Synchronous pulley assembly and synchronous pulley assembly structure

Abstract

The utility model provides a synchronous pulley assembly and a synchronous pulley assembly structure. The synchronous pulley assembly comprises a synchronous pulley, a first shaft sleeve and a second shaft sleeve, a mounting shaft hole is formed in the middle of the synchronous pulley; a first matching hole is formed in the middle of the first shaft sleeve, a first outer matching face of a cylindrical structure is formed on the periphery, a first inner matching face of a conical structure is formed on the inner periphery, and a first fracture is formed in the side edge of the first shaft sleeve. A second matching hole is formed in the middle of the second shaft sleeve, a second outer matching face of a conical structure is formed on the periphery, a second inner matching face of a cylindrical structure is formed on the inner periphery, and a second fracture is formed in the side edge of the second shaft sleeve. The synchronous pulley assembly can be stably connected with the transmission shaft through the first shaft sleeve and the second shaft sleeve, compared with a flat key connection scheme in the prior art, the problem that the connection precision is reduced due to abrasion after long-time loading and rotation is avoided, and the working stability is higher.

Description

Technical Field

[0001] The utility model relates to the technical field of synchronous pulleys, and particularly relates to a synchronous pulley and its assembly structure. Background Art

[0002] A synchronous pulley is an auxiliary transmission element arranged between a transmission shaft and a transmission belt. The transmission shaft passes through a shaft hole in the middle of the synchronous pulley and is relatively fixed to the transmission pulley. The transmission belt cooperates with the outer peripheral surface of the synchronous pulley, making the synchronous movement between the transmission shaft and the transmission belt more stable.

[0003] In the prior art, most synchronous pulleys and transmission shafts are fixedly connected by flat keys. Referring to the patent document with the application number CN202410002379.3, a first clamping groove is arranged on the outer peripheral surface of the transmission shaft, and a second clamping groove is arranged on the inner peripheral surface of the synchronous pulley. The flat key is simultaneously clamped and matched with the first clamping groove and the second clamping groove, so that the transmission shaft and the synchronous pulley cannot rotate relative to each other. Although this method has a simple structure, after long-term load and rotation, gaps will be generated due to fretting wear on both sides of the key and the first clamping groove and the second clamping groove, resulting in a decrease in transmission accuracy and affecting production stability.

[0004] The patent document with the application number CN201420797515.4 discloses a connecting device for a short and thin motor shaft and a synchronous pulley. This technical solution provides an interference-fit clamping sleeve inside the synchronous pulley, and adjusts the inner diameter of the clamping sleeve through screws perpendicular to the transmission shaft to achieve a gapless connection between the clamping sleeve and the transmission shaft. The synchronous pulley is relatively fixed to the clamping sleeve through a pin shaft, improving transmission accuracy and working stability. Although this technical solution ensures the connection stability between the clamping sleeve and the transmission shaft, the pin shaft cannot ensure that there is no looseness between the synchronous pulley and the clamping sleeve under long-term load, and there are still defects in actual application. Summary of the Utility Model

[0005] In order to solve the above problems, the utility model provides a synchronous pulley assembly, which has a simple structure, is easy to assemble, and there will be no movable gap between the synchronous pulley and the transmission shaft after assembly, and the transmission stability is stronger.

[0006] In order to achieve the above object, the utility model adopts the following technical solutions:

[0007] A synchronous pulley assembly includes a synchronous pulley, a first bushing, and a second bushing; a mounting shaft hole is formed in the middle of the synchronous pulley; a first mating hole is formed in the middle of the first bushing, a first outer mating surface with a cylindrical structure is formed on the outer periphery, a first inner mating surface with a conical structure is formed on the inner periphery, and a first break is provided on the side of the first bushing; a second mating hole is formed in the middle of the second bushing, a second outer mating surface with a conical structure is formed on the outer periphery, a second inner mating surface with a cylindrical structure is formed on the inner periphery, and a second break is provided on the side of the second bushing; the taper of the first inner mating surface is the same as that of the second outer mating surface, and the maximum inner diameter of the first inner mating surface is greater than the minimum outer diameter of the second outer mating surface and less than the maximum outer diameter of the second outer mating surface.

[0008] Further, a first limiting portion extending along the generatrix direction is provided on the first inner mating surface, and a second limiting portion extending along the generatrix direction and capable of forming a male-female fit with the first limiting portion is provided on the second outer mating surface.

