Aviation bearing residual stress test sample clamping device

Abstract

The invention discloses an aircraft bearing residual stress test sample clamping device, and relates to the technical field of bearing residual stress test. The problems that in the existing bearing residual stress testing process, due to the fact that the structure of the double half inner rings of the ball bearing is special, it is difficult to guarantee that the testing positions of bearing parts produced in batches are fixed in the testing process, experimental data analysis in the process research process is not facilitated, and the reliability of actual detection data is also difficult to guarantee are solved. A sliding base is in sliding connection with a fixed base, a driving lever penetrates through a driving lever mounting hole, a driving plug is mounted at the end of a horizontal lever section of the driving lever and rotationally connected with the bottom end of the sliding base, the lower end of a stand column is connected with the sliding base, and the upper end of the stand column is rotationally connected with the head end of a workbench connecting base; the end of the rocking handle abuts against a workbench connecting base, a workbench is installed on the workbench connecting base, and the upper surface of the workbench is in threaded connection with a plurality of hanging shafts. The device is used for testing the residual stress of the double-half inner ring part of the bearing.

Description

Technical Field

[0001] The invention relates to the technical field of bearing residual stress testing, and in particular to a specimen clamping device for residual stress testing of aviation bearings. Background Art

[0002] At present, with the increasing demand for long-life bearing parts in the field of aviation engines, in order to obtain a longer rolling fatigue relief life of bearings, research and control of residual stress on the working surface of bearings have been carried out. During the residual stress test, the equipment needs to emit X-rays and receive them through a receiver. It is necessary to ensure that the normal of the collimator is perpendicular to the surface of the area to be tested, and measure the surface residual stress at a specific position on the working surface of the bearing. Due to the special structure of the double semi-inner ring of the ball bearing, it is difficult to ensure that the test position of the bearing parts produced in batches is fixed during the test, which is not conducive to the analysis of experimental data during process research, and it is difficult to ensure the reliability of actual detection data. The present invention takes the residual stress test of the double semi-inner ring of the bearing as the research object, and focuses on how to achieve a fixed test angle and position to ensure accurate measurement of the residual stress on the bearing surface. Summary of the invention

[0003] The purpose of the present invention is to solve the problem that in the existing bearing residual stress test process, due to the special structure of the double semi-inner ring of the ball bearing, it is difficult to ensure that the test position of the bearing parts produced in batches is fixed during the test process, which is not conducive to the experimental data analysis during the process research and it is difficult to ensure the reliability of the actual detection data.

[0004] During the test of the double semi-inner ring of the ball bearing, the test position of the bearing parts that are difficult to mass produce is fixed, and thus a specimen clamping device for residual stress test of aviation bearings is provided.

[0005] The technical solution of the present invention is:

[0006] A specimen clamping device for residual stress test of aviation bearings, the specimen clamping device comprising a fixed base 1, a sliding base 2, a column 3, a workbench connecting seat 4, a workbench 5, a plug and play 6, a lever 7, a crank handle 10 and a plurality of hanging shafts 12, the sliding base 2 and the fixed base 1 are horizontally arranged in sequence from top to bottom, the sliding base 2 is slidably connected to the fixed base 1, a rectangular groove 101 is processed at the center of the upper surface of the fixed base 1, a lever mounting hole 102 which is vertically connected to the rectangular groove 101 is opened in the horizontal direction at the center of the end surface of one side of the fixed base 1, the lever 7 is an L-shaped rod structure, the horizontal rod section of the lever 7 passes through the lever mounting hole 102 horizontally and rotatably from the outside to the inside and extends to the center of the rectangular groove 101, the lever A vertically arranged plug 6 is installed at the end of 7 the horizontal rod section, the head end of the plug 6 is rotatably connected to the center position of the bottom end of the sliding base 2, a vertically arranged column 3 is installed in the middle of the rear side surface of the sliding base 2, the upper end of the column 3 is rotatably connected to the head end of the workbench connecting seat 4, a crank mounting threaded hole 301 is processed in the horizontal direction at the upper center of the rear surface of the column 3, the end of the crank 10 is threadedly installed in the crank mounting threaded hole 301 from outside to inside and extends to the other side to abut against the lower surface of the workbench connecting seat 4, a workbench 5 is installed on the upper surface of the workbench connecting seat 4, a plurality of hanging shaft mounting threaded holes 501 are processed on the upper surface of the workbench 5 close to the column 3, and a plurality of hanging shafts 12 are respectively threadedly connected to the plurality of hanging shaft mounting threaded holes 501.

