A press-fitting device and press-fitting method for an adaptive multi-specification knuckle bearing

Abstract

The application relates to a pressing device and a pressing method of an adaptive multi-specification knuckle bearing, and belongs to the field of mechanical manufacturing and assembly equipment. The device comprises a pressing head, a steel ball retainer assembly, a positioning seat and a base; a V-shaped groove on a bearing seat is used to turn inwards to form a flange, so that the outer ring of the knuckle bearing is covered and locked on the bearing seat. The positioning function is decoupled into two independent modules of the positioning seat and the base, only the corresponding positioning seat needs to be replaced according to the hole diameter specification of the knuckle bearing to be processed, a complete set of tooling does not need to be frequently replaced, different hole diameter specifications of the knuckle bearing can be quickly adapted, the product changeover time is greatly shortened, and the assembly production efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of mechanical manufacturing and assembly equipment, and relates to a press-fitting device and method for adaptive multi-specification joint bearings. Background Technology

[0002] Spherical plain bearings, as special sliding bearings capable of withstanding radial, axial, or combined loads, are widely used in aerospace, engineering machinery, hydraulic transmission, and heavy machinery. They are primarily used in various articulated swing mechanisms, possessing advantages such as high load-bearing capacity, flexible rotation, and good impact resistance, making them crucial basic connecting components in equipment transmission systems. In the component assembly process, precisely pressing the spherical plain bearing into the corresponding mounting hole is a critical step; the quality of the press-fit directly determines the assembly accuracy and smoothness of the entire machine. Therefore, the bearing press-fitting process is a core and critical step in the production assembly process.

[0003] Currently, most existing spherical plain bearing press-fitting equipment adopts a dedicated fixed structure, which suffers from technical defects such as poor versatility and cumbersome operation. For example, utility model patent CN214331242U discloses an "adjustable spherical plain bearing riveting device," which consists of a positioning rod, a lead screw, an adjusting block assembly, and a support base. It adapts to spherical plain bearings of different sizes by changing the position of the adjusting block. However, because the dimensions of its positioning rod and support base are fixed, it cannot adapt to the rapid switching of multiple specifications of spherical plain bearings, resulting in limited equipment versatility. In addition, the riveting head and V-groove in this device adopt a sliding friction fit, which has high frictional resistance, not only increasing the pressing difficulty but also easily causing wear of the riveting head, requiring regular replacement and increasing the cost of use and maintenance.

[0004] For example, invention patent CN108637126B discloses a "portable spherical bearing rolling and closing device," which generates pressure between the steel ball and the V-groove through a rolling head, and uses rotation to deform the V-groove to achieve closing. This invention also belongs to a fixed press-fit structure, which lacks versatility; moreover, before each operation, the steel balls need to be manually rearranged and collected. Due to the small size of the steel balls, this auxiliary process is time-consuming, which seriously restricts the assembly production efficiency.

[0005] With the increasing variety of product models in the equipment manufacturing industry, the flexible production model of "multi-category, small-batch" has become the mainstream. Traditional single-specification dedicated press-fitting equipment can no longer meet the current industry's demand for efficient and flexible assembly. To solve the practical problems of weak versatility, cumbersome changeover, and low efficiency in existing technologies, the market urgently needs to develop a universal press-fitting device that is simple in structure, easy to adjust, and can be quickly adapted to various specifications of spherical plain bearings, so as to improve overall assembly efficiency and equipment adaptability. Summary of the Invention

[0006] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose an adaptive multi-specification spherical plain bearing press-fitting device, which can quickly adapt to spherical plain bearings with different bore diameters without the need for frequent replacement of the entire tooling, greatly shorten product changeover time, and improve assembly production efficiency.

[0007] The solution of the present invention is: a press-fitting device for adaptive multi-specification spherical plain bearings, comprising: using the press-fitting device to turn the V-groove on the bearing housing inward to cover and lock the outer ring of the spherical plain bearing onto the bearing housing; the press-fitting device comprises: a press head, a steel ball cage assembly, a positioning seat and a base; The positioning seat has its lower surface mounted on the base; its upper surface has an annular boss and a central shaft with a common central axis, and an annular cavity between them; the bearing seat is fitted onto the annular boss, and the spherical bearing is fitted onto the central shaft, achieving precise positioning in both the radial and axial directions; the V-groove on the bearing seat is kept facing upwards and in initial contact with the steel balls in the steel ball cage assembly; The pressure head applies pressure to the steel ball during the pressing process and guides it into the V-groove of the bearing housing; The steel ball retainer assembly uses an adjustable diameter steel ball retainer to restrain the steel balls and prevent them from scattering during the pressing process; The base is fixedly installed at the bottom of the press machine for connection with the press machine.

