Miniature grinding machine

Abstract

The utility model discloses a miniature grinding machine which comprises a motor and a shell, the motor is arranged at the rear end of the shell, the front end of a rotating shaft of the motor extends to the front end of the shell, an insertion hole is formed in the front end of the rotating shaft in the axial direction, a clamping device is arranged in the shell corresponding to the front end of the rotating shaft, and the clamping device is used for fixing a grinding head inserted into the insertion hole. The rotating shaft replaces a traditional motor shaft, a traditional main shaft and a traditional chuck, a coupling sleeve is omitted, the number of assembling parts is small, assembling is convenient, the length is shortened after assembling, the overall size is reduced, and using is more flexible. The rotating shaft is integrally designed, so that the concentricity is higher, the operation is more stable, and the noise is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of micro electric grinding equipment, in particular to a grinding machine for grinding or polishing in dental medical treatment, nail art industry, mold or jade carving. Background Art

[0002] For the existing micro grinding machine, see Figure 1 As shown, it includes a motor shaft 100, a coupling sleeve 200, a main shaft 300 and a chuck 400 that are connected in sequence for transmission. The chuck 400 clamps the grinding head to realize the rotation of the grinding head driven by the motor 1. For such a micro grinding machine, the number of transmission parts is large, and the length after assembly is relatively long, about 17 cm, resulting in a large overall volume, a large noise during operation, and it is not flexible enough to use. Content of the Utility Model

[0003] The purpose of the utility model is to provide a micro grinding machine with a reduced volume and a reduced noise compared with the existing technical products.

[0004] The purpose of the utility model is achieved as follows.

[0005] A micro grinding machine includes a motor and a housing. The motor is arranged at the rear end of the housing, and the front end of the rotating shaft of the motor extends to the front end of the housing. An insertion hole is axially arranged at the front end of the rotating shaft. A clamping device is arranged in the housing corresponding to the front end of the rotating shaft, and the clamping device is used to fix the grinding head inserted into the insertion hole.

[0006] The rotating shaft of the utility model replaces the traditional motor shaft, main shaft and chuck, omits the coupling sleeve, has fewer assembled parts, is convenient for assembly, shortens the length after assembly, reduces the overall volume, and is more flexible to use. The rotating shaft is integrally designed, has a higher concentricity, runs more stably, and reduces the noise.

[0007] Further, the clamping device includes a tightening sleeve, an elastic member, at least one cross pin and a limiting device. At least one pin hole communicating with the insertion hole is radially arranged at the front end of the rotating shaft. The cross pin is movably arranged in the pin hole. The tightening sleeve is sleeved on the front end of the rotating shaft. A guiding inclined surface is arranged on the inner peripheral surface of the tightening sleeve corresponding to the pin hole. The outer end of the cross pin abuts against the guiding inclined surface. The elastic member has a tendency to push the tightening sleeve to move axially away from the motor along the rotating shaft. When the tightening sleeve moves away from the motor, the guiding inclined surface pushes the cross pin into the insertion hole along the pin hole, and the limiting device restricts the tightening sleeve from continuing to move away from the motor.

[0008] The clamping device has a simple structure, and it is easy to install and disassemble the grinding head.

[0009] Further, the limiting device includes a fixed sleeve, a tightening compression sleeve and a ball. The fixed sleeve is arranged between the housing and the rotating shaft. The tightening compression sleeve is arranged between the fixed sleeve and the tightening sleeve. The fixed sleeve is provided with an installation hole in the radial direction. The ball is arranged in the installation hole. The outer periphery of the tightening compression sleeve is provided with an annular sliding groove in the radial direction. The ball protrudes from the installation hole and extends into the sliding groove. The tightening compression sleeve and the tightening sleeve are abutted against each other to limit the tightening sleeve from continuing to move away from the motor.

[0010] The limiting device does not affect the rotation of the rotating shaft and limits the displacement range of the tightening sleeve.

[0011] Further, a stepped portion is provided on the outer periphery of the rear end of the tightening sleeve. One end face of the stepped portion away from the motor abuts against the rear end face of the tightening compression sleeve.

[0012] The tightening sleeve and the tightening compression sleeve are abutted against each other for limiting. The tightening compression sleeve rolls in contact with the ball as the tightening sleeve rotates, without affecting the rotation of the rotating shaft.

[0013] Further, a first bearing is provided at the front end of the housing and sleeved on the front end of the rotating shaft.