[0009] Further, the first limiting portion and the first break are symmetric with respect to the axis of the first bushing; the second limiting portion and the second break are symmetric with respect to the axis of the second bushing.

[0010] Further, the synchronous pulley further includes a plug-in shaft hole coaxially arranged with the mounting shaft hole, and the aperture of the plug-in shaft hole is smaller than that of the mounting shaft hole.

[0011] Further, the thickness of the first bushing is not less than the depth of the mounting shaft hole, and the thickness of the second bushing is less than the depth of the mounting shaft hole.

[0012] Further, the minimum outer diameter of the second outer mating surface is greater than the minimum inner diameter of the first inner mating surface.

[0013] Further, an inner abutting surface is formed at the end of the first bushing with a smaller inner diameter, and an outer abutting surface perpendicular to its own axis is formed at the end of the second bushing with a larger outer diameter.

[0014] Further, the taper of the first inner mating surface and the second outer mating surface is 0.5 - 1.15.

[0015] Another object of the present utility model is a synchronous pulley assembly structure, which assembly mechanism includes a transmission shaft, a locking nut, and the above-mentioned synchronous pulley assembly; a connection end is formed at the end of the transmission shaft, the connection end passes through the mounting shaft hole, the first mating hole, and the second mating hole and extends out from the end of the second bushing, an external thread is provided on the extending part of the connection end, the locking nut is threadedly connected with the connection end and abuts against the end of the second bushing, the outer wall of the connection end abuts against the first inner mating surface of the first bushing, the first outer mating surface of the first bushing abuts against the second inner mating surface of the second bushing, and the second outer mating surface of the second bushing abuts against the inner wall of the mounting shaft hole of the synchronous pulley.

[0016] Furthermore, a limiting bump is provided at the root of the connecting end head, and one side surface of the synchronous pulley abuts against the limiting bump.

[0017] The application of the utility model can achieve the following beneficial effects:

[0018] 1. The synchronous pulley assembly provided by the utility model can form a stable connection with the transmission shaft through the first shaft sleeve and the second shaft sleeve. Compared with the flat key connection scheme in the prior art, the utility model will not have the problem of reduced connection accuracy due to wear after long-term load and rotation, and has higher working stability.

[0019] 2. The synchronous pulley assembly provided by the utility model is convenient to install. It only needs to sequentially sleeve the synchronous pulley, the first shaft sleeve and the second shaft sleeve on the transmission shaft and fix them with a locking nut, which saves time and effort. Similarly, disassembly and maintenance are also relatively easy.

[0020] 3. In the synchronous pulley assembly structure provided by the utility model, there is less gap between the synchronous pulley and the transmission shaft, and the connection strength between the two is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is an exploded view of the synchronous pulley assembly structure in the embodiment;

[0022] Figure 2 is a schematic structural view of the first shaft sleeve;

[0023] Figure 3 is a schematic structural view of the second shaft sleeve;

[0024] Figure 4 is Figure 1 a schematic assembly structure view of;

[0025] Figure 5 is a schematic structural view of the first shaft sleeve and the second shaft sleeve in another embodiment;

[0026] In the figure, 1 - synchronous pulley, 11 - mounting shaft hole, 12 - inserting shaft hole, 2 - first shaft sleeve, 21 - first mating hole, 22 - first inner mating surface, 23 - first outer mating surface, 24 - inner abutting surface, 25 - first break, 26 - first limiting part, 3 - second shaft sleeve, 31 - second mating hole, 32 - second inner mating surface, 33 - second outer mating surface, 34 - outer abutting surface, 35 - second break, 36 - second limiting part, 4 - transmission shaft, 41 - connecting end head, 42 - limiting bump, 5 - locking nut. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The technical solution of the present utility model will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model. Embodiment

[0028] Referring to Figures 1 - 4 , this embodiment provides a synchronous pulley assembly and a synchronous pulley assembly structure.

