Special tool suitable for press fitting of universal bearing

Abstract

A special tool suitable for press fitting of a universal bearing is provided with a positioning pull rod, a left punch, a right punch and a special-shaped nut. The positioning pull rod comprises a hexagonal head part, a polished rod part and a threaded part; the left punch and the right punch are both of a sleeve structure, a plurality of boss punching points are arranged on the opposite end faces of the left punch and the right punch, the boss punching points are evenly arranged in the circumferential direction of the end faces of the left punch and the right punch, and the boss punching points can be inserted into grooves formed in an aircraft body around a bearing assembly hole. When the special tool works, the left punch, the right punch and the inner ring of the universal bearing are sleeved outside the polish rod part of the positioning pull rod in a clearance fit manner, the left punch and the right punch are positioned on two sides of the universal bearing, the special-shaped nut is assembled with the thread part of the positioning pull rod, and the outer side wall of the special-shaped nut is connected with the right punch. According to the utility model, the positioning pull rod, the double-side multi-point punch and the special-shaped nut are matched, so that the double sides of the outer ring of the bearing are simultaneously pressed and fastened, and the purpose of ensuring the assembly precision of the universal bearing is achieved.

Description

Technical Field

[0001] This utility model relates to the field of bearing assembly technology, specifically a special tool suitable for press-fitting universal bearings. Background Technology

[0002] Universal bearings play a vital role in aircraft landing gear systems and are key components of these systems. They provide high-precision power transmission under complex motion conditions, therefore, the assembly precision requirements for universal bearings are extremely stringent.

[0003] Currently, the assembly of universal bearings during aircraft overhauls typically involves manual hand-held punches. Pressure is applied point-by-point along the grooves around the outer edge of the universal bearing on the aircraft fuselage to insert it into the bearing mounting hole. However, due to the limited space on the aircraft fuselage where the universal bearing is installed, it is difficult to control the accuracy of the applied force and the appropriate application of pressure. This leads to two problems: first, the punch cannot always be perpendicular to the fuselage surface, causing deviations in the punching position; second, insufficient punching pressure results in insecure installation, while excessive pressure causes the bearing to rotate stiffly. Therefore, the scrap rate of parts during universal bearing assembly is high, increasing aircraft repair costs. Utility Model Content

[0004] This utility model provides a special tool suitable for press-fitting universal bearings. It aims to achieve simultaneous pressure and fastening on both sides of the outer ring of the bearing by using a positioning tie rod, a double-sided multi-point punch and a special-shaped nut, thereby ensuring the assembly accuracy of the universal bearing.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A special tool suitable for press-fitting universal bearings includes a positioning pull rod, a left punch, a right punch, and a shaped nut. The positioning pull rod includes a hexagonal head, a smooth rod, and a threaded part. Both the left and right punches are sleeve structures with several boss punches on their opposite end faces. These boss punches are evenly distributed circumferentially along the end faces of the left and right punches and can be inserted into grooves on the aircraft fuselage surrounding the bearing mounting holes. When the special tool is in operation, the left and right punches and the inner ring of the universal bearing are fitted onto the smooth rod of the positioning pull rod with a clearance fit. The left and right punches are located on both sides of the universal bearing. The shaped nut is fitted with the threaded part of the positioning pull rod, and its outer wall is connected to the right punch.

[0007] The aforementioned special tool suitable for press-fitting universal bearings has a stepped hole on the inner wall of the right punch, and several limiting holes are provided on the side wall of the large-diameter end of the stepped hole of the right punch; one end of the shaped nut is a hexagonal nut, and the other end is a hollow disc. The hollow disc is fitted onto the large-diameter end of the stepped hole of the right punch, and an annular groove is provided on the outer side wall of the hollow disc. The shaped nut is connected to the right punch by a limiting pin that passes through the upper limiting hole of the right punch and the annular groove on the shaped nut.

[0008] The aforementioned special tool suitable for press-fitting universal bearings has a threaded hole on the right punch; the end of the limiting pin that mates with the limiting hole is provided with an external thread.

[0009] The aforementioned special tool suitable for press-fitting universal bearings is further equipped with a pressure bearing at the large-diameter end of the stepped hole. The two end faces of the pressure bearing are in contact with the stepped surface of the stepped hole and the hollow disc end face of the shaped nut, respectively.

[0010] The aforementioned special tool suitable for press-fitting universal bearings has a first chamfered surface for avoiding the inner ring of the universal bearing on the contact surface between the left punch and the universal bearing, and a second chamfered surface for avoiding the inner ring of the universal bearing on the contact surface between the right punch and the universal bearing.

[0011] The aforementioned special tool suitable for press-fitting universal bearings has a stop plate at the connection between the hexagonal head of the positioning rod and the smooth rod.

