A crank bearing mounting tool

Abstract

This invention belongs to the field of assembly tooling, and specifically relates to a crank arm bearing installation tooling, comprising a tooling body, a top support block at the lower end of the tooling body, and a support portion for inserting into the inner part of the crank arm through a square hole, thereby supporting the arm of the crank arm through displacement, rotation, or expansion. In use, the tooling is inserted into the square hole of the crank arm, and the support portion of the top support block supports the arm from within, followed by press-fitting of the crank arm bearing. After press-fitting, the tooling is removed. This tooling is suitable for situations where the crank arm is installed in a closed space, making it impossible to use tools for external support. It is also convenient to assemble and disassemble, and simple to operate.

Description

Technical Field

[0001] This invention relates to a crank arm bearing installation fixture, belonging to the field of assembly fixture technology. Background Technology

[0002] During the opening and closing operation of a circuit breaker, the rotation of the crank arm drives the insulating rod to move, thereby opening and closing the moving contacts. The crank arm and the insulating rod are connected by bearings. The crank arm structure is as follows: Figure 1 and Figure 2 As shown, the crank arm 1 includes a first arm 2 and a second arm 3, which are connected by a connecting part 4. A square hole 5 is provided at one end of the first arm 2 and the second arm 3 away from the connecting part, and a bearing mounting seat 6 is provided. The bearing mounting seat 6 and the square hole 5 are arranged coaxially. The bearing is press-fitted onto the bearing mounting seat 6. Since the bearing is interference-fitted with the crank arm 1 and the first arm 2 and the second arm 3 are spaced apart, that is, the crank arm 1 has an inner crotch, the crank arm 1 has poor rigidity. When the bearing is press-fitted, it will put a lot of pressure on the crank arm 1, which will cause the gap between the first arm 2 and the second arm 3 to shrink and cause the crank arm 1 to deform.

[0003] Traditional crank arm bearing installation typically involves first installing the crank arm in place, then using tools to support the inner part of the crank arm from the outside before installing the bearing. This prevents the crank arm from deforming and failing during the press-fit process, or prevents the bearing from being properly assembled. However, for... Figure 3 and Figure 4 The structure shown creates a closed space after the crank arm is installed, making it impossible to use tools to support it from the outside. Therefore, traditional crank arm bearing installation fixtures and methods are not suitable for this situation. Summary of the Invention

[0004] The purpose of this invention is to provide a crank arm bearing installation fixture to solve the problem that traditional crank arm bearing installation fixtures cannot be used in situations where support cannot be provided from the outside of the crank arm.

[0005] To achieve the above objectives, the crank arm bearing mounting fixture of this invention adopts the following technical solution:

[0006] A crank arm bearing installation fixture includes a fixture body, a top support block at the lower end of the fixture body, and a support part for inserting into the inner crotch of the crank arm through the square hole of the crank arm to support the arm of the crank arm by means of displacement, rotation or expansion.

[0007] Furthermore, the top support block is a square block with the same height as the distance between the upper and lower arm crotches of the crank arm, its side length is less than or equal to the side length of the square hole of the crank arm, and its diagonal dimension is greater than the side length of the square hole of the crank arm.

[0008] Furthermore, a cylinder for centering and engaging with the square hole of the crank arm is coaxially connected to the upper side of the top support block, and the diameter of the cylinder is equal to the side length of the top support block.

[0009] Furthermore, the support portion is the four corners of the top support block.

[0010] Furthermore, the top support block is an expansion block, and the top support block has a support hole inside. An expansion joint is opened on the top support block. In the initial state, the dimension of the top support block in the horizontal direction is less than or equal to the side length of the square hole of the crank arm. After expansion, the dimension in the horizontal direction is greater than the side length of the square hole of the crank arm.

[0011] Furthermore, the top support block is provided with a stepped hole, the upper part of which is a large diameter section and the lower part is a small diameter section, and the large diameter section is provided with a support body.

[0012] Furthermore, a pressure rod is fixedly connected to the upper end of the support body, and the pressure rod presses the support body from the large diameter section to the small diameter section, thereby opening the top support block.

[0013] Furthermore, the pressure rod is a screw rod, and a threaded hole is provided on the tooling body above the expansion joint.

[0014] Furthermore, the top support block is a square block, and a square column is provided on the upper part of the top support block. The side length of the square column is smaller than the side length of the top support block when it expands.

