Mechanical shaft expansion
By designing a piston block and expansion key wedge structure, and combining pneumatic drive and mechanical propulsion, the high load capacity and high speed switching of the air shaft are achieved, solving the shortcomings of load capacity and switching speed in existing technologies, and making it suitable for frequent switching scenarios.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 上海韩东机械科技有限公司
- Filing Date
- 2025-05-22
- Publication Date
- 2026-07-03
AI Technical Summary
Existing pneumatic and mechanical expansion shafts are insufficient in terms of load capacity and switching speed, making it difficult to simultaneously meet the requirements of high load capacity and high-speed switching.
Combining the advantages of pneumatic and mechanical expansion shafts, a wedge-shaped structure of piston block and expansion key is adopted. The piston block is driven to move axially by air pressure, and the wedge surface pushes the expansion key to extend radially, realizing the switching between mechanical high load and pneumatic high speed.
It achieves high load capacity and low vibration while adapting to high-speed switching, combining the load-bearing capacity of a mechanical expansion shaft with the flexible switching capability of a pneumatic expansion shaft, and is small in size and requires little space.
Smart Images
Figure CN224449867U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of winding equipment, and more specifically, it relates to a mechanical expansion shaft. Background Technology
[0002] The air shaft has the function of adjusting the shaft diameter. It is used to expand and fix the material roll or material roll core after it is inserted, and then drive the material roll or material roll core to rotate through the power component to realize unwinding (feeding) or rewinding (rewinding).
[0003] In a pneumatic air shaft, compressed air enters a flat air bladder (made of rubber, similar to a balloon, which can be inflated), causing the air bladder to expand and inflate the key bar; when deflated, the air bladder retracts. In contrast, a mechanical air shaft uses a threaded drive cone block, which in turn uses a wedge surface to drive the key bar, with the axial movement of the wedge surface causing the key bar to extend radially.
[0004] Compared to mechanical expansion shafts, air-filled expansion shafts have a lower load capacity and a larger runout range, but are more weight-friendly. They are also more responsive than mechanical expansion shafts, making them suitable for scenarios with frequent switching, and their maintenance response is also faster.
[0005] This application aims to combine the advantages of air-bladder type air shaft and mechanical air shaft to realize an air shaft that can adapt to high load and low runout with frequent switching. Utility Model Content
[0006] This invention combines the advantages of airbag-type and mechanical expansion shafts to provide an air expansion shaft that combines high load capacity and low vibration while adapting to high-speed switching.
[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:
[0008] A mechanical expander includes a piston block and a shaft tube. Along the circumferential direction of the shaft tube, a plurality of expansion keys are movably connected to the shaft tube. The expansion keys are configured to extend a set distance in the radial direction. The bottom of the expansion keys has an inclined surface. The piston block is provided with a wedge surface adapted to the inclined surface. One end of the shaft tube is elastically connected to the piston block. The other end of the shaft tube forms a piston cavity with the piston block. The shaft tube is provided with an air passage communicating with the piston cavity.
[0009] This application employs a pneumatic drive to move the piston block, offering better speed compared to threaded drives and adapting to high-speed switching scenarios. The piston block is housed within the shaft tube, and pneumatic pressure is generated in the piston chamber at one end of the piston block, overcoming elastic force to cause axial movement of the piston block relative to the shaft tube. The wedge-shaped surface of the axially moving piston block engages with the inclined surface of the expansion key, pushing the expansion key to produce radial displacement, thus amplifying the force by sacrificing displacement distance.
[0010] The piston block and expansion keys are driven mechanically, with each expansion key extending closer to the shaft tube, resulting in better roundness. The mechanical expansion keys transmit force through the rigid structure of wedges and inclined surfaces, providing better load-bearing capacity. Furthermore, the pneumatically driven piston movement offers flexible and high-speed switching; simply adjusting the air pressure allows the piston block and expansion keys to return to their original positions under the action of elasticity.
[0011] Therefore, the solution described in this application has both high load capacity and low vibration, and can adapt to high-speed switching.
[0012] Preferably, an anti-disengagement pressure plate is fixedly connected to the shaft tube, spanning the expansion key. A key return spring is provided between the expansion key and the anti-disengagement pressure plate. The purpose of the anti-disengagement pressure plate is to limit the extension of the expansion key by a set distance. The expansion key has a slot for housing the key return spring. The slot moves against the spring force as the expansion key rises. When the expansion key is no longer driven by the piston block, it is pushed back to its original position under the action of the key return spring. The expansion key is positioned between the anti-disengagement pressure plate and the piston block.