[0029] The synchronous pulley assembly includes a synchronous pulley 1, a first bushing 2, and a second bushing 3;

[0030] An installation shaft hole 11 with a larger aperture and a plug-in shaft hole 12 with a smaller aperture are formed in the middle of the synchronous pulley 1. The installation shaft hole and the plug-in shaft hole are coaxially arranged, and a step surface is formed at the junction of the installation shaft hole and the plug-in shaft hole;

[0031] The first bushing 2 is an annular structure with a first fitting hole 21 in the middle. A conical first inner fitting surface 22 is formed on the inner circumference of the first bushing, a cylindrical first outer fitting surface 23 is formed on the outer circumference, an inner abutting surface 24 is formed at the end with a smaller inner diameter of the first bushing, and a first break 25 is provided on the side of the first bushing. At the first break, the first bushing forms two separated first ends. When the elastic first bushing is subjected to a radially outward or inward pressure, the two first ends can move away from or close to each other, causing the inner diameter or outer diameter of the first bushing to change;

[0032] The second bushing 3 is an annular structure with a second fitting hole 31 in the middle. A cylindrical second inner fitting surface 32 is formed on the inner circumference of the second bushing, a conical second outer fitting surface 33 is formed on the outer circumference, an outer abutting surface 35 is formed at the end with a larger outer diameter of the second bushing, and a second break 25 is provided on the side of the second bushing. At the second break, the second bushing forms two separated second ends. When the elastic second bushing is subjected to a radially outward or inward pressure, the two second ends can move away from or close to each other, causing the inner diameter or outer diameter of the second bushing to change.

[0033] The synchronous pulley assembly structure includes a synchronous pulley 1, a first bushing 2, a second bushing 3, a transmission shaft 4, and a locking nut 5;

[0034] A connection end 41 is formed at the end of the transmission shaft 4, and a limit convex block 42 is provided at the root of the connection end. The connection end includes a smooth rod portion near the limit convex block and a threaded rod portion with an external thread near the end;

[0035] The synchronous pulley 1 is sleeved on the optical rod part through the inserted shaft hole 12, and one side surface of the synchronous pulley abuts against the limiting bump 42;

[0036] The first shaft sleeve 2 is arranged in the mounting shaft hole 11 and sleeved on the optical rod part through the first fitting hole 21. The first outer fitting surface 23 of the first shaft sleeve is in mating contact with the inner wall of the mounting shaft hole, and the inner abutting surface 24 of the first shaft sleeve abuts against the stepped surface at the junction of the mounting shaft hole 11 and the inserted shaft hole 12;

[0037] The second shaft sleeve 3 is arranged in the mounting shaft hole 11 and sleeved on the optical rod part through the second fitting hole 31. The second outer fitting surface 33 of the second shaft sleeve is in mating contact with the first inner fitting surface 22 of the first shaft sleeve, and the second inner fitting surface 32 of the second shaft sleeve is in mating contact with the outer wall of the transmission shaft 4;

[0038] The lock nut 5 is threadedly connected to the lead screw part and abuts against the outer abutting surface 35 of the second shaft sleeve.

[0039] The installation method of the synchronous pulley assembly provided by the present utility model is as follows:

[0040] ① Sleeve the synchronous pulley 1 on the connection end 41 of the transmission shaft through the mounting shaft hole 11, and make one side surface of the synchronous pulley abut against the limiting bump 42;

[0041] ② Sleeve the first shaft sleeve on the connection end, move the first shaft sleeve to the inner side of the mounting shaft hole 11 of the synchronous pulley. The outer diameter of the first shaft sleeve is slightly smaller than the inner diameter of the mounting shaft hole and the minimum inner diameter is slightly larger than the outer diameter of the connection end in the natural state, so that the first shaft sleeve can slide into the mounting shaft hole until the inner abutting surface 24 abuts against the stepped surface;

[0042] ③ Sleeve the second shaft sleeve on the connection end, move the second shaft sleeve to the inner side of the mounting shaft hole of the synchronous pulley until the second outer fitting surface of the second shaft sleeve is in mating contact with the inner fitting surface of the first shaft sleeve. The inner diameter of the second shaft sleeve is slightly larger than the connection end in the natural state, so that the second shaft sleeve can slide. The following relationship is satisfied between the first inner fitting surface and the second outer fitting surface: the taper of the first inner fitting surface and the second outer fitting surface is the same, the maximum inner diameter of the first inner fitting surface is larger than the minimum outer diameter and smaller than the maximum outer diameter of the second outer fitting surface, and the minimum inner diameter of the first inner fitting surface is smaller than the minimum outer diameter of the second outer fitting surface;

[0043] ④ Install a locking nut 5 on the connecting end. During the rotation of the locking nut, it gradually approaches the outer abutting surface at the end of the second bushing. After the locking nut contacts the outer abutting surface, continue to rotate the locking nut to apply an axial pressure to the second bushing. Under the action of the axial pressure, the first bushing is subjected to a radially outward pressure through the first inner mating surface, causing the outer diameter of the first bushing to increase and abut against the inner wall of the mounting shaft hole. At the same time, the second bushing is subjected to a radially inward pressure through the second outer mating surface, causing the inner diameter of the second bushing to decrease and abut against the outer wall of the connecting end. Under the combined action of the first bushing and the second bushing, the synchronous pulley and the transmission shaft are relatively fixed.

