Dynamic balance structure assembly of cross slip ring scroll compressor

Abstract

The utility model belongs to the field of compressors, and provides a dynamic balance structure assembly of a cross slip ring scroll compressor, which comprises a rotating shaft movably arranged in a shell, and a driving disc eccentrically arranged at the end part of the rotating shaft; and the outer slip ring and the inner slip ring are movably arranged on the rotating shaft in a sleeving mode and eccentrically arranged relative to the rotating shaft, the outer slip ring and the inner slip ring are both connected to the driving disc, the outer slip ring and the inner slip ring are both movably connected to the shell in a clamped mode, and the outer slip ring and the inner slip ring are arranged perpendicular to the moving direction of the shell. Compared with the prior art, the utility model has the advantages that the forces generated when the inner slip ring and the outer slip ring move in the mutually vertical direction are superposed, so that the vector values of the forces generated by the inner slip ring and the outer slip ring are constant values all the time, and further accurate balance is carried out through the balance block, thereby solving the problem of vibration of equipment.

Description

TECHNICAL FIELD

[0001] The utility model belongs to compressor field, and specifically relates to a cross slip ring scroll compressor dynamic balance structure assembly. BACKGROUND

[0002] The scroll pump with the cross slip ring structure, since the force generated by the cross slip ring is the reciprocating force along the linear direction of the groove, and the force of the remaining parts is the rotating force (i.e. the circular motion) around the shaft, the two forces cannot be cancelled out in space, thereby forming the unbalanced force, and the unbalanced force directly leads to the vibration aggravation of the whole scroll compressor during operation, which not only affects the normal operation of the equipment, but also accelerates the wear of the mechanical parts. SUMMARY

[0003] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the utility model is to provide a cross slip ring scroll compressor dynamic balance structure assembly with simple overall structure, which can eliminate the unbalanced force and improve the stability and reliability of equipment operation.

[0004] The utility model solves the technical problem by adopting the technical scheme that a cross slip ring scroll compressor dynamic balance structure assembly is provided, which comprises: a rotating shaft movably arranged in a shell, and a driving disc eccentrically arranged at the end of the rotating shaft;

[0005] An outer slip ring and an inner slip ring are movably arranged on the rotating shaft and are eccentrically arranged relative to the rotating shaft, the outer slip ring and the inner slip ring are connected to the driving disc, the outer slip ring and the inner slip ring are movably connected to the shell, and the moving direction of the outer slip ring and the inner slip ring relative to the shell is perpendicular to the shell;

[0006] When the rotating shaft drives the driving disc to eccentrically rotate, the outer slip ring and the inner slip ring can make crosswise reciprocating motion in the shell.

[0007] In the cross slip ring scroll compressor dynamic balance structure assembly, the top wall at the circumference of the outer slip ring is symmetrically provided with a clamping block, the driving disc is symmetrically provided with an extension block along the radial direction of the driving disc, the extension block is formed with a clamping groove, and the clamping block is movably connected to the clamping groove.

[0008] In the cross slip ring scroll compressor dynamic balance structure assembly, the two ends of the rotating shaft are respectively detachably connected with a first counterweight and a second counterweight.

[0009] In the cross slip ring scroll compressor dynamic balance structure assembly, the extension block is further formed with a waist-shaped groove in communication with the clamping groove, and the length direction of the waist-shaped groove is perpendicular to the opening direction of the clamping groove.

[0010] In the cross slide ring scroll compressor dynamic balance structure assembly, the bottom wall at the circumference of the inner slide ring is symmetrically provided with a second guide block, and the second guide block is movably connected to the second guide groove.

[0011] In the cross slide ring scroll compressor dynamic balance structure assembly, the top wall at the circumference of the inner slide ring is symmetrically provided with a connecting block, and the connecting block extends into and abuts against the connecting groove.

[0012] In the cross slide ring scroll compressor dynamic balance structure assembly, the housing is provided with a trajectory disc, and the trajectory disc and the housing jointly form a second guide groove which is arranged at a right angle with the first guide groove.

