Bean grinder

Abstract

The bean grinder comprises a hollow main body, a fixed sleeve shell, a movable sleeve shell, an adjusting piece, an adjusting ring and a sealing cover, the movable sleeve shell is matched with the fixed sleeve shell in a sleeved mode and only slides in the axial direction of the fixed sleeve shell, the movable sleeve shell is provided with a motor, an output shaft of the motor is detachably connected with an inner cutter head, and an outer cutter head is arranged at a discharging port. The inner cutterhead and the outer cutterhead are sleeved, matched and rotationally connected; the lower part of the adjusting piece is rotationally connected with the fixed sleeve shell and is in threaded connection with the movable sleeve shell; the upper part of the adjusting piece extends out of the main body; the adjusting ring is connected with the main body in a rotating and buckling mode, the adjusting ring is coaxially provided with a protective sleeve, and the protective sleeve is matched with the upper portion of the adjusting piece in a sleeved mode and only slides in the axial direction of the adjusting piece. According to the bean grinder, the fineness of ground powder can be accurately adjusted according to requirements, the adjusting mode is flexible, and user experience is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of grinding devices, in particular to a bean grinder. Background Art

[0002] With the improvement of people's living standards, in order to meet the needs of personalization and taste, more and more people begin to use food grinders at home or in the office. Among them, bean grinders are usually used to grind bean ingredients to produce powders such as soy milk powder or coffee powder. Existing bean grinders are usually driven by motors. When using the bean grinder, the top cover is usually taken out and the bean ingredients are placed in the grinding chamber. The rotating shaft of the motor is connected to the grinding tool to drive the grinding tool to rotate for grinding. The grinding tool is an inner blade disc or an outer blade disc. When using the existing bean grinder, the user needs to open the top cover and then manually turn the knob to adjust the gap between the outer wall of the inner blade disc and the inner wall of the outer blade disc to adjust the fineness of the ground powder. However, the existing bean grinder has a single adjustment method and poor adjustment accuracy. In addition, since the space where the knob is located is connected to the grinding chamber, the splashed powder is easy to adhere to the knob, which needs further improvement. Utility Model Content

[0003] The utility model aims to provide a coffee bean grinder designed to solve the deficiencies of the above-mentioned technology, which can more accurately adjust the fineness of the ground powder according to the needs, has a more flexible adjustment method, and improves the user experience.

[0004] In order to solve the above technical problems, the technical solution of the utility model is: a coffee bean grinder, comprising a main body with a hollow interior, a fixed sleeve shell, a movable sleeve shell, an adjusting member, an adjusting ring and a closing cover, wherein the fixed sleeve shell is fixedly connected to the inner wall of the main body, and the outer wall of the fixed sleeve shell cooperates with the inner wall of the main body to form at least one grinding chamber, the upper opening of the grinding chamber is a feed port, and the lower opening of the grinding chamber is a discharge port;

[0005] The movable sleeve shell is sleeved with the fixed sleeve shell and only slides along the axial direction of the fixed sleeve shell. The movable sleeve shell is provided with a motor, and the output shaft of the motor is detachably connected with an inner cutter disc. The material outlet is provided with an outer cutter disc, and the inner cutter disc is sleeved with the outer cutter disc and is rotatably connected.

[0006] The lower part of the adjusting member is rotatably connected to the fixed sleeve shell and is threadedly connected to the movable sleeve shell. A rotating disk is provided at the lower part of the adjusting member. A plurality of gear slots distributed in an annular array are provided on the circumferential side wall of the rotating disk. At least one pressing member is telescopically and movably provided inside the fixed sleeve shell. The pressing member is provided with an elastic structure and is pressed against the corresponding gear slot. The upper part of the adjusting member extends out of the outside of the main body.

[0007] The adjusting ring is connected to the main body by a rotating buckle, and a protective sleeve is coaxially arranged on the adjusting ring. The protective sleeve is sleeved and matched with the upper part of the adjusting member and only slides along the axial direction of the adjusting member. The closing cover is arranged on the adjusting ring to cover the feed port.

[0008] Preferably, the interior of the fixed sleeve shell is hollow, and the upper cover of the fixed sleeve shell is provided with a cover plate, the cover plate cooperates with the inner wall of the main body to form the feed port, the cover plate is penetrated by a rotating hole for the adjustment member to be rotatably connected, the bottom surface of the cover plate is provided with a guide sleeve, the opening of the first end of the guide sleeve is provided with an abutment portion, the tightening member is slidably connected to the opening of the second end of the guide sleeve, and the elastic structure is provided between the abutment portion and the tightening member.

