Mechanical expansion shaft

Abstract

The invention discloses a mechanical expansion shaft, and aims to overcome the defects that an existing screw rod serving as a lead screw drives a conical surface block serving as a sliding block, so that thread loosening and thread failure are easily caused. The screw comprises a threaded rod and a threaded sleeve, the threaded rod comprises an optical axis section and a threaded section, the threaded sleeve is in threaded connection with the threaded section, the threaded sleeve rotates to drive the threaded rod to move in the axial direction, the optical axis section is sleeved with a conical surface block, the conical surface block synchronously moves along with displacement of the threaded rod, and a plurality of expansion keys are arranged on the conical surface of the conical surface block at equal intervals. The expansion key is configured to only move in the radial direction, the expansion key is provided with an inclined face, the inclined face is attached to the conical face, and the expansion key stretches out or retracts in the radial direction along with displacement of the screw. The unthreaded shaft is in butt joint with the conical surface block, the screw rod-sliding block pair is achieved through the threaded sleeve and the threaded rod, the service life of the expansion shaft can be prolonged, and the probability that the expansion shaft loses efficacy due to thread damage is reduced.

Description

Technical Field

[0001] The present invention relates to a coiling device, and more particularly to a mechanical expansion shaft. Background Art

[0002] The reeling and unwinding device is suitable for food machinery, packaging machinery, rubber machinery, and equipment for producing films. It can reel and unwind by rotating, and can store and release flexible sheets or wire bundles of equal cross-sectional size. The material is generally wound onto a hollow roller, and then transferred by a forklift or a transporter.

[0003] For heavy loads or environments where air cannot be supplied, a purely mechanical expansion shaft is required. The existing mechanical expansion shaft adopts a screw-slider pair structure, where the screw rotates to drive the cone block of the slider to move, thereby driving the expansion key to expand.

[0004] However, this method can easily lead to thread damage and failure, thus shortening the life of the expansion shaft. Summary of the invention

[0005] The present invention overcomes the disadvantage that the existing screw rod driving the conical surface block as a slider easily leads to slipping and thread failure, and provides a mechanical expansion shaft, which can improve the reliability and life of the expansion shaft. In order to solve the above technical problems, the present invention adopts the following technical solutions: A mechanical expansion shaft comprises a screw and a screw sleeve, wherein the screw comprises a smooth axis section and a threaded section, the screw sleeve is threadedly connected to the threaded section, the screw sleeve drives the screw to move in the axial direction by rotation, a conical surface block is mounted on the smooth axis section, the conical surface block moves synchronously with the displacement of the screw, a plurality of expansion keys arranged at equal intervals are arranged on the conical surface of the conical surface block, the expansion keys are configured to move only in the radial direction, the expansion keys have an inclined surface, the inclined surface is in contact with the conical surface, and the expansion keys extend or retract in the radial direction with the displacement of the screw.

[0006] The screw rod is connected to the screw rod through the threaded section and the screw rod to form a screw rod-slider pair. The screw rod as the slider is driven to move axially through the forward and reverse rotation of the screw rod. The cone block is installed on the optical axis section of the screw rod and moves synchronously with the screw rod. The expansion key cannot move in the axial direction. The cone block moves relative to the expansion key, and the inclined surface and the cone surface cooperate to generate the radial displacement of the driving expansion key and the corresponding force amplification.

[0007] The design of separating the thread segment and the optical axis segment can better protect the thread, confine the thread to a shorter area, and reduce the difficulty of processing; when the expansion key is subjected to non-radial forces, the thread engagement method is more likely to cause slippage and thread damage than the optical axis contact method.

[0008] As a preference, it further comprises a shaft tube, in which the screw, the conical block and the expansion key are arranged, a positioning pin is installed on the shaft tube, a positioning groove is provided on the conical block along the axial direction, the positioning pin is inserted into the positioning groove, and the conical block is also connected to the screw through a connecting pin, and the connecting pin is arranged along the radial direction. The positioning pin positions the conical block, and the conical block positions the screw, thereby limiting the rotation of the screw through the shaft tube.

[0009] Preferably, the shaft tube is provided with a through hole for passing the expansion key, and when the expansion key is at the stroke limit of the retracted state, the expansion key is flush with the side wall of the shaft tube.

[0010] Preferably, the surface of the expansion key is provided with friction lines to increase the friction force generated by the expansion key.

[0011] Preferably, the screw rod is provided with a plurality of conical blocks. A greater number of conical blocks corresponds to a longer expansion shaft, and the expansion shaft has expansion keys corresponding to a plurality of conical blocks in the length direction, so that the coil can be supported at all locations in the length direction, reducing pressure and avoiding stress concentration.