[0013] In the cross slide ring scroll compressor dynamic balance structure assembly, the inner slide ring is movably arranged in the hollow circle, and the inner diameter of the hollow circle is greater than the outer diameter of the inner slide ring.

[0014] In the cross slide ring scroll compressor dynamic balance structure assembly, the housing is further provided with a fixed disc, the fixed disc is provided with a through hole, the trajectory disc is detachably connected to the top wall of the fixed disc, and the first counterweight block is movably arranged in the through hole.

[0015] In the cross slide ring scroll compressor dynamic balance structure assembly, bearings are installed in the through hole, the housing and the driving disc, and the inner ring of the bearing is in interference fit with the rotating shaft.

[0016] Compared with the prior art, the cross slide ring scroll compressor dynamic balance structure assembly has the following beneficial effects:

[0017] (1) The cross slide ring scroll compressor dynamic balance structure assembly can make the vector value of the force generated by the inner slide ring and the outer slide ring always a constant value when the inner slide ring and the outer slide ring move in the perpendicular direction, and then accurately balance through the balancing block, thereby solving the vibration problem of the equipment.

[0018] (2) The trajectory disc can guide and limit the linear motion of the inner slide ring, and can also cooperate with the driving disc to limit the axial displacement of the inner slide ring, effectively avoiding the axial offset and shaking of the inner slide ring during the radial movement.

[0019] (3) In the process of linear motion of the inner sliding ring and the outer sliding ring, all bearings are complete circumferential motion, which effectively improves the poor working condition of the bearings and the damage condition, and prolongs the service life of the bearings. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a perspective view of the present application;

[0021] Figure 2 is Figure 1 is a cross-sectional view of A-A in the figure;

[0022] Figure 3 is an explosion view of the driving disc, the inner / outer sliding ring and the shell;

[0023] Figure 4 is a schematic view of the mounting structure between the first configuration block, the second counterweight block and the rotating shaft.

[0024] In the figure, 1, shell; 10, first guide groove; 11, track disc; 110, second guide groove; 12, fixed disc; 120, through hole; 13, bearing; 14, bottom cover;

[0025] 2, rotating shaft; 20, first counterweight block; 21, second counterweight block; 220, threaded hole;

[0026] 3, driving disc; 30, extension block; 300, clamping groove; 301, waist-shaped groove; 31, connecting groove;

[0027] 4, outer sliding ring; 40, clamping block; 41, first guide block; 42, hollow circle;

[0028] 5, inner sliding ring; 50, connecting block; 51, second guide block. DETAILED DESCRIPTION

[0029] The following is a specific embodiment of the present application and further describes the technical solutions of the present application in combination with the drawings, but the present application is not limited to these embodiments.

[0030] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly.

[0031] As Figures 1 to 4The utility model discloses a cross slide ring scroll compressor dynamic balance structure assembly, which comprises: a rotating shaft 2 movably arranged in a shell 1, an eccentric driving disc 3 arranged at the end of the rotating shaft 2; an outer slide ring 4 and an inner slide ring 5 movably sleeved on the rotating shaft 2 and arranged eccentrically relative to the rotating shaft 2, the outer slide ring 4 and the inner slide ring 5 are connected to the driving disc 3, the outer slide ring 4 and the inner slide ring 5 are movably clamped to the shell 1, and the moving direction of the outer slide ring 4 and the inner slide ring 5 relative to the shell 1 is arranged perpendicularly; when the rotating shaft 2 drives the driving disc 3 to rotate eccentrically, the outer slide ring 4 and the inner slide ring 5 can make cross reciprocating motion in the shell 1.

