Power transmission assembly and handheld power tool

Abstract

The utility model discloses a power transmission assembly and a handheld power tool. The power transmission assembly comprises a driving motor, a magnetic coupler, a speed reducer and a chuck. The driving motor is provided with a driving output shaft; the magnetic coupler comprises a copper rotor and a magnetic rotor which are coaxially arranged, the copper rotor and the magnetic rotor are arranged at an interval, an air gap is formed between the copper rotor and the magnetic rotor, and the copper rotor is arranged on the driving output shaft in a sleeving manner and can coaxially rotate with the driving output shaft; the speed reducer comprises a transmission input shaft, a transmission mechanism and a transmission output shaft, the transmission input shaft is in transmission connection with the magnetic rotor, and the transmission mechanism is in transmission connection with the transmission input shaft and the transmission output shaft, so that the rotating speed of the transmission output shaft is smaller than that of the transmission input shaft; one end of the chuck is in transmission connection with the transmission output shaft, and the other end is used for mounting a working head; therefore, on one hand, the hand twisting prevention function is achieved, and on the other hand, the power tool can complete the task with the large torsion requirement.

Description

Technical Field

[0001] This utility model relates to the field of power tool technology, and in particular to a power transmission component and a handheld power tool. Background Technology

[0002] Handheld power tools are widely used in construction, decoration, woodworking, metal processing, and automotive repair. Taking handheld drills as an example, they are mainly used to create holes in various materials. During use, when the load is too heavy, the handheld drill may twist due to the working head stalling. Since the user holds the tool with their hand during operation, this twisting can easily cause arm sprains. In existing technologies, a gyroscope is usually integrated into the control board of the handheld drill. Its angular velocity measurement and attitude stabilization functions are used to control the on / off state of the entire machine, thereby improving the twisting problem. However, this solution has two drawbacks: firstly, the control system is relatively complex and difficult to implement; secondly, the control accuracy is not high, resulting in low reliability of power adjustment. Utility Model Content

[0003] The main purpose of this invention is to propose a power transmission component and a handheld power tool, which aims to solve the problems of complex control systems and low reliability of existing handheld tools that rely on integrated gyroscopes to avoid twisting the hand.

[0004] To achieve the above objectives, this utility model proposes a power transmission component, comprising:

[0005] The drive motor has a drive output shaft;

[0006] A magnetic coupler includes a copper rotor and a magnetic rotor coaxially arranged, the copper rotor and the magnetic rotor being spaced apart to form an air gap between them, the copper rotor being sleeved on the drive output shaft and rotatable coaxially with the drive output shaft; and...

[0007] A speed reducer includes a transmission input shaft, a transmission mechanism, and a transmission output shaft. The transmission input shaft is drivenly connected to the magnetic rotor, and the transmission mechanism drivesly connects the transmission input shaft and the transmission output shaft, such that the rotational speed of the transmission output shaft is less than the rotational speed of the transmission input shaft; and...

[0008] The chuck has one end connected to the drive output shaft and the other end used for mounting the working head.

[0009] Optionally, both the copper rotor and the magnetic rotor are arranged in a disc shape, and the copper rotor and the magnetic rotor are arranged side by side with a gap in the axial direction of the drive output shaft;

[0010] The magnetic rotor includes a disc back plate and at least one set of permanent magnets disposed on one side of the disc back plate. Each set of permanent magnets includes a first permanent magnet and a second permanent magnet with different magnetic properties. The first permanent magnet and the second permanent magnet are evenly spaced along the circumference of the disc back plate.

[0011] Optionally, the magnetic rotor includes multiple sets of permanent magnets, which are evenly spaced along the circumference of the disk back plate, with the first permanent magnet and the second permanent magnet in the multiple sets of permanent magnets being arranged alternately.

[0012] Optionally, the position of the copper rotor on the drive output shaft is adjustable in the axial direction of the drive output shaft so that the width of the air gap is adjustable;

[0013] The power transmission assembly further includes a position adjustment mechanism and a mounting base. The mounting base is disposed on the drive output shaft and rotates coaxially with the drive output shaft. The mounting base is located on the side of the copper rotor away from the magnetic rotor. The position adjustment mechanism is disposed on the mounting base and includes an adjustment part. The adjustment part is axially movable along the drive output shaft and is driven to connect to the copper rotor to adjust the position of the copper rotor on the drive output shaft.