[0008] Furthermore, the steel ball retainer assembly includes a retainer and connecting blocks; the number of retainers and connecting blocks are equal and they are alternately connected end to end to form a closed polygonal ring.

[0009] Furthermore, the steel ball retainer assembly also includes a connecting bolt and a connecting nut; the retainer has a first through hole, and the connecting block has a second through hole; the connecting bolt passes through the first through hole and the second through hole in sequence, and engages with the connecting nut threadedly to complete the fastening connection of the retainer and the connecting block.

[0010] Furthermore, the connection between the retainer and the connecting block is at a specified angle, and the angle can be manually adjusted to change the effective diameter of the steel ball retainer assembly to adapt to spherical bearings with different bore diameters.

[0011] Furthermore, the cage includes an upper cage, a lower cage, and screws; The upper cage has a semi-groove structure in the center and symmetrically arranged lugs at both ends, with the three parts connected as a single unit. The lower cage has the same structure as the upper cage; the lower surface of the upper cage contacts the upper surface of the lower cage, and the two semi-grooves form a complete groove structure that matches the steel ball for placing the steel ball; The screws are passed through the upper retainer lug and the lower retainer lug on the same side in sequence to secure the upper and lower retainers.

[0012] Furthermore, the positioning seat has two positioning holes on its lower surface; the base has two positioning pins on its upper surface, which correspond one-to-one with the two positioning holes and fit with a small gap to meet the positioning accuracy requirements during press fitting, while also taking into account the convenience of changing the shape.

[0013] Furthermore, the small gap is 0.01mm-0.02mm.

[0014] Furthermore, the number of positioning seats is several; the size of the annular boss with a common central axis on the upper surface of each positioning seat is different, and the size of the central axis is also different, so as to be adapted to the spherical bearings of different sizes; the size and specifications of the positioning holes on the lower surface of each positioning seat are the same, so as to be matched and installed with the base; during the press-fitting process, a matching positioning seat is selected according to the size of the spherical bearing.

[0015] Furthermore, the pressure head has an annular groove structure added to its lower surface to enhance the stability and adaptability of its fit with the spherical bearing.

[0016] A press-fitting method for adaptive multi-specification spherical plain bearings, comprising: Place the bearing housing to be press-fitted onto the annular boss of the positioning seat, and place the spherical plain bearing onto the central shaft; keep the V-groove on the bearing housing facing upwards and in initial contact with the steel balls in the steel ball cage assembly; The pressure head is controlled to move downward and rotate, guiding the steel ball into the V-groove of the bearing housing through the annular groove on the lower surface; The pressure head continues to descend and rotate until it reaches the set depth. Then, it stops descending and holds pressure to ensure that the V-groove flange on the bearing housing is fully shaped, thus completing the press-fit cycle.

[0017] The advantages of this invention compared to the prior art are: (1) This invention adopts a modular positioning structure design, which decouples the positioning function into two independent modules: a positioning seat and a base, and connects them through a universal interface. Quick adaptation can be achieved simply by changing the corresponding positioning seat according to the bore diameter specification of the bearing to be processed, without needing to replace the entire tooling. This split design greatly simplifies the tooling changeover steps, shortens the changeover time, and significantly improves the flexibility of the production line.

[0018] (2) The steel ball cage assembly designed in this invention is an adjustable diameter steel ball cage assembly, which can be widely adapted to various ball bearings with different bore diameters, significantly optimizes the steel ball loading process, realizes rapid arrangement and efficient collection of steel balls, and improves work efficiency. Attached Figure Description

[0019] Figure 1 This is a cross-sectional view of the mechanism in an embodiment of the present invention; Figure 2 This is an external view of the mechanism in an embodiment of the present invention; Figure 3 This is a cross-sectional view of the positioning seat in an embodiment of the present invention; Figure 4 This is a cross-sectional view of the cage of the steel ball cage assembly in an embodiment of the present invention; Figure 5 This is an external view of the steel ball cage assembly in an embodiment of the present invention; Figure 6 This is a view of the connecting block of the steel ball retainer assembly in an embodiment of the present invention. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] like Figures 1-2 As shown, a press-fitting device for adaptive multi-specification spherical plain bearings includes a press head 1, a ball cage assembly 2, a positioning seat 5, and a base 6. It is mainly used to press-fit and fix the spherical plain bearing 3 onto the bearing housing 4. When the spherical plain bearing 3 is installed on the bearing housing 4, the V-groove flanging process on the bearing housing 4 is used to firmly lock the outer ring of the spherical plain bearing 3 onto the bearing housing 4.