[0012] This utility model provides a special tool suitable for press-fitting universal bearings. It uses a positioning tie rod to connect the left punch, universal bearing, right punch, and special-shaped nut together. Then, a limiting pin passing through the limiting hole of the right punch and the annular groove on the outer wall of the hollow disc of the special-shaped nut connects the special-shaped nut to the right punch. The protrusions on the opposite end faces of the left and right punches are aligned with the grooves on the machine body surrounding the bearing mounting holes for locking. Then, the special-shaped nut is tightened by rotating the side wrench. Thus, under the pressure of the left and right punches, the two ends of the universal bearing outer ring are pressed into the bearing mounting holes on the machine body. Because the bosses on the end faces of the left and right punches in this invention are evenly arranged in several groups along the circumference, during the press-fitting of the universal bearing, the end faces of the left and right punches can be kept parallel to the two end faces of the outer ring of the bearing. This ensures that the pressure applied by the left and right punches is always perpendicular to the end face of the universal bearing. Therefore, the universal bearing can be smoothly press-fitted into the bearing mounting hole on the machine body, thus ensuring the coaxiality of the universal bearing and the bearing mounting hole on the machine body and meeting the strict precision requirements for universal bearing assembly. Attached Figure Description

[0013] Figure 1 A schematic diagram of the overall structure of this utility model;

[0014] Figure 2This is a cross-sectional structural diagram of the assembly of the various components of this utility model;

[0015] Figure 3 This is a schematic diagram of the positioning tie rod structure;

[0016] Figure 4 This is a schematic diagram of the left punch structure;

[0017] Figure 5 This is a schematic diagram of the right punch structure;

[0018] Figure 6 This is a schematic diagram of the cross-sectional structure of the right punch;

[0019] Figure 7 This is a schematic diagram of an irregularly shaped nut structure;

[0020] Figure 8 This is a schematic diagram of the cross-sectional structure of an irregularly shaped nut;

[0021] Figure 9 This is a schematic diagram of the working state of this utility model.

[0022] Explanation of each label in the diagram:

[0023] 1 is the positioning rod, 1-1 is the hexagonal head, 1-2 is the smooth rod part, 1-3 is the threaded part, and 1-4 is the stop plate;

[0024] 2 is the left punch, and 2-1 is the first chamfered surface of the inner ring of the universal bearing;

[0025] 3 is the right punch, 3-1 is the stepped hole, 3-2 is the limiting hole, and 3-3 is the second clearance chamfer surface of the inner ring of the universal bearing;

[0026] 4 is an irregular nut, 4-1 is a hexagonal nut, 4-2 is a hollow disc, and 4-3 is an annular groove;

[0027] 5 is a limit pin;

[0028] 6 represents a pressure bearing;

[0029] 7 is the punching point of the boss;

[0030] 8 represents the body;

[0031] 9 represents a universal bearing. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0033] See Figure 1. Figure 2 , Figure 3 , Figure 9This utility model provides a special tool suitable for press-fitting universal bearings. It is equipped with a positioning pull rod 1, a left punch 2, a right punch 3, and a special-shaped nut 4. The positioning pull rod 1 includes a hexagonal head 1-1, a smooth rod 1-2, and a threaded part 1-3. A retaining plate 1-4 is provided at the connection between the hexagonal head 1-1 and the smooth rod 1-2. The left punch 2 and the right punch 3 are both sleeve structures. Several sets of boss punches 7 are provided on the opposite end faces of the left punch 2 and the right punch 3. The protrusion height of all boss punches 7 is exactly the same and can be inserted into the grooves set around the bearing assembly holes on the aircraft body 8. When the special tool is working, the left punch 2, the right punch 3, and the inner ring of the universal bearing are all fitted outside the smooth rod 1-2 of the positioning pull rod 1 with a clearance fit. The left punch 2 and the right punch 3 are located on both sides of the universal bearing 9. The special-shaped nut 4 is fitted with the threaded part 1-3 of the positioning pull rod 1, and its outer wall is connected to the right punch 3.

[0034] See Figure 2 , Figure 4 , Figure 9 In a preferred embodiment of the special tool for press-fitting universal bearings described in this utility model, eight sets of boss punch points 7 are evenly arranged circumferentially on the end faces of the left punch 2 and the right punch 3, and a first clearance chamfer surface 2-1 of the inner ring of the universal bearing is provided on the contact surface between the left punch 2 and the universal bearing 9. The left punch 2 and the boss punch points 7 on the left punch are made of tool steel.

[0035] See Figure 2 , Figure 5 , Figure 6 , Figure 9 In a preferred embodiment of the special tool for press-fitting universal bearings described in this utility model, eight sets of boss punch points 7 are evenly arranged circumferentially on the end faces of the right punch 3 and the left punch 2, and a second clearance chamfer surface 3-3 of the inner ring of the universal bearing is provided on the contact surface between the right punch 3 and the universal bearing 9; the inner wall of the right punch 3 is a stepped hole 3-1, and four sets of limiting holes 3-2 are provided on the side wall of the large diameter end of the stepped hole 3-1; the right punch 3 and the boss punch points 7 on the right punch are made of tool steel.

