A gearbox structure that can be disengaged from the transmission connection

Abstract

This utility model discloses a gearbox structure that can be disengaged from the transmission connection, relating to the field of gear transmission technology. It includes a housing, a motor, a gear set, a torsion spring, and an output shaft. The motor drives the output shaft to rotate via the gear set. The gear set includes multiple sets of gears meshing sequentially. The gear driving the output shaft has an inner hole formed on it. The torsion spring is fitted into the inner hole with a clearance fit. Several stopping points are provided on the inner wall of the inner hole. The openings at both ends of the torsion spring have outer curved edges formed, and the stopping points abut against the outer curved edges. The output shaft is fitted into the inner ring of the torsion spring with a clearance fit. Compared with the prior art, this utility model allows the output shaft to completely disengage from the gear set and rotate freely after the motor stops, without needing to overcome additional resistance, resulting in extremely low noise during manual adjustment. When the motor is driven, the stopping points push the outer curved edges of the torsion spring, causing the torsion spring to deform and grip the output shaft, forming a self-locking effect through friction, resulting in more stable power transmission and higher transmission efficiency.

Description

Technical Field

[0001] This utility model relates to the field of gear transmission technology, and in particular to a gearbox structure that can be detached from the transmission connection. Background Technology

[0002] In gearbox applications, achieving disengagement or manual adjustment of the output end has always been a technical challenge in the industry. When a conventional gearbox is running, due to the meshing between gears and the magnetic pull of the motor, a large torque is often required to drive the entire transmission structure if a torsional operation is performed from the output end, and it may even fail to rotate, seriously affecting the user's manual operation experience.

[0003] To address this issue, existing technologies often employ solutions such as elastic clutch structures and bidirectional (one-way) sawtooth clutch structures. The core idea behind these structures is to add additional components to create an indirect connection between the output section and the front-end meshing structure, thereby reducing the torque during reverse torque and enabling a certain degree of disengagement or manual twisting of the output shaft.

[0004] Taking the speed reduction device disclosed in announcement number CN211574211U as an example, it achieves gear disengagement through multiple components such as spline sleeve, spring, and adjusting plate. Not only are there many parts and assembly is difficult, but the axial sliding structure also occupies a lot of space, making it unsuitable for the design requirements of ultra-thin gearboxes.

[0005] Similarly, the gear assembly in announcement number CN 210074993 U adopts a multi-stage gear meshing + transmission shaft structure. When manually reversed, it is necessary to overcome the meshing resistance of all gears, making the operation extremely laborious.

[0006] A sawtooth clutch, taking an automatic slack adjuster as an example, can achieve unidirectional transmission, but when operating in the reverse direction, it still needs to overcome the meshing friction of the saw teeth. This not only generates obvious noise, but also results in a large torque when manually reversing, leading to a poor user experience.

[0007] However, the elastic clutch structure, such as the reduction device disclosed in announcement number CN211574211U that facilitates disengagement from the motor, does not achieve complete non-contact disengagement between the output shaft and the gear, and there is still continuous frictional resistance during manual operation.

[0008] None of the aforementioned structures achieves complete non-contact disengagement between the output and meshing parts; the output remains connected to the meshing part. This results in significant noise and the need to overcome a certain torque during reverse torque operation, failing to fundamentally improve the user's manual operation experience. Furthermore, it is difficult to avoid impact damage to the gears caused by reverse torque of the output shaft. Utility Model Content

[0009] To overcome the shortcomings mentioned above, this utility model provides a technical solution that can solve the above problems.