[0014] Optionally, the mounting base has a receiving groove on the side surface facing the copper rotor, and the receiving groove has the same central axis as the drive output shaft;

[0015] The position adjustment mechanism includes a miniature electric actuator, which includes:

[0016] A base is disposed on the mounting seat and at least partially accommodated within the receiving groove, and the base is provided with a guide hole;

[0017] A transmission component includes a lead screw and a lead screw nut, wherein one end of the lead screw passes through the guide hole, and the lead screw nut is sleeved on the lead screw and threadedly connected to the lead screw;

[0018] A piezoelectric motor, mounted on the base and driving the lead screw nut; and,

[0019] An anti-rotation limiting component is disposed between the lead screw and the base to work together with the lead screw nut to allow the lead screw to move axially along the drive output shaft;

[0020] The adjusting part includes the lead screw, and the other end of the lead screw is connected to the copper rotor.

[0021] Optionally, the position adjustment mechanism further includes:

[0022] Circuit board assembly;

[0023] The gear shifting assembly includes at least a first gear position button and a second gear position button, both of which are electrically connected to the circuit board assembly.

[0024] The piezoelectric motor is electrically connected to the circuit board assembly.

[0025] Optionally, the transmission mechanism includes a planetary gear reduction mechanism, which includes a central gear shaft, bearings, a main gear, a first-stage planetary gear mechanism, a second-stage planetary gear mechanism, and a third-stage planetary gear mechanism. The main gear is sleeved on the transmission input shaft and rotates coaxially with the transmission input shaft. The planetary gears in the first-stage planetary gear mechanism mesh with the main gear. The second-stage planetary gear mechanism is drive-connected to the first-stage planetary gear mechanism, and the third-stage planetary gear mechanism is drive-connected to the second-stage planetary gear mechanism.

[0026] The bearing is sleeved on the transmission input shaft and is located between the magnetic rotor and the first-stage planetary gear mechanism.

[0027] The transmission output shaft is connected to the three-stage planetary gear mechanism.

[0028] This utility model also provides a handheld power tool, including the power transmission component described above.

[0029] Optionally, the handheld power tool further includes a mounting housing and a grip handle, the mounting housing and the grip handle together forming a gun-shaped structure, and the extension axis of the grip handle is set at an angle to the extension axis of the mounting housing;

[0030] The mounting housing has a mounting cavity, and the mounting housing has a first opening communicating with the mounting cavity;

[0031] The drive motor, the magnetic coupler, and the reducer are disposed within the mounting cavity, and the clamp is disposed at the first opening.

[0032] Optionally, the mounting housing has a first end and a second end opposite to each other, the first opening is provided on the first end of the mounting housing, and the drive motor, the magnetic coupler, the reducer and the clamp are arranged sequentially in the direction from the second end to the first end;

[0033] The grip handle is disposed on the mounting housing and is located near the second end.

[0034] The technical solution provided by this utility model has at least the following advantages:

[0035] The power transmission assembly provided by this utility model includes a drive motor, a magnetic coupler, a reducer, and a chuck. The drive output shaft of the drive motor is connected to the copper rotor of the magnetic coupler, the magnetic rotor of the magnetic coupler is connected to the transmission input shaft of the reducer, and the transmission output shaft of the reducer is connected to one end of the chuck. The other end of the chuck is used for mounting the working head. In other words, the copper rotor is equivalent to the driving part connected to the drive output shaft, and the magnetic rotor is equivalent to the driven part connected to the load. The torque output by the drive output shaft is transmitted to the reducer through the magnetic field between the copper rotor and the magnetic rotor, and then to the working head on the chuck via the reducer. Since there is no direct mechanical connection between the copper rotor and the magnetic rotor, when the load is too large or a stall occurs during operation, the magnetic... The force coupler automatically slips, meaning the copper rotor (driving part) continues to rotate, but the magnetic rotor (driven part) stops or slows down. This means that, on the one hand, when the load is too high or a stall occurs, the user only needs to overcome a smaller magnetic coupling torque, rather than the entire machine's stall torque, thus reducing the risk of the user being twisted and ensuring operational safety. On the other hand, compared to existing technologies that use control systems to prevent twisting, using a non-contact mechanical structure to achieve the anti-twisting function is not only easier to implement but also offers higher control precision and reliability. Simultaneously, a speed reducer is installed between the magnetic coupler and the chuck, converting the high-speed, low-torque output of the magnetic coupler into a low-speed, high-torque output, enabling the power tool to perform tasks requiring high torque. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0037] Figure 1 A schematic diagram of an embodiment of a power transmission component provided by this utility model;

[0038] Figure 2 for Figure 1 Exploded view of the power transmission assembly;

[0039] Figure 3 for Figure 1 A schematic diagram of the power transmission assembly with respect to the magnetic coupler;

[0040] Figure 4 for Figure 3 The magnetic coupler has a first arrangement diagram of the permanent magnets on the magnetic rotor;

[0041] Figure 5 for Figure 3The magnetic coupler is shown in the second arrangement diagram of the permanent magnets on the magnetic rotor.