[0014] The front end of the rotating shaft is limited by the first bearing, and the rotation of the rotating shaft is stable.

[0015] Further, an installation groove is provided inside the front end of the housing. The front end of the fixed sleeve limits the first bearing in the installation groove.

[0016] The installation of the first bearing is easy to implement.

[0017] Further, the motor includes a motor housing and a second bearing. The second bearing is provided at the front end of the motor housing and sleeved on the rotating shaft. An installation gap for inserting the rear end of the fixed sleeve is provided between the second bearing and the front end of the motor housing.

[0018] The fixed sleeve is inserted into the installation gap to position the second bearing, and it is also convenient to connect the limiting device, the clamping device, the housing and the motor together.

[0019] Further, the elastic member is a first spring. The first spring is sleeved on the rotating shaft. One end of the first spring abuts against the motor, and one end of the first spring abuts against the tightening sleeve.

[0020] The elastic member has a simple structure and low cost.

[0021] Further, the rotating shaft is provided with an exhaust hole communicating with the jack.

[0022] The exhaust hole discharges the air between the grinding head and the jack, avoiding that when the grinding head is installed, due to the too small gap between the grinding head and the jack, the residual air jacks up the grinding head, causing the grinding head to disengage from the jack.

[0023] Furthermore, the motor includes a motor housing, a rear end cover and a third bearing. The rear end cover is arranged near the rear end of the motor housing. The third bearing is arranged on the rear end cover and is inserted into the rotating shaft. The motor housing extends backward out of the rear end cover. A clamping nut is connected to the rear end of the motor housing. The clamping nut is used to install a rechargeable battery compartment. The battery in the rechargeable battery compartment powers the motor.

[0024] The micro grinder does not require a power cord, making it more convenient and flexible to use.

[0025] In another embodiment, the limiting device also includes a second spring, one end of the second spring is against the motor, and the other end of the second spring is against the tightening sleeve. The elastic force of the second spring causes the tightening sleeve to break away from contact with the tightening sleeve. The motor includes a motor housing, a rear end cover and only a third bearing. The rear end cover is arranged near the rear end of the motor housing. The third bearing is arranged on the rear end cover and is inserted into the rotating shaft. The motor housing extends backward out of the rear end cover. A clamping nut is connected to the rear end of the motor housing. The clamping nut is used to install a rechargeable battery compartment. The battery in the rechargeable battery compartment powers the motor.

[0026] The rotating shaft is rotated and positioned only by the third bearing and the first bearing, so the installation is easier and the structure is simpler. During operation, the second spring separates the tightening sleeve from the tightening sleeve to avoid friction between the tightening sleeve and the tightening sleeve.

[0027] The utility model's rotating shaft replaces the traditional motor shaft, spindle, and chuck, omitting the coupling sleeve. This reduces the number of assembly parts and facilitates assembly. After assembly, the micro-grinder is approximately 3 cm shorter than traditional micro-grinders, reducing its overall size and making it more flexible to use. The integrated rotating shaft design improves concentricity, stabilizes operation, and reduces noise. The clamping device has a simple structure, making the grinding head easy to install and remove. The three-bearing design reduces assembly complexity. An exhaust port exhausts air between the grinding head and the socket, preventing the grinding head from falling out of the socket. The micro-grinder does not require a power cord, making it more convenient and flexible to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the cross-sectional structure of an existing micro-grinding machine.

[0029] Figure 2 It is a schematic diagram of the three-dimensional structure of embodiment 1.

[0030] Figure 3 This is a schematic cross-sectional view of the first embodiment.

[0031] Figure 4 This is a schematic diagram of the decomposition structure of Example 1.

[0032] Figure 5 This is another schematic diagram of the decomposed structure of Example 1.

[0033] Figure 6 This is a schematic cross-sectional view of the second embodiment. Detailed implementation mode

[0034] The following further describes the present utility model in conjunction with the accompanying drawings and embodiments.

[0035] Embodiment 1, see Figure 2-5 As shown, a micro grinder includes a motor 1, a housing 2, and a clamping device 3.