[0007] Furthermore, a plug-in connection threaded hole 701 is radially processed on the side surface of the end of the horizontal rod section of the lever 7, and the lever 6 includes a plug-in screw 601 and a plug-in ball 602 which is coaxial with one end of the plug-in screw 601 and integrally formed, and the end of the plug-in screw 601 is threadedly connected to the plug-in connection threaded hole 701, and a plug-in connection circular hole is opened in the center of the lower surface of the sliding base 2 in the vertical direction, and the plug-in ball 602 is rotatably installed in the plug-in connection circular hole.

[0008] Furthermore, the plug-and-play connection circular hole of the sliding base 2 is clearance-matched with the plug-and-play ball 602 .

[0009] Furthermore, two guide rails 103 arranged side by side are respectively provided on the left and right sides of the upper surface of the fixed base 1, and two slide grooves 201 matching the two guide rails 103 are processed on the lower surface of the sliding base 2. The sliding base 2 is slidably connected to the two guide rails 103 of the fixed base 1 through the two slide grooves 201.

[0010] Furthermore, the workbench 5 is a trapezoidal plate structure, and five upper hanging shaft mounting threaded holes are processed on the side of the upper surface of the workbench 5 close to the column 3, and the line connecting the centers of the five upper hanging shaft mounting threaded holes forms an equilateral trapezoid, and two lower hanging shaft mounting threaded holes are processed in the middle of the side of the upper surface of the workbench 5 away from the column 3, and the line connecting the centers of the two lower hanging shaft mounting threaded holes forms a straight line.

[0011] Furthermore, the fixed base 1 and the sliding base 2 are both rectangular plate structures.

[0012] Furthermore, the sample clamping device also includes two baffles 8 , which are rectangular plate-shaped structures and are vertically installed in the middle of the front and rear end surfaces of the fixed base 1 , respectively. The lower surface of the sliding base 2 is arranged lower than the upper surface of the baffles 8 .

[0013] Furthermore, the sample clamping device also includes a pin shaft 9, the column 3 is a rectangular rod-shaped structure, and a pin shaft mounting hole 302 is processed on the upper side of the column 3 in the horizontal direction. The workbench connecting seat 4 is a rectangular plate-shaped structure, and two symmetrically arranged ear plates 401 with shaft holes are provided on the upper part of the rear side of the workbench connecting seat 4. The width of the column 3 is smaller than the spacing between the two ear plates 401 with shaft holes, and the column 3 is inserted between the two ear plates 401 with shaft holes. The column 3 is rotatably connected to the two ear plates 401 with shaft holes through the pin shaft 9.

[0014] Furthermore, the rocker 10 includes a rocker screw 1001 and a rocker disc 1002 which is coaxial with the rocker screw 1001 and integrally formed.

[0015] Furthermore, the sample clamping device also includes a hand crank 11, and the side surface of one end of the hand crank 11 is processed with an external thread, and the end surface of the rocker disc 1002 is processed with a hand crank mounting threaded hole. The hand crank mounting threaded hole is eccentrically arranged with the rocker disc 1002, and the hand crank 11 is threadedly installed in the hand crank mounting threaded hole.

[0016] Compared with the prior art, the present invention has the following effects:

[0017] 1. The aviation bearing residual stress test specimen clamping device described in the present invention has a simple structure, is easy to operate, and has a simple assembly process. The bearing parts are clamped on the hanging shaft of the workbench, and the lever is adjusted by moving the lever forward and backward so that the lever connected to the end of the lever rotates around the axis of the horizontal rod section of the lever, thereby driving the sliding base to slide forward and backward relative to the fixed base through the lever ball, and finally horizontally moving the bearing installed on the hanging shaft of the workbench to a suitable position, shaking the handle to adjust the opening and closing angle between the workbench and the column, and then adjusting the bearing to a suitable angle, and the residual stress test of the specimen can be carried out.