[0012] Preferably, the conical surface block connected by the positioning pin and the connecting pin is the conical surface block at the edge of one side, and the screw rod is provided with a fastener at the other end, and the fastener and the conical surface block clamp and position the remaining conical surface blocks. In addition to being used to limit the screw rod, the aforementioned conical surface block also clamps each conical surface block with the fastener, so that the conical surface block can move with the screw rod.

[0013] Preferably, a spacer is provided on the screw rod, the spacer is provided between adjacent conical blocks, and two ends of the spacer are respectively in contact with adjacent conical blocks. The conical blocks are pushed by the spacer, and the spacer is used to control the distance between adjacent conical blocks.

[0014] Preferably, each expansion key in the same cone block forms an expansion key group, and one expansion key group has j expansion keys. The expansion shaft has i groups of cone blocks. The projections of the expansion key groups corresponding to the same group of cone blocks on the axis coincide. The deflection angle of the expansion key group of the nth cone block about the axis is This structure enables the expansion keys to contact the rollers alternately, reducing stress, expanding the coil more evenly, and achieving higher roundness.

[0015] Preferably, a roller key is provided on the surface of the shaft tube, and the roller key includes a roller key body and a roller connected to the roller key body by a rotating shaft, and the top of the roller is higher than the surface of the shaft tube. This structure can improve the smoothness of introducing the coil. The travel limit of the expansion key extending outward is higher than the height of the roller.

[0016] Preferably, the roller keys are arranged in an array along the axial and circumferential directions of the side wall of the shaft tube.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) Mechanical expansion shaft achieves expansion of the expansion key through mechanical rotation. The expansion shaft can be used in high load or airless environment; (2) The smooth shaft and the conical block are connected, and the screw sleeve and screw are used to realize the screw-slider pair, which can increase the life of the expansion shaft and reduce the probability of failure of the expansion shaft due to thread damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is an axonometric view of the present invention; Figure 2 is a front view of the present invention; Figure 3 yes Figure 2 Sectional view at AA in the middle; Figure 4 yes Figure 2 Cross-section at the middle BB; Figure 5 yes Figure 2 Sectional view at CC; Figure 6 It is a cross-sectional view of the connection between the screw and the sleeve; Figure 7 It is the axonometric view of the cone block and expansion key; Figure 8 It is a schematic diagram of the magnified wedge angle; Fig. 9 The cross-sectional diagram of the change in the top surface shape of the expansion key at the same position under different screw extension amounts in an embodiment; In the figure: Screw 1, threaded sleeve 2, shaft sleeve 3, conical block 4, expansion key 5, optical axis section 6, threaded section 7, locating pin 9, threaded hole 10, locating groove 11, nut 12, spacer 13, through hole 14, sub-key 15, inclined groove 16, roller key 17, connecting pin 18, pressure plate 19, spring 20. DETAILED DESCRIPTION

[0019] The present disclosure is further described below in conjunction with the accompanying drawings and embodiments.

[0020] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0021] It should be noted 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 "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0022] In the present disclosure, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present disclosure, and do not specifically refer to any part or element in the present disclosure and should not be understood as limitations on the present disclosure.

[0023] In the present disclosure, terms such as "fixed connection", "connected", "connection", etc. should be understood in a broad sense, indicating that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. For relevant scientific research or technical personnel in this field, the specific meanings of the above terms in the present disclosure can be determined according to specific circumstances, and they cannot be understood as limitations on the present disclosure.

[0024] Example: A mechanical expansion shaft, Figure 1 , 2 As shown, it includes a screw rod 1, a screw sleeve 2, a shaft sleeve 3, a conical block 4 and an expansion key 5. The screw rod 1 and the screw sleeve 2 are threadedly connected, and the screw rod 1 is restricted so that it cannot rotate. When the power source is connected to the screw sleeve 2, the screw rod 1 can be driven to feed in the axial direction. The structure constitutes a screw slider pair.

[0025] Ginseng Figure 6 The screw rod 1 includes an optical axis section 6 and a threaded section 7. The optical axis section 6 contacts the conical surface block 4, and the threaded section 7 contacts the screw sleeve 2. The screw sleeve 2 drives the threaded section 7 to move in the axial direction by rotating. The threaded section 7 is located at one end of the optical axis section 6.

[0026] Ginseng Figure 3 The optical axis segment 6 is mounted with a conical surface block 4. The conical surface block 4 includes a cone portion, and the conical surface block 4 is a rotating body, and has a through hole on its axis, so as to be mounted on the optical axis segment 6.