[0010] A gearbox structure that can be disengaged from the transmission connection includes a housing, a motor, a gear set, a torsion spring, and an output shaft. The housing has a receiving cavity, in which the motor and the gear set are installed. The output shaft is rotatably mounted in the housing, and the motor drives the output shaft to rotate through the gear set. The gear set includes multiple sets of gears meshing in sequence. The gear driving the output shaft has an inner hole formed on it. A torsion spring is installed in the inner hole with clearance fit. Several stop points are provided on the inner wall of the inner hole. The openings at both ends of the torsion spring are formed with outer curved edges. The stop points abut against the outer curved edges. The output shaft is installed in the inner ring of the torsion spring with clearance fit. The outer curved edges of the openings at both ends of the torsion spring form an angle of 20-80°, and the blocking point is located outside the angle of the torsion spring openings.

[0011] Furthermore: a baffle is installed in the inner hole with clearance fit, and a through hole is formed in the middle of the baffle. The upper end of the output shaft is inserted into the through hole with clearance fit. Several limiting edges are formed on the upper side of the baffle. The number of limiting edges is the same as the number of blocking points, and the limiting edges and blocking points are staggered. When the torsion spring elastically resets, the outer bent edge abuts against the limiting edge.

[0012] Furthermore: the torsion spring is provided in more than one form.

[0013] Furthermore: the gear set includes a worm, a worm wheel, a first transmission gear, a second transmission gear, and a third transmission gear that are sequentially meshed. The motor drives the worm to rotate, and the worm transmits power to the third transmission gear through the meshing of the worm wheel, the first transmission gear, and the second transmission gear. The inner hole is integrally formed and located at the center of the bottom side of the third transmission gear.

[0014] Furthermore, the worm gear, the first transmission gear, the second transmission gear, and the third transmission gear are all rotatably fitted within the housing cavity of the housing.

[0015] Furthermore: the housing includes an upper cover and a lower cover, which are spliced ​​and assembled together, and the output shaft is rotatably mounted on the lower cover.

[0016] Furthermore, the upper cover and the lower cover are connected by screws or snaps.

[0017] Compared with the prior art, the beneficial effects of this utility model are: 1. Manual operation is more convenient. After the motor stops, the torsion spring and the output shaft return to a clearance fit. The output shaft can completely disengage from the gear set and rotate freely without overcoming additional resistance. Operation is more effortless and there is no frictional contact. The noise during manual adjustment is extremely low, greatly improving the user experience.

[0018] 2. The structure is simple and compact. The torsion spring is installed in the inner hole of the gear. Only two core components, the torsion spring and the baffle, are added. The number of parts is small, which ensures the overall compactness of the design and makes it easier to control the axial thickness of the gearbox. It can be adapted to use in ultra-thin and miniaturized equipment.

[0019] 3. Reliable and efficient transmission: When driven by the motor, the stop point pushes the outer curved edge of the torsion spring, causing the torsion spring to deform and hug the output shaft. With the help of friction, a self-locking effect of "the more it rotates, the tighter it becomes" is formed, making the power transmission more stable and the transmission efficiency higher.

[0020] 4. Extend equipment life: During manual operation, the output shaft and gear set are in a completely non-contact state, and the reverse torque will not damage the gears. The baffle limit edge can prevent the torsion spring from over-resetting and failing, thus ensuring the service life of the torsion spring and gears.

[0021] 5. Easy assembly and maintenance with low cost: The upper and lower covers are connected by screws or clips, and the torsion springs are fitted in a clearance fit. The assembly process is simple and fast. The torsion springs and baffles are standardized parts, which reduces the cost of procurement and maintenance and makes them suitable for mass production.

[0022] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0023] 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 these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 yes Figure 1 A structural diagram from another perspective; Figure 3 This is an exploded structural diagram of the present invention; Figure 4 This is a schematic diagram of the installation structure of the torsion spring of this utility model; Figure 5 This is a schematic diagram of the structure of the torsion spring of this utility model; Figure 6 yes Figure 5 A structural diagram from another perspective; Figure 7 This is a cross-sectional structural diagram of the present invention.