[0032] The present scheme mainly solves the problem of large vibration of the cross slide ring structure scroll pump, and specifically, Figures 1 to 4 As shown in the figure, the rotating shaft 2 is movably arranged in the shell 1, and the eccentric driving disc 3 is arranged at the end of the rotating shaft 2, which also makes the rotating shaft 2 drive the driving disc 3 to produce periodic displacement change (i.e. eccentric reciprocating motion) during rotation. It should be emphasized that the inner / outer slide ring 4 is arranged eccentrically relative to the rotating shaft 2, and the positions of the inner slide ring 5 and the outer slide ring 4 movably clamped relative to the shell 1 are arranged at right angles (i.e. the whole is a cross structure), which can be referred to Figure 3 As shown in the figure, when the rotating shaft 2 drives the driving disc 3 to rotate eccentrically, the movement of the driving disc 3 is transmitted to the outer slide ring 4, so that it moves linearly in one direction; due to the relative position and eccentric arrangement of the inner slide ring 5, it will move linearly in another perpendicular direction (i.e. perpendicular to the linear motion direction of the outer slide ring 4) under the eccentric rotation of the driving disc 3. In this way, during the eccentric motion of the rotating shaft 2 driving the driving disc 3, the outer slide ring 4 and the inner slide ring 5 finally realize cross (cross) linear reciprocating motion in the shell 1. Because the outer slide ring 4 and the inner slide ring 5 move in mutually perpendicular directions respectively, the force generated can be equivalent to the circular rotation of a mass along the axis of the shaft, i.e. the force vector sum of the two slide rings in the scheme is exactly a constant, so as to utilize the balance block to offset the unbalanced force, realize the dynamic balance of the equipment, effectively avoid the wear of mechanical parts caused by vibration problem, simplify the overall structure, and prolong the service life of the equipment.

[0033] Further, as shown in the figure, Figures 2 to 4As shown, in this embodiment, a first counterweight 20 and a second counterweight 21 are detachably connected to both ends of the rotating shaft 2. It is worth noting that the first counterweight 20 and the second counterweight 21 are also eccentrically set relative to the rotating shaft 2, that is, the center position of the two counterweights is not on the same straight line as the axis of the rotating shaft 2. Therefore, during the mechanical movement, the inner / outer slip ring 4 makes linear reciprocating motion along mutually perpendicular directions. Under the condition that the inner / outer slip ring 4 has the same weight and the mass points coincide (calculated according to design requirements), the force generated by the inner slip ring 5 and the outer slip ring 4 during operation can be equivalent to the force generated by an object rotating along the axis of the shaft. At this time, with the precise configuration of the mass and position of the first counterweight 20 and the second counterweight 21, the system as a whole can achieve a state of dynamic balance (that is, balance the unbalanced force generated during movement), ensuring the smooth operation of the equipment, and also avoiding the occurrence of vibration problems and noise generation.

[0034] Preferably, in this embodiment, the installation of the first counterweight 20 and the second counterweight 21 is completed in a detachable manner. Specifically, threaded holes 220 are provided at the corresponding installation positions of the first counterweight 20, the second counterweight 21, and the rotating shaft 2. After the threaded holes 220 on the rotating shaft 2 and the counterweight are aligned, they can be fixed together by screws, bolts, or other fasteners (not shown in the figure). This not only ensures the synchronous rotation between the rotating shaft 2 and the counterweight, avoiding relative displacement between them that would affect the elimination of the balance force, but also simplifies the overall assembly steps, providing great convenience for subsequent maintenance and replacement.

[0035] The top wall of the outer slip ring 4 is symmetrically provided with locking blocks 40, and the drive disk 3 is symmetrically provided with extension blocks 30 along its radial direction. The extension blocks 30 have locking grooves 300 formed inside them, and the locking blocks 40 are movably locked into the locking grooves 300.

[0036] Furthermore, such as Figures 1 to 3 As shown, for the installation between the outer slip ring 4 and the drive disk 3, in this embodiment, the drive disk 3 is symmetrically provided with extension blocks 30 along its radial direction. With the design of each extension block 30 and its internal engagement groove 300, on the one hand, the engagement action of the engagement block 40 and the engagement groove 300 ensures that the two can move smoothly together. On the other hand, since the overall position of the extension block 30 is above the outer slip ring 4, it can effectively limit the displacement along the axis of the rotating shaft 2 during the linear reciprocating motion of the slip ring seat, thereby improving the stability and accuracy of the movement of the outer slip ring 4.