[0027] The cone block 4 moves synchronously with the displacement of the screw 1. This is achieved as follows: The screw 1, the conical block 4 and the expansion key 5 are arranged in the shaft tube, and the side of the shaft tube is provided with a threaded hole 10, through which a positioning pin 9 is installed. A positioning groove 11 is provided in the axial direction on the leftmost (or rightmost) conical block 4. The positioning pin 9 is inserted into the positioning groove 11, and the positioning pin 9 is limited by the groove walls on both sides of the positioning groove 11. The above structure makes it impossible for the shaft tube to rotate relative to the screw 1 or the relative rotation stroke is very small (equal to the distance from the positioning pin 9 to the groove walls on both sides). On this basis, the conical block 4 is also connected to the screw 1 through a connecting pin 18, and the connecting pin 18 is arranged in the radial direction. The positioning pin 9 positions the conical block 4, and the conical block 4 positions the screw 1, thereby limiting the rotation of the screw 1 through the shaft tube.

[0028] In some embodiments, the screw 1 is provided with a plurality of conical blocks 4. A greater number of conical blocks 4 corresponds to a longer expansion shaft, and the expansion shaft has a plurality of expansion keys 5 corresponding to the conical blocks 4 in the length direction, so that the coil can be supported at all locations in the length direction, reducing pressure and avoiding stress concentration. For a screw 1 having a plurality of conical blocks 4, each conical block 4 is constrained so that the conical block 4 can move synchronously with the screw 1.

[0029] The aforementioned leftmost conical block 4 not only serves as a medium to fix the shaft tube and the screw 1, so that the conical block 4 can move with the screw 1, but also can position the remaining conical blocks 4. Specifically, the aforementioned conical block 4 is located at the leftmost side of the screw 1, and the screw 1 is provided with a fastener at the rightmost side, and the fastener and the conical block 4 clamp the remaining conical blocks 4 in position. In addition to being used to limit the screw 1, the aforementioned conical block 4 also clamps each conical block 4 with the fastener, so that the conical block 4 can move with the screw 1. In some embodiments, the fastener is a nut 12, and further, two nuts 12 are provided to prevent loosening.

[0030] Ginseng Figure 3 In some embodiments, a spacer 13 is sleeved on the screw 1, and the spacer 13 is arranged between adjacent conical blocks 4, and both ends of the spacer 13 are respectively in contact with adjacent conical blocks 4. The conical blocks 4 are pushed by the spacer 13, and the spacing between adjacent conical blocks 4 is controlled by the spacer 13.

[0031] It is worth noting that in this embodiment, the leftmost conical block 4 is limited to the screw 1 and the sleeve 3, but it is not limited to this. Those skilled in the art can choose to limit the rightmost conical block 4 according to the teachings of the present invention and actual use requirements.

[0032] A plurality of expansion keys 5 arranged at equal intervals are provided on the conical surface of the conical surface block 4, and the expansion keys 5 are configured to move only in the radial direction.

[0033] Ginseng Figure 4and 5 , wherein the expansion key 5 is configured to move only in the radial direction in the following specific manner: the shaft tube is provided with a through hole 14 for passing the expansion key 5, and when the expansion key 5 is at the stroke limit of the retracted state, the expansion key 5 is flush with the side wall of the shaft tube. This means that the expansion key 5 is always in contact with the through hole 14, and is therefore always constrained by the through hole 14. The surface of the expansion key 5 is provided with friction patterns to increase the friction generated by the expansion key 5. In some embodiments, the top surface of the expansion key 5 is an outwardly convex curved surface, so as to better adapt to the coil and reduce local friction.

[0034] Ginseng Figure 1 , each expansion key 5 in the same cone block 4 forms 5 expansion key groups, one expansion key 5 group has j expansion keys 5, the expansion axis has i groups of cone blocks 4, the projections of the 5 expansion keys corresponding to the same group of cone blocks 4 on the axis coincide, and the deflection angle of the 5 expansion keys of the nth cone block 4 on the axis is This structure enables the expansion key 5 to contact the roller alternately, reducing stress, expanding the coil more evenly and achieving higher roundness.

[0035] Specifically in this embodiment, there are i groups of cone blocks 4, and one group of expansion keys 5 has four expansion keys 5, so the deflection angle of the expansion keys 5 corresponding to the even-numbered cone blocks 4 is 45 degrees.

[0036] The surface of the shaft tube is provided with a roller key 17, which includes a roller key 17 body and a roller connected to the roller key 17 body by a rotating shaft, and the top of the roller is higher than the surface of the shaft tube. This structure can improve the smoothness of introducing the coil. The limit of the outward extension of the expansion key 5 is higher than the height of the roller. Specifically, the roller key 17 is arranged in an array along the axial and circumferential directions of the side wall of the shaft tube.

[0037] Ginseng Figure 7 , 8 The expansion key 5 has an inclined surface, which fits the conical surface. The expansion key 5 extends or retracts in the radial direction as the screw 1 moves. As the conical surface block 4 moves, the expansion key 5 extends accordingly. In some embodiments, the top surface of the expansion key 5 is a curved surface.