[0013] Preferably, guide rollers are provided between adjacent expansion keys, and guide rollers are mounted on the guide rollers. This structure improves the smoothness of feeding the roll material. The outward stroke limit of the expansion key is higher than the height of the roller.
[0014] Preferably, one end of the shaft tube is provided with a shaft head, and the other end of the shaft tube is provided with a tail cap. The side wall of the tail cap is provided with several guide rollers. The guide rollers assist the shaft tube in being inserted into the coiled material.
[0015] Preferably, the piston block includes a conical barrel and a guide plate. The guide plate is located at the narrowest end of the conical barrel, and its diameter is the same as that of the widest end of the conical barrel. An annular groove is provided on the side wall of the guide plate, and a guide band is installed on the annular groove. The guide plate assists in the movement of the piston block and keeps the direction of movement of the piston block parallel to the axis of the piston block and the shaft tube.
[0016] Preferably, a plurality of positioning posts are installed at the end of the guide plate away from the cone barrel. These positioning posts are evenly spaced along the circumferential direction of the guide plate, and each post is equipped with a piston return spring, which abuts against the tail cap and the guide plate. The positioning posts prevent the piston return spring from deviating. The piston return spring provides an elastic connection between the shaft tube and the piston block.
[0017] Preferably, the top surface of the expansion key is provided with friction texture. The friction texture is used to increase the friction between the expansion key and the outer coil material.
[0018] Preferably, the air passage is located in the shaft head. The shaft head creates the air passage through a central opening, and the shaft head is also used to connect with the reducer to transmit kinetic energy.
[0019] Preferably, the pressure of the expansion key in the radial direction is K, where K = P / tanα, P is the difference between the piston's air pressure and the spring force, and α is the angle between the generatrix of the cone and the axis.
[0020] Compared with the prior art, the beneficial effects of this utility model are:
[0021] (1) The mechanical expansion shaft action is achieved by the cooperation of the piston block and the wedge face of the expansion key on the inclined surface, which has the high load capacity and low runout of the mechanical expansion shaft;
[0022] (2) Through the cooperation of the air passage, piston chamber and piston block, the gas-driven piston movement is realized, and the high-speed switching capability of the air expansion shaft is achieved.
[0023] (3) The piston chamber and air passage are built into the shaft tube and shaft head, resulting in a smaller overall volume and less space requirement. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of the present invention;
[0025] Figure 2 This is a cross-sectional schematic diagram of the present invention;
[0026] Figure 3 This is a cross-sectional view of the present invention;
[0027] Figure 4 This is a schematic diagram of the piston of this utility model;
[0028] Figure 5 This is a schematic diagram of the expansion key of this utility model;
[0029] Figure 6 This is a schematic diagram of the force amplification principle of this utility model;
[0030] In the picture:
[0031] 1. Piston block, 2. Shaft tube, 3. Expansion key, 4. Tail cover, 5. Inclined surface, 6. Wedge surface, 7. Anti-detachment pressure plate, 8. Expansion key return spring, 9. Friction texture, 10. Piston cavity, 11. Shaft head, 12. Air passage, 13. Positioning pin, 14. Piston return spring, 15. Conical barrel, 16. Guide plate, 17. Guide belt, 18. Sealing ring, 19. Guide wheel roller, 20. Guide roller, 21. Inlet roller. Detailed Implementation
[0032] The present disclosure will be further described below with reference to the accompanying drawings and embodiments.
[0033] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.
[0034] Note that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0035] In the present disclosure, terms such as "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "side", "bottom", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only relationship terms determined for the convenience of describing the structural relationship of various components or elements of the present disclosure and do not specifically refer to any component or element in the present disclosure and should not be construed as a limitation to the present disclosure.
[0036] In the present disclosure, terms such as "fixed connection", "connected", "connected to" should be understood in a broad sense, which may mean a fixed connection, an integral connection or a detachable connection; it may be directly connected or indirectly connected through an intermediate medium. For those related scientific research or technical personnel in the field, the specific meanings of the above terms in the present disclosure can be determined according to specific circumstances and should not be construed as a limitation to the present disclosure.