[0009] Preferably, the protective sleeve is coaxially arranged with the adjustment ring, and a connecting structure is arranged between the inner wall of the adjustment ring and the protective sleeve, the connecting structure comprising a plurality of connecting strips distributed in a ring array, and the gap between two adjacent connecting strips is adapted to the feed port.

[0010] Preferably, a first magnet is provided on the inner wall of the closing cover at a position corresponding to the protective cover, and a second magnet is provided on the inner wall of the protective cover, and the magnetic force between the first magnet and the second magnet is an attractive force.

[0011] Preferably, the upper outer wall of the main body is concavely formed with a docking ring groove, and the lower inner wall of the adjustment ring is convexly formed with at least one docking hook portion, the docking hook portion extends along the circumference of the docking ring groove, and the docking hook portion is clamped in the docking ring groove.

[0012] Preferably, a first concave-convex portion is provided on the circumferential side wall of the upper portion of the adjusting member, and a second concave-convex portion is provided on the inner wall of the protective sleeve, and the first concave-convex portion is matched with the second concave-convex portion.

[0013] Preferably, the lower portion of the main body is detachably connected to a hopper shell, and the discharge port is arranged in the middle portion of the hopper shell.

[0014] Preferably, it also includes a powder bin, the edge of the hopper shell is formed with a mounting ring that matches the inner wall of the lower opening of the main body, the upper part of the powder bin is formed with a mounting ring, and the mounting ring is sleeved and detachably connected to the mounting ring.

[0015] Preferably, a guide structure is provided between the fixed sleeve shell and the movable sleeve shell, the guide structure comprising an inner groove and an outer convex strip, the outer convex strip is slidably connected in the inner groove; the inner wall of the fixed sleeve shell is provided with an inner groove, and the outer wall of the movable sleeve shell is provided with an outer convex strip, or the inner wall of the fixed sleeve shell is provided with an outer convex strip, and the outer wall of the movable sleeve shell is provided with an inner groove.

[0016] Preferably, a step cavity is formed on the lower inner wall of the fixed sleeve shell, and a step portion is formed on the lower outer wall of the movable sleeve shell, and the step portion is concavely matched with the step cavity; a first bearing component is provided at a position of the fixed sleeve shell corresponding to the step cavity, and the first bearing component is sleeve-fitted with the output shaft of the motor; a second bearing component is provided at a position of the movable sleeve shell corresponding to the step portion, and the second bearing component is sleeve-fitted with the output shaft of the motor.

[0017] Compared with the prior art, the beneficial effects of the utility model are:

[0018] The utility model discloses a coffee bean grinder, the adjusting ring is connected with the main body by a rotating buckle, the closing cover is arranged on the adjusting ring to cover the feeding port, during adjustment, the user can rotate the adjusting ring to drive the upper part of the adjusting member to rotate by means of the protective cover, the lower part of the adjusting member is threadedly connected with the moving sleeve shell, so that when the adjusting member rotates, the moving sleeve shell and the motor can be driven to move up and down, thereby adjusting the gap between the inner blade disc and the outer blade disc, the protective cover is used to protect the upper part of the adjusting member to prevent the powder from adhering to the upper part of the adjusting member, the user can also separate the adjusting ring and the closing cover from the main body, the upper part of the adjusting member extends out of the outside of the main body, so that the user can directly screw the upper part of the adjusting member by hand for adjustment, in this process, the tightening member is pressed against the corresponding gear slot of the turntable under the action of the elastic member, and the rotational movement of the adjusting ring is damped, so that the rotation stability of the adjusting member is improved, the coffee bean grinder can adjust the fineness of the ground powder more accurately according to the needs, the adjustment method is more flexible, and the user experience is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of the structure of the coffee grinder in the embodiment;

[0020] Figure 2 is a cross-sectional view of the grinder in the embodiment Figure 1 ;

[0021] Figure 3 The cross-sectional view of the grinder in the embodiment Figure 2 ;

[0022] Figure 4 A cross-sectional view of a rotating disk and a tightening member in an embodiment;

[0023] Figure 5 is an exploded view of the coffee grinder in the embodiment;

[0024] Figure 6 Schematic diagram of the structure of the adjusting ring, the adjusting member and the movable sleeve housing in the embodiment.