[0038] The expansion shaft is provided with pressure plates 19 at both ends of the length direction of the through hole 14 through fasteners. The expansion key 5 is limited by the pressure plate 19 to prevent the expansion key 5 from falling out. A spring 20 is provided between the pressure plate 19 and the expansion key 5. The spring 20 is used to press the expansion key 5 toward the axis in the retracted state.

[0039] The inclination of the cone is , is the thrust on the cone block 4, then the thrust in the radial direction is Satisfy the formula For a cone block 4 corresponding to n expansion keys 5, the thrust of a single expansion key 5 is Satisfy the formula Ginseng Fig. 9 , for the scenario where the inner diameter of the expanded roll has several or uncertain, the expansion key 5 includes several sub-keys 15, the number of which is an odd number and is symmetrically arranged about the center line of the expansion key 5. The adjacent sub-keys 15 are slidably matched by the guide rail-slider, and are matched by steps and elastic members to realize a reset structure similar to that between the pressure plate 19 and the expansion key 5. The conical surface is provided with an inclined groove 16 corresponding to the sub-key 15 close to the middle, and the inclination of the inclined groove 16 is less than the inclination of the conical surface. The more backward the position, the greater the height difference between the conical surface and the inclined groove 16. When the expansion key 5 moves relative to the conical surface block 4, the expansion key 5 expands, and the expansion rate of the middle sub-key 15 is lower than that of the sub-keys 15 on both sides, thereby obtaining a smaller curvature to adapt to the coil with a larger inner diameter. For the coil with a small inner diameter, due to the small displacement distance of the screw 1, the distance between the inclined groove 16 and the conical surface is short. Therefore, the curvature formed on the top surface of each sub-key 15 is larger, which is suitable for the coil with a smaller inner diameter.

[0040] The design of separating the thread segment 7 and the optical axis segment 6 can better protect the thread, confine the thread to a shorter area, and reduce the difficulty of processing; when the expansion key 5 is subjected to non-radial force, the thread engagement method is more likely to cause slippage and thread damage than the optical axis contact method.

[0041] The embodiments described above are only preferred solutions of the present invention and are not intended to limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solutions described in the claims.

Claims

1. A mechanical expansion shaft, characterized in that: It includes a screw and a screw sleeve. The screw includes an optical axis section and a threaded section. The screw sleeve is threadedly connected to the threaded section. The screw sleeve drives the screw to move in the axial direction by rotation. A conical block is mounted on the optical axis section. The conical block moves synchronously with the displacement of the screw. A plurality of expansion keys are arranged at equal intervals on the conical surface of the conical block. The expansion keys are configured to move only in the radial direction. The expansion key has an inclined surface. The inclined surface is in contact with the conical surface. The expansion key extends or retracts in the radial direction with the displacement of the screw.

2. The mechanical expansion shaft according to claim 1, characterized in that: It also includes a shaft tube, a screw rod, a conical block and an expansion key arranged in the shaft tube, a positioning pin is installed on the shaft tube, a positioning groove opened along the axial direction is provided on the conical block, the positioning pin is inserted into the positioning groove, and the conical block is also connected to the screw rod through a connecting pin, and the connecting pin is arranged along the radial direction.

3. A mechanical expansion shaft according to claim 2, characterized in that: The shaft tube is provided with a through hole for passing the expansion key. When the expansion key is at the stroke limit of the retracted state, the expansion key is flush with the side wall of the shaft tube.

4. The mechanical expansion shaft according to claim 1, characterized in that: The surface of the expansion key is provided with friction lines.

5. The mechanical expansion shaft according to claim 3, characterized in that: A plurality of conical blocks are arranged on the screw rod.

6. The mechanical expansion shaft according to claim 3 is characterized in that: The conical surface block connected by the positioning pin and the connecting pin is the conical surface block at the edge of one side. The screw rod is provided with a fastener at the other end. The fastener and the conical surface block clamp and position the remaining conical surface blocks.

7. The mechanical expansion shaft according to claim 6, characterized in that: A spacer sleeve is sleeved on the screw rod, and the spacer sleeve is arranged between adjacent cone surface blocks, and two ends of the spacer sleeve are respectively in contact with the adjacent cone surface blocks.

8. The mechanical expansion shaft according to claim 5, characterized in that: Each expansion key in the same cone block forms an expansion key group. There are j expansion keys in one expansion key group. The expansion axis has i groups of cone blocks. The projections of the expansion key groups corresponding to the same group of cone blocks on the axis coincide. The deflection angle of the expansion key group of the nth cone block about the axis is .

9. The mechanical expansion shaft according to claim 1, characterized in that: A roller key is arranged on the surface of the shaft tube. The roller key comprises a roller key body and a roller rotatably connected to the roller key body through a rotating shaft. The top of the roller is higher than the surface of the shaft tube.

10. The mechanical expansion shaft according to claim 9, characterized in that: The roller keys are arranged in an array along the axial and circumferential directions of the side wall of the shaft tube.

Images