[0015] Furthermore, the large-diameter segment and the small-diameter segment are transitioned by a chamfer.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention is an improved invention. Specifically, when using this tooling, the tooling is inserted into the square hole of the crank arm, so that the top support block is located in the inner crotch of the crank arm (i.e., in the gap between the first and second arms of the crank arm). Then, the supporting part of the top support block supports the crank arm, and then the crank arm bearing is press-fitted. After the press-fitting is completed, the tooling is removed. This tooling is inserted into the square hole of the crank arm. Compared with the prior art, which uses a tool to support the inner crotch of the crank arm from the outside, this tooling is suitable for situations where the crank arm is installed in place and a closed space is formed, making it impossible to use tools to support the crank arm from the outside. This solves the problems of the crank arm not being able to be supported, the bearing not being able to be assembled, or the crank arm easily deforming and failing during bearing assembly. Moreover, it is convenient to disassemble and assemble, and simple to operate. Attached Figure Description

[0017] Figure 1 This is the front view of the crank arm;

[0018] Figure 2 for Figure 1 Top view;

[0019] Figure 3 A structural diagram showing the enclosed space formed after the crank arm is installed in place;

[0020] Figure 4 for Figure 3 Partial sectional view along the AA direction;

[0021] Figure 5 This is a front view of Embodiment 1 of the crank arm bearing mounting fixture in this invention;

[0022] Figure 6 for Figure 5 Top view;

[0023] Figure 7-9 This is a schematic diagram showing the usage state of Embodiment 1 of the crank arm bearing mounting fixture in this invention.

[0024] in, Figure 7 A schematic diagram showing the installation fixture for the crank arm bearing not being inserted into the square hole of the crank arm.

[0025] Figure 8 A schematic diagram showing the top support block of the crank arm bearing installation fixture being placed in the inner crotch of the crank arm.

[0026] Figure 9 A schematic diagram showing how the crank arm bearing installation fixture supports the crank arm after rotating 45°.

[0027] Figure 10 This is a front view of Embodiment 2 of the crank arm bearing mounting fixture in this invention;

[0028] Figure 11 This is a front view of Embodiment 2 of the crank arm bearing mounting fixture of the present invention, excluding the screw and the support hole body;

[0029] Figure 12 for Figure 8 Top view;

[0030] Figure 13 for Figure 8 A bottom view;

[0031] Figure 14-16 This is a schematic diagram showing the usage state of Embodiment 2 of the crank arm bearing mounting fixture in this invention.

[0032] in, Figure 14 A schematic diagram showing the installation fixture for the crank arm bearing not being inserted into the square hole of the crank arm.

[0033] Figure 15 A schematic diagram showing the top support block of the crank arm bearing installation fixture being placed in the inner crotch of the crank arm.

[0034] Figure 16 A schematic diagram showing how the top support block supports the crank arm after the support hole of the crank arm bearing installation fixture is opened.

[0035] In the diagram: 1-crank arm; 2-first arm; 3-second arm; 4-connecting part; 5-square hole; 6-bearing mounting seat; 7-tool body; 8-top support block; 81-large diameter section; 82-small diameter section; 83-chamfer; 9-hand handle; 10-screw; 11-threaded hole. Detailed Implementation

[0036] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0037] This invention provides a crank arm bearing installation fixture, hereinafter referred to as the fixture, comprising a fixture body, a top support block at the lower end of the fixture body, and a support portion for inserting into the inner part of the crank arm through a square hole, thereby supporting the crank arm through displacement, rotation, or expansion. In use, the fixture is inserted into the square hole of the crank arm, and the support portion of the top support block supports the crank arm. Then, the crank arm bearing is press-fitted. After press-fitting, the fixture is removed. This fixture, inserted through the square hole of the crank arm, is suitable for situations where the crank arm is installed in a closed space, making it impossible to use tools to support it from the outside. This solves the problems of the crank arm being unable to be supported, the bearing being unable to be assembled, or the crank arm easily deforming and failing during bearing assembly.

[0038] Specific embodiment 1 of the crank arm bearing mounting fixture provided by the present invention:

[0039] like Figure 5 and Figure 6As shown, the top support block 8 of this fixture is a square block. The height of the top support block 8 is the same as the distance between the two arms of the crank arm 1 (i.e., the interval between the first arm 2 and the second arm 3). Its side length is less than or equal to the side length of the square hole 5 of the crank arm 1, and its diagonal dimension is greater than the side length of the square hole 5 of the crank arm 1. Thus, the top support block 8 can be inserted into the square hole 5 of the crank arm 1, and can support the arm of the crank arm 1 after rotating 45°. The fixture body 7 includes a platform and a column. The platform is located on top of the column, and the column is located on top of the top support block 8. The platform and column are coaxially arranged with the top support block 8. In this embodiment, the platform is a frustum of a cylinder, and the column is a cylinder. The diameter of the base of the frustum is equal to the diameter of the cylinder, and the diameter of the cylinder is equal to the side length of the top support block 8. This is used for centering with the square hole 5 of the crank arm 1, ensuring that the top support block 8 does not become eccentric during rotation and can stably support the crank arm 1. This design facilitates processing and allows the fixture body 7 to be easily inserted into the square hole 5 of the crank arm 1. Furthermore, when the top support block 8 of the fixture rotates within the crank arm 1, the fixture body 1 will not interfere with the square hole 5 of the crank arm 1, thus preventing the fixture from rotating. In other embodiments, the diameter of the cylinder can be smaller than the side length of the top support block 8. In other embodiments, the diameter of the base of the frustum can be smaller than the diameter of the cylinder. In other embodiments, the cylinder can be a square prism, but the diagonal dimension of the square prism must be less than or equal to the side length of the square hole 5 of the crank arm 1, so that the square prism will not interfere with the square hole 5 when the fixture rotates. In other embodiments, the frustum can be a pyramid. In other embodiments, a frustum may not be required.