[0037] More preferably, in this embodiment, an oblong groove 301 communicating with the engaging groove 300 is also provided in the extension block 30, such as... Figure 3As shown, the length direction of the waist-shaped slot 301 is perpendicular to the opening direction of the clamping slot 300, that is, the two side walls of the length direction of the waist-shaped slot 301 are not in the same plane as the inner wall of the clamping slot 300. By using the design of the waist-shaped slot 301, not only can the sliding space of the clamping block 40 in the clamping slot 300 when the driving disc 3 is eccentrically rotated (the clamping slot 300 slides relative to the clamping block 40 when the extension block 30 is eccentrically rotated) be provided, effectively avoiding the position interference or jamming phenomenon between the two to affect the normal operation of the equipment, but also with the eccentric rotation of the driving disc 3, a part of the clamping block 40 is clamped in the clamping slot 300, and the other part is movably inserted into the waist-shaped slot 301, which can ensure the close fit between the two, ensure the smooth and normal linear reciprocating motion of the outer sliding ring 4, and also reduce the contact area between the clamping block 40 and the extension block 30, providing protection for the smoothness and stability of the eccentric rotation of the driving disc 3.

[0038] The bottom wall at the circumference of the outer sliding ring 4 is symmetrically provided with a first guide block 41, and the first guide block 41 is arranged at a right angle with the clamping block 40. A first guide slot 10 is symmetrically formed in the housing 1, and the first guide block 41 is movably clamped in the first guide slot 10.

[0039] As shown in the figure, Figures 1 to 3 By means of the bearing 13 between the driving disc 3 and the top end of the rotating shaft 2, the rotating shaft 2 can drive the eccentrically arranged driving disc 3 to make eccentric reciprocating motion relative to the housing 1 through the cooperation of the inner and outer rings of the bearing 13. In this process, the force of the eccentric rotation of the driving disc 3 can act on the outer sliding ring 4 through the movable clamping cooperation between the clamping block 40 and the clamping slot 300, and finally drive the first guide block 41 to make linear reciprocating motion along the opening direction of the first guide slot 10. Because of the sliding cooperation between the two, additional support and restraint force is provided to ensure that the outer sliding ring 4 does not deviate or tilt during movement.

[0040] The top wall at the circumference of the inner sliding ring 5 is symmetrically provided with a connecting block 50, and the driving disc 3 is symmetrically provided with a connecting slot 31 arranged at a right angle with the extension block 30. The connecting block 50 is inserted and abuts in the connecting slot 31.

[0041] Similarly, as shown in the figure, Figures 1 to 3 For the connection between the inner sliding ring 5 and the driving disc 3, the embodiment uses the connecting block 50 and the connecting slot 31 to realize it. Specifically, the connecting block 50 on the inner sliding ring 5 protrudes outward along the axis direction of the rotating shaft 2, Figure 3 and Figure 4As can be seen, the connecting groove 31 and the extension block 30 are positioned at right angles on the drive disk 3. This design does not affect the installation between the drive disk 3 and the inner / outer slip ring 4, and the right angle design can also ensure that the inner slip ring 5 always moves along the predetermined trajectory during the movement, which significantly improves the accuracy and stability during the movement.

[0042] A track disk 11 is provided inside the housing 1. The track disk 11 and the housing 1 together form a second guide groove 110 that is perpendicular to the first guide groove 10. A second guide block 51 is symmetrically provided on the bottom wall of the inner slip ring 5. The second guide block 51 is movably engaged with the second guide groove 110.

[0043] Furthermore, such as Figures 1 to 3 As shown, it is worth noting that the first guide groove 10 and the second guide groove 110 are set at right angles in the opening direction within the housing 1 (i.e., the direction in which the inner / outer slip ring 4 makes cross-shaped reciprocating motion), and the connection between the drive disk 3 and the inner slip ring 5 (the engaging groove 300 and the engaging block 40) is set at a right angle to the first guide groove 10. Similarly, the connection between the drive disk 3 and the outer slip ring 4 (the connecting block 50 and the connecting groove 31) is also set at an angle to the second guide groove 110. In this way, when the drive disk 3 makes eccentric movements, the driving force for the reciprocating linear motion of the outer slip ring 4 along the opening direction of the first guide groove and the reciprocating linear motion of the inner slip ring 5 along the opening direction of the second guide groove can be accurately applied, thereby improving the accuracy and stability of the equipment during operation.