[0042] Figure 6 for Figure 1 A schematic diagram of the power transmission assembly with respect to the position adjustment mechanism;

[0043] Figure 7 for Figure 1 A schematic diagram of the power transmission assembly with respect to the reducer;

[0044] Figure 8 for Figure 7 An exploded view of the reducer's structure;

[0045] Figure 9 A schematic diagram of an embodiment of a power transmission component provided by this utility model;

[0046] Figure 10 for Figure 9 A schematic diagram of the handheld power tool (with half of the housing hidden).

[0047] Explanation of icon numbers:

[0048] 1000 handheld power tools;

[0049] 100 Power transmission assembly; 1 Drive motor; 11 Drive output shaft; 2 Magnetic coupler; 21 Copper rotor; 22 Magnetic rotor; 221 Disc back plate; 222 Permanent magnet; 2221 First permanent magnet; 2222 Second permanent magnet; 23 Air gap; 3 Reducer; 31 Transmission input shaft; 32 Transmission mechanism; 321 Bearing; 322 Main gear; 323 First-stage planetary gear mechanism; 3231 First planetary gear; 3232 First internal gear; 3233 First planetary disk; 3234 First boss; 324 Second-stage planetary gear mechanism Structure; 3241 Second planetary gear; 3242 First turntable; 3243 Second planetary disk; 3244 Second boss; 325 Three-stage planetary gear mechanism; 3251 Third planetary gear; 3252 Second turntable; 3253 Third planetary disk; 33 Transmission output shaft; 4 Chuck; 5 Position adjustment mechanism; 5a Adjustment part; 51 Miniature electric push rod; 511 Base; 512 Transmission component; 5121 Lead screw; 52 Shift assembly; 521 First gear button; 522 Second gear button; 53 Circuit board assembly; 6 Mounting base;

[0050] 200 Mounting housing; 200a First end; 200b Second end; 200c Outer shell; 201 Mounting cavity; 202 First opening; 203 Second opening; 204 End cap;

[0051] 300 grip handle; 301 switch button.

[0052] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0053] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0054] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0055] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0056] In one aspect, embodiments of this application provide a power transmission assembly 100, please refer to... Figures 1 to 3The power transmission assembly 100 includes a drive motor 1, a magnetic coupler 2, a reducer 3, and a chuck 4. The drive motor 1 has a drive output shaft 11. The magnetic coupler 2 includes a copper rotor 21 and a magnetic rotor 22 arranged coaxially, with the copper rotor 21 and magnetic rotor 22 spaced apart to form an air gap 23 between them. The copper rotor 21 is sleeved on the drive output shaft 11 and can rotate coaxially with the drive output shaft 11. The reducer 3 includes a transmission input shaft 31, a transmission mechanism 32, and a transmission output shaft 33. The transmission input shaft 31 is connected to the magnetic rotor 22. The transmission mechanism 32 is connected to the transmission input shaft 31 and the transmission output shaft 33 so that the rotational speed of the transmission output shaft 33 is less than the rotational speed of the transmission input shaft 31. One end of the chuck 4 is connected to the transmission output shaft 33, and the other end is used for mounting the working head.

[0057] In the embodiments provided in this application, the power transmission assembly 100 includes a drive motor 1, a magnetic coupler 2, a reducer 3, and a chuck 4; the drive output shaft 11 of the drive motor 1 is connected to the copper rotor 21 of the magnetic coupler 2, the magnetic rotor 22 of the magnetic coupler 2 is connected to the transmission input shaft 31 of the reducer 3, the transmission output shaft 33 of the reducer 3 is connected to one end of the chuck 4, and the other end of the chuck 4 is used for mounting the working head.

[0058] It is known that the magnetic coupler 2 includes a copper rotor 21 and a magnetic rotor 22 arranged coaxially. The copper rotor 21 and the magnetic rotor 22 are spaced apart to form an air gap 23 between them. The copper rotor 21 is equivalent to the driving part connected to the drive output shaft 11, and the magnetic rotor 22 is equivalent to the driven part connected to the load. When the drive output shaft 11 drives the copper rotor 21 to rotate, since the copper rotor 21 is in the magnetic field generated by the magnetic rotor 22, the conductor on the copper rotor 21 cuts the magnetic lines of force to generate an induced current. The induced current forms a magnetic field in opposite direction inside the copper rotor 21. The magnetic field formed inside the copper rotor 21 interacts with the magnetic field of the magnetic rotor 22, thereby causing the magnetic rotor 22 to rotate with the copper rotor 21.

