (11). One end of the positioning rod (5) is inserted into the positioning post (12). Positioning holes (13) are provided on both sides of the positioning rod (5) near the positioning post (12). The positions of the positioning holes (13) and the positioning pin holes (9) correspond to each other and are engaged by positioning pins. The positioning pin is threaded into the positioning pin hole (9) and its end is inserted into the corresponding positioning hole (13). A square guide hole (14) is provided inside the piston rod (3) and along the axial direction. The positioning rod (5) is inserted into the square guide hole (14).
2. A hydraulic cylinder for preventing piston rod rotation according to claim 1, characterized in that: The outer wall of the positioning rod (5) is in close sliding contact with the inner wall of the square guide hole (14) of the piston rod (3), and an oil drain groove (15) is also provided on the upper surface of the positioning rod (5) along the length direction.
3. A hydraulic cylinder for preventing piston rod rotation according to claim 1, characterized in that: The piston (4) has several rubber rings on its outer surface and along the circumferential direction, which cooperate with the inner wall of the cylinder (1).
4. A hydraulic cylinder for preventing piston rod rotation according to claim 1, characterized in that: The end cap (2) and cylinder (1) are sealed together by sealing elements, as are the end cap (2) and piston rod (3).
5. A hydraulic cylinder for preventing piston rod rotation according to claim 1, characterized in that: The outer end of the end cap (2) is also provided with a sealing cap (16) by bolts.
6. A hydraulic cylinder for preventing piston rod rotation according to claim 1, characterized in that: The cylinder (1) has a first connecting hole (17) at the end away from the end cap (2), and the piston rod (3) has a second connecting hole (18) at the end away from the piston (4).
7. A hydraulic cylinder for preventing piston rod rotation according to claim 1, characterized in that: The positioning pin hole (9) adopts a countersunk hole structure.