A logarithmic spiral movable tooth transmission precision reduction device

Abstract

The present invention relates to a logarithmic spiral movable tooth transmission precision reduction device, belonging to the technical field of industrial transmission machinery, comprising two transmission components, the transmission component comprising a single-wave cam, a movable component and an inner gear ring, the cam is arranged in a movable component including a plurality of movable components, and the cam and the movable component are in contact in a relatively rotatable manner, the inner gear ring is sleeved on the outer side of the movable component and meshes with the movable component, so that the inner gear ring and the movable component perform meshing movement; the two transmission components are connected facing each other, and the two cams in the two transmission components are arranged in a manner that the initial positions differ by 180°, so that the two cams form a motion structure with relatively balanced forces. The present invention assembles and connects the two cam components in a manner that the long semi-axis corresponds to the short semi-axis, solves the problem of unbalanced forces on the single-wave cam, and is used to achieve a transmission effect with high reduction ratio, high precision and low backlash.

Description

Technical Field

[0001] The invention relates to the technical field of industrial transmission machinery, and in particular to a logarithmic spiral movable tooth transmission precision reduction device. Background Art

[0002] At present, commonly used precision reducers mainly include harmonic reducers and planetary gear reducers. Harmonic reducer is a flexible transmission structure, which consists of three components: wave generator, flexible wheel and rigid wheel. With the continuous advancement of technology and the reduction of costs, harmonic reducers are gradually widely used in industrial robots, precision instruments, medical equipment and other fields. Its working principle is to drive the gear meshing between the flexible wheel and the rigid wheel through the elliptical deformation generated by the wave generator to generate relative motion, thereby achieving a transmission effect with high reduction ratio, high precision and low backlash. Although harmonic reducers are prone to fatigue and wear under high-speed operation and high-load conditions, their durability and reliability have been significantly improved by using high-strength materials and advanced manufacturing processes.

[0003] The planetary gear reducer is a compact and efficient transmission device, which consists of four parts: sun gear, planetary gear, inner ring gear and cage. This reducer achieves deceleration by rotating the planetary gear around the sun gear, and has high load-bearing capacity, high transmission efficiency and compact size. Planetary gear reducers are widely used in automation equipment, engineering machinery, automotive transmission systems and other fields. They can adapt to different input and output configurations and realize various forms of deceleration or speed-up transmission. With the development of materials science and manufacturing technology, the performance of planetary gear reducers has been continuously improved, such as the use of high-strength alloy materials, precision processing technology and advanced lubrication systems to improve their working efficiency and service life.

[0004] In addition, the new movable tooth transmission reducer is a new transmission form evolved from the KHV type differential planetary gear transmission. It transforms the rigid connection between the planetary gear teeth and the hub into a flexible hinge, making the planetary gear teeth a group of independent moving bodies that can circulate. This design improves the flexibility and adaptability of the transmission, reduces the mutual interference between gears, and thus improves the transmission efficiency and stability. The new movable tooth transmission reducer has broad application prospects in the fields of precision reduction devices, robot joints, and precision positioning systems. Its high precision and high reliability make it an important development direction for future precision transmission technology. However, the new movable tooth transmission reducer still faces some technical challenges in the design and manufacturing process, such as how to ensure that the independent motion characteristics of the movable teeth remain stable and efficient under various working conditions.

[0005] CN113503353A discloses a logarithmic spiral conjugate tooth profile harmonic reducer, comprising a rigid wheel, a flexible wheel, a wave generator and a flexible bearing. The tooth profiles of the rigid wheel and the flexible wheel in the meshing state are designed by using curves of two different intervals on the same logarithmic spiral line, and the origin of the logarithmic spiral line coincides with the rotation center of the flexible wheel, so that complete conjugation is achieved during the meshing transmission process.

[0006] CN117588529A discloses a compact cycloid precision reducer for industrial robots, which has two-stage transmission, the first stage is an involute gear transmission with an internal gear, the second stage is a cycloid wheel meshing transmission, the input center wheel is an input shaft and a gear integrated structure, the planetary gear set meshes between the center wheel and the internal gear, the planetary carrier pin used by the planetary gear set connects the planetary carrier, the planetary carrier is connected to the eccentric shaft, the eccentric shaft is connected to the cycloid wheel, the needle roller on the cycloid wheel and the needle roller on the housing are meshed with each other with a small tooth difference, and the output disk connected to the cycloid wheel performs output motion.

