Gear adjustment mechanism for impact gun drill

Abstract

The application provides a gear adjusting mechanism of an impact gun drill, and relates to the technical field of electric tools, which comprises a torque adjusting ring, a gear adjusting ring, and first, second and third gaskets arranged axially in sequence; the inner ring gear of the gear box is provided with a ratchet groove at the upper end, and a first rolling body is arranged in the ratchet groove; the first gasket presses the first rolling body against the ratchet groove through an elastic element to realize rolling gear jumping; a second rolling body is arranged between the second gasket and the third gasket to form rolling contact. The application converts traditional sliding friction into rolling friction through a double-rolling-body structure, which not only significantly reduces gear jumping wear and impact feeling, but also effectively eliminates the gear shifting resistance caused by the dramatic increase of normal pressure under the maximum torque working condition, ensures smooth and easy gear shifting, and guarantees the stability and reliability of multi-gear switching.

Description

Technical Field

[0001] This invention relates to the field of power tool technology, and more specifically, to a gear adjustment mechanism for an impact drill. Background Technology

[0002] The gear shifting structure of an impact drill is a key component determining its functional versatility and ease of operation. Chinese authorized invention patent CN113400262B proposes a user-friendly gearbox that utilizes a three-piece adjustment structure consisting of a shift plate, an adjusting plate, and a support plate. The stable switching between screw, drill, and hammer modes is achieved through the cooperation of a stop post beneath the adjusting plate and the inner groove of the shift plate, effectively avoiding gear shifting issues between the drill and impact modes and improving the gearbox's operational reliability.

[0003] However, the above structure still has the following shortcomings in actual use: On the one hand, when the gearbox is in the screw position and the torque adjustment ring is adjusted to the maximum torque position, the spring is compressed significantly, and the normal pressure applied to the adjustment plate through the support plate increases sharply, resulting in a significant increase in the friction between the adjustment plate and the adjacent plates. At this time, when the user rotates the gear adjustment ring to shift gears, they need to overcome this huge friction, resulting in a heavy shifting feel and difficult operation. On the other hand, its shifting mechanism adopts a sliding lifting method of boss and pin, and the pin and boss are in sliding friction contact. After long-term use, wear is likely to occur, affecting the shifting accuracy and reliability, and the shifting impact is strong, affecting the comfort of use. Summary of the Invention

[0004] The problem this invention addresses is how to reduce shifting resistance and improve the shifting feel under high torque while ensuring shifting accuracy.

[0005] To solve the above problems, the present invention provides a gear adjustment mechanism for an impact drill, including a torque adjustment ring, a gear adjustment ring and a gearbox with an output shaft, and further including a first rolling element, a second rolling element and a first shim, a second shim and a third shim arranged sequentially from bottom to top and movably disposed along the axial direction.

[0006] The gearbox is provided with an internal gear ring that meshes with the planetary gear set, and the planet carrier of the planetary gear set is fixedly connected to the output shaft; the upper end face of the internal gear ring is provided with a ratchet groove along the circumferential direction, and the first rolling element is disposed in the ratchet groove;

[0007] The first shim presses against the first rolling element and applies a locking force to the internal gear ring through an elastic element; the elastic element is disposed on the third shim, and the torque adjusting ring adjusts the elastic force of the elastic element to set the locking torque of the internal gear ring; when the driving torque of the planetary gear set acting on the internal gear ring is greater than the locking torque, the first rolling element rolls along the ratchet groove and generates a jumping motion.

[0008] The second pad is rotatably sandwiched between the first pad and the third pad, and all three move axially synchronously; the second pad and the third pad form rolling contact through the second rolling element, and the second pad rotates with the gear adjustment ring to realize gear switching.

[0009] Optionally, the second gasket has a plurality of second mounting holes along its circumference, and each second mounting hole is provided with a second rolling element. A portion of the sphere of the second rolling element protrudes from the upper surface of the second gasket to form the rolling contact with the third gasket.

[0010] Optionally, the second gasket and the first gasket are in surface contact to provide frictional damping between the second gasket and the first gasket, preventing the second gasket from rotating unexpectedly due to vibration during non-shifting operations.

[0011] Optionally, the gearbox has a mounting ring that protrudes radially outward on the outer periphery corresponding to the internal gear ring. The mounting ring has a plurality of first mounting holes spaced apart circumferentially. Each of the first mounting holes is provided with a first rolling element. A portion of the spherical part of the first rolling element protrudes from the lower surface of the mounting ring to form rolling contact with the upper end face of the internal gear ring.

[0012] Optionally, the ratchet groove extends continuously circumferentially along the upper end face of the internal gear ring, and the ratchet groove has a crest and a trough. When the internal gear ring rotates, the first rolling element rolls along the ratchet groove and generates axial jump in the alternation of the crest and trough.

[0013] Optionally, the first gasket is disposed on the upper end face of the mounting ring, and the first gasket is in surface contact with the upper end face of the mounting ring.