[0037] Example:
[0038] A mechanical expansion shaft, referring Figure 1 and Figure 2 as shown, includes a piston block 1 and a shaft tube 2. The side wall of the shaft tube 2 has several openings, and expansion keys 3 are installed at the opening positions. The expansion keys 3 are configured to be able to extend a set distance in the radial direction. The shaft tube 2 is a cylinder with both ends open. One end of the shaft tube 2 is provided with a shaft head 11, and the other end of the shaft tube 2 is provided with a tail cover 4. The shaft tube 2 is respectively connected to the shaft head 11 and the tail cover 4 through fasteners.
[0039] The shaft tube 2 is a hollow tube body, and the piston block 1 is installed in the shaft tube 2. The piston block 1 and the shaft tube 2 constitute a piston system. At least part of the side wall of the piston block 1 is in contact with the inner wall of the shaft tube 2 so that both sides at the contact part are sealed.
[0040] Referring Figure 3 and Figure 5As shown, along the circumferential direction of the shaft tube 2, the expansion key 3 is movably connected to the shaft tube 2, and the expansion key 3 is configured to be able to extend a set distance in the radial direction. The expansion key 3 is a block with a flat top, an inclined surface 5 at the bottom, and smooth side walls. Through the guiding of the expansion key 3 by the side wall of the opening of the shaft tube 2, the expansion key 3 expands and contracts in the radial direction. The piston block 1 is provided with a wedge surface 6 adapted to the inclined surface 5. When the piston block 1 moves along the axial direction, the expansion key 3 can be driven to extend radially outward by the pushing of the wedge surface 6 on the inclined surface 5. A retaining pressure plate 7 is fixedly connected to the shaft tube 2. The retaining pressure plate 7 straddles the expansion key 3, and an expansion key return spring 8 is provided between the expansion key 3 and the retaining pressure plate 7. The function of the retaining pressure plate 7 is to limit the extension distance of the expansion key 3. The expansion key 3 is provided with a slot for placing the expansion key return spring 8, and the slot moves with the rise of the expansion key 3 against the elastic force. When the expansion key 3 is no longer driven by the piston block 1, under the action of the expansion key return spring 8, the expansion key 3 is pushed back to its original position. The expansion key 3 is positioned between the retaining pressure plate 7 and the piston block 1. The top surface of the expansion key 3 is provided with friction lines 9. The friction lines 9 are used to increase the frictional force between the expansion key 3 and the external coiled material.
[0041] One end of the shaft tube 2 away from the shaft head 11 is elastically connected to the piston block 1. A piston chamber 10 is formed between the other end of the shaft tube 2 and the piston block 1. The shaft tube 2 is provided with an air passage 12 communicating with the piston chamber 10. A plurality of positioning columns 13 are installed at one end of the guide plate 16 away from the cone barrel 15. The positioning columns 13 are arranged at equal intervals along the circumferential direction of the guide plate 16. A piston return spring 14 is provided on the positioning columns 13, and the piston return spring 14 abuts between the end cover 4 and the guide plate 16. The positioning columns 13 prevent the piston return spring 14 from deviating. The piston return spring 14 realizes the elastic connection between the shaft tube 2 and the piston block 1. The air passage 12 is arranged in the shaft head 11. The shaft head 11 generates the air passage 12 by means of a central opening, and the shaft head 11 is also used for connecting with a reducer to transmit kinetic energy.
[0042] Refer Figure 4 As shown, the piston block 1 includes a cone barrel 15 and a guide plate 16. The guide plate 16 is arranged at the thinnest end of the cone barrel 15. The diameter of the guide plate 16 is the same as the thickest end of the cone barrel 15. A ring groove is provided on the side wall of the guide plate 16, and a guide belt 17 is installed on the ring groove. The guide plate 16 assists the movement of the piston block 1 and keeps the movement direction of the piston block 1 parallel to the axes of the piston block 1 and the shaft tube 2. The outer diameter of the thickest end of the cone barrel 15 is the same as the inner diameter of the shaft tube 2. A sealing ring 18 is also provided at the thickest part to prevent the gas in the piston chamber 10 from leaking.