[0025] In the figure: 1, main body; 101, plane; 102, docking ring groove; 2, fixed sleeve shell; 201, step cavity; 202, first bearing member; 3, movable sleeve shell; 301, step portion; 302, second bearing member; 4, adjusting member; 401, first concave-convex portion; 5, adjusting ring; 501, second concave-convex portion; 502, docking hook portion; 503, friction pattern; 504, scale; 6, protective sleeve; 7, connecting strip; 8, closing cover; 9, powder bin; 901, mounting ring; 10, grinding chamber; 11, feed port; 12. Discharge port; 13. Motor; 14. Inner blade disc; 15. Outer blade disc; 16. Turntable; 1601. Gear slot; 17. Fastening member; 18. Elastic structure; 19. Cover plate; 1901. Rotary hole; 20. Guide sleeve; 21. Abutment portion; 22. Hopper shell; 2201. Assembly ring; 23. First magnet; 24. Second magnet; 25. Inner groove; 26. Outer convex strip; 27. Battery; 28. Circuit board; 29. ​​Charging port; 30. Button; 31. Indicator light; 32. Knob. DETAILED DESCRIPTION

[0026] The present invention will be further described below by way of embodiments in conjunction with the accompanying drawings.

[0027] refer to Figures 1 to 6 A coffee bean grinder includes a main body 1, a fixed sleeve shell 2, a movable sleeve shell 3, an adjusting member 4, an adjusting ring 5, a closing cover 8 and a powder bin 9. The main body 1 is hollow inside, and two parallel planes 101 are symmetrically arranged on the surface of the main body 1 so that the user can hold the main body 1. The fixed sleeve shell 2 is fixedly connected to the inner wall of the main body 1, and the lower part of the main body 1 is detachably connected with a hopper shell 22, and the hopper shell 22 is connected to the lower part of the main body 1 by bolts. The outer wall of the fixed sleeve shell 2 cooperates with the inner wall of the main body 1 to form two symmetrically arranged grinding chambers 10, and the inner cavity of the hopper shell 22 is adapted to the grinding chamber 10. The upper opening of the grinding chamber 10 is a feed port 11, and the lower opening of the grinding chamber 10 is a discharge port 12, and the discharge port 12 is arranged in the middle of the hopper shell 22.

[0028] The interior of the fixed sleeve shell 2 is hollow for the movable sleeve shell 3 to be sleeved and matched. A guide structure extending along the axial direction of the fixed sleeve shell 2 is provided between the fixed sleeve shell 2 and the movable sleeve shell 3. The guide structure includes an inner groove 25 and an outer convex strip 26. The outer convex strip 26 is slidably connected in the inner groove 25. The inner wall of the fixed sleeve shell 2 is provided with an inner groove 25, and the outer wall of the movable sleeve shell 3 is provided with an outer convex strip 26, or the inner wall of the fixed sleeve shell 2 is provided with an outer convex strip 26, and the outer wall of the movable sleeve shell 3 is provided with an inner groove 25. The setting of the guide structure enables the movable sleeve shell 3 to slide only along the axial direction of the fixed sleeve shell 2. The lower inner wall of the fixed sleeve shell 2 is formed with a step cavity 201, and the lower outer wall of the movable sleeve shell 3 is formed with a step portion 301. The step portion 301 is matched with the step cavity 201 in a concave-convex manner to limit the sliding movement of the movable sleeve shell 3 in the fixed sleeve shell 2.

[0029] A motor 13 is arranged inside the movable sleeve shell 3, and the output shaft of the motor 13 passes through the movable sleeve shell 3 and the fixed sleeve shell 2 in sequence, and the output shaft of the motor 13 is detachably connected with the inner cutter disc 14, the inner cutter disc 14 is sleeved and matched with the output shaft of the motor 13, and the end of the output shaft of the motor 13 extending out of the inner cutter disc 14 is screwed and connected with a knob member 32, and the knob member 32 is relatively abutted against the inner cutter disc 14, and an outer cutter disc 15 is arranged at the discharge port 12, and the inner cutter disc 14 is sleeved and matched with the outer cutter disc 15 and is rotatably connected, and the abutting contact surfaces of the inner cutter disc 14 and the outer cutter disc 15 are grinding surfaces. A first bearing member 202 is provided at a position of the fixed sleeve shell 2 corresponding to the step cavity 201, and the first bearing member 202 is sleeved and matched with the output shaft of the motor 13 to reduce the friction between the output shaft of the motor 13 and the fixed sleeve shell 2; a second bearing member 302 is provided at a position of the movable sleeve shell 3 corresponding to the step portion 301, and the second bearing member 302 is sleeved and matched with the output shaft of the motor 13 to reduce the friction between the output shaft of the motor 13 and the movable sleeve shell 3.

