High-precision main shaft structure for numerical control machine tool

Abstract

The utility model relates to a high-precision main shaft structure for a numerical control machine tool, which comprises a main shaft comprising a bearing seat, a sheath, a shaft core, a bearing and a rear cover; the damping piece comprises a mounting shell, a magnetic piece, a movable piece and a spring, and the mounting shell comprises a cover plate and a mounting block; the magnetic part is arranged between the cover plate and the mounting block and comprises a permanent magnet; the movable part is arranged in the magnetic part, extends to the outside of the mounting shell and is in contact with the outer surface of the shaft core; and the spring is arranged between the movable part and the mounting shell. The bearing seat, the damping part and other parts are arranged, the balls are tightly attached to the surface of the shaft core through the matching relation between the spring and the movable part, and therefore when the shaft core is subjected to thermal expansion and rotates due to temperature rise, the shaft core shakes in the rotating process to drive the movable part to move; and a magnetic damping phenomenon is generated between the movable part and the permanent magnet.

Description

Technical Field

[0001] The utility model relates to the technical field of CNC machine tool spindles, and particularly to a high-precision spindle structure for CNC machine tools. Background Technique

[0002] The spindle of a CNC machine tool refers to the shaft that drives the workpiece or tool to rotate on the machine tool. Generally, the whole structure composed of a bearing seat, bearings, a sheath, a shaft core, and a rear cover is also called a spindle.

[0003] In order to ensure the accuracy of machined parts, the spindle of a CNC machine tool usually needs to be equipped with a high-precision spindle (abbreviated as a high-precision spindle). During use, the high-precision spindle is worn due to reasons such as friction and heat, resulting in a decrease in accuracy. Especially after heating, the spindle expands and deforms, and then the shaft core shakes when rotating, which will lead to a decrease in machining accuracy. The traditional solution is to cool down to make the phenomenon of thermal expansion disappear. However, it is difficult to completely reduce the temperature of the shaft core to the extent that the thermal expansion phenomenon completely disappears. Therefore, the cooled shaft core will still have problems with reduced machining accuracy due to shaking. For this reason, a high-precision spindle structure for CNC machine tools is proposed to solve the above-mentioned problems. Content of the Utility Model

[0004] Based on the above description, the utility model provides a high-precision spindle structure for CNC machine tools to solve the problem that the existing high-precision spindles are prone to accuracy reduction under high-temperature conditions.

[0005] The technical solution for the utility model to solve the above technical problems is as follows: A high-precision spindle structure for CNC machine tools, comprising: a spindle, the spindle includes a bearing seat, a sheath, a shaft core, bearings, and a rear cover. The bearing seat includes a mounting groove. The damping member includes a mounting shell, a magnetic member, a movable member, and a spring. The mounting shell includes a cover plate and a mounting block. The magnetic member is arranged between the cover plate and the mounting block and includes a permanent magnet. The movable member is arranged inside the magnetic member and extends outside the mounting shell and contacts the outer surface of the shaft core. The spring is arranged between the movable member and the mounting shell.

[0006] Based on the above technical solution, the utility model can be further improved as follows.

[0007] Further, the bearing seat includes a main body seat, and a mounting groove is arranged on the outer surface of the main body seat.

[0008] Further, a sheath and a rear cover are respectively arranged at both ends of the main body seat. A shaft core is arranged inside the main body seat, and a bearing is arranged between the shaft core and the bearing seat.

[0009] Further, the installation shell includes a horizontal plate, and installation blocks are arranged at both ends of the horizontal plate. A cover plate is arranged on one side of the installation block away from the horizontal plate.

[0010] Further, movable grooves are arranged on the opposite sides of the cover plate and the installation block. The cover plate and the installation block are both arranged inside the installation groove and extend into the bearing seat.

[0011] Further, the magnetic member includes a U-shaped frame, and placement grooves are arranged on both sides of the U-shaped frame. Permanent magnets are arranged inside the placement grooves.

[0012] Further, the movable member includes a metal stress plate. The metal stress plate is arranged inside the magnetic member. On the side of the metal stress plate close to the axis core, a connecting column, a threaded column, and a hemispherical groove are sequentially arranged.

[0013] Further, an internal thread cover is arranged on the outside of the threaded column. A through hole is arranged on the side of the internal thread cover close to the axis core. A ball is arranged inside the hemispherical groove. The ball penetrates through the through hole and contacts the outer surface of the axis core. A spring is arranged on the side of the metal stress plate away from the axis core.

[0014] Compared with the prior art, the technical solution of the present application has the following beneficial technical effects:

[0015] 1. By arranging components such as a bearing seat and a damping member, through the cooperation relationship between the spring and the movable member, the ball is tightly attached to the surface of the axis core. Thus, when the axis core expands thermally and rotates due to temperature rise, the axis core shakes during rotation and drives the movable member to move, resulting in a magnetic damping phenomenon between the movable member and the permanent magnet.