[0014] Optionally, the inner circumference of the mounting ring is provided with positioning grooves that extend radially inward;

[0015] The first gasket has a first positioning protrusion extending radially inward at intervals on its inner circumference, and the third gasket has a third positioning protrusion extending radially inward at intervals on its inner circumference. Both the first positioning protrusion and the third positioning protrusion are embedded in the positioning groove to restrict the circumferential rotation of the first gasket and the third gasket relative to the mounting ring.

[0016] Optionally, the outer side wall of the gearbox is provided with an axially extending clearance groove, which is axially connected to the positioning groove.

[0017] The inner circumference of the second gasket is provided with locking tabs that extend radially inward;

[0018] The second washer has a first circumferential position corresponding to the screw stop, in which the locking piece is embedded in the clearance groove;

[0019] The first positioning protrusion, the locking piece, and the third positioning protrusion all have axial clearances with the clearance groove and the positioning groove, so that the first pad, the second pad, and the third pad can move synchronously along the axial direction, so as to achieve synchronous jumping when the first rolling body rolls along the ratchet groove and generates jumping.

[0020] Optionally, the outer side wall of the gearbox is provided with a plurality of locking protrusions that protrude radially outward at intervals along the circumferential direction, and each of the locking protrusions and the clearance groove are arranged alternately along the circumferential direction;

[0021] The second washer has a second circumferential position corresponding to the drill stop and the hammer stop. In the second circumferential position, the locking piece rotates circumferentially to be directly below the locking protrusion and axially abuts against the lower end face of the locking protrusion to restrict the second washer from moving axially upward.

[0022] Optionally, the gear adjustment ring is sleeved on the outer periphery of the gearbox, and the inner peripheral wall of the gear adjustment ring is provided with a plurality of radially outward protruding insertion grooves at intervals; the outer periphery of the second gasket is provided with a plurality of radially outward protruding insertion blocks at intervals along the circumferential direction, the insertion blocks are embedded in the insertion grooves, and the insertion blocks and the insertion grooves are mutually limited in the circumferential direction, so that the second gasket rotates synchronously with the gear adjustment ring;

[0023] A threaded sleeve is fitted around the outer periphery of the gearbox. The torque adjusting ring is fitted around the outer periphery of the gearbox and located axially outside the gear shift adjusting ring. The inner peripheral wall of the torque adjusting ring is threadedly connected to the outer peripheral wall of the threaded sleeve. One end of the elastic element abuts against the threaded sleeve, and the other end of the elastic element abuts against the third washer. When the torque adjusting ring rotates, it drives the threaded sleeve to move axially to adjust the elastic force of the elastic element.

[0024] The beneficial effects of the gear shifting mechanism of the impact drill of the present invention are as follows: On the one hand, by using a first rolling element to replace the traditional sliding boss structure, the sliding friction during the gear shifting process is transformed into rolling friction. This not only significantly reduces the wear rate of the contact surface, effectively extends the service life of the gearbox and maintains the long-term accuracy of the gear shifting action, but also absorbs the impact kinetic energy by utilizing the rolling characteristics of the rolling element, significantly reducing the jerking sensation at the moment of gear shifting and improving the overall operating comfort of the machine. On the other hand, by setting a second rolling element between the second and third shims, the relative motion between the two under high axial positive pressure conditions is transformed from sliding contact to rolling contact. This effectively avoids the problem of a sharp increase in friction caused by the large compression of the elastic element when the torque adjustment ring is in the maximum torque gear, significantly reduces the rotational resistance of the gear shifting ring, and ensures that the gear shifting operation is still easy and smooth under heavy load conditions, greatly improving the user's gear shifting feel and operating efficiency.

[0025] This invention, through the synergistic cooperation of a layered shim structure and dual rolling elements, systematically solves the technical contradiction between wear and operating force in traditional structures, while ensuring precise torque adjustment and stable switching between screw, drill, and hammer modes. This comprehensively improves the operational reliability and human-machine interaction quality of impact drills under long-term heavy-duty use scenarios. Attached Figure Description

[0026] Figure 1 This is a cross-sectional structural schematic diagram of a gear adjustment mechanism according to one embodiment of the present invention;

[0027] Figure 2 An exploded view of a gear adjustment mechanism according to one embodiment of the present invention;

[0028] Figure 3 This is a partial cross-sectional view of the gear adjustment mechanism of one embodiment of the present invention from another perspective.