[0036] The motor 1 includes a rotating shaft 10, a motor housing 11, a second bearing 12, a rear end cover 13, a third bearing 14, a stator 15, and a rotor 16. The stator 15 is fixed inside the motor housing 11, the rotor 16 is sleeved on the rotating shaft 10, and the rotor 16 rotates inside the stator 15. The second bearing 12 is provided at the front end of the motor housing 11 and is sleeved on the rotating shaft 10. There is an installation gap 18 between the second bearing 12 and the front end of the motor housing 11. The rear end cover 13 is provided at the rear end of the motor housing 11 close to the rear end. The third bearing 14 is arranged on the rear end cover 13 and is sleeved on the rotating shaft 10. The rear end of the motor housing 11 extends out of the rear end cover 13, and a compression nut 17 is connected to the rear end of the motor housing 11. The compression nut 17 is used to install a charging battery compartment, and the battery in the charging battery compartment supplies power to the motor 1. Preferably, the compression nut 17 is also used to install a control circuit board. The control circuit board is electrically connected to the battery in the charging battery compartment, and the control circuit board is connected to a wireless charging module (not shown in the figure). The wireless charging module can wirelessly charge the battery in the charging battery compartment. Preferably, the motor 1 is a brushless motor.

[0037] The motor 1 is arranged at the rear end of the housing 2. The front end of the rotating shaft 10 of the motor 1 extends to the front end of the housing 2. An insertion hole 101 is axially provided at the front end of the rotating shaft 10, and three pin holes 102 communicating with the insertion hole 101 are radially provided at the front end of the rotating shaft 10. The three pin holes 102 are evenly spaced. An exhaust hole 103 communicating with the insertion hole 101 is radially provided on the rotating shaft 10. The exhaust hole 103 is located between the pin hole 102 and the motor 1.

[0038] The clamping device 3 includes a tightening sleeve 4, an elastic member 5, three cross pins 6, and a limiting device 7. Each cross pin 6 is movably arranged in a pin hole 102. The tightening sleeve 4 is sleeved on the front end of the rotating shaft 10. A guiding inclined surface 41 corresponding to the pin hole 102 is provided on the inner peripheral surface of the front end of the tightening sleeve 4, and the outer end of the cross pin 6 abuts against the guiding inclined surface 41. The elastic member 5 has a tendency to push the tightening sleeve 4 axially away from the motor 1 along the rotating shaft 10. When the tightening sleeve 4 moves away from the motor 1, the guiding inclined surface 41 pushes the cross pin 6 into the insertion hole 101 along the pin hole 102, and the limiting device 7 restricts the tightening sleeve 4 from continuing to move away from the motor 1. Among them, the elastic member 5 is a first spring, the first spring is sleeved on the rotating shaft 10, one end of the first spring abuts against the third bearing 14 of the motor 1, and one end of the first spring abuts against the tightening sleeve 4.

[0039] The limiting device 7 includes a fixed sleeve 8, a tightening compression sleeve 9, and a ball 71. The fixed sleeve 8 is disposed between the housing 2 and the rotating shaft 10. The tightening compression sleeve 9 is disposed between the fixed sleeve 8 and the tightening sleeve 4. The fixed sleeve 8 is provided with an installation hole 81 in the radial direction. The ball 71 is disposed in the installation hole 81. The outer periphery of the tightening compression sleeve 9 is provided with an annular sliding groove 91 in the radial direction. The outer end of the ball 71 abuts against the housing 2. The ball 71 protrudes out of the installation hole 81 and extends into the sliding groove 91. The outer periphery of the rear end of the tightening sleeve 4 is provided with a stepped portion 42. The end face of the stepped portion 42 away from the motor 1 abuts against the rear end face of the tightening compression sleeve 9 to limit the tightening sleeve 4 from continuing to move away from the motor 1. Preferably, the installation hole 81 is strip-shaped and is inclined along the axial direction of the fixed sleeve 8. The ball 71 and the tightening compression sleeve 9 can move back and forth within a certain range in the axial direction of the rotating shaft 10 through the installation hole 81, avoiding hard contact between the tightening sleeve 4 and the tightening compression sleeve 9.

[0040] An installation groove 21 and a first bearing 22 are provided inside the front end of the housing 2. The first bearing 22 is sleeved on the front end of the rotating shaft 10. The front end of the fixed sleeve 8 abuts against the first bearing 22, so that the first bearing 22 is limited in the installation groove 21. In this embodiment, the housing 2 is composed of two front and rear sections. The housing 2 and the motor housing 11 can be detachably connected or integrally connected, such as being integrally formed by ultrasonic welding.

[0041] During installation, the clamping device 3 is pre-installed on the rotating shaft 10 of the motor 1, that is, the rear end of the fixed sleeve 8 is inserted into the installation gap 18 for positioning, and then the housing 2 is sleeved outside the clamping device 3. The first bearing 22 can be installed on the rotating shaft 10 after the clamping device 3 is installed, or can be directly installed into the housing 2.