[0025] The following components are shown in the diagram: 1. Housing; 1.1. Top cover; 1.2. Bottom cover; 2. Motor; 3. Gear set; 3.1. Worm; 3.2. Worm wheel; 3.3. First transmission gear; 3.4. Second transmission gear; 3.5. Third transmission gear; 4. Torsion spring; 5. Output shaft; 6. Receiving cavity; 7. Inner hole; 8. Stop; 9. Outer bend; 10. Baffle; 11. Through hole; 12. Limiting edge. Detailed Implementation

[0026] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0027] The components of the present invention embodiments described and shown in the accompanying drawings can typically be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0028] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0029] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] like Figure 1-7As shown, the present invention provides a gearbox structure that can be disengaged from the transmission connection, including a housing 1, a motor 2, a gear set 3, a torsion spring 4, and an output shaft 5. The housing 1 is provided with a receiving cavity 6, and the motor 2 and the gear set 3 are both installed in the receiving cavity 6. The output shaft 5 is rotatably installed in the housing 1, and the motor 2 drives the output shaft 5 to rotate through the gear set 3. The gear set 3 includes multiple sets of gears meshing in sequence. The gear driving the output shaft 5 has an inner hole 7 formed on it. The torsion spring 4 is installed in the inner hole 7 with clearance fit. Several stop points 8 are provided on the inner wall of the inner hole 7. The openings at both ends of the torsion spring 4 are formed with outer curved edges 9. The stop points 8 abut against the outer curved edges 9. The output shaft 5 is installed in the inner ring of the torsion spring 4 with clearance fit. The outer curved edges 9 of the openings at both ends of the torsion spring 4 form an angle of 20-80°, and the blocking point 8 is located outside the angle of the openings of the torsion spring 4.

[0032] The principle is as follows: Under the basic kinematic relationship, the torsion spring 4 is installed in the inner hole 7 of the gear. The outer circle of the torsion spring 4 and the inner hole 7 of the gear are fixedly fitted (such as an interference fit or a positioning structure to restrict relative rotation). Therefore, when the gear rotates, the torsion spring 4 will rotate synchronously with the gear.

[0033] In the initial state when the motor 2 stops working, the inner ring of the torsion spring 4 is in clearance fit with the output shaft 5 (the diameter of the inner ring of the torsion spring 4 is slightly larger than the diameter of the output shaft 5). At this time, although the torsion spring 4 rotates with the gear, it has no frictional contact with the output shaft 5, and the output shaft 5 can rotate freely (i.e., not tightly closed), realizing the complete separation between the output shaft 5 and the gear set 3, which facilitates the manual reverse torque of the output shaft 5.

[0034] When motor 2 drives gear set 3 to rotate forward (e.g., clockwise), torsion spring 4 will rotate along with the gear. At the same time, the torque of rotation causes torsion spring 4 to undergo active deformation, so that the inner ring of torsion spring 4 grips the output shaft 5. The specific process is as follows: As the gear rotates synchronously, the stop point 8 of the gear inner hole 7 will directly impact the outer curved edge 9 at the opening of the torsion spring 4 (because the stop point 8 is located outside the included angle of the opening of the torsion spring 4). This impact force will force the opening angle of the torsion spring 4 to shrink (such as from the initial 60° to 30°). At this time, the diameter of the inner ring of the torsion spring 4 will decrease accordingly, and the clearance fit between the output shaft 5 and the inner ring of the torsion spring 4 will change to an interference fit. At this time, the inner ring of the torsion spring 4 and the surface of the output shaft 5 will come into contact with each other and generate friction. When the torsion spring 4 rotates clockwise with the gear, the contact friction between the torsion spring 4 and the output shaft 5 is opposite to the resistance direction of the output shaft 5. Assuming the gear rotates clockwise, the torsion spring 4 rotates clockwise with the gear, and the output shaft 5 has a counterclockwise resistance torque due to the load. At this time, the friction between the inner ring of the torsion spring 4 and the output shaft 5 will further tighten the torsion spring 4 (similar to the tightening effect when wringing a towel), causing the inner ring diameter of the torsion spring 4 to further decrease. The clamping force will increase with the increase of the resistance of the output shaft 5, forming a mechanical self-locking principle that gets tighter as it rotates. After the torsion spring 4 clamps the output shaft 5, the rotational force of the gear is self-locked to the output shaft 5 through the friction of the torsion spring 4, so that the output shaft 5 rotates synchronously with the gear and the torsion spring 4. At this time, the three (gear, torsion spring 4, and output shaft 5) form a rigid transmission system, realizing power output.

