Mechanism for fixing gear

Abstract

The utility model discloses a mechanism for fixing a gear, which comprises a gear, a shaft hole is arranged in the middle of the gear, and an inclined circular key hole is arranged on the inner wall of the shaft hole. A key pin is inserted into the circular key hole, a shaft body is inserted into the shaft hole, and a convex shoulder is fixedly connected to the surface of the shaft body; an inclined special-shaped key groove is formed in the surface of the shaft body, the lower end of the key pin penetrates through the round key hole and then is inserted into the special-shaped key groove, the upper end of the key pin abuts against the protruding shoulder, the key pin is inserted into the round key hole, the shaft body is sleeved with the gear, the gear is pushed to slide, and the gear drives the key pin to be installed in the locking hole and the special-shaped key groove. The required length of the shaft body is greatly shortened, and the installation is convenient; through the design of the magnitude of interference in the length direction of the key pin, structural self-locking is achieved, loosening is prevented, and meanwhile, through the design of the assembling clearance between the diameter of the key pin and the diameter of the round key hole, the gear assembling stability can be well guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of gear transmissions, in particular to a mechanism for fixing gears. Background Art

[0002] Currently, gear mechanisms can be used to transmit motion and power between any two axes in space. They have the characteristics of a wide transmission power range, high efficiency, accurate transmission ratio, long service life, safe and reliable operation, etc. Therefore, they are also one of the most widely used transmission mechanisms in modern machinery.

[0003] However, the methods for mounting and securing gears on shafts are relatively limited and each has its own drawbacks. For example, gears mounted using a key and slot design cannot transmit torque in the circumferential direction unless additional axial limiting structures or components are added, such as a retaining ring for limiting the position on the shaft and a limiting nut intended to lock the gear. This complicates the structural design and increases the axial spatial distance of the gear mechanism.

[0004] Another example is the gears installed by means of red sleeves. Before installation, the inner hole on the gear used for installation must be heated. Moreover, when high power is transmitted, the interference fit of the red sleeve is too large. Simply heating the inner hole to expand it affects the metallographic structure of the gear material, reducing the material's performance or life. In addition, the process is cumbersome and the inner hole of the gear is prone to cracking, leading to gear damage. Utility Model Content

[0005] The purpose of the present invention is to provide a mechanism for fixing gears to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a mechanism for fixing a gear, comprising a gear, wherein a shaft hole is provided in the middle of the gear, and an inclined circular key hole is provided on the inner wall of the shaft hole, and the circular key hole penetrates the gear;

[0007] A key pin is inserted into the circular key hole, a shaft body is inserted into the shaft hole, and a boss is fixedly connected to the surface of the shaft body;

[0008] The surface of the shaft body is provided with an inclined special-shaped keyway, the lower end of the key pin passes through the circular keyhole and is inserted into the special-shaped keyway, and the upper end of the key pin presses against the boss to fix the gear and the shaft body in connection. The connection between the gear and the shaft body is stable and not easy to separate.

[0009] Furthermore, the upper end of the key pin has an inclined surface, and the lower end of the key pin has a spherical surface, and the spherical surface matches the special-shaped key slot, thereby improving the firmness of the key pin installation, reducing the gap, and avoiding abnormal noise and looseness.

[0010] Furthermore, a locking hole is provided on the surface of the boss, and the inclined surface is pressed tightly against the inside of the locking hole, so that the key pin will not loosen after installation.

[0011] Furthermore, the axis of the circular keyhole is parallel to the axis of the special-shaped keyway, and one end of the special-shaped keyway inside the shaft hole has a sunken straight edge, which helps the key pin to be smoothly installed inside the special-shaped keyway.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] (1) The key pin is inserted into the circular key hole, and the gear is put on the shaft body, pushing the gear to slide. The gear drives the key pin to be installed into the locking hole and the special-shaped keyway. The structure is streamlined, the required shaft length is greatly shortened, and the installation is convenient.

[0014] (2) By designing the interference fit in the length direction of the key pin, the structure can be self-locked and prevented from loosening. At the same time, by designing the assembly clearance between the key pin diameter and the circular key hole diameter, the stability of the gear assembly can be well guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A three-dimensional diagram of the gear of the present invention;

[0016] Figure 2 A three-dimensional diagram of the key pin of the utility model;

[0017] Figure 3 This is a cross-sectional view of the shaft body of the utility model;

[0018] Figure 4 It is a cross-sectional view of the gear assembly of the utility model;

[0019] Figure 5 This is a schematic diagram of the gear, key pin, and shaft body of the utility model ready for installation;

[0020] Figure 6 Schematic diagram of the contact between the key pin and the shoulder of the utility model;

[0021] Figure 7 The key pin of the utility model is intended to be installed into the interior of the special-shaped keyway;

[0022] Figure 8 This is a schematic diagram of the connection between the key pin and the locking hole of the utility model.