[0040] In this embodiment, as Figure 5 As shown, the upper part of the tooling body 7 is provided with a handle, which is a handle rod 9. Specifically, the handle rod 9 is a square rod. The design of the handle facilitates the rotation of the tooling. In other embodiments, the handle rod 9 can be a round rod. Alternatively, in other embodiments, the handle may not be provided. In this embodiment, the support part is the four corners of the top support block 8.

[0041] When using this tooling, if Figure 7-9 As shown, first insert the tooling into the square hole 5 of the crank arm 1, so that the top support block 8 passes through the square hole 5 and enters the inner crotch of the crank arm 1. After the top support block 8 is fully inserted into the inner crotch of the crank arm 1, the operator holds the handle 9 and rotates the tooling 45° so that the four corners of the top support block 8 are supported at the outer edge of the square hole 5 in the inner crotch of the crank arm 1. After the support is completed, press the crank arm bearing into place. After the bearing is installed, rotate the tooling 45° again and remove the tooling from the square hole 5 of the crank arm 1. In this way, the installation of the crank arm bearing is completed using the tooling.

[0042] In other embodiments, the cylinder can be eccentrically connected to the top support block 8. In this case, the diameter of the cylinder is smaller than the side length of the top support block 8. After the tooling is inserted into the square hole 5 of the crank arm 1, the top support block 8 enters the inner crotch of the crank arm 1. The top support block 8 is moved between the upper and lower arms of the crank arm 1 by the displacement tooling, and supports the upper arm of the crank arm 1.

[0043] Specific embodiment 2 of the crank arm bearing mounting fixture provided by the present invention:

[0044] like Figure 10-13 As shown, the top support block 8 of this tooling is an expansion block, and the top support block 8 has a support hole 9 inside. Figure 12 and Figure 13 As shown, an expansion joint is provided on the outer surface of the top support block 8 to ensure that the top support block 8 can expand outward under radial pressure and return to its original state when the radial force disappears. In its initial state, the horizontal dimension of the top support block 8 is less than or equal to the side length of the square hole 5 of the crank arm 1. After expansion, the horizontal dimension of the top support block 8 is greater than the side length of the square hole 5 of the crank arm 1. Thus, the top support block 8 of the tooling can be inserted into the square hole 5 of the crank arm 1. After the top support block 8 is expanded by the support body 5, its expanded outer surface can press against the square hole 5 of the crank arm 1 to support the inner crotch of the crank arm 1. Alternatively, the upper surface of the expanded top support block 8 can support the inner crotch of the crank arm 1 at the outer edge of the square hole 5.

[0045] like Figure 10 and Figure 11 As shown, the top support block 8 has a stepped hole, wherein the upper part of the stepped hole is a large-diameter section 81 and the lower part is a small-diameter section 82, and the support body 9 is disposed in the large-diameter section 81. The stepped hole design facilitates processing, and the top support block 8 has a significant opening effect, which can provide good support for the inner crotch of the crank arm 1. In other embodiments, the hole in the top support block 8 is a tapered hole that gradually narrows from top to bottom.

[0046] like Figure 10 and Figure 11 As shown, a pressure rod is fixedly connected to the upper end of the support body 9. The pressure rod presses the support body 9 from the large diameter section 81 to the small diameter section 82, thereby opening the top support block 8. Specifically, the pressure rod is a screw 10, and a threaded hole 11 is provided inside the platform of the tooling body 7 above the expansion joint. This tooling opens the top support block 8 by screwing the screw 10, pressing the support body 9 from the large diameter section 81 to the small diameter section 82 inside the top support block 8. Designing the pressure rod as a screw makes it easier for the operator to press down the support body 9, and the screw and threaded hole are easy to process, resulting in low processing costs. In other embodiments, the pressure rod can be an ordinary round rod, which the operator applies a vertical downward force to press down the support body 9. In other embodiments, the pressure rod can be omitted, and a tool can be used to press the support body 9 into the top support block 8. After the bearing is installed, the support body 9 can be removed using a tool.

