CN110547845B - Grinding handle power transmission mechanism with adjustable swing angle and grinding tool - Google Patents

Abstract

The invention provides a grinding handle power transmission mechanism with an adjustable swing angle and a grinding cutter, which comprise an input shaft and an output shaft which are arranged in a shell, wherein an intermediate transmission part for transmitting power is arranged between the input shaft and the output shaft, an eccentric transmission part is eccentrically arranged on the input shaft, the intermediate transmission part is provided with an input part matched with the eccentric transmission part of the input shaft and an output part matched with the output shaft, the eccentric transmission part and the input part convert unidirectional rotation motion of the input shaft into reciprocating swing of the intermediate transmission part, and the output part drives the output shaft to swing reciprocally; the shell is also provided with an adjusting structure for adjusting the relative distance between one of the middle transmission piece, the input shaft and the output shaft and the other two. The invention converts continuous unidirectional circular rotation motion into reciprocating swing within a certain angle range in the circumferential direction, thereby avoiding the cutter head from winding soft tissues; and can realize the regulation of swing angle, adapt to the demand of different swing amplitudes.

Description

Power transmission mechanism of grinding handle with adjustable swing angle and grinding tool

Technical Field

The invention belongs to the technical field of medical devices, and in particular relates to a grinding handle power transmission mechanism with adjustable swing angle and a grinding tool.

Background technique

In surgical operations, medical grinding tools are usually used to grind bone tissue or soft tissue in the human body. Existing grinding tools generally use a power handle to drive the grinding head/knife head to rotate at high speed for grinding. Since the grinding head/knife head performs 360° circular rotation, there is a risk of entanglement with surrounding soft tissue during the operation. Under high-speed rotation, once the soft tissue is entangled, it will be twisted off; in particular, the degree of damage to soft tissues such as blood vessels and nerves is high. Once the edge of the grinding head/knife head entangles the nerves, it will cause great harm to the patient.

Although grinding tools capable of reciprocating swing are now available, the swing angle range is not adjustable, and thus the adaptability is poor.

Summary of the invention

In view of the above-mentioned deficiencies of the prior art, an object of the present invention is to provide a grinding handle power transmission mechanism with adjustable swing angle, which changes the circular motion into reciprocating swing, prevents the cutter head from being entangled with soft tissue, and can adjust the swing angle.

To achieve the above purpose and other related purposes, the technical solution of the present invention is as follows:

A power transmission mechanism for a grinding handle with an adjustable swing angle is used to transmit the power of a power handle to a cutter head, comprising an input shaft for receiving power and an output shaft for connecting to the cutter head, arranged in a shell, wherein an intermediate transmission member for transmitting power is arranged between the input shaft and the output shaft, an eccentric transmission member is eccentrically arranged on the input shaft, the intermediate transmission member has an input part that cooperates with the eccentric transmission member of the input shaft and an output part that cooperates with the output shaft, the eccentric transmission member and the input part convert the unidirectional rotational motion of the input shaft into reciprocating swing of the intermediate transmission member, and the output part transmits the reciprocating swinging power to the output shaft, driving the output shaft to swing reciprocatingly; an adjustment structure is also arranged on the shell, and the adjustment structure is used to drive the intermediate transmission member, the input shaft or the output shaft to offset in a direction perpendicular to the axis of the input shaft, and adjust the relative distance between one of the intermediate transmission member, the input shaft and the output shaft and the other two.

By adopting the above structure, the circular rotation mode of the traditional cutter head is changed, and the continuous unidirectional circular rotation motion is converted into reciprocating swing within a certain angle range in the circumferential direction. When the cutter head is connected to the power output shaft, the cutter head reciprocates in the circumferential direction of the power output shaft around the center line of the power output shaft, thereby preventing the cutter head from entangled with soft tissue; and the soft tissue has a certain elasticity, and when the cutter head reciprocates, it can avoid the cutter head, reducing damage to the soft tissue. In addition, since an intermediate transmission member is provided between the input shaft and the output shaft, and the offset distance between the input shaft and the intermediate transmission member and/or between the output shaft and the intermediate transmission member can be changed by adjusting the input shaft, the output shaft or the intermediate transmission member, the swing amplitude during the transmission process can be changed, thereby realizing the adjustment of the swing angle to meet the needs of different swing amplitudes.