[0007] CN116816896A relates to a movable tooth reducer with a logarithmic spiral tooth profile, comprising an outer gear ring, a cam and a retaining frame, wherein a transmission ratio is generated and torque is transmitted between the outer gear ring and the retaining frame by driving a plurality of movable teeth arranged on the cam and capable of moving radially through the retaining frame, the movable teeth are divided into at least two groups, the two groups of movable teeth are spaced apart from each other in the axial direction of the cam, and at least one group of movable teeth serves as a compensation mechanism for harmonic transmission jitter, so as to compensate for the vibration caused by the load borne by the retaining frame as the output shaft.

[0008] However, the above precision reducers all have some common disadvantages, including:

[0009] (1) The load-bearing capacity of the harmonic reducer is weak, fatigue damage is prone to occur, and the transmission process is not stable. The harmonic reducer transmits torque through the deformation of the flexible wheel, which increases the risk of material fatigue damage. In addition, the motion accuracy may also be significantly reduced as the use time increases.

[0010] (2) The planetary gear reducer has a small transmission ratio in single-stage reduction, and the use scenarios of multi-stage reduction are also limited. The minimum single-stage reduction ratio of the planetary gear reducer is 3, and generally does not exceed 10. When a larger reduction ratio is required, the single-stage planetary gear transmission system cannot meet the demand, and 2~3 stages of reduction are required to achieve a larger reduction ratio. This increases the number of transmission stages and gears, which in turn increases the length and weight of the reducer, thereby limiting its use scenarios.

[0011] (3) The reduction ratio of the new movable tooth transmission reducer is also limited. In order to keep the input force of the component movement parallel, the new movable tooth transmission reducer adopts a symmetrical double-wave cam. The double-wave cam has two contour cycles per cycle, which limits the upper limit of the reduction ratio to a certain extent.

[0012] Therefore, how to increase the reduction ratio while keeping the reducer small and achieve single-wave cam force balance so that the reducer can be suitable for various industrial scenarios is a technical problem that has not yet been solved.

[0013] In addition, on the one hand, there are differences in understanding among those skilled in the art; on the other hand, the applicant studied a large number of documents and patents when making the present invention, but due to space limitations, not all details and contents are listed in detail. However, this does not mean that the present invention does not have the characteristics of these prior arts. On the contrary, the present invention already has all the characteristics of the prior art, and the applicant reserves the right to add relevant prior art to the background technology. Summary of the invention

[0014] At present, precision reducers have some common shortcomings, including:

[0015] (1) The load-bearing capacity of the harmonic reducer is weak, fatigue damage is prone to occur, and the transmission process is not very stable.

[0016] (2) The transmission ratio of the planetary gear reducer is relatively small when single-stage reduction is used, and the use scenarios of multi-stage reduction are also limited.

[0017] (3) The reduction ratio of the new movable tooth transmission reducer is also subject to certain limitations.

[0018] Therefore, how to increase the reduction ratio while keeping the reducer small and achieve single-wave cam force balance so that the reducer can be suitable for various industrial scenarios is a technical problem that has not yet been solved.

[0019] The prior art has disclosed a technical solution for setting a cam structure based on logarithmic spiral movable tooth transmission to achieve a stable transmission process. For example, the patent document with publication number CN118100515A discloses a drive-transmission integrated device based on logarithmic spiral movable tooth transmission, including a coaxially connected driving part, a transmission part and a driven part, the rotor in the driving part is arranged on the central axis of the cam in the transmission part in a circumferential arrangement to form a drive-transmission integrated mechanism, the driving part and the transmission part are connected by the drive-transmission integrated mechanism, the transmission part is connected to the driven part, and when the drive-transmission integrated mechanism rotates based on the magnetic field, the transmission part transmits the power of the driving part to the driven part. This technical solution realizes the integrated design of the driving part and the transmission part by setting the drive-transmission integrated mechanism, and reduces the redundant transmission chain. However, this technical solution only involves a single conventional cam structure, and the conventional cam structure has two different base circle diameters and top diameters, forming two major axes and two minor axes. This design makes the cam profile present two different motion cycles, which can achieve a more complex motion mode. This cam belongs to a multi-wave form cam, or more specifically, a double-wave form cam. Double-wave cams are typically used in mechanical devices that require higher-frequency reciprocating motion, or when a single-wave cam cannot meet specific motion requirements. For example, double-wave cams are very useful in high-speed stamping machines, certain types of internal combustion engines (such as two-stroke engines), and other automated equipment that requires continuous or high-frequency motion. As mentioned above, since it has two contour cycles, this limits the upper limit of the reduction ratio, resulting in its inability to meet the higher requirements for the reduction ratio in certain specific applications. On the contrary, the cam form of the present invention is a single-wave cam, which has only one long axis and one short axis. This setting method can not only reduce the structural size of the reducer, reduce manufacturing costs and complexity, but more importantly, it can provide a wider range of reduction ratio settings, which enables the single-wave cam to adapt to more diverse motion control needs, especially in those occasions that require more precise adjustment of speed and range of motion.