[0029] Figure 4 This is a schematic diagram of the structure of a gearbox according to one embodiment of the present invention;

[0030] Figure 5 This is an exploded view of some components in the gear adjustment mechanism of one embodiment of the present invention.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1. Torque adjusting ring; 2. Gear adjusting ring; 21. Insertion groove; 3. Gearbox; 31. Output shaft; 32. Planetary gear set; 33. Internal gear ring; 331. Ratchet groove; 34. Planetary carrier; 35. Mounting ring; 351. First mounting hole; 352. Positioning groove; 36. Clearance groove; 37. Locking protrusion; 38. Threaded sleeve; 4. First rolling element; 5. Second rolling element; 6. First washer; 61. First positioning protrusion; 7. Second washer; 71. Second mounting hole; 72. Locking piece; 73. Insertion block; 8. Third washer; 81. Third positioning protrusion; 9. Elastic element. Detailed Implementation

[0033] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0034] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0035] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0036] like Figure 1 , Figure 2 As shown, the gear adjustment mechanism of an impact drill provided in this embodiment of the invention includes a torque adjustment ring 1, a gear adjustment ring 2 and a gearbox 3 with an output shaft 31, and also includes a first rolling element 4, a second rolling element 5 and a first shim 6, a second shim 7 and a third shim 8 arranged sequentially from bottom to top and movably disposed along the axial direction.

[0037] The gearbox 3 is provided with an internal gear ring 33 that meshes with the planetary gear set 32. The planet carrier 34 of the planetary gear set 32 ​​is fixedly connected to the output shaft 31. The upper end face of the internal gear ring 33 is provided with a ratchet groove 331 along the circumferential direction, and the first rolling element 4 is disposed in the ratchet groove 331.

[0038] The first shim 6 presses against the first rolling element 4 and applies a locking force to the internal gear ring 33 through the elastic element 9; the elastic element 9 is provided on the third shim 8, and the torque adjusting ring 1 adjusts the elastic force of the elastic element 9 to set the locking torque of the internal gear ring 33; when the driving torque of the planetary gear set 32 ​​acting on the internal gear ring 33 is greater than the locking torque, the first rolling element 4 rolls along the ratchet groove 331 and generates a jumping motion;

[0039] The second shim 7 is rotatably clamped between the first shim 6 and the third shim 8, and the three move axially synchronously; the second shim 7 and the third shim 8 form rolling contact through the second rolling element 5, and the second shim 7 rotates with the gear adjustment ring 2 to realize gear switching.

[0040] Specifically, during equipment operation, the motor drives the planetary gear set 32 ​​to rotate through the sun gear. The planetary gear set 32 ​​achieves deceleration by meshing with the internal gear ring 33 and drives the output shaft 31 to output rotational torque and impact torque.

[0041] Under normal load, the first rolling element 4 is stably pressed against the bottom of the ratchet groove 331 by the first washer 6, and the internal gear ring 33 remains locked, allowing the device to continuously output the set torque. When the screw is tightened, the output shaft 31 is restricted from rotation, and the resistance it experiences continuously increases, causing the driving torque applied to the internal gear ring 33 by the planetary gear set 32 ​​to rise synchronously. Once this driving torque exceeds the locking torque set by the torque adjusting ring 1, the first rolling element 4 overcomes the resistance of the elastic element 9, rolls along the slope of the ratchet groove 331, and pushes the first washer 6 upward, generating a momentary jump and impact release, thereby achieving torque overload protection and effectively preventing component damage.

[0042] When gear shifting is required, the user rotates the gear adjustment ring 2, causing the second washer 7 to rotate relative to the third washer 8. Since the second washer 7 and the third washer 8 form rolling contact through the second rolling element 5, the relative motion between the washers during gear shifting is changed from traditional sliding friction to rolling friction, which greatly reduces rotational resistance and makes gear shifting easy and effortless.

[0043] Utilizing a layered mating structure with three gaskets, the transmission and locking states can be precisely matched across different gear positions, stably achieving smooth, low-wear switching between screw gear (internal gear ring 33 is locked and torque is adjustable), drill gear (internal gear ring 33 is axially fixed to transmit full torque), and hammer gear (output head periodically releases to generate impact pulses). Through the differentiated engagement of two sets of rolling elements, this mechanism achieves the dual core functions of adaptive torque overload response and lightweight gear switching.

[0044] In this embodiment, by improving the contact method between the second shim 7 and the third shim 8 to a rolling contact achieved through the second rolling element 5, the sliding friction required to overcome the normal pressure during gear shifting is transformed into rolling friction, which greatly reduces the friction force. Even when the torque adjustment ring 1 is at the maximum torque position, causing the elastic element 9 to be compressed significantly and the normal pressure to increase sharply, the user can still perform gear shifting operations with a light and effortless feel, effectively solving the pain points of heavy gear shifting and laborious operation in the prior art. The rolling cooperation between the first rolling element 4 and the ratchet groove 331 replaces the traditional sliding lifting gear shifting structure of the boss and pin, resulting in minimal rolling friction wear. Even after long-term use, it can still maintain accurate gear shifting thresholds and action consistency, significantly improving gear shifting accuracy and long-term working reliability. At the same time, the rolling process of the rolling element along the ratchet groove 331 is smooth and the impact energy is dispersed, avoiding the hard impact of the sliding lifting structure and greatly improving the user comfort. The overall structure is compact, with each shim axially movable and moving synchronously. The gear shifting and torque adjustment functions are independent yet coordinated, ensuring the working reliability of the gearbox 3 and optimizing the human-machine interaction experience.