[0030] The upper opening of the fixed housing 2 is provided so that the movable housing 3 can be assembled in the fixed housing 2, and the inner cavity of the fixed housing 2 is also provided with a battery 27, a circuit board 28, a charging interface 29, a button 30, and an indicator light 31. The battery 27, the motor 13, the charging interface 29, the button 30, and the indicator light 31 are all electrically connected to the circuit board 28 and controlled by it. The charging interface 29, the button 30, and the indicator light 31 are all located on one of the planes 101 of the main body 1. The charging interface 29 is connected to an external power source to charge the battery 27. The user can control the motor 13 by operating the button 30. Preferably, the indicator light 31 is a plurality of arc-shaped lamp bodies distributed in a circular array, and each arc-shaped lamp body is arranged around the button 30 to illuminate the different states of the grinder. The upper cover of the fixed housing 2 is provided with a cover plate 19, and the cover plate 19 cooperates with the inner wall of the main body 1 to form a feed port 11. The cover plate 19 is bolted to the fixed housing 2 to protect the components in the fixed housing 2.

[0031] The cover plate 19 has a rotating hole 1901 through which the adjusting member 4 is rotatably connected, so that the adjusting member 4 can rotate relative to the fixed sleeve shell 2. The upper part of the adjusting member 4 extends out of the outside of the main body 1, and the lower part of the adjusting member 4 extends into the fixed sleeve shell 2 and is threadedly connected to the movable sleeve shell 3.

[0032] A protective sleeve 6 is coaxially arranged on the inner wall of the adjusting ring 5 , and a connecting structure is arranged between the inner wall of the adjusting ring 5 and the protective sleeve 6 . The connecting structure comprises four connecting strips 7 distributed in a ring array, and the gap between two adjacent connecting strips 7 is adapted to the feed port 11 .

[0033] The upper outer wall of the main body 1 is concavely formed with a docking ring groove 102, and the lower inner wall of the adjusting ring 5 is convexly formed with four docking hooks 502 distributed in a ring array, the docking hooks 502 extend circumferentially along the docking ring groove 102, and the docking hooks 502 are snap-fitted into the docking ring groove 102, so that the adjusting ring 5 and the main body 1 are rotatably snap-fitted; the circumferential side wall of the upper part of the adjusting member 4 is provided with a first concave-convex portion 401, and the inner wall of the protective cover 6 is provided with a second concave-convex portion 501, the first concave-convex portion 401 and the second concave-convex portion 501 are concave-convex matched, preferably, the first concave-convex portion 401 is a plurality of strip grooves distributed in a ring array, and the second concave-convex portion 501 is a convex strip portion inserted into the strip groove, so that the protective cover 6 is sleeved and matched with the upper part of the adjusting member 4 and only slides along the axial direction of the adjusting member 4.

[0034] The closing cover 8 is placed on the adjusting ring 5 to cover each feed port 11. A first magnet 23 is provided on the inner wall of the closing cover 8 corresponding to the position of the protective cover 6. A second magnet 24 is provided on the inner wall of the protective cover 6. The magnetic force between the first magnet 23 and the second magnet 24 is an attractive force, which is used to maintain the closed state between the closing cover 8 and the adjusting ring 5.

[0035] An assembly ring 2201 is formed on the edge of the hopper shell 22 and is adapted to the inner wall of the lower opening of the main body 1. A mounting ring 901 is formed on the upper part of the powder bin 9. The mounting ring 901 is sleeved and detachably connected to the assembly ring 2201. A threaded connection is adopted between the outer wall of the mounting ring 901 and the inner wall of the mounting ring 2201 so that the powder layer is reliably connected to the main body 1.