[0044] In a further embodiment, a male-female mating structure can also be provided between the first bushing and the second bushing to prevent relative rotation between the two. Referring to Figure 5 , the first bushing is provided with a first limiting portion 26 extending along the generatrix of the first inner mating surface. The first limiting portion is arranged at a position symmetrical to the first fracture. The second bushing is provided with a second limiting portion 36 extending along the generatrix of the second outer mating surface. The second limiting portion is arranged at a position symmetrical to the second fracture. The first limiting portion and the second limiting portion can be male-female mated, and the first bushing and the second bushing can slide relative to each other axially in the mated state to facilitate the pressing and fixing of the locking nut.

[0045] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A synchronous pulley assembly, characterized in that: It includes a synchronous pulley, a first sleeve and a second sleeve; a mounting shaft hole is formed in the middle of the synchronous pulley; a first matching hole is formed in the middle of the first sleeve, the outer circumference forms a first outer matching surface of a cylindrical structure, the inner circumference forms a first inner matching surface of a conical structure, and the side of the first sleeve has a first fracture; a second matching hole is formed in the middle of the second sleeve, the outer circumference forms a second outer matching surface of a conical structure, the inner circumference forms a second inner matching surface of a cylindrical structure, and the side of the second sleeve has a second fracture; the first inner matching surface and the second outer matching surface have the same taper, and the maximum inner diameter of the first inner matching surface is greater than the minimum outer diameter of the second outer matching surface and smaller than the maximum outer diameter of the second outer matching surface.

2. A synchronous pulley assembly according to claim 1, characterized in that: The first inner mating surface is provided with a first limiting portion extending along the busbar direction, and the second outer mating surface is provided with a second limiting portion extending along the busbar direction and capable of forming a male-female fit with the first limiting portion.

3. A synchronous pulley assembly according to claim 2, characterized in that: The first limiting portion and the first break are symmetrical relative to the axial center position of the first sleeve; the second limiting portion and the second break are symmetrical relative to the axial center position of the second sleeve.

4. A synchronous pulley assembly according to claim 1, characterized in that: The synchronous belt wheel also includes a plug-in shaft hole coaxially arranged with the installation shaft hole, and the hole diameter of the plug-in shaft hole is smaller than the installation shaft hole.

5. A synchronous pulley assembly according to claim 1, characterized in that: The thickness of the first sleeve is not less than the depth of the mounting shaft hole, and the thickness of the second sleeve is less than the depth of the mounting shaft hole.

6. A synchronous pulley assembly according to claim 1, characterized in that: The minimum outer diameter of the second outer mating surface is greater than the minimum inner diameter of the first inner mating surface.

7. A synchronous pulley assembly according to claim 1, characterized in that: An end of the first sleeve with a smaller inner diameter forms an inner abutment surface, and an end of the second sleeve with a larger outer diameter forms an outer abutment surface perpendicular to its own axis.

8. A synchronous pulley assembly according to claim 1, characterized in that: The taper of the first inner mating surface and the second outer mating surface is 0.5-1.

15.

9. A synchronous pulley assembly structure, characterized in that: It includes a transmission shaft, a locking nut and a synchronous pulley assembly as described in any one of claims 1 to 8; the end of the transmission shaft forms a connecting end, the connecting end passes through the mounting shaft hole, the first matching hole and the second matching hole and extends from the end of the second sleeve, the extending part of the connecting end is provided with an external thread, the locking nut is threadedly connected to the connecting end and abuts against the end of the second sleeve, the outer wall of the connecting end abuts against the first inner matching surface of the first sleeve, the first outer matching surface of the first sleeve abuts against the second inner matching surface of the second sleeve, and the second outer matching surface of the second sleeve abuts against the inner wall of the mounting shaft hole of the synchronous pulley.

10. A synchronous pulley assembly structure according to claim 9, characterized in that: A limiting protrusion is provided at the root of the connecting end, and one side surface of the synchronous belt wheel abuts against the limiting protrusion.

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