Electric drill speed reduction structure and electric drill

Abstract

The invention relates to an electric drill speed reduction structure and an electric drill, and provides the electric drill speed reduction structure which comprises a wheel type continuously variable transmission and a cycloidal pin wheel speed reducer. The invention further provides an electric drill. The electric drill is provided with the electric drill speed reduction structure. The speed reduction structure of the electric drill comprises a wheel type continuously variable transmission and a cycloidal pin gear speed reducer, has the characteristics of wide speed regulation range, stepless speed regulation, balanced operation, low noise and the like, and simultaneously overcomes the problems that lubricating grease of a gear box is easy to flow out of a gear shifting hole and the gear shifting is blocked in the traditional structure; the electric drill provided with the electric drill speed reduction structure is far superior to a traditional gear box type electric hand drill in the aspects of rotating speed, torsion and impact rate in a screw driver mode, and due to the fact that stepless speed regulation can be achieved, no matter how power is needed, a user can always enable a power motor to work under the working condition of the maximum power or the maximum energy efficiency by adjusting the speed ratio of speed reduction all the time.

Description

Technical Field

[0001] The invention relates to an electric drill speed reduction structure and an electric drill. Background Art

[0002] At present, the mainstream screwdriver and electric drill reducer uses three sets of NGW planetary gear mechanisms to achieve its deceleration, shifting and torque adjustment functions. This structure has several disadvantages as follows: 1. Traditional reduction gearboxes usually have only two gears, which are sparse and have a narrow speed ratio range. The sparse gears mean that the motor cannot run at full capacity in many cases. For example, when an electric drill with a speed of 0-600RPM / 0-2100RPM is used at a speed of 700RPM, the motor of the electric drill can only work at 33% of the maximum speed. The narrow speed ratio range means that the speed of the electric drill will not be too fast in high gear and the torque will not be too large in low gear.

[0003] 2. Traditional gearboxes shift gears by shifting the inner gear ring of the second-stage planetary gear mechanism back and forth with the shift fork, so holes must be left on the gearbox housing for the shift fork. Grease will flow out of these holes and contaminate the inner cavity of the electric drill. And as the grease in the gearbox decreases, the wear of the planetary gear mechanism will accelerate.

[0004] 3. During the gear shifting process of a traditional gearbox, the tooth tip of the inner gear ring may be blocked by the tooth tip of the gear meshing with it, making it impossible to shift gears. Summary of the invention

[0005] In view of the shortcomings existing in the above problems, the present invention provides an electric drill speed reduction structure and an electric drill.

[0006] To achieve the above-mentioned object, on the one hand, the present invention provides an electric drill reduction structure, comprising a power motor, a wheel-type continuously variable transmission configured at the output end of the power motor, and a cycloid pinwheel reducer configured at the output end of the wheel-type continuously variable transmission; The wheel-type continuously variable transmission comprises a transmission case, wherein an active ring disc, a wheel rudder, a driven ring disc, and a plane bearing are sequentially arranged in the transmission case along the power transmission direction, wherein the wheel rudder is rotatably arranged on the transmission case and forms a mutually meshing structure through a tooth plate at the passing end, wherein a freely rotating roller is arranged in the middle of the wheel rudder, and the power of the power motor is output to the driven ring disc via the active ring disc and the roller, and a knob shifting device for adjusting the meshing state of the tooth plate is arranged outside the transmission case; The cycloid pinwheel reducer includes an input shaft that rotates synchronously with the driven ring disk, two eccentric bearings arranged on the input shaft, two cycloid disks connected to the input shaft via the two eccentric bearings, a ring gear arranged outside the two cycloid disks and an output shaft. The input shaft transmits power to the output shaft via the eccentric motion of the two cycloid disks.

[0007] Furthermore, the power motor is connected to the active ring disk by a motor shaft, and a compression spring is arranged on the motor shaft. The compression spring keeps the active ring disk and the roller in close contact with each other through elastic force.

[0008] Furthermore, the contact surfaces of the roller and the active ring disk and the driven ring disk are spherical surfaces that match each other.