[0059] Since the copper rotor 21 and the magnetic rotor 22 do not require a direct mechanical connection but interact through a magnetic field, non-contact power transmission is achieved. During operation, when the load is too large or a stall occurs, the magnetic coupler 2 will automatically slip, meaning the copper rotor 21 (driving part) continues to rotate, but the magnetic rotor 22 (driven part) stops or slows down. Thus, on the one hand, when the load is too large or a stall occurs, the user only needs to overcome a small magnetic coupling torque, rather than the entire machine's stall torque, thereby reducing the risk of the user being twisted and ensuring user safety. On the other hand, compared to existing technologies that use control systems to prevent twisting, using a non-contact mechanical structure to achieve the anti-twisting function is not only easier to implement but also offers higher control precision and reliability.

[0060] Furthermore, the torque output by the drive output shaft 11 is reduced to a smaller magnetic coupling torque after passing through the magnetic coupler 2. In order to meet the working requirements, a reducer 3 is set between the magnetic coupler 2 and the chuck 4. The reducer 3 can convert the high-speed, low-torque output of the magnetic coupler 2 into a low-speed, high-torque output, thereby enabling the power tool to complete tasks requiring high torque.

[0061] This application does not impose specific limitations on the structure of the magnetic coupler 2. The copper rotor 21 and magnetic rotor 22 of the magnetic coupler 2 can be configured as a ring structure or a disc structure.

[0062] In one embodiment, please refer to Figure 3 Both the copper rotor 21 and the magnetic rotor 22 are arranged in a disc shape, and are arranged side by side at intervals along the axial direction of the drive output shaft 11.

[0063] The copper rotor 21 is typically made of highly conductive copper or copper alloy. Due to copper's excellent conductivity, it can efficiently sense changes in the magnetic field and generate corresponding eddy currents. The copper rotor 21 has slots or holes to reduce weight and increase heat dissipation area. The copper rotor 21 is mounted on the drive output shaft 11. To ensure that the copper rotor 21 rotates coaxially with the drive output shaft 11, it is usually fixedly connected to the drive output shaft 11 using key connections or screw fastening.

[0064] The magnetic rotor 22 includes permanent magnets 222, a support structure, and a protective layer. The support structure is used to mount the permanent magnets 222, maintain the position of the permanent magnets 222, and withstand the mechanical stress generated during operation. The protective layer is disposed around the permanent magnets 222 to protect them from environmental factors (such as moisture, dust, and corrosion). In an exemplary embodiment, the magnetic rotor 22 includes a disk back plate 221 and at least one set of permanent magnets 222 disposed on one side of the disk back plate 221. Each set of permanent magnets 222 includes a first permanent magnet 2221 and a second permanent magnet 2222 with opposite magnetic properties. The first permanent magnet 2221 and the second permanent magnet 2222 are evenly spaced along the circumference of the disk back plate 221.

[0065] The disk backplate 221 is made of metal, such as steel or aluminum; the first permanent magnet 2221 and the second permanent magnet 2222 are made of neodymium iron boron (NdFeB) or samarium cobalt (SmCo) to give the first permanent magnet 2221 and the second permanent magnet 2222 high magnetic energy product and good anti-demagnetization ability.

[0066] This application does not impose a specific limitation on the number of permanent magnets 222. In one embodiment, please refer to... Figure 4The magnetic rotor 22 includes a set of permanent magnets 222, wherein the first permanent magnet 2221 and the second permanent magnet 2222 are evenly spaced along the circumference of the disk back plate 221. In one embodiment, please refer to... Figure 5 The magnetic rotor 22 includes multiple sets of permanent magnets 222, which are evenly spaced along the circumference of the disk back plate 221. The first permanent magnet 2221 and the second permanent magnet 2222 in the multiple sets of permanent magnets 222 are arranged alternately. By arranging the first permanent magnet 2221 and the second permanent magnet 2222 alternately in a certain order, an effective magnetic field distribution is ensured, which helps to maximize the magnetic field strength and uniformity, thereby improving the torque transmission efficiency.

[0067] It is understandable that in the magnetic coupler 2, the copper rotor 21 and the magnetic rotor 22 are arranged at intervals to form an air gap 23 between them; an appropriate air gap 23 size can ensure sufficient magnetic field strength for effective torque transmission. In other words, the size of the air gap 23 affects the efficiency and torque transmission capability of the magnetic coupler 2, and the torque transmitted by the magnetic coupler 2 can be adjusted by adjusting the size of the air gap 23.