Optionally, the relative distance between one of the intermediate transmission member, the input shaft and the output shaft and the other two can be adjusted in one of the following ways: adjusting the offset distance of the swing center of the intermediate transmission member relative to the axis of the input shaft and the axis of the output shaft, adjusting the offset distance of the axis of the input shaft relative to the swing center of the intermediate transmission member, adjusting the offset distance of the eccentric transmission member relative to the swing center of the intermediate transmission member, adjusting the offset distance of the swing center of the intermediate transmission member relative to the axis of the output shaft, adjusting the offset distance of the axis of the output shaft relative to the swing center of the intermediate transmission member, or adjusting the offset distance of the output part relative to the axis of the output shaft.

Optionally, the input shaft is installed in the housing through a first bearing, and the eccentric transmission member is a first transmission shaft eccentrically arranged at the output end of the input shaft, and a second bearing is sleeved on the first transmission shaft.

Optionally, the intermediate transmission member includes an intermediate shaft, the input portion is a pair of first ear plates arranged at the input end of the intermediate shaft, and the second bearing is located between the two first ear plates and is tangent to the second ear plate.

Optionally, the output portion is a second transmission shaft arranged at the output end of the intermediate shaft, the second transmission shaft is eccentrically arranged relative to the intermediate shaft, and a third bearing is sleeved on the second transmission shaft.

Optionally, two second ear plates are arranged opposite to the input end of the output shaft, and the third bearing is located between the two second ear plates and is tangent to the second ear plates.

Optionally, the axes of the input shaft and the output shaft coincide, or the input end of the input shaft is connected to a power access shaft via a reduction mechanism, the input shaft is mounted on the housing via an eccentric bearing seat, the axes of the output shaft and the power access shaft coincide, and the axis of the input shaft is offset relative to the axis of the output shaft.

Optionally, the adjustment structure includes a support seat for installing an intermediate transmission member and an adjusting component for moving the support seat along an axial direction perpendicular to the input shaft. The intermediate transmission member is rotatably mounted on the support seat, and its rotation center line is parallel to the axis of the input shaft. When the adjusting component is operated, the support seat drives the intermediate transmission member to be offset relative to the input shaft and/or the output shaft.

Optionally, the support seat is an adjusting shaft installed on the shell vertically relative to the input shaft, one end of the adjusting shaft has an external thread, the adjusting component is a nut rotatably arranged on the shell along its own axis, the nut is sleeved on the threaded section of the adjusting shaft, and the shell limits the axial movement of the nut on the adjusting shaft.

Optionally, a limiting structure for limiting the rotation of the support seat is provided on the shell.

Optionally, a mounting groove is provided on the inner wall of the shell, the first end of the adjusting shaft cooperates with the adjusting component, the second end of the adjusting shaft extends into the mounting groove, an elastic element is provided in the mounting groove, and the elastic element abuts against the second end of the adjusting shaft.

Optionally, a window for installing the support seat is opened on the shell, a cover plate with a through hole is installed on the window, and the nut is installed in the through hole of the cover plate and extends out of the cover plate.

The invention also provides a grinding tool, comprising the grinding handle power transmission mechanism with adjustable swing angle.

As described above, the beneficial effects of the present invention are: the present invention changes the circular rotational motion mode of the traditional cutter head, and converts the continuous rotational motion into a circular reciprocating swing within a certain angle range. When the cutter head is connected to the power output shaft, the cutter head swings reciprocatingly in the circumferential direction around the center line of the power output shaft, thereby avoiding the cutter head from entangled with the soft tissue; and the soft tissue has a certain elasticity, and can avoid the cutter head when the cutter head swings reciprocatingly, thereby reducing damage to the soft tissue.