[0047] like Figure 12 As shown, the top support block 8 is a square block, and the tooling body 7 includes a square column and a frustum. The square column is located on top of the top support block, and the frustum is located on top of the square column. The side length of the lower surface of the frustum is equal to the side length of the square column. In other embodiments, the frustum may not be provided. In this embodiment, the side length of the square column is smaller than the side length of the top support block 8 when it expands, so that when the supporting hole body 9 supports the top support block 8, it can open the top support block 8. After it is opened, the side of the column contacts the square hole 5 of the crank arm 1, and the upper end surface of the opened part of the top support block 8 forms a support part. The design of the square column facilitates the insertion of the tooling body 7 into the square hole 5 of the crank arm 1, and when the top support block 8 of the tooling is opened by the supporting hole body 9, the four sides of the square column can fit against the side wall of the square hole 5 of the crank arm 1, thereby ensuring that the top support block 8 is subjected to uniform force and achieving a better support effect. In other embodiments, the side length of the bottom surface of the frustum may be smaller than the side length of the square column. In other embodiments, the frustum and the column may be a frustum of a cylinder and a cylinder, respectively.

[0048] like Figure 10 and Figure 11 As shown, the large-diameter section 81 and the small-diameter section 82 are transitioned by a chamfer 83. Correspondingly, the lower end of the support body 9 is also chamfered. The chamfer design serves as a guide for the support body 9, making it easier for the operator to press the support body 9 down. In other embodiments, the chamfer may not be provided. In other embodiments, the chamfer 83 may only be provided between the large-diameter section 81 and the small-diameter section 82, and no chamfer may be provided on the support body 9.

[0049] When using this tooling, if Figure 14-16 As shown, first, insert the tooling into the square hole 5 of the crank arm 1, so that the top support block 8 passes through the square hole 5 and enters the inner crotch of the crank arm 1. After the top support block 8 is fully inserted into the inner crotch of the crank arm 1, the operator screws the screw 10 to press the support hole body 9 inside the top support block 8 from the large diameter section 81 to the small diameter section 82, thereby opening the top support block 8 so that the upper end of the opened part of the top support block faces the outer edge of the square hole 5 in the inner crotch of the crank arm 1 for support. After the support is completed, press the crank arm bearing into place. After the bearing is installed, screw the screw 10 again to pull the support hole body 9 from the small diameter section 82 to the large diameter section 81 of the top support block 8. The top support block 8 springs back to its original position due to elastic deformation, and the tooling is removed from the square hole 5 of the crank arm 1. In this way, the installation of the crank arm bearing is completed using the tooling.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. A crank arm bearing mounting fixture, characterized in that, The tooling body includes a top support block at its lower end. The top support block has a support portion for inserting into the inner crotch of the crank arm through the square hole of the crank arm, so as to support the arm of the crank arm by means of displacement, rotation or expansion.

2. The crank arm bearing installation fixture according to claim 1, characterized in that, The top support block is a square block with the same height as the distance between the upper and lower arm crotches of the crank arm. Its side length is less than or equal to the side length of the square hole of the crank arm, and its diagonal dimension is greater than the side length of the square hole of the crank arm.

3. The crank arm bearing installation fixture according to claim 2, characterized in that, The upper side of the top support block is coaxially connected to a cylinder for centering with the square hole of the crank arm, and the diameter of the cylinder is equal to the side length of the top support block.

4. The crank arm bearing mounting fixture according to claim 2 or 3, characterized in that, The supporting parts are the four corners of the top support block.

5. The crank arm bearing installation fixture according to claim 1, characterized in that, The top support block is an expansion block, and the top support block has a support hole inside. An expansion joint is opened on the top support block. In the initial state, the dimension of the top support block in the horizontal direction is less than or equal to the side length of the square hole of the crank arm. After expansion, the dimension in the horizontal direction is greater than the side length of the square hole of the crank arm.

6. The crank arm bearing installation fixture according to claim 5, characterized in that, The top support block has a stepped hole, the upper part of which is a large diameter section and the lower part is a small diameter section, and the large diameter section has a support body.

7. The crank arm bearing installation fixture according to claim 6, characterized in that, A pressure rod is fixedly connected to the upper end of the support body. The pressure rod presses the support body from the large diameter section to the small diameter section, thereby opening the top support block.

8. The crank arm bearing mounting fixture according to claim 7, characterized in that, The pressure rod is a screw rod, and the tooling body has a threaded hole at a position above the expansion joint.

9. The crank arm bearing mounting fixture according to any one of claims 5-8, characterized in that, The top support block is a square block, and a square column is provided on the top of the top support block. The side length of the square column is smaller than the side length of the top support block when it expands.

10. The crank arm bearing mounting fixture according to any one of claims 6-8, characterized in that, The large-diameter section and the small-diameter section are transitioned by a chamfer.

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