[0045] Optionally, such as Figure 3 As shown, the second gasket 7 has a plurality of second mounting holes 71 along the circumferential direction, and a second rolling element 5 is respectively provided in each second mounting hole 71. Part of the ball of the second rolling element 5 protrudes from the upper surface of the second gasket 7 to form rolling contact with the third gasket 8.

[0046] Specifically, a plurality of second mounting holes 71 adapted to the outer diameter of the second rolling element 5 are evenly provided in the circumferential direction of the second gasket 7. Each second rolling element 5 is correspondingly embedded in each second mounting hole 71, and the hole wall of the second mounting hole 71 forms a radial limit for it to prevent the second rolling element 5 from circumferentially shifting or falling off during the rotation of the second gasket 7. At the same time, part of the ball of the second rolling element 5 protrudes outward from the upper surface of the second gasket 7, so that the protruding ball surface directly forms a point contact rolling fit with the lower surface of the third gasket 8.

[0047] When the gear adjustment ring 2 causes the second shim 7 to rotate circumferentially relative to the third shim 8, the second rolling elements 5 in each of the second mounting holes 71 simultaneously perform pure rolling motion on the lower surface of the third shim 8, transforming the original whole-surface sliding friction between the second shim 7 and the third shim 8 into multiple dispersed spherical rolling frictions. Therefore, even under the large axial positive pressure applied by the elastic element 9, the circumferential rotation of the second shim 7 only needs to overcome the slight rolling resistance of each of the second rolling elements 5 to complete the rotation.

[0048] In this optional embodiment, by creating mounting holes in the second pad 7 and embedding the second rolling element 5 therein, it is ensured that the rolling element is reliably positioned and constrained under axial pressure, preventing radial movement or dislodgement, while also ensuring that the rolling element can roll freely, thereby improving the stability and consistency of the structure. Simultaneously, the design of a portion of the spherical part of the second rolling element 5 protruding from the upper surface of the second pad 7 ensures that the rolling contact point is precisely located at the critical interface between the third pad 8 and the second pad 7, which bears the maximum positive pressure of the elastic element 9. This achieves a fundamental change in the friction mode at the location where friction reduction is most needed, significantly reducing the resistance during gear shifting. Furthermore, the multiple second mounting holes 71 are evenly distributed circumferentially, ensuring a uniform distribution of rolling support force throughout the circumference. This effectively avoids uneven wear or jamming caused by uneven local force distribution, ensuring the smoothness and stability of the second pad 7 during rotation, and extending the wear life of the friction pair during long-term use, further consolidating the beneficial effects of easy gear shifting and long-term reliability.

[0049] Optionally, such as Figure 3 As shown, the second gasket 7 and the first gasket 6 are in surface contact fit to provide frictional damping between the second gasket 7 and the first gasket 6, preventing the second gasket 7 from rotating unexpectedly due to vibration during non-shifting operations.

[0050] Specifically, during operation, the axial positive pressure generated by the elastic element 9 is transmitted sequentially through the third washer 8 and the second rolling element 5 to the second washer 7, and then further downwards to the contact interface between the second washer 7 and the first washer 6. Since the two are in surface contact, the contact area is large, and under the action of the positive pressure, this interface naturally forms a certain static frictional resistance. When the user actively rotates the gear shifting ring 2 to change gears, the applied external force must first overcome the frictional damping of this interface. However, since this damping is much smaller than the frictional resistance between the third washer 8 and the second washer 7, which has been significantly reduced by the second rolling element 5, the overall gear shifting operation remains easy and effortless.

[0051] When the impact drill is in operation and the user does not operate the gear adjustment ring 2, the high-frequency vibration generated inside the machine will be transmitted to each pad assembly. At this time, the friction damping provided by the surface contact can effectively resist the small tangential torque caused by the vibration, preventing the second pad 7 from unexpectedly rotating or shifting its position under vibration excitation, thereby ensuring that the current gear is stably locked.

[0052] In this optional embodiment, firstly, by setting a surface contact fit between the second washer 7 and the first washer 6, controllable frictional damping is intentionally introduced, cleverly solving the potential side effects of the rolling contact structure—namely, insufficient friction leading to inadequate gear position stability—and achieving a delicate balance between "friction reduction" and "loosening prevention." Secondly, this frictional damping is adaptive based on axial positive pressure; that is, the greater the compression of the elastic element 9 and the greater the positive pressure, the greater the damping. This positive correlation perfectly matches the actual need for gear locking under high load conditions, eliminating the need for additional springs or locking elements, resulting in a simple structure and low cost. Thirdly, this surface contact fit only needs to overcome limited frictional resistance during gear shifting and is independent of the rolling friction between the interface of the third washer 8 and the second washer 7. It does not sacrifice shifting ease for the sake of increasing damping, achieving a balance between "smooth shifting" and "reliable gear locking."