In addition, since an intermediate transmission member is provided between the input shaft and the output shaft, and the position of the input shaft, the output shaft or the intermediate transmission member in the direction perpendicular to the handle axis can be adjusted through an adjustment structure, the relative offset between the input shaft and the intermediate transmission member or between the output shaft and the intermediate transmission member can be changed, thereby changing the swing amplitude during the transmission process, and then realizing the adjustment of the swing angle to meet the needs of different swing amplitudes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the installation of a power transmission mechanism on a handle housing in an embodiment of the present invention;

FIG2 is a partial enlarged view of FIG1;

FIG3 is a schematic diagram of a transmission structure of a power transmission mechanism in an embodiment of the present invention;

4 and 5 are exploded views of the power transmission mechanism in the embodiment of the present invention;

FIG6 is a schematic structural diagram of an intermediate transmission member in an embodiment of the present invention;

FIG7 is a schematic diagram of the structure of an output shaft in an embodiment of the present invention;

FIG8 is a schematic structural diagram of a support base according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of the structure of the cover plate in an embodiment of the present invention.

FIG. 10 is a schematic diagram of another implementation of the power transmission mechanism in an embodiment of the present invention.

Part Number Description:

100-housing; 101-mounting groove; 200-input shaft; 201-first transmission shaft; 202-second bearing; 203-bearing seat; 204-first bearing; 300-intermediate shaft; 301-first ear plate; 302-second transmission shaft; 303-third bearing; 304-fifth bearing; 400-output shaft; 401-second ear plate; 402-fourth bearing; 500-driving claw; 600-support seat; 601-threaded section; 602-nut; 603-elastic element; 604-through hole; 605-rotation limit block; 606-knob; 700-power access shaft; 800-reduction mechanism; 900-cover plate; 901-limiting groove; 902-limiting step.

Detailed ways

The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

The front and back directions in this example are that when the grinding tool is working, the side facing the patient is the front, and the side away from the patient is the back.

Example

As shown in Figures 1 to 5, a power transmission mechanism of a grinding handle with adjustable swing angle is provided, wherein the grinding tool includes a power handle, a cutter head for grinding and other components. The power transmission mechanism of the present invention is used to transmit the power of the power handle to the cutter head, and the power transmission mechanism is directly or indirectly connected to the drive motor of the power handle.

The power transmission mechanism includes an input shaft 200 and an output shaft 400 arranged in the housing 100, wherein the input shaft 200 is used to receive power (such as the rotational power transmitted directly or indirectly by the motor), and the output shaft 400 is used to connect with the cutter head to transmit the reciprocating swing to the cutter head; the key is that an intermediate transmission member for transmitting power is arranged between the input shaft 200 and the output shaft 400, an eccentric transmission member is eccentrically arranged on the input shaft 200, and the eccentric transmission member is eccentrically arranged relative to the axis of the input shaft 200, and the intermediate transmission member has an input part that cooperates with the eccentric transmission member of the input shaft 200. When working, the input shaft 200 performs unidirectional continuous rotational motion, and the matching structure of the eccentric transmission member and the input part converts the unidirectional rotational motion of the input shaft 200 into the reciprocating swing of the intermediate transmission member. The intermediate transmission member also has an output part that cooperates with the output shaft 400, and the output part reciprocates with the intermediate transmission member, and transmits the reciprocating swing power to the output shaft 400, driving the output shaft 400 to reciprocate.

The axis of the input shaft 200 is parallel to or coincides with the axis of the output shaft 400 , and the swing center line of the intermediate transmission member is parallel to the axes of the input shaft 200 and the output shaft 400 .