[0043] Guide wheel rollers 19 are also provided between adjacent expansion keys 3, and guide rollers 20 are provided on the guide wheel rollers 19. This structure can improve the smoothness of guiding the coiled material. The limit of the outward extension stroke of the expansion key 3 is higher than the height of the rollers. A number of inlet rollers 21 are provided on the side wall of the end cover 4. The inlet rollers 21 assist the insertion of the shaft tube 2 into the coiled material.
[0044] As shown Figure 6 in Figure 3, the sum of the pressures of the expansion keys 3 in the radial direction is K, and K = P / tanα, where P is the difference between the air pressure of the piston and the spring force, and α is the angle between the generatrix of the conical barrel 15 and the axis.
[0045] This application uses a gas-driven method to push the piston block 1 to move, which has better speed compared with the screw-driven method and is suitable for high-speed switching scenarios. The piston block 1 is arranged in the shaft tube 2. An air pressure is generated in the piston cavity 10 at one end of the piston block 1 to overcome the elastic force and cause the piston block 1 to move axially relative to the shaft tube 2. The wedge surface 6 of the axially moving piston block 1 fits with the inclined surface 5 of the expansion key 3, pushing the expansion key 3 to generate a radial displacement, and achieving force amplification by sacrificing the displacement distance.
[0046] The piston block 1 and the expansion keys 3 are pushed mechanically. The distances that each expansion key 3 extends out of the shaft tube 2 are close to each other, having better roundness. The expansion keys 3 of the mechanical structure conduct force through the rigid structure of the wedge surface 6 and the inclined surface 5, having better bearing capacity. And the method of using air pressure to drive the piston to move also has the characteristics of flexible and high-speed switching. Only by adjusting the air pressure of the air source, under the action of the elastic force, the piston block 1 and the expansion keys 3 will reset accordingly.
[0047] Therefore, the solution described in this application can both have high load-bearing and low runout while being able to adapt to high-speed switching.
[0048] The above-described embodiments are only the preferred solutions of the present utility model, and do not impose any form of limitation on the present utility model. There are other variations and modifications without exceeding the technical solutions recorded in the claims.
Claims
1. A mechanical expansion shaft, characterized in that, It includes a piston block and a shaft tube. Along the circumferential direction of the shaft tube, several expansion keys are movably connected to the shaft tube. The expansion keys are configured to extend a set distance in the radial direction. The bottom of the expansion key has an inclined surface. The piston block is provided with a wedge surface adapted to the inclined surface. One end of the shaft tube is elastically connected to the piston block. The other end of the shaft tube forms a piston cavity with the piston block. The shaft tube is provided with an air passage communicating with the piston cavity.
2. A mechanical shaft expander as claimed in claim 1, wherein, An anti-detachment pressure plate is fixedly connected to the shaft tube. The anti-detachment pressure plate spans the expansion key, and an expansion key return spring is provided between the expansion key and the anti-detachment pressure plate.
3. A mechanical shaft expander as claimed in claim 1, wherein, Guide rollers are provided between adjacent expansion keys, and guide rollers are provided on the guide rollers.
4. A mechanical shaft expander as claimed in claim 1, wherein, One end of the shaft tube is provided with a shaft head, and the other end of the shaft tube is provided with a tail cap. Several guide rollers are provided on the side wall of the tail cap.
5. A mechanical shaft expander as claimed in claim 1, wherein, The piston block includes a cone barrel and a guide plate. The guide plate is located at the narrowest end of the cone barrel, and the diameter of the guide plate is the same as that of the widest end of the cone barrel. The side wall of the guide plate is provided with an annular groove, and a guide band is installed on the annular groove.
6. A mechanical shaft expander as claimed in claim 5, wherein, A number of positioning posts are installed at the end of the guide plate away from the cone. The positioning posts are evenly spaced along the circumferential direction of the guide plate. A piston return spring is provided on the positioning post, and the piston return spring abuts between the tail cover and the guide plate.
7. A mechanical shaft expander as claimed in claim 1, wherein, The top surface of the expansion key is provided with friction texture.
8. A mechanical shaft expander as claimed in claim 4, wherein, The air passage is located in the shaft head.
9. A mechanical expansion shaft according to claim 1, characterized in that, The pressure exerted by the expansion joint in the radial direction is K, where K = P / tanα, P is the difference between the piston's air pressure and the spring force, and α is the angle between the generatrix of the cone and the axis.