Speed reducer with hook-shaped flat key transmission structure

Abstract

The speed reducer with the hook-shaped flat key transmission structure comprises a hook-shaped flat key, an output shaft, a screw, a screw rod, a machine barrel and a gear box, the machine barrel is fixedly connected with the gear box, the output shaft is installed in the gear box, the screw rod penetrates through the machine barrel and then is fixedly connected with the output shaft in the gear box, and the hook-shaped flat key is fixedly installed on the output shaft through the screw. The hook-shaped flat key comprises a flat key body and a hook-shaped part, the flat key body and the hook-shaped part are vertically distributed, a first groove matched with the flat key body is formed in the outer wall of the screw rod, a second groove matched with the hook-shaped part is formed in the inner wall of the output shaft, a through hole is formed in the hook-shaped part, a threaded hole is formed in the second groove, and the threaded hole is matched with the first groove. Screws penetrate through the through holes and are matched with the threaded holes, so that the hook-shaped flat key is fixedly installed on the output shaft. The speed reducer adopts the hook-shaped flat key to replace a common standard flat key, and the hook-shaped flat key is fixed on the output shaft of the speed reducer, so that the situation that the common standard flat key interferes with a machine barrel can be avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of speed reducer, especially a speed reducer with hook-shaped flat key transmission structure. BACKGROUND

[0002] The prior art extrusion equipment is generally connected with a barrel and a speed reducer, and the commonly used transmission structures include flat keys, various splines, etc. However, the speed reducers with flat key transmission structures or spline transmission structures have their own defects:

[0003] I. Structural characteristics and installation bottleneck of flat key transmission: when using flat key structure transmission, the flat key needs to be installed on the screw first, and then the screw is passed through the inside of the barrel and connected with the speed reducer. When the inner hole of the barrel and the outer diameter of the screw are very close, the normal standard flat key will interfere with the barrel, resulting in the situation that the screw cannot pass through the barrel, as shown in Figure 1 and Figure 2 Specifically, the conventional flat key assembly process requires that the flat key be embedded in the keyway of the screw shaft end in advance, and the meshing with the output shaft of the speed reducer is completed through axial sliding. This assembly method will cause assembly interference when the gap between the outer diameter of the screw and the inner diameter of the barrel is small. Especially when the gap is less than or equal to 2mm, the protruding part of the flat key is prone to scratching the inner wall of the barrel. Experimental data shows that when the gap is less than 1.5mm, the assembly success rate will be less than 40%.

[0004] II. Cost dilemma of spline transmission: when using spline structure transmission, the manufacturing cost of the output shaft and the screw will increase. Specifically, the processing cost analysis shows that the single piece manufacturing cost of the spline shaft increases by about 220% compared with the flat key structure, among which the time-consuming of the hobbing process increases by 65%, and the difficulty of controlling the subsequent heat treatment deformation increases by 40%. The spline tooth surface needs to be nitrided, which increases the material cost by about 35% compared with the quenching and tempering treatment of the flat key, and the surface treatment cost increases by 180%. INVENTION CONTENTS

[0005] The technical problem to be solved by the utility model is to overcome the deficiencies in the prior art, and to provide a speed reducer with hook-shaped flat key transmission structure, which uses a hook-shaped flat key to replace a normal standard flat key, and fixes the hook-shaped flat key on the output shaft of the speed reducer, so that the situation of interference between the normal standard flat key and the barrel can be avoided.

[0006] The technical solution adopted by this utility model to solve its technical problem is as follows: a reducer with a hook-shaped flat key transmission structure, including a hook-shaped flat key, an output shaft, a screw, a threaded rod, a barrel, and a gearbox. The barrel is fixedly connected to the gearbox, the output shaft is installed inside the gearbox, the threaded rod passes through the barrel and is fixedly connected to the output shaft inside the gearbox, and the hook-shaped flat key is fixedly mounted on the output shaft by the screw. The hook-shaped flat key includes a flat key body and a hook-shaped part, which are vertically distributed. The outer wall of the threaded rod is provided with a first groove that matches the flat key body, and the inner wall of the output shaft is provided with a second groove that matches the hook-shaped part. A through hole is opened on the hook-shaped part, and a threaded hole is opened on the second groove. The hook-shaped flat key is fixedly mounted on the output shaft by passing the screw through the through hole and engaging with the threaded hole.

[0007] To be further specific, the flat key body and the hook-shaped part are an integral structure.

[0008] To be further specific, the two hook-shaped flat keys are symmetrically mounted and fixed on the output shaft.

[0009] To be further specific, all corners of the hook-shaped flat key are chamfered.

[0010] The beneficial effects of this utility model are: the reducer with the hook-shaped flat key transmission structure makes it easier to disassemble and assemble the screw by fixing the hook-shaped flat key on the output shaft. At the same time, it avoids the interference between the ordinary standard flat key and the barrel. In addition, the hook-shaped flat key structure has a lower manufacturing cost than the spline structure. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the structure of a current-technical speed reducer;

[0013] Figure 2 This is a schematic diagram of a keyed transmission structure in a current-technical speed reducer;

[0014] Figures 1-2 The labels in the code are: 1', standard flat key; 2', output shaft; 3', screw; 4', threaded rod; 5', barrel; 6', gearbox;

[0015] Figure 3This is a schematic diagram of the reducer with a hook-shaped flat key transmission structure according to this utility model;

[0016] Figure 4 This is a schematic diagram of the hook-shaped flat key transmission structure in the reducer of this utility model;

[0017] Figure 5 This is an exploded view of the hook-shaped flat key transmission structure in the reducer of this utility model;

[0018] Figure 6 This is a schematic diagram of the hook-shaped flat key in the speed reducer of this utility model.