[0036] When the bean grinder is in use, the user disassembles the closing cover 8 to open the feed port 11 so as to pour the bean ingredients to be ground into the grinding chamber 10. Afterwards, the user covers the closing cover 8 and presses the button 30 to start the motor 13. The output shaft of the motor 13 drives the inner blade disc 14 to rotate, so that the bean ingredients are ground into powder under the interaction of the inner blade disc 14 and the outer blade disc 15 and fall into the powder bin 9 through the discharge port 12.

[0037] The fineness of the powder ground by the grinder is adjustable. When adjusting, the user can rotate the adjusting ring 5 to drive the upper part of the adjusting member 4 to rotate with the help of the protective cover 6. The lower part of the adjusting member 4 is threadedly connected with the movable housing 3, so that when the adjusting member 4 rotates, the movable housing 3 and the motor 13 can be driven to move up and down, thereby adjusting the gap between the inner blade disc 14 and the outer blade disc 15. The protective cover 6 is used to protect the upper part of the adjusting member 4 to prevent the powder from adhering to the upper part of the adjusting member 4. Preferably, the outer wall of the adjusting ring 5 is provided with friction patterns 503 and scales 504. The friction patterns 503 are provided so that the user can hold the adjusting ring 5 for rotation operation, and the scales 504 are provided so that the user can control the rotation angle of the adjusting ring 5 more finely. The user can also separate the adjusting ring 5 and the closing cover 8 from the main body 1, and the upper part of the adjusting member 4 extends out of the outside of the main body 1, so that the user can directly turn the upper part of the adjusting member 4 by hand for adjustment.

[0038] A turntable 16 is provided at the lower part of the adjusting member 4, and a plurality of gear slots 1601 distributed in a ring array are provided on the circumferential side wall of the turntable 16, and a guide sleeve 20 is provided on the bottom surface of the cover plate 19, and an abutting portion 21 is provided in the opening of the first end of the guide sleeve 20, and the pressing member 17 is slidably connected to the opening of the second end of the guide sleeve 20, and an elastic structure 18 is provided between the abutting portion 21 and the pressing member 17, and the elastic structure 18 is a spring. The pressing member 17 is driven to extend out of the opening of the second end of the guide sleeve 20 under the action of the elastic structure 18. During the rotation of the adjusting member 4, the pressing member 17 is pressed against the corresponding gear slot 1601 of the turntable 16 under the action of the elastic member, bringing a damping force to the rotational movement of the adjusting ring 5, thereby ensuring the stability of the rotation of the adjusting member 4. The grinder can adjust the fineness of the ground powder more accurately according to the needs, and the adjustment method is more flexible, thereby improving the user experience.

[0039] Of course, the above are only typical examples of the present invention. In addition, the present invention may have many other specific implementations. Any technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention.

Claims

1. A coffee bean grinder, characterized by: The invention comprises a main body (1) with a hollow interior, a fixed sleeve shell (2), a movable sleeve shell (3), an adjusting member (4), an adjusting ring (5) and a closing cover (8); the fixed sleeve shell (2) is fixedly connected to the inner wall of the main body (1), and the outer wall of the fixed sleeve shell (2) cooperates with the inner wall of the main body (1) to form at least one grinding chamber (10); the upper opening of the grinding chamber (10) is a feed port (11), and the lower opening of the grinding chamber (10) is a discharge port (12); The movable sleeve shell (3) is sleeved and matched with the fixed sleeve shell (2) and only slides along the axial direction of the fixed sleeve shell (2); the movable sleeve shell (3) is provided with a motor (13); the output shaft of the motor (13) is detachably connected with an inner cutter disc (14); an outer cutter disc (15) is provided at the discharge port (12); the inner cutter disc (14) is sleeved and matched with the outer cutter disc (15) and is rotatably connected; The lower part of the adjusting member (4) is rotatably connected to the fixed sleeve shell (2) and is threadedly connected to the movable sleeve shell (3); a rotating disk (16) is provided at the lower part of the adjusting member (4); a plurality of gear slots (1601) distributed in a ring array are provided on the circumferential side wall of the rotating disk (16); at least one pressing member (17) is telescopically and movably provided inside the fixed sleeve shell (2); the pressing member (17) is provided with an elastic structure (18) and is pressed against the corresponding gear slot (1601); the upper part of the adjusting member (4) extends out of the outside of the main body (1); The adjusting ring (5) is connected to the main body (1) by a rotatable snap-fit ​​connection, and the adjusting ring (5) is coaxially provided with a protective sleeve (6), the protective sleeve (6) is sleeve-fitted with the upper part of the adjusting member (4) and only slides along the axial direction of the adjusting member (4), and the closing cover (8) is covered on the adjusting ring (5) to cover the feed port (11).