[0009] Furthermore, the number of the wheel rudders is two, and the knob shift device includes a knob, a gear spring sheet, a torsion spring, and a synchronizer ring. The synchronizer ring is fixedly connected to the end of one of the wheel rudders, and the knob is rotatably mounted on the outside of the synchronizer ring. A first fan-shaped groove is formed on the synchronizer ring, and a matching second fan-shaped groove is formed on the knob. The torsion spring is arranged between the synchronizer ring and the knob, and two torsion arms of the torsion spring abut against the first fan-shaped groove and the second fan-shaped groove.

[0010] Furthermore, the gear spring piece is mounted on the outer shell of the electric drill, and the gear spring piece is adapted to the gear grooves evenly arranged on the outer circumference of the knob.

[0011] Furthermore, the wheel rudder equipped with the synchronization ring is also provided with a synchronously rotating pointer at the other end away from the synchronization ring. For the convenience of indication, the outer shell is provided with scales or dials at the knob and the pointer.

[0012] On the other hand, the present invention provides an electric drill, which has the above-mentioned electric drill deceleration structure and also includes a torque adjustment device, wherein the torque adjustment device includes a top, a top pressure plate, a torque adjustment spring, a screw ring, and a torque adjustment ring. The torque adjustment ring is rotatably arranged on the outer shell, and the screw ring is connected to the torque adjustment ring by a thread. The torque adjustment spring is supported between the screw ring and the top pressure plate. The top is arranged on the side of the top pressure plate away from the torque adjustment spring and is tightly pressed against the ring gear. The ring gear is rotatably arranged in the outer shell, and the end face of the ring gear is formed with a convex portion that can interact with the top to drive the top pressure plate to move.

[0013] Furthermore, the electric drill also includes a mode switching ring, which is rotatably arranged on the outer shell. The mode switching ring can lock the head pressure plate by rotating, so that the ring gear cannot rotate.

[0014] The beneficial effects of the present invention compared to the prior art are: 1. The electric drill deceleration structure consists of a wheel-type stepless transmission and a cycloidal pinwheel reducer. It has the characteristics of wide speed regulation range, stepless speed regulation, balanced operation, low noise, etc. It also overcomes the problem of gearbox grease easily flowing out of the shift hole and shift jamming in the traditional structure. 2. The electric drill equipped with this electric drill reduction structure is far superior to the traditional gearbox hand drill in terms of speed, torque and impact rate in the screwdriver mode. Because it can achieve stepless speed regulation, no matter how much power is required, the user can always adjust the speed ratio of the reduction gear to make the power motor always work at the maximum power or highest energy efficiency condition; 3. The electric drill is equipped with a torque adjustment device, which can realize output torque adjustment and overload protection functions.

[0015] 4. The knob shift device can realize the pre-loading function. In the stopped state, the speed ratio of the wheel-type continuously variable transmission can be adjusted to the set value by turning the knob and according to the scale or dial on the outer shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A three-dimensional diagram of a speed reduction structure of an electric drill involved; Figure 2 for Figure 1 Exploded diagram of Figure 3 for Figure 2 An exploded view of the wheel-type continuously variable transmission; Figure 4 for Figure 2 Exploded diagram of the cycloid reducer in; Figure 5 is a schematic diagram of the electric drill involved; Figure 6 A schematic diagram of a knob shift device configured on a wheel-type continuously variable transmission; Figure 7 for Figure 6 Exploded diagram of Figure 8 It is a schematic diagram of the connection between the knob shift device and a wheel rudder; Fig. 9 A schematic diagram of a torque adjustment device inside the electric drill involved.