[0068] To adapt to different working scenarios, the output torque of the power transmission assembly 100 needs to be adjusted. In one embodiment of this application, please refer to... Figure 1 , Figure 2 and Figure 6 Along the axial direction of the drive output shaft 11, the position of the copper rotor 21 on the drive output shaft 11 is adjustable so that the width of the air gap 23 is adjustable. The power transmission assembly 100 also includes a position adjustment mechanism 5 and a mounting base 6. The mounting base 6 is disposed on the drive output shaft 11 and rotates coaxially with the drive output shaft 11. The mounting base 6 is located on the side of the copper rotor 21 away from the magnetic rotor 22. The position adjustment mechanism 5 is disposed on the mounting base 6. The position adjustment mechanism 5 includes an adjustment part 5a. The adjustment part 5a can move along the axial direction of the drive output shaft 11. The adjustment part 5a drives and connects to the copper rotor 21 to adjust the position of the copper rotor 21 on the drive output shaft 11.

[0069] In this embodiment, a mounting base 6 is also provided on the drive output shaft 11. When the drive output shaft 11 rotates, it can drive the mounting base 6 and the copper rotor 21 to rotate synchronously. A position adjustment mechanism 5 is provided on the mounting base 6. The position adjustment mechanism 5 has a movable adjustment part 5a. The adjustment part 5a drives and connects to the copper rotor 21. During the movement of the adjustment part 5a along the axial direction of the drive output shaft 11, it can drive the copper rotor 21 to move along the axial direction of the drive output shaft 11, thereby adjusting the position of the copper rotor 21 on the drive output shaft 11, and then adjusting the size of the air gap 23 between the copper rotor 21 and the magnetic rotor 22.

[0070] In one exemplary embodiment, please refer to Figure 6The mounting base 6 has a receiving groove on the side facing the copper rotor 21, and the receiving groove has the same central axis as the drive output shaft 11; the position adjustment mechanism 5 includes a miniature electric push rod 51, which includes a base 511, a transmission component 512, a piezoelectric motor (not shown in the figure), and an anti-rotation limiting component (not shown in the figure); the base 511 is disposed on the mounting base 6 and is at least partially housed in the receiving groove, and the base 511 is provided with a guide hole; the transmission component 512 includes a lead screw 5121 and a lead screw... A screw nut (not shown in the figure) is provided. One end of the screw 5121 passes through the guide hole. The screw nut is sleeved on the screw 5121 and threadedly connected to the screw 5121. A piezoelectric motor is provided on the base 511 and drives the screw nut. An anti-rotation limiting member is provided between the screw 5121 and the base 511 to work together with the screw nut to make the screw 5121 move axially along the drive output shaft 11. The adjusting part 5a includes the screw 5121, and the other end of the screw 5121 is connected to the copper rotor 21.

[0071] During the adjustment process, the piezoelectric motor drives the lead screw nut to rotate, and the rotation of the lead screw nut cooperates with the anti-rotation limit component to make the lead screw 5121 move linearly; the lead screw 5121 pushes the copper rotor 21 to move on the drive output shaft 11; thus, the high-precision position adjustment of the copper rotor 21 is achieved.

[0072] It is known that piezoelectric motors utilize the inverse piezoelectric effect of piezoelectric materials to convert electromechanical energy, that is, the piezoelectric ceramic material deforms under the action of an electric field to drive the movement of the mover in motor 1. In other words, the direct-drive characteristic of piezoelectric motors allows the miniature electric actuator 51 to have a small size; at the same time, piezoelectric motors have extremely high stepping accuracy, thus enabling the miniature electric actuator 51 to have nanometer precision. This application does not specifically limit the type of piezoelectric motor; generally, a linear piezoelectric motor is selected. Preferably, an L1-B2 type piezoelectric motor is used.

[0073] Furthermore, during the driving process, in order to ensure that the lead screw 5121 moves linearly, thereby guaranteeing the operating accuracy and thrust of the miniature electric actuator 51, an anti-rotation limiting component needs to be set between the lead screw 5121 and the base 511. In one embodiment, the anti-rotation limiting component includes a locking groove (not shown in the figure) and a locking block that engage with each other. One of the groove and the locking block is set on the lead screw 5121, and the other is correspondingly set on the base 511. The groove is set as an elongated groove that extends along the axial direction of the lead screw 5121. The elongated groove serves as the running track for the locking block, ensuring that the locking block can move smoothly along the axial direction of the lead screw 5121, thereby limiting the lead screw 5121 and the lead screw nut in the circumferential direction, and thus ensuring the linear movement of the lead screw 5121.

[0074] Following the previous statement that "the size of the air gap 23 is adjusted by adjusting the size of the adjusting part 5a to change the magnitude of the torque transmitted by the magnetic coupler 2," to improve the adjustment accuracy of the air gap 23 and make the torque output more precise, an adjustment range design can be added. In one embodiment, please refer to... Figure 9 and Figure 10 The position adjustment mechanism 5 also includes a circuit board assembly 53 and a shift assembly 52. ​​The shift assembly 52 includes at least a first gear button 521 and a second gear button 522, both of which are electrically connected to the circuit board assembly 53. The piezoelectric motor is electrically connected to the circuit board assembly 53.