Among them, the housing 100 is also provided with an adjustment structure, which is used to drive the intermediate transmission member, the input shaft 200 or the output shaft 400 to shift in a direction perpendicular to the axis of the input shaft 200, that is, to shift in the radial direction of the input shaft 200 or the output shaft 400, so as to adjust the relative distance between the intermediate transmission member, the input shaft 200 and the output shaft 400 and the other two; since the swing amplitude is mainly affected by two transmission links: the transmission between the input shaft 200 and the intermediate connecting member, and the transmission between the intermediate connecting member and the output shaft 400; therefore, the relative distance between the intermediate transmission member and the input shaft 200 (the relative distance in the direction perpendicular to the axial direction of the input shaft 200) and/or the relative distance between the intermediate transmission member and the output shaft 400 (the relative distance in the direction perpendicular to the axial direction of the input shaft 200) is mainly adjusted.

By adopting the above structure, the circular rotation mode of the traditional cutter head is changed, and the continuous unidirectional circular rotation motion is converted into a reciprocating swing within a certain angle range in the circumferential direction. When the cutter head is connected to the power output shaft 400, the cutter head reciprocates in the circumferential direction of the power output shaft 400 around the center line of the power output shaft 400, thereby preventing the cutter head from entangled with the soft tissue; and the soft tissue has a certain elasticity, and when the cutter head reciprocates, it can avoid the cutter head, reducing the damage to the soft tissue. In addition, since an intermediate transmission member is provided between the input shaft 200 and the output shaft 400, and the input shaft 200, the output shaft 400 or the intermediate transmission member can be adjusted by adjusting the structure to change the offset distance between the input shaft 200 and the intermediate transmission member and/or between the output shaft 400 and the intermediate transmission member, thereby changing the swing amplitude during the transmission process, and then realizing the adjustment of the swing angle to meet the needs of different swing amplitudes.

The relative distance between the intermediate transmission member and the input shaft 200 may be adjusted by one or more of the following methods:

The input shaft 200 and the output shaft 400 are stationary, so that the intermediate transmission member is offset in parallel with respect to the input shaft 200; that is, the offset of the swing center of the intermediate transmission member relative to the axis of the input shaft 200 and the axis of the output shaft 400 is changed; or, the intermediate transmission member and the output shaft 400 are stationary, so that the input shaft 200 is offset relative to the intermediate transmission member; the offset of the axis of the input shaft 200 relative to the swing center of the intermediate transmission member is changed, and of course, the relative distance between the input shaft 200 and the output shaft 400 is changed at the same time; or, the intermediate transmission member and the input shaft 200 are both stationary, and the offset of the eccentric transmission member relative to the swing center of the intermediate transmission member is adjusted, that is, the position of the eccentric transmission member in the radial direction of the input shaft 200 is adjusted. In this way, the swing angle between the input shaft 200 and the intermediate transmission member is changed, and the swing angle of the output shaft 400 is indirectly changed.

The adjustment of the relative distance between the intermediate transmission member and the output shaft 400 may be carried out in one or more of the following ways: the input shaft 200 and the output shaft 400 are kept stationary, the intermediate transmission member is offset relative to the output shaft 400, and the offset of the swing center of the intermediate transmission member relative to the axis of the output shaft 400 is adjusted; or, the intermediate transmission member and the input shaft 200 are kept stationary, the output shaft 400 is offset relative to the intermediate transmission member, that is, the offset of the axis of the output shaft 400 relative to the swing center of the intermediate transmission member is adjusted; or both the intermediate transmission member and the output shaft 400 are kept stationary, and the offset of the center of the output part relative to the axis of the output shaft 400 is adjusted, that is, the radial position of the output part in the intermediate transmission member is changed.

In this example, the swing center line of the intermediate transmission member is changed for illustration, and the principles of other methods are the same:

As shown in Figures 2 to 7, specifically, the input shaft 200 is installed in the housing 100 through a first bearing 204 and a bearing seat 203, and the axial position is limited by a clamping ring or the like; the eccentric transmission member is a first transmission shaft 201 arranged on the output end face of the input shaft 200, the first transmission shaft 201 is parallel to the input shaft 200, the axis of the first transmission shaft 201 is offset relative to the axis of the input shaft 200, and a second bearing 202 is mounted on the first transmission shaft 201.