[0018] 2. The specimen clamping device for residual stress test of aviation bearings of the present invention is used for residual stress test of double-half inner ring parts of bearings. The device is used to fix the test position and angle of the double-half inner ring bearing, and does not introduce factors such as test position change and test angle change to affect the test results.

[0019] 3. The aviation bearing residual stress test specimen clamping device described in the present invention is suitable for residual stress testing of double semi-inner rings of bearing parts. It does not require special professional skills to operate, and the convenience, stability and work efficiency of the test are greatly improved. At the same time, it can realize fixed-point and fixed-angle surface residual stress testing of a large number of bearings of the same model but different batches, ensuring the accuracy and reliability of the residual stress detection results. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a front view of the specimen clamping device for residual stress test of aviation bearings according to the present invention;

[0021] Figure 2 It is a side view of the specimen clamping device for residual stress test of aviation bearings according to the present invention;

[0022] Figure 3 It is a rear view of the specimen clamping device for residual stress testing of aviation bearings according to the present invention;

[0023] Figure 4 It is an axonometric view of a fixed base in the sample clamping device of the present invention;

[0024] Figure 5 It is an axonometric view of a sliding base in the sample clamping device of the present invention;

[0025] Figure 6 It is an axonometric view of a column in the sample clamping device of the present invention;

[0026] Figure 7 It is an axonometric view of a workbench connection seat in the sample clamping device of the present invention;

[0027] Figure 8 It is an axonometric view of a workbench in the sample clamping device of the present invention;

[0028] Fig. 9 It is an axonometric diagram of the insertion and removal of the sample clamping device of the present invention;

[0029] Fig.10 It is an axonometric view of a lever in the sample clamping device of the present invention;

[0030] Fig.11 It is an axonometric view of a baffle in the sample clamping device of the present invention;

[0031] Fig.12 It is a front view of the pin shaft in the sample clamping device of the present invention;

[0032] Fig.13 It is a side view of a pin shaft in the sample clamping device of the present invention;

[0033] Fig.14It is an axonometric view of a crank in the sample clamping device of the present invention;

[0034] Fig.15 It is a front view of the hand crank in the sample clamping device of the present invention;

[0035] Fig.16 It is a side view of the hand crank in the sample clamping device of the present invention;

[0036] Fig.17 It is an axonometric view of the hanging axis in the sample clamping device described in the present invention.

[0037] In the figure: 1. fixed base; 101. rectangular groove; 102. lever mounting hole; 103. guide rail; 2. sliding base; 201. slide groove; 3. column; 301. crank handle mounting threaded hole; 302. pin shaft mounting hole; 4. workbench connecting seat; 401. ear plate with shaft hole; 5. workbench; 501. hanging shaft mounting threaded hole; 6. plug and play; 601. plug and play screw; 602. plug and play ball; 7. lever; 701. plug and play connecting threaded hole; 8. baffle; 9. pin shaft; 10. crank handle; 1001. rocker screw; 1002. rocker disc; 11. hand crank; 12. hanging shaft. DETAILED DESCRIPTION

[0038] Specific implementation method 1: Combination Figures 1 to 17 The present embodiment is described. The present embodiment is a specimen clamping device for residual stress test of aviation bearings. The specimen clamping device comprises a fixed base 1, a sliding base 2, a column 3, a workbench connecting seat 4, a workbench 5, a plug and play 6, a lever 7, a crank handle 10 and a plurality of hanging shafts 12. The sliding base 2 and the fixed base 1 are horizontally arranged in sequence from top to bottom. The sliding base 2 is slidably connected to the fixed base 1. A rectangular groove 101 is machined at the center of the upper surface of the fixed base 1. A lever mounting hole 102 which is perpendicular to the rectangular groove 101 and is opened in the horizontal direction at the center of the end surface of one side of the fixed base 1. The lever 7 is an L-shaped rod structure. The horizontal rod section of the lever 7 passes through the lever mounting hole 102 horizontally and rotatably from the outside to the inside and extends to the rectangular groove 1. 01 center, a vertically arranged dial plug 6 is installed at the end of the horizontal rod section of the dial rod 7, and the head end of the dial plug 6 is rotatably connected to the center position of the bottom end of the sliding base 2, and a vertically arranged column 3 is installed in the middle of the rear side surface of the sliding base 2, and the upper end of the column 3 is rotatably connected to the head end of the workbench connecting seat 4, and a crank mounting threaded hole 301 is processed in the horizontal direction at the upper center of the rear surface of the column 3, and the end of the crank 10 is threadedly installed in the crank mounting threaded hole 301 from outside to inside and extends to the other side to abut against the lower surface of the workbench connecting seat 4, and a workbench 5 is installed on the upper surface of the workbench connecting seat 4, and a plurality of hanging shaft mounting threaded holes 501 are processed on the upper surface of the workbench 5 close to the column 3. The plurality of hanging shafts 12 are respectively threadedly connected to the plurality of hanging shaft mounting threaded holes 501.