[0075] In this embodiment, the position adjustment mechanism 5 includes a first gear button 521 and a second gear button 522. The first gear button 521, the second gear button 522, and the piezoelectric motor are all electrically connected to the circuit board assembly 53. The first gear button 521 corresponds to a first rated current and a first rated voltage, thereby enabling the piezoelectric motor to drive the lead screw nut to rotate a first predetermined number of turns, thereby causing the lead screw 5121 to move a first predetermined distance. The second gear button 522 corresponds to a second rated current and a second rated voltage, thereby enabling the piezoelectric motor to drive the lead screw nut to rotate a second predetermined number of turns, thereby causing the lead screw 5121 to move a second predetermined distance. Thus, by switching between the first gear button 521 and the second gear button 522, the position of the copper rotor 21 can be precisely adjusted.

[0076] This application does not impose a specific limit on the number of gear shift buttons. There can be two gear shift buttons, such as the first gear shift button 521 and the second gear shift button 522 mentioned above; or there can be three or four, and the adjustment method is the same as above.

[0077] In most cases, for small motors or low-power devices, the air gap 23 of the magnetic coupler 2 is usually set to 1mm to 2mm to ensure high efficiency and compact design; based on this, the adjustment range of the air gap 23 can be set to 1mm; assuming that in the above-mentioned miniature electric actuator 51, the lead of the lead screw nut and the lead screw 5121 is 0.25mm, that is, when the lead screw nut rotates one revolution, the distance that the lead screw 5121 moves is 0.25mm.

[0078] When two gear buttons are set, the two gear buttons correspond to 1mm and 2mm respectively. When switching between the two gear buttons, the lead screw nut will rotate four times to move the lead screw 5121 by 1mm, thereby moving the copper rotor 21 to the preset position.

[0079] When three gear buttons are set, the three gear buttons correspond to 1mm, 1.5mm and 2mm respectively. When switching between two adjacent gear buttons, the lead screw nut will rotate two revolutions to move the lead screw 5121 by 0.5mm, thereby moving the copper rotor 21 to the preset position.

[0080] Following on from the aforementioned "a speed reducer 3 is installed between the magnetic coupler 2 and the chuck 4 to convert the high-speed, low-torque output of the magnetic coupler 2 into a low-speed, high-torque output," please refer to [link to previous text]. Figure 7 and Figure 8 The transmission mechanism 32 includes a planetary gear reduction mechanism, which includes a bearing 321, a main gear 322, a first-stage planetary gear mechanism 323, a second-stage planetary gear mechanism 324, and a third-stage planetary gear mechanism 325. One end of the transmission input shaft 31 is connected to the magnetic rotor 22. The main gear 322 is sleeved on the transmission input shaft 31 and rotates coaxially with the transmission input shaft 31. The planetary gears in the first-stage planetary gear mechanism 323 mesh with the main gear 322. The second-stage planetary gear mechanism 324 is driven by the first-stage planetary gear mechanism 323, and the third-stage planetary gear mechanism 325 is driven by the second-stage planetary gear mechanism 324. The transmission output shaft 33 is driven by the third-stage planetary gear mechanism 325. The bearing 321 is sleeved on the transmission input shaft 31 and is located between the magnetic rotor 22 and the first-stage planetary gear mechanism 323.

[0081] In one exemplary embodiment, please refer to Figure 8 The first-stage planetary gear mechanism 323 includes three first planetary gears 3231, a first internal gear 3232, and a first planetary disk 3233. The first internal gear 3232 and the main gear 322 have the same central axis. The three first planetary gears 3231 are disposed on the end face of the first internal gear 3232 facing the main gear 322. The three first planetary gears 3231 are evenly distributed around the circumference of the transmission input shaft 31 and mesh with the main gear 322 respectively. The first planetary disk 3233 is sleeved on the transmission input shaft 31. The internal teeth of the first planetary disk 3233 mesh with the teeth of the three first planetary gears 3231 respectively. The hub of the first internal gear 3232 protrudes from the side opposite to the main gear 322 with a first boss 3234. The circumference of the first boss 3234 is provided with gear teeth. The bearing 321 is sleeved on the transmission input shaft 31 and is located between the magnetic rotor 22 and the first planetary disk 3233.

[0082] The secondary planetary gear mechanism 324 includes three second planetary gears 3241, a first turntable 3242, and a second planetary disk 3243. The first turntable 3242 and the first internal gear 3232 have the same central axis. The three second planetary gears 3241 are disposed on the end face of the first turntable 3242 facing the first internal gear 3232. The three second planetary gears 3241 are evenly distributed around the circumference of the first boss 3234 and mesh with the teeth of the first boss 3234 respectively. The second planetary disk 3243 is arranged around the outside of the three second planetary gears 3241, and its internal teeth mesh with the teeth of the three second planetary gears 3241 respectively. The end face of the first turntable 3242 protrudes from the side opposite to the first internal gear 3232, and the second boss 3244 has the same central axis as the first boss 3234 and its circumference is provided with teeth.