2. A coffee bean grinder according to claim 1, characterized in that: The interior of the fixed sleeve shell (2) is hollow, and the upper cover of the fixed sleeve shell (2) is provided with a cover plate (19), and the cover plate (19) cooperates with the inner wall of the main body (1) to form the feed port (11), and the cover plate (19) is penetrated by a rotating hole (1901) for the adjustment member (4) to be rotatably connected, and the bottom surface of the cover plate (19) is provided with a guide sleeve (20), and an abutment portion (21) is provided in the opening of the first end of the guide sleeve (20), and the tensioning member (17) is slidably connected in the opening of the second end of the guide sleeve (20), and the elastic structure (18) is provided between the abutment portion (21) and the tensioning member (17).

3. The coffee bean grinder according to claim 1, characterized in that: The protective sleeve (6) is coaxially arranged with the adjustment ring (5), and a connection structure is arranged between the inner wall of the adjustment ring (5) and the protective sleeve (6), wherein the connection structure comprises a plurality of connection strips (7) distributed in a ring array, and a gap between two adjacent connection strips (7) is adapted to the feed port (11).

4. A coffee bean grinder according to claim 3, characterized in that: A first magnet (23) is arranged on the inner wall of the closing cover (8) at a position corresponding to the protective cover (6), and a second magnet (24) is arranged on the inner wall of the protective cover (6), and the magnetic force between the first magnet (23) and the second magnet (24) is an attractive force.

5. The coffee bean grinder according to claim 3, characterized in that: The upper outer wall of the main body (1) is concavely formed with a docking ring groove (102), and the lower inner wall of the adjustment ring (5) is convexly formed with at least one docking hook portion (502), the docking hook portion (502) extends along the circumference of the docking ring groove (102), and the docking hook portion (502) is snap-connected to the docking ring groove (102).

6. The coffee bean grinder according to claim 1, characterized in that: The circumferential side wall of the upper part of the adjusting member (4) is provided with a first concave-convex portion (401), and the inner wall of the protective sleeve (6) is provided with a second concave-convex portion (501), and the first concave-convex portion (401) and the second concave-convex portion (501) are matched in a concave-convex manner.

7. The coffee bean grinder according to claim 1, characterized in that: The lower part of the main body (1) is detachably connected to a hopper shell (22), and the discharge port (12) is arranged in the middle part of the hopper shell (22).

8. The coffee bean grinder according to claim 7, characterized in that: It also includes a powder bin (9), wherein the edge of the hopper shell (22) is formed with an assembly ring (2201) that is mutually compatible with the inner wall of the lower opening of the main body (1), and the upper part of the powder bin (9) is formed with a mounting ring (901), and the mounting ring (901) is sleeved and matched with the assembly ring (2201) and is detachably connected.

9. The coffee bean grinder according to claim 1, characterized in that: A guide structure is provided between the fixed sleeve shell (2) and the movable sleeve shell (3), the guide structure comprising an inner groove (25) and an outer convex strip (26), the outer convex strip (26) being slidably connected in the inner groove (25); the inner wall of the fixed sleeve shell (2) is provided with the inner groove (25), and the outer wall of the movable sleeve shell (3) is provided with the outer convex strip (26), or the inner wall of the fixed sleeve shell (2) is provided with the outer convex strip (26), and the outer wall of the movable sleeve shell (3) is provided with the inner groove (25).

10. The coffee bean grinder according to claim 9, characterized in that: A step cavity (201) is formed on the lower inner wall of the fixed sleeve shell (2), and a step portion (301) is formed on the lower outer wall of the movable sleeve shell (3), and the step portion (301) is concavely matched with the step cavity (201); a first bearing component (202) is provided at a position of the fixed sleeve shell (2) corresponding to the step cavity (201), and the first bearing component (202) is sleeve-matched with the output shaft of the motor (13); a second bearing component (302) is provided at a position of the movable sleeve shell (3) corresponding to the step portion (301), and the second bearing component (302) is sleeve-matched with the output shaft of the motor (13).

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