[0017] In the figure: 1, power motor; 11, motor shaft; 12, compression spring; 2, wheel type stepless transmission; 21, transmission housing; 22, active ring disk; 23, gear plate; 24, wheel rudder; 25, roller; 26, driven ring disk; 27, plane bearing; 3, cycloid pinwheel reducer; 31, input shaft; 32, eccentric bearing; 33, cycloid disk; 34, ring gear; 341, convex part; 35, output shaft; 4, outer housing; 5, mode switching ring; 6, torque adjustment ring; 7, screw ring; 8, torque adjustment spring; 9, top pressure plate; 10, top; 20, knob shift device; 201, knob; 2011, second sector groove; 2012, gear slot; 202, gear spring sheet; 203, torsion spring; 204, synchronizer ring; 2041, first sector groove; 205, pointer. DETAILED DESCRIPTION

[0018] like Figures 1 to 4 As shown, an electric drill reduction structure according to an embodiment of the present invention comprises a power motor 1, a wheel-type continuously variable transmission 2 arranged at the output end of the power motor 1, and a cycloid pinwheel reducer 3 arranged at the output end of the wheel-type continuously variable transmission 2; The wheel-type continuously variable transmission 2 comprises a transmission case 21. Along the power transmission direction, an active ring disc 22, a wheel rudder 24, a driven ring disc 26 and a plane bearing 27 are sequentially arranged in the transmission case 21. The wheel rudder 24 can be rotatably arranged on the transmission case 21 and forms a mutually meshing structure through a tooth plate 23 at the passing end. A freely rotating roller 25 is arranged in the middle of the wheel rudder 24. The power of the power motor 1 is output to the driven ring disc 26 via the active ring disc 22 and the roller 25. A knob shift device 20 for adjusting the meshing state of the tooth plate 23 is arranged outside the transmission case 21. The power motor 1 is connected to the active ring disc 22 by a motor shaft 11. A compression spring 11 is arranged on the motor shaft 11. The compression spring 11 keeps the active ring disc 22 and the roller 25 in close contact with each other through elastic force. The contact surfaces of the roller 25, the active ring disc 22 and the driven ring disc 26 are spherical surfaces that match each other. The cycloid pinwheel reducer 3 includes an input shaft 31 that rotates synchronously with the driven ring disk 26, two eccentric bearings 32 disposed on the input shaft 31, two cycloid disks 33 connected to the input shaft 31 via the two eccentric bearings 32, a ring gear 34 disposed outside the two cycloid disks 33, and an output shaft 35. The input shaft 31 transmits power to the output shaft 35 via the eccentric motion of the two cycloid disks 33. In the figure, there are two wheel rudders 24. The rotation of the wheel rudder 24 can deflect the roller 25, so that the center of the contact line between the roller 25 and the active ring disk 22 and the driven ring disk 26 changes in the radial direction of the ring disk surface, thereby achieving speed change; of course, the number of wheel rudders 24 and rollers 25 can also be increased to three to improve the stability of the ring disk. In this case, the toothed plate 23 on the wheel rudder 24 needs to be changed from straight teeth to bevel teeth.

[0019] like Figures 6-8 As shown, the knob shift device 20 includes a knob 201, a gear spring sheet 202, a torsion spring 203, and a synchronizer ring 204. The synchronizer ring 204 is fixedly connected to the end of one of the wheel rudders 24. The knob 201 is rotatably sleeved on the outside of the synchronizer ring 204. The synchronizer ring 204 is formed with a first fan-shaped groove 2041, and the knob 201 is formed with a matching second fan-shaped groove 2011. The torsion spring 203 is arranged between the synchronizer ring 204 and the knob 201. The torsion arm abuts against the first sector groove 2041 and the second sector groove 2011; the gear spring sheet 202 is installed on the outer shell 4 of the electric drill, and the gear spring sheet 202 is adapted to the gear groove 2012 evenly arranged on the outer circumference of the knob 201; the wheel rudder 24 equipped with a synchronizer ring 204 is also provided with a synchronously rotating pointer 205 at the other end away from the synchronizer ring 204, and for the convenience of indication, the outer shell 4 is provided with scales or dials at the knob 201 and the pointer 205; The gear shifting process of the knob shifting device 20 is as follows: during the operation of the electric drill, the rotation of the knob 201 drives the wheel rudder 24 to rotate via the torsion spring 203 and the synchronizer ring 204, so that the center of the contact line between the roller 25 and the active ring disk 22 and the driven ring disk 26 changes in the radial direction of the ring disk surface, thereby achieving speed change; when the motor is stopped, the knob 201 can also be rotated to achieve preloading. At this time, the roller 25 is pressed by the active ring disk 22 and the driven ring disk 26 and is difficult to rotate, so that the synchronizer ring 204 will also be difficult to rotate, and the knob 201 and the synchronizer ring 204 rotate relative to each other, causing the torsion spring 203 to generate A preload torque, when the electric drill runs again, the preload torque causes the wheel rudder 24 and the roller 25 to gradually rotate to the set speed ratio; the outer shell 4 is generally provided with a scale at a position corresponding to the knob 201, and the outer shell 4 is generally provided with a transparent dial at a position corresponding to the pointer 205, so that the user can adjust to the required speed ratio according to the working conditions; in addition, a gear spring sheet 202 is provided on the outer shell 4, and the protrusion of the gear spring sheet 202 is inserted into the gear groove 2012 evenly arranged on the outer circumference of the knob 201, so that in the case of non-human rotation, the gear spring sheet 202 prevents the knob 201 from rotating.