[0053] Optionally, such as Figure 3 , Figure 4 As shown, the gearbox 3 has a mounting ring 35 that protrudes radially outward on the outer periphery of the internal gear ring 33. The mounting ring 35 has a plurality of first mounting holes 351 spaced apart in the circumferential direction. Each first mounting hole 351 is provided with a first rolling element 4. Part of the ball of the first rolling element 4 protrudes from the lower surface of the mounting ring 35 to form rolling contact with the upper end face of the internal gear ring 33.

[0054] Specifically, a radially outwardly protruding mounting ring 35 is integrally formed on the outer circumference of the gearbox 3 corresponding to the position of the internal gear ring 33, serving as the bearing base for the first rolling element 4. Several axially penetrating first mounting holes 351 are spaced apart along the circumference of the mounting ring 35. The first rolling elements 4 are successively fitted into each mounting hole, and the hole walls radially limit the first rolling elements 4, constraining them within a preset motion trajectory. A portion of the spherical part of the first rolling element 4 protrudes from the lower surface of the mounting ring 35, directly forming a rolling engagement with the ratchet groove 331 formed on the upper end face of the lower internal gear ring 33.

[0055] During actual operation, when the driving torque transmitted from the planetary gear set 32 ​​to the internal gear ring 33 exceeds the preset locking torque, the internal gear ring 33 tends to rotate under the action of the driving torque. The profile of the ratchet groove 331 pushes the first rolling element 4 to roll along the limiting space of the mounting hole. At the same time, the convex spherical surface of the first rolling element 4 rolls along the slope of the ratchet groove 331 and lifts the first washer 6 upward, realizing the overload slippage and jumping action under the screw position. During this process, the first rolling element 4 is always radially constrained by the first mounting hole 351 and will not move or fall off, ensuring that the jumping action is accurate and reliable.

[0056] In this optional embodiment, by setting a dedicated mounting ring 35 and a corresponding mounting hole structure to accommodate the first rolling element 4, not only is the uniform arrangement of the rolling element along the circumferential direction achieved, but the physical limitation of the mounting hole also prevents the rolling element from radially shifting or dislodging under high-speed impact conditions, significantly improving the stability of the structure and the assembly processability. At the same time, part of the spherical part of the first rolling element 4 protrudes from the lower surface of the mounting ring 35, so that the contact position between the rolling element and the ratchet groove 331 of the internal gear ring 33 is exactly located at the critical friction interface of the shifting action, transforming the original sliding lifting friction into rolling friction, greatly reducing the wear rate of the contact surface, and maintaining a precise shifting threshold even after long-term use. Moreover, the rolling process of the rolling element along the ratchet groove 331 is smooth and gentle, and the impact energy is dispersed and absorbed, effectively improving the comfort of use.

[0057] Optionally, such as Figure 3 As shown, the ratchet groove 331 extends continuously along the upper end face of the internal gear ring 33 in the circumferential direction. The ratchet groove 331 has a crest and a trough. When the internal gear ring 33 rotates, the first rolling element 4 rolls along the ratchet groove 331 and generates axial jump in the alternation of the crest and trough.

[0058] Specifically, during operation, the internal gear ring 33 tends to rotate around its own axis under the driving torque of the planetary gear set 32. When the driving torque is less than the locking torque set by the elastic element 9, the first rolling element 4 is pressed against the trough of the ratchet groove 331 by the first washer 6. At this time, the internal gear ring 33 is locked and cannot rotate, and the gearbox 3 is in normal torque transmission or overload protection state. Once the driving torque exceeds the locking torque, the internal gear ring 33 begins to rotate relative to the fixed mounting ring 35 and the first rolling element 4 mounted thereon. Since the ratchet groove 331 is a wavy annular track that extends continuously in the circumferential direction, while the first rolling element 4 rotates in its own mounting hole, it will climb from the trough to the crest along the contour curve of the ratchet groove 331. This climbing action forces the first rolling element 4, together with the first washer 6 pressing against it, to overcome the axial force of the elastic element 9 and move axially upward. After the first rolling element 4 passes the crest, it quickly falls into the next trough under the restoring force of the elastic element 9, thus completing a full axial roll.

[0059] When the internal gear ring 33 rotates continuously, the first rolling element 4 continuously generates periodic axial reciprocating jumps in the alternating cycle of the crest and trough, thereby achieving continuous overload slippage under the screw stop, and converting the circumferential rotation of the internal gear ring 33 into the periodic axial jumps of the first rolling element 4.

[0060] In this optional embodiment, by setting a continuously extending annular ratchet groove 331 with crests and troughs, its smoothly transitioning wave-shaped surface ensures that the first rolling element 4 has no rigid jamming points during the entire rolling process, significantly reducing the wear rate between the rolling element and the groove wall. This effectively avoids the failure problems such as tooth tip breakage and wear deformation that are prone to occur after long-term use of traditional ratchet structures, and makes the axial runout process during overload slippage more gentle and smooth, eliminating the severe impact noise common in traditional pawl structures. At the same time, the structural characteristic of the ratchet groove 331 extending continuously in the circumferential direction allows the internal gear ring 33 to achieve continuous slippage at any rotation angle, without being limited by the angle step caused by the number of discrete ratchet teeth, thereby making the torque overload protection response of the screw stop more sensitive and the action more continuous and smooth.