[0016] 2. By arranging the threaded column, the internal thread cover, and the ball, the sliding friction between the axis core and the movable member is converted into rolling friction, thereby reducing the degree of wear of the axis core caused by friction. This enables the device to consume energy when the axis core shakes, so as to weaken the problem of reduced machining accuracy caused by the shaking of the axis core. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of a high-precision spindle structure for a numerical control machine tool provided by an embodiment of the present utility model;

[0018] Figure 2 is Figure 1 a structural cross-sectional view of;

[0019] Figure 3 is Figure 2 a partial enlarged schematic view of area A in;

[0020] Figure 4 is Figure 2 a structural schematic diagram of another perspective;

[0021] Figure 5 is a structural schematic diagram of the damping member in the embodiment of the present utility model;

[0022] Figure 6 is a structural schematic diagram of the bearing seat in the embodiment of the present utility model;

[0023] Figure 7 is a structural schematic diagram of the mounting shell in the embodiment of the present utility model;

[0024] Figure 8 is a structural schematic diagram of the magnetic member in the embodiment of the present utility model;

[0025] Figure 9 is a structural schematic diagram of the movable member in the embodiment of the present utility model;

[0026] In the drawings, the list of components represented by each reference numeral is as follows:

[0027] 1, bearing seat; 11, main body seat; 12, mounting groove; 2, sheath; 3, shaft core; 4, bearing; 5, mounting shell; 51, cross plate; 52, cover plate; 53, mounting block; 54, movable groove; 6, magnetic member; 61, U-shaped frame; 62, placing groove; 63, permanent magnet; 7, movable member; 71, metal stress plate; 72, connecting column; 73, threaded column; 74, hemispherical groove; 75, internal thread cover; 76, through hole; 77, ball; 8, spring; 9, rear cover. Detailed implementation manners

[0028] To facilitate the understanding of the present application, the present application will be described more comprehensively below with reference to the relevant drawings. Embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs. The terms used in the specification of the present application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0030] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising", "including" or "having" and the like specify the presence of the stated features, wholes, steps, operations, components, parts or combinations thereof, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0031] Please refer to FIG. Figures 1-4 , a high-precision spindle structure for a numerically controlled machine tool, comprising:

[0032] A spindle, which includes a bearing seat 1, a sheath 2, a shaft core 3, a bearing 4 and a rear cover 9. Among them,

[0033] The bearing seat 1 includes a main body seat 11, and an installation groove 12 is provided on the outer surface of the main body seat 11;

[0034] The sheath 2 and the rear cover 9 are respectively arranged at both ends of the main body seat 11, the shaft core 3 is arranged inside the main body seat 11, and a bearing 4 is arranged between the shaft core 3 and the bearing seat 1;

[0035] Based on the above, the bearing seat 1, the sheath 2, the shaft core 3, the bearing 4 and the rear cover 9 are all prior arts. The description of the prior arts here is only for the convenience of describing the structure and movement principle of the damping member. The setting of the installation groove 12 enables the installation shell 5 to be connected to the bearing seat 1 and to contact the shaft core 3.

[0036] As Figures 2-5 and Figure 7 shown, an installation shell 5, which includes a cover plate 52 and an installation block 53;

[0037] The installation shell 5 includes a cross plate 51, installation blocks 53 are arranged at both ends of the cross plate 51, a cover plate 52 is arranged on one side of the installation block 53 away from the cross plate 51, movable grooves 54 are arranged on the opposite sides of the cover plate 52 and the installation block 53, and the cover plate 52 and the installation block 53 are both arranged inside the installation groove 12 and extend into the bearing seat 1;

[0038] Based on the above, the cover plate 52 and the installation block 53 are connected to each other by screws. The movable groove 54 provides a movable space for the movable member 7, enabling the movable member 7 to move normally. The setting of the cross plate 51 enables the installation shell 5 to be connected and fixed to the bearing seat 1.

[0039] As Figure 2 , Figure 3 and Figure 8 shown, a magnetic member 6, which is arranged between the cover plate 52 and the installation block 53;

[0040] The magnetic member 6 comprises a U-shaped frame 61, both sides of the U-shaped frame 61 are provided with placement grooves 62, and permanent magnets 63 are arranged inside the placement grooves 62;

[0041] Based on the above, the magnetic part 6 provides the effect of the magnetic field, so that the movable part 7 can cut the magnetic flux lines when moving, thereby achieving the effect of generating the magnetic damping phenomenon, thereby consuming the shaking of the shaft core 3.

[0042] like Figure 2 , Figure 3 as well as Figure 9 As shown, the movable member 7 is arranged inside the magnetic member 6, extends to the outside of the mounting shell 5, and contacts the outer surface of the shaft core 3;

[0043] The movable member 7 includes a metal force-bearing plate 71, which is arranged inside the magnetic member 6. A connecting column 72, a threaded column 73 and a hemispherical groove 74 are sequentially arranged on the side of the metal force-bearing plate 71 close to the shaft core 3. An internal threaded cover 75 is arranged outside the threaded column 73. A through hole 76 is arranged on the side of the internal threaded cover 75 close to the shaft core 3. A ball 77 is arranged inside the hemispherical groove 74. The ball 77 passes through the through hole 76 and contacts the outer surface of the shaft core 3. A spring 8 is arranged on the side of the metal force-bearing plate 71 away from the shaft core 3.