[0020] like Figure 5 , Figure 6As shown, an electric drill according to an embodiment of the present invention has the above-mentioned electric drill deceleration structure, and also includes a torque adjustment device, which includes a top head 10, a top head pressure plate 9, a torque adjustment spring 8, a screw ring 7, and a torque adjustment ring 6. The torque adjustment ring 6 is rotatably arranged on the outer shell 4, and the screw ring 7 is connected in the torque adjustment ring 6 by a thread. The torque adjustment spring 8 is supported between the screw ring 7 and the top head pressure plate 9. The top head 10 is arranged on the side of the top head pressure plate 9 away from the torque adjustment spring 8 and is tightly pressed on the ring gear 34. The ring gear 34 is rotatably arranged in the outer shell 4, and the end surface of the ring gear 34 is formed with a convex portion 341 that can interact with the top head 10 to drive the top head pressure plate 9 to move; the electric drill also includes a mode switching ring 5, which is rotatably arranged on the outer shell On the body 4, the mode switching ring 5 can lock the top pressure plate 9 by rotating, so that the ring gear 34 cannot rotate; because the torque adjustment ring 6 and the screw ring 7 are threaded, when the torque adjustment ring 6 is rotated, the screw ring 7 moves axially, so that the pressure of the torque adjustment spring 8 on the top pressure plate 9 changes; when the cycloid pinwheel reducer 3 outputs torque, the ring gear 34 will be subjected to reverse torque rotation; when the ring gear 34 is turned to the convex part 341 position, it will try to lift the top pressure plate 9 and squeeze the torque adjustment spring 8, so that the tighter the torque adjustment spring 8 is pressed, the greater the obstacle to the ring gear 34, and thus a greater torque can be output; in addition, the top pressure plate 9 can be locked by rotating the mode switching ring 5, so that the ring gear 34 cannot rotate, and the torque adjustment device loses torque limit and outputs hard torque.

[0021] The electric drill reduction structure comprises a wheel-type continuously variable transmission and a cycloidal pinwheel reducer. It has the characteristics of wide speed regulation range, stepless speed regulation, balanced operation, low noise, etc., and overcomes the problem of gear box grease easily flowing out of the shift hole and shift jamming in the traditional structure. The electric drill equipped with the electric drill reduction structure is far superior to the traditional gear box hand drill in terms of speed, torque and impact rate in the screwdriver mode. Because it can achieve stepless speed regulation, no matter how the power is required, the user can always adjust the speed ratio of the reduction to make the power motor always work under the maximum power or highest energy efficiency condition. The electric drill is equipped with a torque adjustment device to realize output torque adjustment and overload protection functions. The knob shift device can realize the pre-loading function. In the stopped state, the speed ratio of the wheel-type continuously variable transmission can be adjusted to the set value by turning the knob and according to the scale or dial on the outer shell.