[0044] It should be added that the eccentric reciprocating motion of the drive disk 3 mentioned in this embodiment does not mean that the drive disk 3 moves in a circular motion relative to the housing 1 as the shaft 2 rotates. Rather, it means that the drive disk 3 moves in an eccentric circular motion around the shaft 2 without rotating itself, due to the eccentric rotation of the bearing 13 (the bearing 13 between the drive disk 3 and the shaft 2 is also eccentrically set relative to the shaft 2). During this process, when the drive disk 3 is eccentrically positioned to the first guide block 41, it can drive the first guide block 41 to move in a linear reciprocating motion within the first guide groove 10. Similarly, when the drive disk 3 is eccentrically positioned to the second guide block 51, it can drive the second guide block 51 to move in a linear reciprocating motion within the second guide groove 110. During this process, both the bearing 13 and the shaft 2 are in circular motion, and the vector sum of the forces of the inner and outer slip rings 4 moving in mutually perpendicular directions is the force value that the two counterweights need to balance.

[0045] Preferably, such as Figure 1 and Figure 3As shown, as the connecting block 50 extends into and abuts against the connecting groove 31, the outer slip ring 4 is completely at the bottom of the drive disk 3, while the inner slip ring 5 is in the limiting cavity (not shown in the figure) formed by the track disk 11 and the drive disk 3. This also limits the displacement of the inner slip ring 5 along the axis of the rotating shaft 2, ensuring the smoothness and stability of the inner slider when it makes a linear reciprocating motion along the opening direction of the second guide groove, and avoiding unnecessary axial (i.e., axis of the rotating shaft 2) displacement of the inner slider.

[0046] More preferably, such as Figure 3 As shown, this embodiment also includes a hollow circle 42 inside the outer slip ring 4, and an inner slip ring 5 is movably disposed inside the hollow circle 42. As the inner / outer slip rings 4 are installed at corresponding positions on the housing 1 and the track disk 11, the inner slip ring 5 and the outer slip ring 4 can perform linear reciprocating motion in mutually perpendicular directions along their respective guide grooves by the eccentric rotation of the drive disk 3. Since the inner diameter of the hollow circle 42 is larger than the outer diameter of the inner slip ring 5, this design allows the inner slip ring 5 to move freely in the outer slip ring 4, while ensuring that the inner / outer slip rings 4 can perform cross-shaped reciprocating motion in their respective predetermined tracks. Combined with the elimination of unbalanced forces by the two counterweights, the vibration problem during equipment operation is effectively solved.

[0047] The housing 1 is also provided with a fixed plate 12, and a through hole 120 is provided in the fixed plate 12. The track disk 11 is detachably connected to the top wall of the fixed plate 12, and the first counterweight 20 is movably disposed in the through hole 120.

[0048] More preferably, in this embodiment, the fixed plate 12 provides a certain supporting force for the installation of the track plate 11. During the installation process of the track plate 11 and the fixed plate 12, detachable assembly can be achieved through screws, bolts, and other connecting components, simplifying the assembly steps and providing convenience for subsequent maintenance and replacement. It also indirectly ensures that the second guide groove formed by the track plate 11 and the housing 1 provides stability for the reciprocating linear motion of the inner slip ring 5. Figure 2 As shown, the through hole 120 in the fixed plate 12 is T-shaped, and the first counterweight 20 is movably disposed in the through hole 120 of the fixed plate 12. Its position and mass can be flexibly adjusted according to actual needs to achieve the best dynamic balance effect and further optimize the operating performance of the equipment.

[0049] Further preferably, the driving of the rotating shaft 2 can be replaced by a stepping motor, a servo motor or other driving devices, and the bottom cover 14 is detachably connected to the bottom of the shell 1 by screws or bolts, so as to facilitate the disassembly and replacement of the internal components of the shell 1. Therefore, in order to further improve the smoothness of the rotating shaft 2 driving the driving disc 3 to rotate, bearings 13 are installed in the through hole 120 and the shell 1 (the position of the bottom cover 14), which provides protection for the smoothness and stability of the equipment during operation, and avoids frequent maintenance operations.