The intermediate transmission member includes an intermediate shaft 300, the input end of the intermediate shaft 300 is provided with the input part, and the output end is provided with the output part, wherein the input part is a pair of first ear plates 301 provided at the input end of the intermediate shaft 300 (or a radial through groove is provided on the end surface of the input end of the intermediate shaft 300, and the two side walls of the through groove are in contact with the outer ring of the second bearing 202), the two first ear plates 301 are arranged opposite to each other, the second bearing 202 is located between the two first ear plates 301, and contacts with the first ear plate 301 when the first transmission shaft 201 rotates, and drives the intermediate shaft 300 to swing back and forth through the first ear plate 301. The second bearing 202 reduces the friction and impact force when the first transmission shaft 201 and the first ear plate 301 generate relative motion.

The output part is a second transmission shaft 302 arranged on the output end face of the intermediate shaft 300 . The second transmission shaft 302 is parallel to the intermediate shaft 300 . The second transmission shaft 302 is eccentrically arranged relative to the intermediate shaft 300 . A third bearing 303 is mounted on the second transmission shaft 302 .

The output shaft 400 is installed in the housing 100 through the fourth bearing 402, and two second ear plates 401 are relatively arranged at the input end of the output shaft 400 (or a radial through groove is opened on the end face of the input end of the output shaft 400, and the two side walls of the through groove are in contact with the outer ring of the third bearing 303). The third bearing 303 is located between the two second ear plates 401 and is in contact with at least one second ear plate 401, usually in contact with both ear plates, to reduce impact, so that when the second transmission shaft 302 swings, the output shaft 400 is driven to swing through the third bearing 303 and the second ear plate 401.

In this example, in order to achieve deceleration at the input end, a deceleration mechanism 800 and a power access shaft 700 are also provided at the input end of the input shaft 200, wherein the power access shaft 700 is directly or indirectly connected to the output end of the motor, and the axis of the power access shaft 700 coincides with the axis of the output shaft 400; the bearing seat 203 is an eccentric structure, and after the input shaft 200 is installed on the bearing seat 203, the axis of the input shaft 200 is offset relative to the power access shaft 700, and the deceleration mechanism 800 is a meshing gear set, one of which is connected to the power access shaft 700, and the other is fixed to the input shaft 200, which is an internal meshing gear set in this example, as shown in Figures 1 and 2.

In another embodiment, the axes of the input shaft 200 and the output shaft 400 coincide with each other, and there is no reduction mechanism 800 and the power input shaft 700, as shown in FIG. 10 .

To facilitate docking with the cutter head, the output end of the output shaft 400 is connected with a synchronously swinging driving claw 500 .

As shown in Figures 2, 8 and 9, the adjustment structure includes a support seat 600 for installing the intermediate transmission member and an adjustment component for moving the support seat 600 along an axial direction perpendicular to the input shaft 200. The intermediate transmission member can be rotatably installed on the support seat 600 along its own axis, and its rotation center line is parallel to the axis of the input shaft 200. In this example, a through hole 604 is opened on the support seat 600 along the axial direction of the input shaft 200. The intermediate transmission member is a columnar structure (i.e., the intermediate shaft 300 mentioned above), and the intermediate shaft 300 is installed in the through hole 604 through a fifth bearing 304 and is axially limited; when the adjustment component is operated, the support seat 600 drives the intermediate transmission member to deviate relative to the input shaft 200 and the output shaft 400, thereby changing the positional relationship between the first transmission shaft 201 and the first ear plate 301, and between the second transmission shaft 302 and the second ear plate 401 of the output shaft 400, so as to achieve the purpose of changing the swing angle.

The support base 600 and the adjustment component can be adjusted by means of threads or teeth, such as a screw nut, a gear rack, a worm gear, etc. Of course, the support base 600 can also be pulled out and locked by a pin and a hole. In this example, the screw nut structure is used as an example.