[0039] Specific implementation method 2: Combination Figures 1 to 5 , Fig. 9 and Fig.10 To explain this embodiment, the side surface of the end of the horizontal rod section of the lever 7 of this embodiment is processed with a plug-in connection threaded hole 701 along the radial direction, and the plug-in 6 includes a plug-in screw 601 and a plug-in ball 602 that is coaxial with one end of the plug-in screw 601 and is integrally formed. The end of the plug-in screw 601 is threadedly connected to the plug-in connection threaded hole 701, and a plug-in connection circular hole is opened in the center of the lower surface of the sliding base 2 along the vertical direction, and the plug-in ball 602 is rotatably installed in the plug-in connection circular hole. In this arrangement, by pushing the lever 7 forward or backward, the plug-in 6 connected to the end of the lever 7 rotates around the axis of the horizontal rod section of the lever 7, thereby driving the sliding base 2 to slide forward and backward relative to the fixed base 1 through the plug-in ball 602. Other components and connection relationships are the same as those of the specific embodiment one.

[0040] Specific implementation method three: Combination Figures 1 to 3 , Fig. 9 and Fig.10 To explain this embodiment, the plug-in connection circular hole of the sliding base 2 of this embodiment is clearance-matched with the plug-in ball 602. With such a configuration, since the plug-in ball 602 and the plug-in connection circular hole are clearance-matched, the plug-in ball 602 can rotate relatively in the plug-in connection circular hole. Other components and connection relationships are the same as those of the first or second embodiment.

[0041] Specific implementation method four: Combination Figure 4 and Figure 5 To explain this embodiment, two guide rails 103 arranged side by side are respectively provided on the left and right sides of the upper surface of the fixed base 1 of this embodiment, and two slide grooves 201 matching the two guide rails 103 are processed on the lower surface of the sliding base 2, and the sliding base 2 is slidably connected to the two guide rails 103 of the fixed base 1 through the two slide grooves 201. Other components and connection relationships are the same as those of the specific embodiments one, two or three.

[0042] Specific implementation method five: Combination Figures 1 to 3 , Figure 8 and Fig.17 To explain this embodiment, the workbench 5 of this embodiment is a trapezoidal plate structure. Five upper hanging shaft mounting threaded holes are processed on the side of the upper surface of the workbench 5 close to the column 3. The line connecting the centers of the five upper hanging shaft mounting threaded holes forms an equilateral trapezoid. Two lower hanging shaft mounting threaded holes are processed in the middle of the side of the upper surface of the workbench 5 away from the column 3. The line connecting the centers of the two lower hanging shaft mounting threaded holes forms a straight line. In this way, the hanging shaft 12 of the workbench 5 is used to clamp bearing parts. Other components and connection relationships are the same as those of the specific embodiments one, two, three or four.

[0043] Specific implementation method six: Combination Figure 4 and Figure 5 To explain this embodiment, the fixed base 1 and the sliding base 2 of this embodiment are both rectangular plate structures. Other components and connection relationships are the same as those of the first, second, third, fourth or fifth embodiments.

[0044] Specific implementation method seven: Combination Figures 1 to 3 , Figure 5 and Fig.11 To explain this embodiment, the sample clamping device of this embodiment further includes two baffles 8, which are rectangular plate-shaped structures. The two baffles 8 are respectively installed vertically in the middle of the front and rear end surfaces of the fixed base 1, and the lower surface of the sliding base 2 is arranged lower than the upper surface of the baffles 8. In this way, the front and rear baffles 8 are used to achieve the front and rear limit of the sliding base 2. Other components and connection relationships are the same as those of the specific embodiments one, two, three, four, five or six.