[0019] Figures 3-6 The labels in the text are:

[0020] 1. Hook-shaped flat key; 11. Flat key body; 12. Hook-shaped part; 13. Through hole;

[0021] 2. Output shaft; 21. Second groove; 22. Threaded hole;

[0022] 3. Screws;

[0023] 4. Screw; 41. First groove;

[0024] 5. Machine barrel;

[0025] 6. Gearbox. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, 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.

[0027] See Figure 3 , Figure 4 and Figure 5 The present invention discloses a speed reducer with a hook-shaped flat key transmission structure, comprising a hook-shaped flat key 1, an output shaft 2, a screw 3, a threaded rod 4, a barrel 5, and a gearbox 6. The barrel 5 is fixedly connected to the gearbox 6, the output shaft 2 is installed inside the gearbox 6, the threaded rod 4 passes through the barrel 5 and is fixedly connected to the output shaft 2 inside the gearbox 6, and the hook-shaped flat key 1 is fixedly mounted on the output shaft 2 by the screw 3.

[0028] See Figure 6The hook-shaped flat key 1 includes a flat key body 11 and a hook-shaped part 12. The flat key body 11 and the hook-shaped part 12 are vertically distributed. The outer wall of the screw 4 is provided with a first groove 41 that is adapted to the flat key body 11. The inner wall of the output shaft 2 is provided with a second groove 21 that is adapted to the hook-shaped part 12. The hook-shaped part 12 is provided with a through hole 13. The second groove 21 is provided with a threaded hole 22. The hook-shaped flat key 1 is installed and fixed on the output shaft 2 by passing a screw 3 through the through hole 13 and engaging with the threaded hole 22.

[0029] The key body 11 and the hook-shaped part 12 are integrated structures. This integrated structure avoids stress concentration points caused by bolts, welding, or adhesive bonding in traditional assembly structures, resulting in more uniform load distribution and stronger resistance to deformation and impact. Preferably, the key body 11 is made of 45 steel.

[0030] Specifically, the outer wall of the screw 4 is provided with two first grooves 41 that are adapted to the flat key body 11, and the inner wall of the output shaft 2 is provided with two second grooves 21 that are adapted to the hook-shaped part 12. The two hook-shaped flat keys 1 are symmetrically installed and fixed on the output shaft 2. The two symmetrically distributed hook-shaped flat keys 1 can evenly distribute the transmitted torque and avoid the failure of a single hook-shaped flat key 1 due to overload. This design significantly improves the overall load-bearing capacity. In addition, the two symmetrically distributed hook-shaped flat keys 1 make the force on the output shaft 2 more balanced, reduce local stress concentration, and extend the service life of the output shaft 2.

[0031] The hook-shaped flat key 1 has chamfers at all corners. The chamfer design makes it easier for the hook-shaped flat key 1 to be aligned and slide into the groove during installation, which plays a good guiding role, reduces frictional resistance, and ensures that the hook-shaped flat key 1 is installed smoothly. At the same time, the chamfer disperses stress through a smooth transition, improves the fatigue resistance of the hook-shaped flat key 1, and extends its service life. In addition, the chamfer can remove burrs, ensure dimensional accuracy and surface quality, ensure a tight fit, and reduce assembly problems caused by burrs.

[0032] The reducer with a hook-shaped flat key transmission structure uses a hook-shaped flat key 1 instead of a standard flat key. Fixing the hook-shaped flat key 1 on the output shaft 2 of the reducer makes it easier to disassemble and assemble the screw 4. At the same time, it avoids interference between the standard flat key and the barrel 5. In addition, the hook-shaped flat key structure has a lower manufacturing cost than the spline structure.

[0033] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A speed reducer with a hook-shaped flat key transmission structure, characterized in that: The assembly includes a hook-shaped flat key (1), an output shaft (2), a screw (3), a threaded rod (4), a barrel (5), and a gearbox (6). The barrel (5) is fixedly connected to the gearbox (6). The output shaft (2) is installed inside the gearbox (6). The threaded rod (4) passes through the barrel (5) and is fixedly connected to the output shaft (2) inside the gearbox (6). The hook-shaped flat key (1) is fixedly mounted on the output shaft (2) by the screw (3). The hook-shaped flat key (1) includes a flat key body (11) and a hook-shaped part (12). The flat key body (11) and the hook-shaped part (12) are vertically distributed. The outer wall of the screw (4) is provided with a first groove (41) that is adapted to the flat key body (11). The inner wall of the output shaft (2) is provided with a second groove (21) that is adapted to the hook-shaped part (12). The hook-shaped part (12) is provided with a through hole (13). The second groove (21) is provided with a threaded hole (22). The screw (3) passes through the through hole (13) and engages with the threaded hole (22) to realize the installation and fixation of the hook-shaped flat key (1) on the output shaft (2).

2. The speed reducer with a hook-shaped flat key transmission structure as described in claim 1, characterized in that: The flat key body (11) and the hook-shaped part (12) are an integral structure.

3. The speed reducer with a hook-shaped flat key transmission structure as described in claim 1, characterized in that: The two hook-shaped flat keys (1) are symmetrically mounted and fixed on the output shaft (2).

4. The reducer with a hook-shaped flat key transmission structure as described in claim 1, characterized in that: The hook-shaped flat key (1) has chamfers at all corners.

Images