[0023] In the figure: 1. Gear; 2. Shaft hole; 3. Circular keyhole; 4. Key pin; 5. Shaft body; 6. Boss; 7. Locking hole; 8. Special-shaped keyway; 9. Spherical surface; 10. Inclined surface. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] Example:

[0026] See also Figure 1-8 The utility model provides a technical solution: a mechanism for fixing a gear, comprising a gear 1, wherein a shaft hole 2 is provided in the middle of the gear 1, and an inclined circular key hole 3 is provided on the inner wall of the shaft hole 2, one end of the circular key hole 3 penetrates the surface of the gear 1, and the other end is open to the shaft hole 2, and the axis of the circular key hole 3 is inclined to the end face of the gear 1;

[0027] A key pin 4 is inserted into the circular key hole 3, and the key pin 4 is cylindrical in shape. A shaft body 5 is inserted into the shaft hole 2, and a boss 6 is fixedly connected to the surface of the shaft body 5;

[0028] The surface of the shaft body 5 is provided with an inclined special-shaped key groove 8, which is tubular as a whole. The lower end of the key pin 4 passes through the circular key hole 3 and is inserted into the special-shaped key groove 8. The upper end of the key pin 4 presses against the boss 6 to fix the gear 1 and the shaft body 5 to ensure synchronous rotation of the gear 1 and the shaft body 5.

[0029] In this embodiment, if Figure 2 As shown, the upper end of the key pin 4 has an inclined surface 10, and the lower end of the key pin 4 has a spherical surface 9, and the spherical surface 9 matches the special-shaped key groove 8, so that the key pin 4 is in close contact with the special-shaped key groove 8 and will not loosen.

[0030] In this embodiment, if Figure 3 As shown, a locking hole 7 is provided on the surface of the boss 6, and the inclined surface 10 is pressed against the inside of the locking hole 7, so that the key pin 4 is in full contact with the locking hole 7, which has a better fixing effect on the key pin 4.

[0031] In this embodiment, if Figure 4 As shown, the axis of the circular keyhole 3 is parallel to the axis of the special-shaped keyway 8. The special-shaped keyway 8 has a sunken straight edge at one end inside the shaft hole 2, which facilitates the key pin 4 to fall into the special-shaped keyway 8.

[0032] Specifically, when using Figure 5 As shown, half of the key pin 4 is inserted into the circular key hole 3, and the gear 1 is sleeved on the shaft body 5 through the shaft hole 2, and the key pin 4 is aligned with the special-shaped key groove 8;

[0033] like Figure 6As shown, the gear 1 is pressed toward the boss 6 until the inclined surface 10 of the key pin 4 abuts against the surface of the boss 6. During this process, the key pin 4 is kept aligned with the special-shaped key groove 8, and the key pin 4 slides along with the gear 1.

[0034] like Figure 7 As shown, the gear 1 continues to be pressed toward the boss 6. Due to the restriction of the boss 6, the spherical end 9 of the key pin 4 is inserted into the special-shaped key groove 8 as the gear 1 is fed. At the same time, because the key pin 4 is long in the length direction, that is, the length direction is designed with an interference, so as the gear 1 is subsequently pressed, the key pin 4 is continuously compressed in the length direction, causing the key pin 4 to slide into the special-shaped key groove 8.

[0035] like Figure 8 As shown, gear 1 is pressed further into forward shoulder 6 until the inclined surface 10 of key pin 4 sinks into locking hole 7, completely locking key pin 4 in place. The compression of key pin 4, i.e., the interference in the longitudinal direction, can be maintained at a slight interference of, for example, 0.05-0.10 mm, as needed. Gear 1 and shaft 5 are now assembled.

[0036] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A mechanism for fixing a gear, characterized in that: The gear (1) comprises a shaft hole (2) provided in the middle of the gear (1), and an inclined circular key hole (3) provided on the inner wall of the shaft hole (2); A key pin (4) is inserted into the circular key hole (3), a shaft body (5) is inserted into the shaft hole (2), and a boss (6) is fixedly connected to the surface of the shaft body (5); The surface of the shaft body (5) is provided with an inclined special-shaped keyway (8), the lower end of the key pin (4) passes through the circular key hole (3) and is inserted into the special-shaped keyway (8), and the upper end of the key pin (4) presses against the boss (6) to fix the gear (1) and the shaft body (5).

2. A mechanism for fixing a gear according to claim 1, characterized in that: The upper end of the key pin (4) is provided with an inclined surface (10), and the lower end of the key pin (4) is provided with a spherical surface (9), and the spherical surface (9) matches the special-shaped key groove (8).

3. A mechanism for fixing a gear according to claim 2, characterized in that: A locking hole (7) is provided on the surface of the boss (6), and the inclined surface (10) is tightly pressed against the inside of the locking hole (7).

4. The mechanism for fixing a gear according to claim 1, characterized in that: The axis of the circular keyhole (3) is parallel to the axis of the special-shaped keyway (8), and one end of the special-shaped keyway (8) located inside the shaft hole (2) has a sunken straight edge.

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