[0022] The base 6 is fixedly installed at the bottom of the pressing machine, serving as the connection interface between the pressing machine and the pressing device. The installation and positioning accuracy of the base 6 directly determines the alignment accuracy during the pressing process, thus having a critical impact on the final pressing quality.

[0023] The lower surface of the positioning seat 5 has two positioning holes that mate with the corresponding two positioning pins on the base 6. The fit is a small clearance, which satisfies both the positioning accuracy requirements during press-fitting and the ease of changeover. Furthermore, the positioning seat 5 has an annular boss and a central shaft sharing a common central axis, with an annular cavity between them. The central shaft protrudes more than the annular boss relative to the upper surface of the positioning seat 5. During press-fitting, the bearing seat 4 is mounted on the annular boss above the central shaft of the spherical bearing 3, achieving precise radial and axial positioning. Multiple positioning seats can be machined according to different spherical bearing sizes. The dimensions of the annular boss and central shaft on each seat are adapted to different spherical bearing sizes, but the dimensions and positions of the two positioning holes that mate with the base 6 remain unchanged. The two positioning pins on the base 6 have a small clearance fit, and both the positioning pins and positioning holes are chamfered for easy replacement of the positioning seats during changeover.

[0024] The lower surface of the pressure head 1 is enhanced with a multi-ring groove structure, which improves the stability and adaptability of the fit between the pressure head 1 and the spherical plain bearing 3. This effectively solves the problem that a single pressure head is difficult to be compatible with spherical plain bearings 3 of different sizes, improves the accuracy and pass rate of part pressing, and ensures the smoothness of the pressing process.

[0025] (1) Step-by-step description of the pressing action and the force transmission path: The pressing process of the device of the present invention is a precise process of mechanical transfer and material plastic deformation.

[0026] A press-fitting method for adaptive multi-specification spherical plain bearings comprises the following four steps, with the force transmission path as follows: Step S1: Initial positioning and clamping Action Description: The operator places the bearing housing 4 to be press-fitted onto the annular boss of the positioning seat 5 and inserts the spherical plain bearing 3 onto the central shaft. At this time, the V-groove on the bearing housing 4 faces upward and is in initial contact with the steel ball 2-1 in the steel ball cage assembly 2.

[0027] Force state: At this time, the system is in a zero-load state, with only a small preload caused by gravity.

[0028] Step S2: Applying pressure and initial contact Action Description: The main shaft of the press machine drives the press head 1 to move downwards and rotate. The annular groove on the lower surface of the press head 1 guides the steel ball 2-1 into the depth of the V-groove of the bearing housing 4.

[0029] The force is transmitted sequentially through: press machine, press head 1, and upper part of steel ball 2-1.

[0030] Mechanical analysis: Indenter 1 applies an axially downward normal pressure to steel ball 2-1. Due to the restriction of the annular groove, steel ball 2-1 cannot detach axially and can only roll or slide along the V-groove wall.

[0031] Step S3: Radial extrusion and plastic deformation (core stage) Action description: As the pressure head 1 continues to descend and rotate, the steel ball 2-1 is subjected to the reaction force of the side wall within the V-groove.

[0032] The force is transmitted sequentially through: steel ball 2-1 and the V-groove sidewall of bearing housing 4.

[0033] Mechanical breakdown: The resultant force on steel ball 2-1 can be decomposed into a normal force perpendicular to the contact surface. and tangential frictional force parallel to the contact surface .

[0034] Normal force Pointing towards the center of the V-groove, it generates a huge radial compressive force, forcing the V-groove metal material to yield.

[0035] Tangential force The steel ball is driven to rotate in the V-groove, which makes the pressure distribution uniform and avoids pitting or uneven indentation caused by local stress concentration.

[0036] Result: The V-groove metal undergoes plastic flow, folds inward to form a "flanged edge", and tightly wraps around the outer ring of the spherical bearing 3.

[0037] Step S4: Pressure holding and return stroke Action Description: Once the pressure head 1 reaches the set depth, the press machine stops descending and holds pressure briefly (2-3 seconds) to ensure the flanging is fully shaped. Then the main shaft lifts, and pressure head 1 moves upward, completing one press cycle.

[0038] Force release: The external load is removed, elastic deformation is restored, plastic deformation is retained, and permanent fixation is achieved.