[0045] Specific implementation method eight: Combination Figures 1 to 3 , Figure 6 , Figure 7 , Fig.12 and Fig.13 To explain this embodiment, the sample clamping device of this embodiment also includes a pin shaft 9, the column 3 is a rectangular rod-shaped structure, the upper side of the column 3 is processed with a pin shaft installation hole 302 in the horizontal direction, the workbench connecting seat 4 is a rectangular plate-shaped structure, and the upper part of the rear side of the workbench connecting seat 4 is provided with two symmetrically arranged lug plates 401 with shaft holes, the width of the column 3 is less than the spacing between the two lug plates 401 with shaft holes, the column 3 is inserted between the two lug plates 401 with shaft holes, and the column 3 is rotatably connected to the two lug plates 401 with shaft holes through the pin shaft 9. In this way, the column 3 is rotatably connected to the workbench connecting seat 4 through the pin shaft 9, and the opening and closing angle between the workbench 5 and the column 3 is adjusted by adjusting the screw-in depth of the rocker screw 1001. Other components and connection relationships are the same as those of the specific embodiments one, two, three, four, five, six or seven.

[0046] Specific implementation method nine: Combination Figures 1 to 3 , Figures 14 to 16 To explain this embodiment, the crank handle 10 of this embodiment includes a rocker screw 1001 and a rocker disc 1002 coaxial with and integrally formed with the rocker screw 1001. Other components and connection relationships are the same as those of the first, second, third, fourth, fifth, sixth, seventh or eighth embodiments.

[0047] Specific implementation method ten: Combination Figures 1 to 17To explain this embodiment, the sample clamping device of this embodiment also includes a hand crank 11, one end of the hand crank 11 is processed with an external thread, and the end surface of the rocker disc 1002 is processed with a hand crank installation threaded hole, the hand crank installation threaded hole is eccentrically arranged with the rocker disc 1002, and the hand crank 11 is threadedly installed in the hand crank installation threaded hole. In this way, the hand crank 11 is used to facilitate the adjustment of the screw-in depth of the rocker screw 1001. The other components and connection relationships are the same as those of the first, second, third, fourth, fifth, sixth, seventh, eighth or ninth embodiments.

[0048] How it works

[0049] Combination Figures 1 to 17 The working principle of the specimen clamping device for residual stress test of aviation bearings of the present invention is described as follows: First, clamp the bearing parts on the hanging shaft 12 of the workbench 5. Then, push the lever 7 forward or backward, so that the plug 6 connected to the end of the lever 7 rotates around the axis of the horizontal rod section of the lever 7, thereby driving the sliding base 2 to slide forward and backward relative to the fixed base 1 through the plug sphere 602, and finally horizontally moving the bearing installed on the hanging shaft 12 of the workbench 5 to a suitable position. Finally, shake the handle 10 to adjust the opening and closing angle between the workbench 5 and the column 3, and then adjust the bearing to a suitable angle, and then perform residual stress test on the specimen.

[0050] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A specimen clamping device for residual stress test of aviation bearings, characterized by: The sample clamping device comprises a fixed base (1), a sliding base (2), a column (3), a workbench connecting seat (4), a workbench (5), a plug (6), a lever (7), a crank (10) and a plurality of hanging shafts (12). The sliding base (2) and the fixed base (1) are horizontally arranged in sequence from top to bottom. The sliding base (2) is slidably connected to the fixed base (1). A rectangular groove (101) is processed at the center of the upper surface of the fixed base (1). A lever mounting hole (102) vertically penetrating the rectangular groove (101) is opened at the center of one end surface of the fixed base (1) in the horizontal direction. The lever (7) is an L-shaped rod structure. The horizontal rod section of the lever (7) horizontally and rotatably passes through the lever mounting hole (102) from the outside to the inside and extends to the center of the rectangular groove (101). A vertically arranged plug (6) is installed at the end, and the head end of the plug (6) is rotatably connected to the center position of the bottom end of the sliding base (2). A vertically arranged column (3) is installed in the middle of the rear side surface of the sliding base (2), and the upper end of the column (3) is rotatably connected to the head end of the workbench connecting seat (4). A crank handle mounting threaded hole (301) is processed in the center of the upper rear surface of the column (3) along the horizontal direction. The end of the crank handle (10) is threadedly installed in the crank handle mounting threaded hole (301) from the outside to the inside and extends to the other side to abut against the lower surface of the workbench connecting seat (4). A workbench (5) is installed on the upper surface of the workbench connecting seat (4). A plurality of hanging shaft mounting threaded holes (501) are processed on the upper surface of the workbench (5) close to the column (3). The plurality of hanging shafts (12) are respectively threadedly connected to the plurality of hanging shaft mounting threaded holes (501).