[0061] Optionally, such as Figure 3 , Figure 4 As shown, the first gasket 6 is disposed on the upper end face of the mounting ring 35, and the first gasket 6 is in surface contact with the upper end face of the mounting ring 35.

[0062] Specifically, the first washer 6 is placed against the upper end face of the mounting ring 35 of the gearbox 3, and the two form a surface contact fit with their flat end faces. When the first rolling element 4 is driven upward by the ratchet groove 331 on the internal gear ring 33, the first washer 6 moves smoothly along the end face of the mounting ring 35 with a small axial stroke, and remains coaxial and non-skewed throughout the movement, thereby uniformly transmitting the lifting force generated by the first rolling element 4 to the second washer 7, the third washer 8 and the elastic element 9 above.

[0063] In this optional embodiment, the surface contact structure can provide full circumferential restraint for the first gasket 6, effectively preventing it from swaying or jamming during axial movement; at the same time, the structure can evenly distribute the axial pressure to the end face of the mounting ring 35, reducing wear and deformation of parts caused by local stress concentration.

[0064] Optionally, such as Figure 4 , Figure 5 As shown, the inner circumference of the mounting ring 35 is provided with positioning grooves 352 that extend radially inward at intervals.

[0065] The inner circumference of the first gasket 6 is provided with a first positioning protrusion 61 extending radially inward, and the inner circumference of the third gasket 8 is provided with a third positioning protrusion 81 extending radially inward. Both the first positioning protrusion 61 and the third positioning protrusion 81 are embedded in the positioning groove 352 to restrict the circumferential rotation of the first gasket 6 and the third gasket 8 relative to the mounting ring 35.

[0066] Specifically, the mounting ring 35 has several radial positioning grooves 352 spaced circumferentially on its inner circumference. These positioning grooves 352 simultaneously accommodate the first positioning protrusion 61 on the inner circumference of the first gasket 6 and the third positioning protrusion 81 on the inner circumference of the third gasket 8. The sidewall of the positioning groove 352 forms a circumferential limit on the two protrusions, so that the first gasket 6 and the third gasket 8 can only move up and down along the axial direction of the positioning groove 352. Their circumferential rotational freedom relative to the mounting ring 35 is completely locked, leaving only axial movement space. This ensures that the two gaskets remain circumferentially fixed with the gearbox 3 during gear shifting and torque adjustment, and will not be affected by the rotation of the second gasket 7.

[0067] In this optional embodiment, the circumferential anti-rotation limit of the two components, the first gasket 6 and the third gasket 8, can be achieved simultaneously through the same set of positioning grooves 352. There is no need to set up independent anti-rotation structures for each gasket, which greatly simplifies the part layout and assembly process, and effectively avoids the problem of the first gasket 6 and the third gasket 8 rotating unexpectedly due to vibration or shifting action.

[0068] Optionally, such as Figure 4 , Figure 5 As shown, the outer side wall of the gearbox 3 is provided with an axially extending clearance groove 36, which is axially connected to the positioning groove 352.

[0069] The inner circumference of the second gasket 7 is provided with locking pieces 72 that extend radially inward;

[0070] The second washer 7 has a first circumferential position corresponding to the screw stop, in which the locking piece 72 is embedded in the relief groove 36;

[0071] The first positioning protrusion 61, the locking piece 72, and the third positioning protrusion 81 all have axial clearances with the clearance groove 36 and the positioning groove 352, so that the first shim 6, the second shim 7, and the third shim 8 can move synchronously along the axial direction, so as to achieve synchronous jumping when the first rolling body 4 rolls along the ratchet groove 331 and generates jumping.

[0072] Specifically, the axial clearance groove 36 on the outer wall of the gearbox 3 is axially connected to the positioning groove 352 of the mounting ring 35. When the locking piece 72 on the inner circumference of the second washer 7 is in the first circumferential position corresponding to the screw stop, it is precisely embedded in the clearance groove 36. At the same time, the first positioning protrusion 61, the locking piece 72 and the third positioning protrusion 81 are reserved with a uniform axial gap between the clearance groove 36 and the positioning groove 352. When the first rolling body 4 rolls along the ratchet groove 331 and generates axial lifting and jumping, the first washer 6, the second washer 7 and the third washer 8 can be lifted synchronously along the axial direction without jamming, so that the entire three-piece washer assembly can complete the synchronous axial jumping action with the first rolling body 4.

[0073] In this optional embodiment, the locking piece 72 and the clearance groove 36 are engaged to achieve circumferential locking of the second washer 7 and the gearbox 3, preventing the second washer 7 from rotating unexpectedly due to vibration during screw operation. At the same time, the uniformly reserved axial clearance ensures the synchronous axial runout of the three washer pieces, which will not interfere with the torque overload slippage function under the screw position, and there is no need to add an additional independent gear locking part, simplifying the overall structure and further improving the reliability of gear positioning and the consistency of operation feel.