[0036] See Figure 2 , Figure 7 , Figure 8 , Figure 9 The special tool for press-fitting universal bearings described in this utility model has a special-shaped nut 4 with one end being a hexagonal nut 4-1 and the other end being a hollow disc 4-2. The hollow disc is fitted onto the large-diameter end of the stepped hole 3-1 of the right punch 3, and an annular groove 4-3 is provided on the outer wall of the hollow disc 4-2. The special-shaped nut 4 is connected to the right punch 3 by a limiting pin 5 that passes through the upper limit hole 3-2 of the right punch 3 and the annular groove 4-3 on the outer wall of the hollow disc 4-2 of the special-shaped nut 4.

[0037] See Figure 2 , Figure 9 The special tool for press-fitting universal bearings described in this utility model is equipped with a pressure bearing 6 at the large diameter end of the stepped hole 3-1 of the right punch 3. The two end faces of the pressure bearing 6 are in contact with the stepped surface of the stepped hole 3-1 and the end face of the hollow disc 4-2 of the eccentric nut 4, respectively.

[0038] See Figures 1 to 9 When using this invention to press-fit the universal bearing 9 onto the fuselage 8 of an aircraft, firstly, the positioning rod 1 is used to connect the left punch 2, the universal bearing 9, the right punch 3, and the shaped nut 4 together. Then, the shaped nut 4 is connected to the right punch 3 by the limiting pin 5 passing through the limiting hole 3-2 of the right punch 3 and the annular groove 4-3 on the outer wall of the hollow disc 4-2 of the shaped nut 4. The protrusion punches 7 on the opposite end faces of the left punch 2 and the right punch 3 are aligned with the grooves on the fuselage 8 surrounding the bearing mounting holes for locking. Then, the hexagonal nut 4-1 of the shaped nut 4 is clamped by the side wrench, and the shaped nut 4 is rotated to tighten it. The thrust of the shaped nut 4 is transmitted to the right punch 3 through the pressure bearing 6, so that the two ends of the outer ring of the universal bearing 9 bear the vertical pressing force of the left punch 2 and the right punch 3 respectively. In this way, the outer ring of the universal bearing 9 is smoothly pressed into the bearing mounting hole on the fuselage 8.

Claims

1. A special tool suitable for press-fitting universal bearings, characterized in that: The device includes a positioning pull rod (1), a left punch (2), a right punch (3), and a shaped nut (4). The positioning pull rod (1) includes a hexagonal head (1-1), a smooth rod (1-2), and a threaded part (1-3). Both the left punch (2) and the right punch (3) are sleeve structures. Several boss punch points (7) are provided on the opposite end faces of the left punch (2) and the right punch (3). The boss punch points (7) are evenly arranged circumferentially along the end faces of the left punch (2) and the right punch (3). Point (7) can be inserted into the groove set around the bearing assembly hole on the aircraft body (8); when the special tool is working, the inner rings of the left punch (2), right punch (3) and universal bearing (9) are all fitted outside the smooth rod part (1-2) of the positioning pull rod (1) in a clearance fit manner. The left punch (2) and right punch (3) are located on both sides of the universal bearing (9). The shaped nut (4) is fitted with the threaded part (1-3) of the positioning pull rod (1), and its outer wall is connected to the right punch (3).

2. The special tool suitable for press-fitting universal bearings according to claim 1, characterized in that: The inner wall of the right punch (3) is a stepped hole (3-1), and several limiting holes (3-2) are provided on the side wall of the large diameter end of the stepped hole (3-1) of the right punch (3); one end of the shaped nut (4) is a hexagonal nut (4-1), and the other end is a hollow disc (4-2). The hollow disc is fitted onto the large diameter end of the stepped hole (3-1), and an annular groove (4-3) is provided on the outer side wall of the hollow disc (4-2). The shaped nut (4) is connected to the right punch (3) by a limiting pin (5) that passes through the upper limit hole (3-2) of the right punch (3) and the annular groove (4-3) on the shaped nut (4).

3. The special tool suitable for press-fitting universal bearings according to claim 2, characterized in that: The limiting hole (3-2) on the right punch (3) is a threaded hole; the end of the limiting pin (5) that mates with the limiting hole (3-2) is provided with an external thread.

4. The special tool suitable for press-fitting universal bearings according to claim 2 or 3, characterized in that: A pressure bearing (6) is also assembled at the large diameter end of the stepped hole (3-1). The two end faces of the pressure bearing (6) are in contact with the stepped surface of the stepped hole (3-1) and the end face of the hollow disk (4-2) of the eccentric nut, respectively.

5. The special tool suitable for press-fitting universal bearings according to claim 4, characterized in that: The contact surface between the left punch (2) and the universal bearing (9) is provided with a first clearance chamfer surface (2-1) for the inner ring of the universal bearing, and the contact surface between the right punch (3) and the universal bearing (9) is provided with a second clearance chamfer surface (3-3) for the inner ring of the universal bearing.

6. The special tool suitable for press-fitting universal bearings according to claim 5, characterized in that: A baffle (1-4) is provided at the connection between the hexagonal head (1-1) of the positioning rod (1) and the smooth rod part (1-2).

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