[0042] The mounting shaft of the grinding head is inserted into the jack 101. The mounting shaft presses the cross pin 6 to move outward, and then uses the guiding inclined surface 41 to push the tightening sleeve 4 towards the motor 1 and compress the elastic member 5. When the mounting shaft is inserted to a sufficient length and then released, the elastic member 5 pushes the tightening sleeve 4 towards the grinding head until the tightening sleeve 4 abuts against the tightening compression sleeve 9. The guiding inclined surface 41 of the tightening sleeve 4 presses the cross pin 6 to move inward to clamp the mounting shaft, thereby achieving the purpose of fixing the grinding head. In this way, when the motor 1 operates, the rotating shaft 10 rotates to drive the grinding head to rotate.

[0043] The micro-grinding machine of the present utility model is applicable to places with small spaces and fine processing, such as grinding and polishing teeth in dental medicine, grinding and polishing nails in the nail art industry, mold polishing, or jade carving and grinding, etc. The micro-grinding machine has the advantages of small volume, high speed, good stability, almost no vibration, can be operated with one hand, and is not easy to cause fatigue. By replacing the grinding head, functions such as carving, engraving, drilling, grinding, polishing, and lapping can be achieved, and the workpiece can reach the effects of rough carving, fine grinding, and high mirror surface brightness.

[0044] Example two, see Figure 6As shown, the difference from the first embodiment is that the limiting device 7 further includes a second spring 72. One end of the second spring 72 abuts against the motor 1, and the other end of the second spring 72 abuts against the tightening bushing 9. The elastic force of the second spring 72 causes the tightening bushing 9 to disengage from contact with the tightening sleeve 4. During operation, after the elastic forces of the first spring and the second spring 72 are released, there is a gap between the tightening bushing 9 and the tightening sleeve 4. When the tightening sleeve 4 rotates with the rotating shaft 10, it will not drive the tightening bushing 9 to rotate, avoiding friction between the tightening sleeve 4 and the tightening bushing 9.

[0045] The motor 1 includes a motor housing 11, a rear end cover 13, and only a third bearing 14. The rear end cover 13 is provided at the rear end of the motor housing 11 close to the rear end. The third bearing 14 is disposed on the rear end cover 13 and sleeved on the rotating shaft 10. The motor housing 11 extends backward beyond the rear end cover 13. A compression nut 17 is connected to the rear end of the motor housing 11. A rechargeable battery compartment 23 is installed behind the compression nut 17. The battery in the rechargeable battery compartment 23 supplies power to the motor 1. A limiting piece 101 is circumferentially provided on the rotating shaft 10. The rear end of the first spring abuts against the limiting piece 101, and the front end of the first spring abuts against the tightening sleeve 4.

[0046] A control circuit board 24 is installed in the rechargeable battery compartment 23. The control circuit board 24 is electrically connected to the battery in the rechargeable battery compartment 23. The rotating shaft 10 is positioned only by the first bearing 22 and the third bearing 14, which is easier to ensure the coaxiality of the first bearing 22 and the third bearing 14 and facilitates assembly.

[0047] In the present utility model, terms such as first and second are used, which do not represent any order, quantity, or importance, but are only used for distinction.

[0048] In the present utility model, terms such as one and a kind are used, which do not represent a limitation of quantity, but represent the existence of at least one mentioned object.

[0049] In the present utility model, terms indicating directions or positions such as front end, rear end, top, bottom, side, longitudinal, transverse, middle, center, outer, inner, horizontal, vertical, left, right, upper, lower, etc. mean relative positions, rather than absolute positions. For example, the front end refers to the end close to the grinding head, and the front end refers to the end far from the grinding head.

[0050] In the present utility model, terms such as approximately, overall, approximate, similar, etc. are limiting terms used to indicate the existence of features but allowing certain deviations. The amount of allowable deviation may vary depending on the specific background.