[0074] Optionally, such as Figure 4 , Figure 5 As shown, the outer side wall of the gearbox 3 is provided with a number of locking protrusions 37 that protrude radially outward at intervals along the circumference, and each locking protrusion 37 and the relief groove 36 are arranged alternately along the circumference.

[0075] The second washer 7 has a second circumferential position corresponding to the drill stop and the hammer stop. In the second circumferential position, the locking piece 72 rotates circumferentially to be directly below the locking protrusion 37 and axially abuts against the lower end face of the locking protrusion 37 to restrict the second washer 7 from moving upward in the axial direction.

[0076] Specifically, the locking protrusions 37 and clearance grooves 36 arranged alternately along the circumference of the outer wall of the gearbox 3, during the process of the second washer 7 rotating from the first circumferential position of the screw stop to the second circumferential position corresponding to the drill stop and hammer stop, the locking piece 72 originally embedded in the clearance groove 36 rotates synchronously with the second washer 7 and eventually moves to the bottom of the locking protrusion 37. At this time, the upper end face of the locking piece 72 and the lower end face of the locking protrusion 37 form an axial abutment. The locking protrusion 37 completely restricts the upward movement of the second washer 7 through mechanical limiting. Even if the first rolling element 4 is driven by the internal gear ring 33 to generate an axial lifting force, it cannot drive the second washer 7 to rise, thereby cutting off the torque slippage path under the drill stop and hammer stop and realizing the rigid transmission locking of the corresponding gear position.

[0077] In this optional embodiment, the axial movement authority can be switched between different gears by means of the circumferentially alternating clearance grooves 36 and locking protrusions 37, relying solely on the circumferential rotation of the second washer 7. In the screw gear, the locking piece 72 can jump synchronously with the washer assembly to retain the torque overload function. In the drill and hammer gears, the locking piece 72 is axially limited by the locking protrusions 37 and completely locks the upward stroke, thus completely avoiding the problem of slippage and free rotation in the drill and hammer gears. There is no need to set up an additional independent gear clutch part, which greatly improves the reliability and structural compactness of multi-gear switching.

[0078] Optionally, such as Figure 5 As shown, the gear adjustment ring 2 is sleeved on the outer periphery of the gearbox 3, and the inner peripheral wall of the gear adjustment ring 2 is provided with a plurality of radially outward protruding insertion grooves 21 at intervals; the outer periphery of the second gasket 7 is provided with a plurality of radially outward protruding insertion blocks 73 at intervals along the circumferential direction, the insertion blocks 73 are embedded in the insertion grooves 21, and the insertion blocks 73 and the insertion grooves 21 are mutually limited in the circumferential direction, so that the second gasket 7 rotates synchronously with the gear adjustment ring 2.

[0079] A threaded sleeve 38 is also fitted around the outer periphery of the gearbox 3. The torque adjusting ring 1 is fitted around the outer periphery of the gearbox 3 and is located axially outside the gear position adjusting ring 2. The inner peripheral wall of the torque adjusting ring 1 is threadedly connected to the outer peripheral wall of the threaded sleeve 38. One end of the elastic element 9 abuts against the threaded sleeve 38, and the other end of the elastic element 9 abuts against the third washer 8. When the torque adjusting ring 1 rotates, it drives the threaded sleeve 38 to move axially to adjust the elastic force of the elastic element 9.

[0080] Specifically, the gear adjustment ring 2 forms a circumferential engagement limit with the insertion block 73 on the outer periphery of the second washer 7 through the insertion groove 21 on its inner circumferential wall. When the gear adjustment ring 2 is rotated, it can directly drive the second washer 7 to rotate synchronously in the circumferential direction, realizing the precise switching of the circumferential position of the second washer 7 in different gear positions. The torque adjustment ring 1 cooperates with the threaded sleeve 38 on the outer periphery of the gearbox 3 through its internal thread. When the torque adjustment ring 1 is rotated, it can drive the threaded sleeve 38 to move back and forth along the axial direction of the gearbox 3 to adjust the axial compression of the elastic element 9 between the threaded sleeve 38 and the third washer 8, thereby precisely changing the axial preload applied by the elastic element 9 to the third washer 8, and finally realizing the continuous adjustment of the locking torque under the screw position.

[0081] In this optional embodiment, a plug-in circumferential transmission structure enables high-torque synchronous transmission between the gear adjustment ring 2 and the second washer 7, facilitating assembly and eliminating the risk of circumferential slippage during long-term use. Simultaneously, the threaded engagement between the threaded sleeve 38 and the torque adjustment ring 1 allows for precise adjustment of the elastic force of the elastic element 9, significantly improving the accuracy of torque setting and the feel of gear shifting. The overall structure is compact and rationally designed, perfectly suited to the limited internal space of the impact drill gearbox 3.