[0083] The three-stage planetary gear mechanism 325 includes three third planetary gears 3251, a second turntable 3252, and a third planetary disk 3253. The second turntable 3252 and the first turntable 3242 have the same central axis. The three third planetary gears 3251 are disposed on the end face of the second turntable 3252 facing the first turntable 3242. The three third planetary gears 3251 are evenly distributed around the circumference of the second boss 3244 and mesh with the gear teeth of the second boss 3244 respectively. The third planetary disk 3253 is arranged around the outside of the three third planetary gears 3251, and its internal teeth mesh with the gear teeth of the three third planetary gears 3251 respectively. The transmission output shaft 33 is connected to the second turntable 3252 through bearing transmission and can rotate coaxially with the second turntable 3252.

[0084] Secondly, embodiments of this application provide a handheld power tool 1000, please refer to... Figure 9 and Figure 10 The handheld power tool 1000 includes a power transmission assembly 100. It should be noted that the power transmission assembly 100 is configured as described above, which means it includes all the technical features of the power transmission assembly 100. Therefore, the handheld power tool 1000 also includes all the technical features of the power transmission assembly 100, and thus has the technical effects brought about by all the technical features described above.

[0085] This application does not impose specific limitations on the handheld power tool 1000. The handheld power tool 1000 can be an electric drill, screwdriver, screwdriver, electric hammer, etc.

[0086] In one embodiment, please refer to Figure 9The handheld power tool 1000 also includes a mounting housing 200 and a grip 300. The mounting housing 200 and the grip 300 together form a gun-shaped structure, with the grip 300 set at an angle to the mounting housing 200. In actual operation, the user needs to hold the grip 300. Typically, when the angle between the line connecting the thumb and palm to the middle of the wrist and the axis along the length of the phalanges connecting the thumb and palm is between 110° and 130°, the hand is in a naturally bent position, making operation with the grip 300 more comfortable. To conform to ergonomics, the extension axis of the grip 300 is set at an angle to the extension axis of the mounting housing 200, and the angle θ between the extension axis of the grip 300 and the extension axis of the mounting housing 200 is set to 110°–130°, thus improving the user experience and comfort.

[0087] Furthermore, a mounting cavity 201 is formed inside the mounting housing 200, and a first opening 202 communicating with the mounting cavity 201 is provided on the mounting housing 200; wherein, the drive motor 1, the magnetic coupler 2 and the reducer 3 are disposed inside the mounting cavity 201, and the clamp 4 is disposed at the first opening 202.

[0088] The mounting housing 200 can be assembled from at least two outer shells 200c. Please refer to [link / reference]. Figure 10 In one embodiment, the mounting housing 200 is formed by splicing two outer shells 200c, which together define the mounting cavity 201 of the mounting housing 200. The accompanying drawings provided in this application retain one of the outer shells 200c, while concealing the other shell, in order to illustrate the connection between the grip handle 300 and the mounting housing 200.

[0089] In one exemplary embodiment, please refer to Figure 10 The mounting housing 200 has a first end 200a and a second end 200b. A first opening 202 is provided on the first end 200a of the mounting housing 200. The drive motor 1, magnetic coupler 2, reducer 3, and chuck 4 are arranged sequentially from the second end 200b towards the first end 200a. A grip handle 300 is disposed on the mounting housing 200 and positioned close to the second end 200b. By positioning the grip handle 300 close to the drive motor 1, and in conjunction with the aforementioned power transmission assembly 100, the anti-twisting function of the handheld power tool 1000 is improved.

[0090] Furthermore, the mounting housing 200 has a second opening 203 that communicates with the mounting cavity 201, and the second opening 203 is located at the second end 200b; the mounting housing 200 also includes an end cover 204, which covers the second opening 203, and one end of the drive output shaft 11 is rotatably mounted on the end cover 204.

[0091] The handheld power tool 1000 also includes a switch button 301, which is located on the handle 300 and electrically connected to the circuit board assembly 53. The handheld power tool 1000 can be turned on or off by the switch button 301.