[0035] To prevent the torsion spring 4 from spinning freely and failing to engage properly when rotating with the gear, the following design parameters are required: 1. The opening angle of the outer curved edge 9 of the torsion spring 4 and the position of the stop point 8: The opening angle must be greater than the initial gap between the stop point 8 and the torsion spring 4 (e.g., if the opening is 60°, the initial gap between the stop point 8 and the torsion spring 4 is 30°) to ensure that the stop point 8 can effectively push the torsion spring 4 to deform when rotating forward. 2. The spring constant of torsion spring 4: It needs to match the load torque of output shaft 5. If the spring constant is too small, it will result in insufficient clamping force. If the spring constant is too large, it will increase the driving load of motor 2. It is usually balanced by calculating the wire diameter (0.8-1.5mm) and number of coils (2-4 coils) of torsion spring 4. 3. Fitting accuracy between torsion spring 4 and output shaft 5: The initial gap needs to be controlled within 0.1-0.3mm to ensure that the output shaft 5 can rotate freely and that the torsion spring 4 can quickly form an interference fit with the output shaft 5 after deformation.

[0036] Furthermore: A baffle 10 is fitted in the inner hole 7 with a clearance fit. A through hole 11 is formed in the middle of the baffle 10. The upper end of the output shaft 5 is inserted into the through hole 11 with a clearance fit. Several limiting edges 12 are formed on the upper side of the baffle 10. The number of limiting edges 12 is the same as the number of blocking points 8. The limiting edges 12 and the blocking points 8 are staggered. When the torsion spring 4 elastically resets, the outer bent edge 9 abuts against the limiting edge 12.

[0037] The limiting edge 12 of the baffle 10 is placed within the inner hole 7. The baffle 10 is not an independent rotating component, but rather a part of the gear inner hole 7 that is inserted and fitted together. Its limiting edge 12 and the stop point 8 are both protruding structures within the inner hole 7. The stop point 8 and the limiting edge 12 have different functions, among which: 1. Stop 8: Located on the active force-bearing side of the outer curved edge 9 of the torsion spring 4, it directly pushes the torsion spring 4 to deform when the gear rotates; 2. Limiting edge 12: Located on the passive limiting side of the outer curved edge 9 of the opening of the torsion spring 4, it is "asymmetrically distributed" with the stop point 8 on the inner wall of the gear hole 7 (the included angle is greater than the opening angle of the torsion spring 4). Its function is to limit the torsion spring 4 from being over-opened, rather than to transmit rotational force.

[0038] The through hole 11 inside the baffle 10 ensures the stable rotation of the output shaft 5, and the limiting edge 12 prevents the torsion spring 4 from over-resetting, ensuring the stability of the torsion spring 4 in each self-locking of the output shaft 5.

[0039] Furthermore, the torsion spring 4 is provided in more than one form, which can achieve a better self-locking effect.

[0040] Furthermore, the gear set 3 includes a worm 3.1, a worm wheel 3.2, a first transmission gear 3.3, a second transmission gear 3.4, and a third transmission gear 3.5 that are sequentially meshed. The motor 2 drives the worm 3.1 to rotate. The worm 3.1 transmits power to the third transmission gear 3.5 through the meshing of the worm wheel 3.2, the first transmission gear 3.3, and the second transmission gear 3.4. The inner hole 7 is integrally formed and located at the center of the bottom side of the third transmission gear 3.5. The stable operation of the motor 2 can be achieved through the cooperation of the worm 3.1 and the worm wheel 3.2. The third transmission gear 3.5 is driven to operate through the meshing connection between the worm wheel 3.2, the first transmission gear 3.3, and the second transmission gear 3.4. The transmission speed can be adjusted by adjusting the module, number of teeth, diameter, and other parameters of each gear. It can be applied to accelerators and reducers, and has a wider range of applications.