[0082] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A gear adjustment mechanism for an impact drill, comprising a torque adjustment ring, a gear adjustment ring, and a gearbox with an output shaft, characterized in that: It includes a first rolling element, a second rolling element, and a first gasket, a second gasket, and a third gasket arranged sequentially from bottom to top and movable along the axial direction; The gearbox is provided with an internal gear ring that meshes with the planetary gear set, and the planet carrier of the planetary gear set is fixedly connected to the output shaft; the upper end face of the internal gear ring is provided with a ratchet groove along the circumferential direction, and the first rolling element is disposed in the ratchet groove; The first washer presses against the first rolling element and applies a locking force to the internal gear ring through an elastic element; The elastic element is disposed on the third gasket, and the torque adjusting ring adjusts the elastic force of the elastic element to set the locking torque of the internal gear ring; When the driving torque of the planetary gear set acting on the internal gear ring is greater than the locking torque, the first rolling element rolls along the ratchet groove and generates a jumping motion. The second pad is rotatably sandwiched between the first pad and the third pad, and all three move axially synchronously; the second pad and the third pad form rolling contact through the second rolling element, and the second pad rotates with the gear adjustment ring to realize gear switching; The gearbox has a mounting ring that protrudes radially outward on the outer periphery corresponding to the internal gear ring. The mounting ring has a plurality of first mounting holes spaced apart circumferentially. Each of the first mounting holes is provided with a first rolling element. A portion of the spherical part of the first rolling element protrudes from the lower surface of the mounting ring to form a rolling contact with the upper end face of the internal gear ring. The first gasket is disposed on the upper end face of the mounting ring, and the first gasket is in surface contact with the upper end face of the mounting ring; The mounting ring has a positioning groove that extends radially inward at intervals on its inner circumference. The first gasket has a first positioning protrusion extending radially inward at intervals on its inner circumference, and the third gasket has a third positioning protrusion extending radially inward at intervals on its inner circumference. Both the first positioning protrusion and the third positioning protrusion are embedded in the positioning groove to restrict the circumferential rotation of the first gasket and the third gasket relative to the mounting ring. The outer wall of the gearbox is provided with an axially extending clearance groove, which is axially connected to the positioning groove. The inner circumference of the second gasket is provided with locking tabs that extend radially inward; The second washer has a first circumferential position corresponding to the screw stop, in which the locking piece is embedded in the clearance groove; The first positioning protrusion, the locking piece, and the third positioning protrusion all have axial clearances with the clearance groove and the positioning groove, so that the first pad, the second pad, and the third pad can move synchronously along the axial direction, so as to achieve synchronous jumping when the first rolling body rolls along the ratchet groove and generates jumping. The outer side wall of the gearbox is provided with a plurality of locking protrusions that protrude radially outward at intervals along the circumference, and each of the locking protrusions and the clearance groove are arranged alternately along the circumference. The second washer has a second circumferential position corresponding to the drill stop and the hammer stop. In the second circumferential position, the locking piece rotates circumferentially to be directly below the locking protrusion and axially abuts against the lower end face of the locking protrusion to restrict the second washer from moving axially upward.

2. The gear adjustment mechanism for the impact drill according to claim 1, characterized in that, The second gasket has a plurality of second mounting holes along its circumference, and each second mounting hole is provided with a second rolling element. A portion of the sphere of the second rolling element protrudes from the upper surface of the second gasket to form the rolling contact with the third gasket.

3. The gear adjustment mechanism of the impact drill according to claim 1, characterized in that, The second gasket and the first gasket are in surface contact fit to provide frictional damping between the second gasket and the first gasket, preventing the second gasket from rotating unexpectedly due to vibration during non-shifting operations.

4. The gear adjustment mechanism of the impact drill according to claim 1, characterized in that, The ratchet groove extends continuously along the upper end face of the internal gear ring in the circumferential direction. The ratchet groove has a crest and a trough. When the internal gear ring rotates, the first rolling element rolls along the ratchet groove and generates axial jump in the alternation of the crest and trough.

5. The gear adjustment mechanism of the impact drill according to claim 1, characterized in that, The gear adjustment ring is sleeved on the outer periphery of the gearbox, and the inner peripheral wall of the gear adjustment ring is provided with a plurality of radially outward protruding insertion grooves at intervals; the outer periphery of the second gasket is provided with a plurality of radially outward protruding insertion blocks at intervals along the circumferential direction, the insertion blocks are embedded in the insertion grooves, and the insertion blocks and the insertion grooves are mutually limited in the circumferential direction, so that the second gasket rotates synchronously with the gear adjustment ring; A threaded sleeve is fitted around the outer periphery of the gearbox. The torque adjusting ring is fitted around the outer periphery of the gearbox and located axially outside the gear shift adjusting ring. The inner peripheral wall of the torque adjusting ring is threadedly connected to the outer peripheral wall of the threaded sleeve. One end of the elastic element abuts against the threaded sleeve, and the other end of the elastic element abuts against the third washer. When the torque adjusting ring rotates, it drives the threaded sleeve to move axially to adjust the elastic force of the elastic element.

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