[0039] (2) Detailed description of the steel ball cage adjustment mechanism Structural principles: such as Figure 4 , Figure 5 As shown, the steel ball retainer assembly 2 includes a retainer and connecting blocks; the number of retainers and connecting blocks are equal and they are connected end to end alternately to form a closed polygonal ring.

[0040] The retainer, consisting of an upper retainer 2-2, a lower retainer 2-3, and screws 2-4, is used to restrain the steel ball 2-1 and prevent it from scattering during the pressing process; The upper retainer 2-2 has a semi-groove structure in the center and symmetrical lugs at both ends, and the three are connected as a whole. The lower retainer 2-3 has the same structure as the upper retainer 2-2. The lower surface of the upper retainer 2-2 contacts the upper surface of the lower retainer 2-3. The two semi-groove structures are opposite each other to form a full groove structure that matches the steel ball 2-1, which is used to place the steel ball 2-1. The screw 2-4 passes through the lugs of the upper retainer 2-2 and the lower retainer 2-3 on the same side in sequence to complete the fixation of the upper retainer 2-2 and the lower retainer 2-3.

[0041] like Figure 6 The diagram shows the connecting block. The cage and the connecting block are connected together by connecting bolts 2-5 and connecting nuts 2-6. The tightening torque of the connecting nuts should be such that the angle between the cage and the connecting block has minimal damping during adjustment.

[0042] The cage has a first through hole, and the connecting block has a second through hole; the connecting bolts 2-5 pass through the first through hole and the second through hole in sequence, and are threadedly engaged with the connecting nuts 2-6 to complete the fastening connection of the cage and the connecting block.

[0043] Adjustment method: Manually adjust the angle between the cage and the connecting block to change the effective diameter of the entire ball array until the diameter of the ball array approximately matches the V-groove size of the current bearing housing. During press fitting, the steel balls experience a tangential force parallel to the contact surface. This will cause the diameter of the steel ball array to be slightly adjusted again, so as to fit the V-groove size of the current bearing housing well.

[0044] Advantages: This mechanical adjustment structure allows for quick and easy fine-tuning without tools, and the steel ball 2-1 remains within the grooves of the upper and lower retainers during the adjustment process, preventing it from falling out. This solves the problems of easy loss and difficult cleaning in traditional ball-scattering operations.

[0045] (3) Detailed description of the connection method between the positioning seat and the base To ensure the accuracy and convenience of modular changeover, the positioning seat 5 and the base 6 adopt a "double-column small-clearance fit" connection method: Two cylindrical locating pins (tolerance zone g6) are machined on the base 6, and two cylindrical locating holes (tolerance zone H7) are provided at corresponding positions on the bottom of the locating seat 5. These two components form a small clearance fit (clearance controlled between 0.01mm and 0.02mm). Both the locating pins and the locating hole entrances are designed with a 15° chamfer for easy and quick insertion and alignment. The fit between the two locating pins and the locating holes restricts the circumferential rotational freedom of the locating seat, and the small clearance fit ensures both ease of installation and positioning accuracy.

[0046] (4) Comparison of press-fitting cases for two specifications of spherical plain bearings: To visually demonstrate the advantages of this invention in terms of changeover time and improved press-fitting efficiency, two commonly used specifications of spherical plain bearings were selected for comparative testing. The test records are shown in Table 1. Specification A: Inner diameter 12mm, outer diameter 22mm, matching bearing housing V-groove diameter φ24mm.

[0047] Specification B: Inner diameter 15mm, outer diameter 26mm, matching bearing housing V-groove diameter φ28mm.

[0048] Table 1 Comparative test results of two commonly used specifications of spherical plain bearings

[0049] Case Analysis Conclusion: In the above case, when switching from production specification A to specification B, the traditional solution requires a downtime of more than 10 minutes for tooling change, and the manual ball placement is inefficient, resulting in a long first-piece debugging time. The solution of this invention only requires replacing the positioning seat and adjusting the diameter of the steel ball retainer by simple rotation, reducing the changeover time to 2 minutes and improving efficiency by nearly 80%. Simultaneously, by avoiding manual ball placement, the single pressing time is reduced from 2 minutes to less than 30 seconds, improving efficiency by nearly 75%.