[0041] Furthermore, the worm gear 3.2, the first transmission gear 3.3, the second transmission gear 3.4, and the third transmission gear 3.5 are all rotatably fitted into the receiving cavity 6 of the housing 1, making the installation of the gear set 3 in the receiving cavity 6 more stable.

[0042] Furthermore: the housing 1 includes an upper cover 1.1 and a lower cover 1.2, which are spliced ​​together. The output shaft 5 is rotatably mounted on the lower cover 1.2. Since the upper cover 1.1 and the lower cover 1.2 can be spliced ​​together, maintenance can be achieved by disassembling the housing 1 in case of failure, thereby reducing maintenance costs.

[0043] Furthermore, the upper cover 1.1 and the lower cover 1.2 are connected by screws or snaps, which allows for quick assembly and disassembly of the upper cover 1.1 and the lower cover 1.2, facilitating practical use.

[0044] This embodiment does not impose any limitation on the shape, material, structure, etc. of this utility model. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this utility model shall fall within the protection scope of this utility model.

Claims

1. A gearbox structure that can be disengaged from the transmission connection, characterized in that: It includes a housing, a motor, a gear set, a torsion spring, and an output shaft. The housing has a receiving cavity, in which the motor and gear set are installed. The output shaft is rotatably mounted in the housing, and the motor drives the output shaft to rotate through the gear set. The gear set includes multiple sets of gears meshing in sequence. The gear driving the output shaft has an inner hole formed on it. A torsion spring is installed in the inner hole with clearance fit. Several stop points are provided on the inner wall of the inner hole. The openings at both ends of the torsion spring are formed with outer curved edges. The stop points abut against the outer curved edges. The output shaft is installed in the inner ring of the torsion spring with clearance fit. The outer curved edges of the openings at both ends of the torsion spring form an angle of 20-80°, and the blocking point is located outside the angle of the torsion spring openings.

2. The gearbox structure detachable from the transmission connection according to claim 1, characterized in that: A baffle is installed in the inner hole with clearance fit. A through hole is formed in the middle of the baffle. The upper end of the output shaft is inserted into the through hole with clearance fit. Several limiting edges are formed on the upper side of the baffle. The number of limiting edges is the same as the number of blocking points. The limiting edges and blocking points are staggered from each other. When the torsion spring is elastically reset, the outer bent edge abuts against the limiting edge.

3. A gearbox structure detachable from the transmission connection according to any one of claims 1 or 2, characterized in that: There is one or more torsion springs.

4. The gearbox structure detachable from the transmission connection according to claim 1, characterized in that: The gear set includes a worm, a worm wheel, a first transmission gear, a second transmission gear, and a third transmission gear that are sequentially meshed. The motor drives the worm to rotate, and the worm transmits power to the third transmission gear through the meshing of the worm wheel, the first transmission gear, and the second transmission gear. The inner hole is integrally formed and located at the center of the bottom side of the third transmission gear.

5. A gearbox structure detachable from the transmission connection according to claim 4, characterized in that: The worm gear, the first transmission gear, the second transmission gear, and the third transmission gear are all rotatably fitted into the housing cavity of the housing.

6. The gearbox structure detachable from the transmission connection according to claim 1, characterized in that: The housing includes an upper cover and a lower cover, which are spliced ​​and assembled together, and the output shaft is rotatably mounted on the lower cover.

7. A gearbox structure detachable from the transmission connection according to claim 6, characterized in that: The upper and lower covers are connected by screws or clips.

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