As shown in FIG. 2 , the support seat 600 is an adjustment shaft vertically mounted on the housing 100 relative to the input shaft 200. In the figure, the upper end of the adjustment shaft has a threaded section 601, and the adjustment shaft can move up and down in the housing 100 (in the position shown in the figure). The adjustment component is a nut 602 rotatably arranged on the housing 100 along its own axis. The nut 602 is sleeved on the threaded section 601 of the adjustment shaft. The housing 100 limits the up and down movement of the nut 602. When the nut 602 is screwed, the nut 602 only rotates and does not move up and down, so that the adjustment shaft can move up and down to adjust the position of the intermediate shaft 300. For the convenience of screwing, a knob 606 is fixedly mounted on the nut 602.

In order to prevent the adjusting shaft from rotating along its own axis when the nut 602 rotates, a limiting structure for limiting the self-rotation of the adjusting shaft is provided on the housing 100. Specifically, a flat groove can be provided on the housing 100, and a flat block matching the groove can be provided on the adjusting shaft to prevent the rotation thereof. In this example, a non-circular limiting block 605 is provided on the adjusting shaft, and a limiting groove 901 is correspondingly provided on the housing 100.

Specifically, the housing 100 is provided with a window (the top of the housing 100 in FIG. 2 ) for the support seat 600 to be installed, and a cover plate 900 is fixedly and sealedly installed on the window. There is a through hole in the middle of the cover plate 900, and the nut 602 is installed in the through hole of the cover plate 900, and the top extends out of the cover plate 900. In this example, a limiting groove 901 is arranged on the inner side of the cover plate 900, and the rotation limiting block 605 extends into the limiting groove 901; a limiting step 902 is arranged at the outer end of the through hole of the cover plate 900, and the nut 602 is installed into the through hole from the inner side of the cover plate 900, and the boss of the outer wall of the nut 602 is against the limiting step 902 to prevent the nut 602 from sliding out of the cover plate 900, thereby realizing axial limiting. Sealing rings are respectively arranged between the nut 602 and the cover plate 900, and between the cover plate 900 and the housing 100.

In one embodiment, in order to prevent the end of the adjusting shaft (the lower end in FIG. 2 ) away from the nut 602 from swinging after adjustment, a mounting groove 101 is provided on the inner wall at the bottom of the shell 100, the first end of the adjusting shaft (the upper end in FIG. 2 ) cooperates with the nut 602, and the second end (the lower end) of the adjusting shaft extends into the mounting groove 101, and an elastic element 603 is provided in the mounting groove 101, and the elastic element 603 abuts against the second end of the adjusting shaft, thereby ensuring that the adjusting shaft is tightly abutted at any adjustment position to prevent swinging; in this example, a hole is provided on the end face of the second end of the adjusting shaft, one end of the elastic element 603 extends into the hole, and the other end abuts against the bottom of the mounting groove 101, and the elastic element 603 can be a spring.

In this example, the cover plate 900 further limits the stroke of the adjustment shaft for lifting and lowering. In another embodiment, the mounting groove 101 and the second end of the adjustment shaft can be designed as a structure for limiting the rotation of the adjustment shaft.

On this basis, the present invention further provides a grinding tool, comprising a power transmission mechanism of a grinding handle with adjustable swing angle as described in any of the above embodiments, wherein the output end of the power transmission mechanism is connected to the tool head, and the input end is connected to the motor.

The present invention changes the circular rotational motion mode of the traditional cutter head and converts the continuous rotational motion into a circular reciprocating swing within a certain angle range. When the cutter head is connected to the power output shaft 400, the cutter head swings back and forth circumferentially around the center line of the power output shaft 400, thereby preventing the cutter head from being entangled with the soft tissue. In addition, the soft tissue has a certain elasticity and can avoid the cutter head when the cutter head swings back and forth, thereby reducing damage to the soft tissue.

In addition, since an intermediate transmission member is provided between the input shaft 200 and the output shaft 400, and the position of the input shaft 200, the output shaft 400 or the intermediate transmission member in a direction perpendicular to the handle axis can be adjusted through an adjustment structure, the relative offset between the input shaft 200 and the intermediate transmission member or between the output shaft 400 and the intermediate transmission member can be changed, thereby changing the swing amplitude during the transmission process, and then realizing the adjustment of the swing angle, adapting to the needs of different swing amplitudes, and easy operation.