Claims

1. A micro grinder, comprising a motor (1) and a housing (2), characterized in that, The motor (1) is arranged at the rear end of the housing (2). The front end of the rotating shaft (10) of the motor (1) extends to the front end of the housing (2). An insertion hole (101) is axially provided at the front end of the rotating shaft (10). A clamping device (3) is provided in the housing (2) corresponding to the front end of the rotating shaft (10). The clamping device (3) is used to fix the grinding head inserted into the insertion hole (101). The clamping device (3) includes a tightening sleeve (4), an elastic member (5), at least one cross pin (6) and a limiting device (7). At least one pin hole (102) communicating with the insertion hole (101) is radially provided at the front end of the rotating shaft (10). The cross pin (6) is movably arranged in the pin hole (102). The tightening sleeve (4) is sleeved on the front end of the rotating shaft (10). A guiding inclined surface (41) is provided on the inner peripheral surface of the tightening sleeve (4) corresponding to the pin hole (102). The outer end of the cross pin (6) abuts against the guiding inclined surface (41). The elastic member (5) has a tendency to push the tightening sleeve (4) to move axially away from the motor (1) along the rotating shaft (10). When the tightening sleeve (4) moves away from the motor (1), the guiding inclined surface (41) pushes the cross pin (6) into the insertion hole (101) along the pin hole (102). The limiting device (7) restricts the tightening sleeve (4) from continuing to move away from the motor (1).

2. The micro grinder according to claim 1, characterized in that, The limiting device (7) includes a fixing sleeve (8), a tightening compression sleeve (9) and a ball (71). The fixing sleeve (8) is arranged between the housing (2) and the rotating shaft (10). The tightening compression sleeve (9) is arranged between the fixing sleeve (8) and the tightening sleeve (4). The fixing sleeve (8) is provided with a mounting hole (81) in the radial direction. The ball (71) is arranged in the mounting hole (81). An annular sliding groove (91) is provided on the outer periphery of the tightening compression sleeve (9) in the radial direction. The ball (71) protrudes from the mounting hole (81) and extends into the sliding groove (91). The tightening compression sleeve (9) abuts against the tightening sleeve (4) to restrict the tightening sleeve (4) from continuing to move away from the motor (1).

3. The micro grinder according to claim 2, characterized in that, A step portion (42) is provided on the outer periphery of the rear end of the tightening sleeve (4). One end surface of the step portion (42) away from the motor (1) abuts against the rear end surface of the tightening compression sleeve (9).

4. The miniaturized grinding machine according to claim 2, characterized in that, A first bearing (22) sleeved on the front end of the rotating shaft (10) is provided at the front end of the housing (2).

5. The micro-polisher according to claim 4, characterized in that, An installation groove (21) is provided inside the front end of the housing (2). The front end of the fixing sleeve (8) limits the first bearing (22) in the installation groove (21).

6. The micro-polishing machine according to claim 4, characterized in that, The motor (1) includes a motor housing (11) and a second bearing (12). The second bearing (12) is arranged at the front end of the motor housing (11) and sleeved on the rotating shaft (10). An installation gap (18) for inserting the rear end of the fixing sleeve (8) is provided between the second bearing (12) and the front end of the motor housing (11).

7. The mini grinder according to claim 1, characterized in that, The elastic member (5) is a first spring. The first spring is sleeved on the rotating shaft (10). One end of the first spring abuts against the motor (1), and the other end of the first spring abuts against the tightening sleeve (4).

8. The micro grinder according to claim 1, characterized in that, An exhaust hole (103) communicating with the insertion hole (101) is radially provided on the rotating shaft (10).

9. The micro-polisher according to any one of claims 1 or 6, characterized in that, The motor (1) includes a motor housing (11), a rear end cover (13) and a third bearing (14). The rear end cover (13) is provided at the rear end of the motor housing (11). The third bearing (14) is disposed on the rear end cover (13) and sleeved on the rotating shaft (10). The motor housing (11) extends backward beyond the rear end cover (13). A compression nut (17) is connected to the rear end of the motor housing (11). The compression nut (17) is used for installing a charging battery compartment. The battery in the charging battery compartment supplies power to the motor (1).

10. The micro-polisher according to claim 2 or 4, characterized in that, The limiting device (7) further includes a second spring (72). One end of the second spring (72) abuts against the motor (1), and the other end of the second spring (72) abuts against the tightening sleeve (9). The elastic force of the second spring (72) causes the tightening sleeve (9) to disengage from contact with the tightening collar (4). The motor (1) includes a motor housing (11), a rear end cover (13) and only the third bearing (14). The rear end cover (13) is provided at the rear end of the motor housing (11). The third bearing (14) is disposed on the rear end cover (13) and sleeved on the rotating shaft (10). The motor housing (11) extends backward beyond the rear end cover (13). A compression nut (17) is connected to the rear end of the motor housing (11). The compression nut (17) is used for installing a charging battery compartment. The battery in the charging battery compartment supplies power to the motor (1).

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