[0050] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A press-fitting device for adaptive multi-specification spherical plain bearings, characterized in that, The V-groove on the bearing housing (4) is turned inward by the press fitting device to cover and lock the outer ring of the spherical plain bearing (3) onto the bearing housing (4); the press fitting device includes: a press head (1), a steel ball cage assembly (2), a positioning seat (5) and a base (6). The positioning seat (5) is mounted on the base (6) on its lower surface; the upper surface is provided with an annular boss and a central shaft with a common central axis, and there is an annular cavity between them; the bearing seat (4) is fitted on the annular boss, and the spherical bearing (3) is fitted on the central shaft to achieve precise positioning in both the radial and axial directions; the V-groove on the bearing seat (4) is kept facing upward and is in initial contact with the steel ball (2-1) in the steel ball cage assembly (2); The pressure head (1) applies pressure to the steel ball (2-1) during the pressing process and guides it into the V-groove of the bearing housing (4); The steel ball retainer assembly (2) adopts an adjustable diameter steel ball retainer to restrain the steel balls (2-1) and prevent them from falling out during the pressing process; The base (6) is fixedly installed at the bottom of the press machine for connection with the press machine.

2. The press-fitting device for an adaptive multi-specification spherical plain bearing according to claim 1, characterized in that, The steel ball retainer assembly (2) includes a retainer and a connecting block; The cage and connecting blocks are of equal number and are alternately connected end to end to form a closed polygonal loop.

3. The press-fitting device for an adaptive multi-specification spherical plain bearing according to claim 2, characterized in that, The steel ball retainer assembly (2) further includes a connecting bolt (2-5) and a connecting nut (2-6); the retainer has a first through hole and the connecting block has a second through hole; the connecting bolt (2-5) passes through the first through hole and the second through hole in sequence, and is threadedly engaged with the connecting nut (2-6) to complete the fastening connection of the retainer and the connecting block.

4. The press-fitting device for an adaptive multi-specification spherical plain bearing according to claim 2, characterized in that, The connection between the cage and the connecting block is at a specified angle, and the angle is manually adjusted to change the effective diameter of the steel ball cage assembly (2) to adapt to spherical bearings (3) with different bore diameter specifications.

5. The press-fitting device for an adaptive multi-specification spherical plain bearing according to claim 2, characterized in that, The cage includes an upper cage (2-2), a lower cage (2-3), and a screw (2-4). The upper retainer (2-2) has a semi-groove structure in the center and symmetrically arranged lugs at both ends, with the three parts connected as a single unit; The lower retainer (2-3) has the same structure as the upper retainer (2-2); the lower surface of the upper retainer (2-2) contacts the upper surface of the lower retainer (2-3), and the two semi-groove structures form a complete groove structure that matches the steel ball (2-1) for placing the steel ball (2-1). Screws (2-4) are passed through the upper retainer (2-2) lug and the lower retainer (2-3) lug on the same side in sequence to complete the fixation of the upper retainer (2-2) and the lower retainer (2-3).

6. The press-fitting device for an adaptive multi-specification spherical plain bearing according to claim 1, characterized in that, The positioning seat (5) has two positioning holes on its lower surface; the base (6) has two positioning pins on its upper surface, which correspond one-to-one with the two positioning holes and fit with a small gap to meet the positioning accuracy requirements during press fitting, while also taking into account the convenience of changing the model.

7. The press-fitting device for an adaptive multi-specification spherical plain bearing according to claim 6, characterized in that, The small gap is 0.01mm-0.02mm.

8. The press-fitting device for an adaptive multi-specification spherical plain bearing according to claim 6, characterized in that, The number of positioning seats (5) is several; the size of the annular boss with a common central axis on the upper surface of each positioning seat (5) is different, and the size of the central axis is also different, which is used to adapt to the spherical bearings (3) of different sizes; the size of the positioning hole on the lower surface of each positioning seat (5) is the same, which is used to match and install with the base (6); during the press-fitting process, a matching positioning seat (5) is selected according to the size of the spherical bearing (3).

9. The press-fitting device for an adaptive multi-specification spherical plain bearing according to claim 1, characterized in that, The pressure head (1) has an annular groove structure added to its lower surface to enhance the stability and adaptability of its fit with the spherical bearing (3).

10. A pressing method for an adaptive multi-specification spherical plain bearing pressing device according to any one of claims 1 to 9, characterized in that, include: The bearing housing (4) to be press-fitted is fitted onto the annular boss of the positioning seat (5), and the spherical bearing (3) is fitted onto the central shaft; keep the V-groove on the bearing housing (4) facing upward and in initial contact with the steel ball (2-1) in the steel ball cage assembly (2); The pressure head (1) is controlled to move downward and rotate, and the steel ball (2-1) is guided into the V-groove of the bearing seat (4) through the annular groove on the lower surface; Control the pressure head (1) to continue descending and rotating until it reaches the set depth, then stop descending and hold pressure to ensure that the V-groove flange on the bearing seat (4) is fully shaped and complete the press-fit cycle.

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