[0092] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the concept of this utility model and the contents of the specification and drawings of this utility model, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. A power transmission component, characterized in that, include: The drive motor has a drive output shaft; A magnetic coupler includes a copper rotor and a magnetic rotor coaxially arranged, the copper rotor and the magnetic rotor being spaced apart to form an air gap between them, the copper rotor being sleeved on the drive output shaft and rotatable coaxially with the drive output shaft; and... The speed reducer includes a transmission input shaft, a transmission mechanism, and a transmission output shaft. The transmission input shaft is connected to the magnetic rotor, and the transmission mechanism is connected to the transmission input shaft and the transmission output shaft so that the rotational speed of the transmission output shaft is less than the rotational speed of the transmission input shaft. as well as, The chuck has one end connected to the drive output shaft and the other end used for mounting the working head.

2. The power transmission assembly according to claim 1, characterized in that, Both the copper rotor and the magnetic rotor are arranged in a disc shape, and are arranged side by side with a gap in the axial direction of the drive output shaft; The magnetic rotor includes a disc back plate and at least one set of permanent magnets disposed on one side of the disc back plate. Each set of permanent magnets includes a first permanent magnet and a second permanent magnet with different magnetic properties. The first permanent magnet and the second permanent magnet are evenly spaced along the circumference of the disc back plate.

3. The power transmission assembly according to claim 2, characterized in that, The magnetic rotor includes multiple sets of permanent magnets, which are evenly spaced along the circumference of the disk back plate, with the first permanent magnet and the second permanent magnet in the multiple sets of permanent magnets being arranged alternately.

4. The power transmission assembly according to claim 1, characterized in that, The position of the copper rotor on the drive output shaft is adjustable in the axial direction of the drive output shaft so that the width of the air gap is adjustable. The power transmission assembly further includes a position adjustment mechanism and a mounting base. The mounting base is disposed on the drive output shaft and rotates coaxially with the drive output shaft. The mounting base is located on the side of the copper rotor away from the magnetic rotor. The position adjustment mechanism is disposed on the mounting base and includes an adjustment part. The adjustment part is axially movable along the drive output shaft and is driven to connect to the copper rotor to adjust the position of the copper rotor on the drive output shaft.

5. The power transmission assembly according to claim 4, characterized in that, The mounting base has a receiving groove on the side surface facing the copper rotor, and the receiving groove has the same central axis as the drive output shaft; The position adjustment mechanism includes a miniature electric actuator, which includes: A base is disposed on the mounting seat and at least partially accommodated within the receiving groove, and the base is provided with a guide hole; A transmission component includes a lead screw and a lead screw nut, wherein one end of the lead screw passes through the guide hole, and the lead screw nut is sleeved on the lead screw and threadedly connected to the lead screw; A piezoelectric motor, mounted on the base and driving the lead screw nut; and, An anti-rotation limiting component is disposed between the lead screw and the base to work together with the lead screw nut to allow the lead screw to move axially along the drive output shaft; The adjusting part includes the lead screw, and the other end of the lead screw is connected to the copper rotor.

6. The power transmission assembly according to claim 5, characterized in that, The position adjustment mechanism further includes: Circuit board assembly; The gear shifting assembly includes at least a first gear position button and a second gear position button, both of which are electrically connected to the circuit board assembly. The piezoelectric motor is electrically connected to the circuit board assembly.

7. The power transmission assembly according to claim 1, characterized in that, The transmission mechanism includes a planetary gear reduction mechanism, which includes a bearing, a main gear, a first-stage planetary gear mechanism, a second-stage planetary gear mechanism, and a third-stage planetary gear mechanism. The main gear is sleeved on the transmission input shaft and rotates coaxially with the transmission input shaft. The planetary gears in the first-stage planetary gear mechanism mesh with the main gear. The second-stage planetary gear mechanism is driven by the first-stage planetary gear mechanism, and the third-stage planetary gear mechanism is driven by the second-stage planetary gear mechanism. The bearing is sleeved on the transmission input shaft and is located between the magnetic rotor and the first-stage planetary gear mechanism. The transmission output shaft is connected to the three-stage planetary gear mechanism.

8. A handheld power tool, characterized in that, Includes the power transmission assembly as described in any one of claims 1 to 7.

9. The handheld power tool according to claim 8, characterized in that, The handheld power tool also includes a mounting housing and a grip handle. The mounting housing and the grip handle together form a gun-shaped structure, and the extension axis of the grip handle is set at an angle to the extension axis of the mounting housing. The mounting housing has a mounting cavity, and the mounting housing has a first opening communicating with the mounting cavity; The drive motor, the magnetic coupler, and the reducer are disposed within the mounting cavity, and the clamp is disposed at the first opening.

10. The handheld power tool according to claim 9, characterized in that, The mounting housing has a first end and a second end opposite to each other. The first opening is provided on the first end of the mounting housing, and the drive motor, the magnetic coupler, the reducer and the clamp are arranged in sequence from the second end to the first end. The grip handle is disposed on the mounting housing and is located near the second end.

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