[0044] Based on the above, the threaded column 73 and the internal threaded cover 75 cooperate with each other, so that the ball 77 can be set inside the hemispherical groove 74 and extend from the through hole 76. The extended ball 77 contacts the outer surface of the shaft core 3, so that the friction between the shaft core 3 and the movable part 7 is rolling friction, which reduces the wear caused by the friction as much as possible. The metal force plate 71 preferably uses a metal that cannot be magnetized, such as aluminum. When the metal force plate 71 moves between the permanent magnets 63, magnetic damping occurs, which consumes the energy during shaking. The setting of the spring 8 allows the ball 77 to always be in contact with the outer surface of the shaft core 3.

[0045] In actual use of this embodiment, the mounting shell 5 is mounted inside the mounting groove 12 by means of screws. During this process, the ball 77 contacts the outer surface of the shaft core 3, and the movable member 7 moves toward the direction close to the spring 8, so that the spring 8 is compressed to generate elastic force, thereby ensuring that the ball 77 is tightly fitted with the shaft core 3 under the action of the elastic force.

[0046] When the shaft core 3 rotates, rolling friction will be generated with the ball 77. If the shaft core 3 is slightly deformed, the movable part 7 will be pushed to move in the direction away from or close to the spring 8. At this time, the metal force plate 71 and the permanent magnet 63 move relative to each other. The metal force plate 71 cuts the magnetic flux lines to generate induced current and induced magnetic field, and then magnetic damping occurs under the action of the induced magnetic field and current. The occurrence of magnetic damping can consume energy caused by the shaking of the shaft core 3 when it rotates due to deformation, and reduce the impact of reduced accuracy caused by shaking as much as possible.

[0047] Compared with the traditional high-precision spindle, this high-precision spindle structure can consume the energy of the shaking that occurs during the rotation of the spindle through the provision of damping parts, thereby avoiding the problem of reduced precision due to shaking.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. High-precision spindle structure for numerical control machine tools, characterized in that, Comprising: A main shaft, which includes a bearing housing (1), a sheath (2), a shaft core (3), bearings (4) and a rear cover (9), wherein, The bearing housing (1), which includes a mounting groove (12); A damping member, which includes a mounting shell (5), a magnetic member (6), a movable member (7) and a spring (8), wherein, The mounting shell (5), which includes a cover plate (52) and a mounting block (53); The magnetic member (6), which is disposed between the cover plate (52) and the mounting block (53), and includes a permanent magnet (63); The movable member (7), which is disposed inside the magnetic member (6), extends outside the mounting shell (5), and contacts the outer surface of the shaft core (3); The spring (8), which is disposed between the movable member (7) and the mounting shell (5).

2. The high-precision spindle structure for a numerical control machine tool according to claim 1, characterized in that The bearing housing (1) includes a main body housing (11), and the outer surface of the main body housing (11) is provided with a mounting groove (12).

3. The high-precision spindle structure for a numerically controlled machine tool according to claim 2, characterized in that, Both ends of the main body housing (11) are respectively provided with a sheath (2) and a rear cover (9), the inside of the main body housing (11) is provided with a shaft core (3), and bearings (4) are arranged between the shaft core (3) and the bearing housing (1).

4. The high-precision spindle structure for a numerically controlled machine tool according to claim 1, characterized in that, The mounting shell (5) includes a cross plate (51), both ends of the cross plate (51) are provided with mounting blocks (53), and a cover plate (52) is arranged on the side of the mounting block (53) away from the cross plate (51).

5. The high-precision spindle structure for a numerically controlled machine tool according to claim 4, characterized in that, Both the cover plate (52) and the side of the mounting block (53) opposite thereto are provided with movable grooves (54), and both the cover plate (52) and the mounting block (53) are arranged inside the mounting groove (12) and extend into the bearing housing (1).

6. The high-precision spindle structure for a numerically controlled machine tool according to claim 1, characterized in that The magnetic member (6) includes a U-shaped frame (61), both sides of the U-shaped frame (61) are provided with placement grooves (62), and permanent magnets (63) are arranged inside the placement grooves (62).

7. The high-precision spindle structure for a numerically controlled machine tool according to claim 1, characterized in that, The movable member (7) includes a metal stress plate (71), the metal stress plate (71) is disposed inside the magnetic member (6), and on the side of the metal stress plate (71) close to the shaft core (3), there are successively arranged a connecting column (72), a threaded column (73) and a hemispherical groove (74).

8. The high-precision spindle structure for a numerically controlled machine tool according to claim 7, characterized in that, An internal thread cover (75) is arranged outside the threaded column (73), a through hole (76) is arranged on the side of the internal thread cover (75) close to the shaft core (3), a ball (77) is arranged inside the hemispherical groove (74), the ball (77) passes through the through hole (76) and contacts the outer surface of the shaft core (3), and a spring (8) is arranged on the side of the metal stress plate (71) away from the shaft core (3).

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