Anyone familiar with the technology may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person skilled in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims (7)

1. A power transmission mechanism for a grinding handle with adjustable swing angle, used for transmitting power of the power handle to a cutter head, characterized in that: it comprises an input shaft for receiving power and an output shaft for connecting to the cutter head, which are arranged in a housing, an intermediate transmission member for transmitting power is arranged between the input shaft and the output shaft, an eccentric transmission member is eccentrically arranged on the input shaft, the intermediate transmission member has an input part matched with the eccentric transmission member of the input shaft and an output part matched with the output shaft, the eccentric transmission member and the input part convert the unidirectional rotational motion of the input shaft into reciprocating swing of the intermediate transmission member, the output part transmits the reciprocating swinging power to the output shaft, and drives the output shaft to swing reciprocatingly; an adjusting structure is also arranged on the housing, and the adjusting structure is used to drive the intermediate transmission member to deviate in a direction perpendicular to the axis of the input shaft, and adjust the distance between the intermediate transmission member and the input shaft and the output shaft; The input shaft is installed in the housing through a first bearing, the eccentric transmission member is a first transmission shaft eccentrically arranged at the output end of the input shaft, and the first transmission shaft is sleeved with a second bearing; the intermediate transmission member includes an intermediate shaft, the input part is a pair of first ear plates arranged at the input end of the intermediate shaft, the second bearing is located between the two first ear plates and is tangent to the first ear plates; the output part is a second transmission shaft arranged at the output end of the intermediate shaft, the second transmission shaft is eccentrically arranged relative to the intermediate shaft, and the second transmission shaft is sleeved with a third bearing; the input end of the output shaft is oppositely provided with two second ear plates, the third bearing is located between the two second ear plates and is tangent to the second ear plates; The axes of the input shaft and the output shaft coincide, or the input end of the input shaft is connected to a power access shaft via a reduction mechanism, the input shaft is mounted on the housing via an eccentric bearing seat, the axes of the output shaft and the power access shaft coincide, and the axis of the input shaft is offset relative to the axis of the output shaft. 2. The power transmission mechanism of a grinding handle with adjustable swing angle according to claim 1 is characterized in that: the adjustment structure includes a support seat for installing an intermediate transmission member and an adjustment component for moving the support seat along an axial direction perpendicular to the input shaft, and the intermediate transmission member is rotatably mounted on the support seat, and its rotation center line is parallel to the axis of the input shaft. When the adjustment component is operated, the support seat drives the intermediate transmission member to offset relative to the input shaft and the output shaft. 3. The power transmission mechanism of a grinding handle with adjustable swing angle according to claim 2 is characterized in that: the support seat is an adjusting shaft installed on the shell vertically relative to the input shaft, one end of the adjusting shaft has an external thread, and the adjusting component is a nut rotatably arranged on the shell along its own axis, the nut is sleeved on the threaded section of the adjusting shaft, and the shell limits the axial movement of the nut on the adjusting shaft. 4. The power transmission mechanism of the grinding handle with adjustable swing angle according to claim 2, characterized in that a limiting structure for limiting the rotation of the support seat is provided on the housing. 5. The power transmission mechanism of a grinding handle with adjustable swing angle according to claim 3 is characterized in that: a mounting groove is opened on the inner wall of the shell, the first end of the adjusting shaft cooperates with the adjusting component, the second end of the adjusting shaft extends into the mounting groove, and an elastic element is arranged in the mounting groove, and the elastic element abuts against the second end of the adjusting shaft. 6. The power transmission mechanism of the grinding handle with adjustable swing angle according to claim 5 is characterized in that: a window for installing the support seat is opened on the shell, a cover plate with a through hole is installed on the window, and the nut is installed in the through hole of the cover plate and extends out of the cover plate. 7. A grinding tool, characterized by comprising a power transmission mechanism of a grinding handle with adjustable swing angle as claimed in any one of claims 1 to 6.