[0022] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An electric drill deceleration structure, characterized in that: It comprises a power motor (1), a wheel-type continuously variable transmission (2) arranged at the output end of the power motor (1), and a cycloid pinwheel reducer (3) arranged at the output end of the wheel-type continuously variable transmission (2); The wheel-type continuously variable transmission (2) comprises a transmission case (21), wherein an active ring disc (22), a wheel rudder (24), a driven ring disc (26), and a plane bearing (27) are sequentially arranged in the transmission case (21) along the power transmission direction; the wheel rudder (24) is rotatably arranged on the transmission case (21) and forms a mutually meshing structure at the exit end through a toothed plate (23); a freely rotatable roller (25) is arranged in the middle of the wheel rudder (24); the power of the power motor (1) is output to the driven ring disc (26) via the active ring disc (22) and the roller (25); and a knob shift device (20) for adjusting the meshing state of the toothed plate (23) is arranged outside the transmission case (21); The cycloid pinwheel reducer (3) comprises an input shaft (31) that rotates synchronously with the driven ring disk (26), two eccentric bearings (32) arranged on the input shaft (31), two cycloid disks (33) connected to the input shaft (31) via the two eccentric bearings (32), a ring gear (34) arranged outside the two cycloid disks (33) and an output shaft (35), wherein the input shaft (31) transmits power to the output shaft (35) via the eccentric motion of the two cycloid disks (33).

2. The electric drill deceleration structure according to claim 1, characterized in that: The power motor (1) is connected to the active ring disk (22) by a motor shaft (11), and a compression spring (11) is arranged on the motor shaft (11). The compression spring (11) keeps the active ring disk (22) and the roller (25) in close contact with each other through elastic force.

3. The electric drill deceleration structure according to claim 2, characterized in that: The contact surfaces of the roller (25) and the active ring disc (22) and the driven ring disc (26) are spherical surfaces that match each other.

4. The electric drill deceleration structure according to claim 3, characterized in that: The number of the wheel rudders (24) is two, and the knob shift device (20) comprises a knob (201), a gear spring sheet (202), a torsion spring (203), and a synchronizing ring (204); the synchronizing ring (204) is fixedly connected to the end of one of the wheel rudders (24); the knob (201) is rotatably sleeved on the outside of the synchronizing ring (204); a first fan-shaped groove (2041) is formed on the synchronizing ring (204); a matching second fan-shaped groove (2011) is formed on the knob (201); the torsion spring (203) is arranged between the synchronizing ring (204) and the knob (201); two torsion arms of the torsion spring (203) are against the first fan-shaped groove (2041) and the second fan-shaped groove (2011).

5. The electric drill deceleration structure according to claim 4, characterized in that: The gear spring sheet (202) is mounted on the outer housing (4) of the electric drill, and the gear spring sheet (202) is adapted to the gear slots (2012) evenly arranged on the outer peripheral surface of the knob (201).

6. The electric drill deceleration structure according to claim 5, characterized in that: The wheel rudder (24) equipped with the synchronization ring (204) is also provided with a synchronously rotating pointer (205) at the other end away from the synchronization ring (204). For the convenience of indication, the outer shell (4) is provided with scales or dials at the knob (201) and the pointer (205).

7. An electric drill having the electric drill speed reduction structure according to any one of claims 1 to 6, characterized in that: The invention also comprises a torque adjustment device, which comprises a top head (10), a top head pressure plate (9), a torque adjustment spring (8), a spiral ring (7), and a torque adjustment ring (6). The torque adjustment ring (6) is rotatably arranged on the outer shell (4). The spiral ring (7) is connected to the torque adjustment ring (6) by a thread. The torque adjustment spring (8) is supported between the spiral ring (7) and the top head pressure plate (9). The top head (10) is arranged on a side of the top head pressure plate (9) away from the torque adjustment spring (8) and is pressed against the ring gear (34). The ring gear (34) is rotatably arranged in the outer shell (4). The end surface of the ring gear (34) is formed with a convex portion (341) that can interact with the top head (10) to drive the top head pressure plate (9) to move.

8. An electric drill according to claim 7, characterized in that: It also comprises a mode switching ring (5), wherein the mode switching ring (5) is rotatably arranged on the outer shell (4), and the mode switching ring (5) can lock the top pressure plate (9) by rotating, so that the ring gear (34) cannot rotate.

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