[0050] It should be noted that all bearings 13 in the embodiment can be deep groove ball bearings, four-point contact bearings, and other bearings such as cylindrical roller bearings or needle bearings can be replaced under heavy load.

[0051] It should be noted that the descriptions such as "first", "second", "one" and the like in the present application are only for the purpose of description, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited. The terms "connection", "fixation" and the like should be understood broadly, for example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through an intermediate medium; can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0052] In addition, the technical solutions of each embodiment of the present application can be combined with each other, but it must be based on the realization of the ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor within the scope of protection required by the present application.

[0053] The specific embodiments described herein are merely illustrative of the spirit of the present application. Those skilled in the art of the present application can make various modifications or supplements to the described specific embodiments or replace them with similar ways, but without deviating from the spirit of the present application or exceeding the scope defined by the appended claims.

Claims

1. A cross slide ring scroll compressor dynamic balance structure assembly, characterized in that, The utility model provides a kind of cross slide, including: Rotary shaft is arranged in shell, and the eccentric end of rotary shaft is provided with driving disc; Outer slide ring and inner slide ring are movably arranged on rotary shaft and are eccentric to rotary shaft, outer slide ring and inner slide ring are connected to driving disc, outer slide ring and inner slide ring are movably connected to shell, and the direction of movement of outer slide ring and inner slide ring is perpendicular to shell; When rotary shaft drives driving disc to eccentric rotate, outer slide ring and inner slide ring can do cross slide reciprocating motion in shell.

2. A dynamic balance structure assembly of a cross slide ring scroll compressor according to claim 1, characterized in that, The top wall of the outer slide ring is symmetrically provided with a clamping block, the driving disc is symmetrically provided with an extension block in the radial direction thereof, the extension block has a clamping groove formed therein, and the clamping block is movably connected to the clamping groove.

3. A dynamic balance structure assembly of a cross slide ring scroll compressor according to claim 2, characterized in that, The two ends of the rotary shaft are respectively detachably connected with a first counterweight and a second counterweight.

4. A dynamic balance structure assembly of a cross slide ring scroll compressor according to claim 2, characterized in that, The extension block further has a waist-shaped groove formed therein, which is in communication with the clamping groove, and the length direction of the waist-shaped groove is perpendicular to the opening direction of the clamping groove.

5. A dynamic balance structure assembly of a cross slide ring scroll compressor according to claim 3, characterized in that, The bottom wall of the outer slide ring is symmetrically provided with a first guide block, the first guide block is arranged at a right angle to the clamping block, the shell has a first guide groove symmetrically formed therein, and the first guide block is movably connected to the first guide groove.

6. A dynamic balance structure assembly of a cross slide ring scroll compressor according to claim 2, characterized in that, The top wall of the inner slide ring is symmetrically provided with a connecting block, the driving disc has a connecting groove symmetrically formed therein, which is arranged at a right angle to the extension block, and the connecting block extends into and abuts against the connecting groove.

7. A dynamic balance structure assembly of a cross slide ring scroll compressor according to claim 5, characterized in that, The shell has a track disc arranged therein, the track disc and the shell jointly form a second guide groove arranged at a right angle to the first guide groove, the bottom wall of the inner slide ring is symmetrically provided with a second guide block, and the second guide block is movably connected to the second guide groove.

8. A dynamic balance structure assembly of a cross slide ring scroll compressor according to claim 1, characterized in that, The outer slide ring has a hollow circle arranged therein, the inner slide ring is movably arranged in the hollow circle, and the inner diameter of the hollow circle is greater than the outer diameter of the inner slide ring.

9. A dynamic balance structure assembly of a cross slide ring scroll compressor according to claim 7, characterized in that, The shell further has a fixed disc arranged therein, the fixed disc has a through hole formed therein, the track disc is detachably connected to the top wall of the fixed disc, and the first counterweight is movably arranged in the through hole.

10. A dynamic balance structure assembly of a cross slide ring scroll compressor according to claim 9, characterized in that, Bearing is mounted in the through hole, the shell and the driving disc, and the inner ring of the bearing is in interference fit with the rotary shaft.

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