2. The device for clamping a specimen for residual stress test of an aviation bearing according to claim 1, characterized in that: A plug-in connection threaded hole (701) is radially processed on the side surface of the end of the horizontal rod section of the lever (7); the lever (6) comprises a plug-in screw (601) and a plug-in ball (602) coaxial with one end of the plug-in screw (601) and integrally formed; the end of the plug-in screw (601) is threadedly connected to the plug-in connection threaded hole (701); a plug-in connection circular hole is vertically opened at the center of the lower surface of the sliding base (2); and the plug-in ball (602) is rotatably mounted in the plug-in connection circular hole.

3. The device for clamping a specimen for residual stress test of an aviation bearing according to claim 2, characterized in that: The plug-in connection circular hole of the sliding base (2) is clearance-matched with the plug-in sphere (602).

4. The device for clamping a specimen for residual stress test of an aviation bearing according to claim 3, characterized in that: Two guide rails (103) arranged side by side are respectively provided on the left and right sides of the upper surface of the fixed base (1); two slide grooves (201) matching the two guide rails (103) are processed on the lower surface of the sliding base (2); the sliding base (2) is slidably connected to the two guide rails (103) of the fixed base (1) via the two slide grooves (201).

5. The device for clamping a specimen for residual stress test of an aviation bearing according to claim 4, characterized in that: The workbench (5) is a trapezoidal plate-shaped structure. Five upper hanging shaft mounting threaded holes are processed on a side of the upper surface of the workbench (5) close to the column (3), and the line connecting the centers of the five upper hanging shaft mounting threaded holes forms an equilateral trapezoid. Two lower hanging shaft mounting threaded holes are processed in the middle of a side of the upper surface of the workbench (5) away from the column (3), and the line connecting the centers of the two lower hanging shaft mounting threaded holes forms a straight line.

6. The specimen clamping device for residual stress test of aviation bearings according to claim 5, characterized in that: The fixed base (1) and the sliding base (2) are both rectangular plate structures.

7. The specimen clamping device for residual stress test of aviation bearings according to claim 6, characterized in that: The sample clamping device further comprises two baffles (8), the baffles (8) being rectangular plate-shaped structures, the two baffles (8) being respectively vertically mounted at the middle position of the front and rear end surfaces of the fixed base (1), and the lower surface of the sliding base (2) being arranged lower than the upper surface of the baffles (8).

8. The specimen clamping device for residual stress test of aviation bearings according to claim 7, characterized in that: The sample clamping device also includes a pin shaft (9), the column (3) is a rectangular rod-shaped structure, the upper side surface of the column (3) is processed with a pin shaft mounting hole (302) in the horizontal direction, the workbench connecting seat (4) is a rectangular plate-shaped structure, and the upper part of the rear side surface of the workbench connecting seat (4) is provided with two symmetrically arranged ear plates with shaft holes (401), the width of the column (3) is smaller than the spacing between the two ear plates with shaft holes (401), the column (3) is inserted between the two ear plates with shaft holes (401), and the column (3) is rotatably connected to the two ear plates with shaft holes (401) through the pin shaft (9).

9. The aircraft bearing residual stress test specimen clamping device according to claim 1 or 8, characterized in that: The rocker (10) comprises a rocker screw (1001) and a rocker disc (1002) which is coaxial with the rocker screw (1001) and integrally formed.

10. The specimen clamping device for residual stress test of aviation bearings according to claim 9, characterized in that: The sample clamping device also includes a hand crank (11), one end of which is processed with an external thread on the side surface, and an end surface of the crank disc (1002) is processed with a hand crank mounting threaded hole, the hand crank mounting threaded hole is eccentrically arranged with the crank disc (1002), and the hand crank (11) is threadedly mounted in the hand crank mounting threaded hole.

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