[0020] In view of the shortcomings of the prior art, the present invention provides a logarithmic spiral movable tooth transmission precision reduction device, comprising two transmission components, the transmission components comprising a single-wave cam, a movable component and an inner gear ring, the cam is arranged in a movable component including a plurality of movable components, and the cam and the movable component are in contact in a relatively rotatable manner, the inner gear ring is sleeved on the outer side of the movable component and meshes with the movable component, so that the inner gear ring and the movable component perform meshing movement; the two transmission components are connected to each other, and the two cams in the two transmission components are arranged in a manner that the initial positions differ by 180°, so that the two cams form a motion structure with relatively balanced forces. The initial positions of the two cams rotate by 180°, and the initial positions of the movable components and the inner gear rings that cooperate with them also differ by 180°, but the instantaneous rotation speed of the cams is exactly the same, and the speed transmitted to the inner gear rings on both sides is also exactly the same, thus ensuring the stability of the overall structure. Different from the prior art, the present invention replaces the conventional single-body cam structure by setting two sets of connected single-wave cams. Based on the above-mentioned distinguishing technical features, the problems to be solved by the present invention may include: how to achieve a more stable and precise deceleration effect while ensuring transmission efficiency. Specifically, the present invention achieves uniform force distribution during transmission by adopting active teeth in the shape of logarithmic spirals, reduces the impact and vibration caused by torque fluctuations, and thus improves the stability of transmission. In addition, the present invention connects two transmission components in opposite directions, so that the initial positions of the single-wave cam and the inner gear ring differ by 180°. This layout not only achieves force balance, but also reduces structural deformation or wear caused by uneven force during transmission through symmetrical design, further improving the stability and durability of the reduction device.

[0021] According to a preferred embodiment, the cam is a symmetrical eccentric structure, and its profile curve has a long semi-axis and a short semi-axis. When the cam rotates one circle, the movable member and the inner gear ring complete a cycle of meshing movement. There is only one movement cycle when the two cams rotate one circle, which further increases the reduction ratio of the reducer.

[0022] According to a preferred embodiment, the movable assembly includes a retaining frame and a plurality of movable components, the movable components include a driven bearing and a movable tooth, the driven bearing passes through the through hole of the movable tooth and is rotatably connected to the movable tooth; the tooth profile of the movable tooth is inserted into the tooth hole on the retaining frame, so that the movable tooth is circumferentially distributed on the retaining frame, and the driven bearing contacts the cam surface; when the cam rotates, the cam drives the movable assembly to move according to its profile. Compared with the structure of the prior art using a needle roller, a sliding shoe and a movable tooth, the movable component has fewer overall parts, a simple and compact structure, and does not need to consider the problem of contact surface curvature matching.

[0023] According to a preferred embodiment, the tooth profile of the movable tooth penetrates the tooth hole on the retainer and meshes with the inner teeth on the inner gear ring, and when the cam rotates, the cam drives the movable assembly to push the inner gear ring to rotate. In this way, the cam pushes the inner gear ring to rotate through the movable teeth, so that the two gear rings rotate synchronously.

[0024] According to a preferred embodiment, a motion groove is provided on the cam, and when the two cams are connected to each other, the two motion grooves are connected, and the driven bearing in the movable component contacts and cooperates with the cam in the motion groove. Different from the prior art, the present invention provides a motion groove on the cam to allow the driven bearing in the movable component to contact and cooperate with the cam in the motion groove, thereby achieving a more precise and controllable transmission movement. Based on the above-mentioned distinguishing technical features, the problems to be solved by the present invention may include: how to achieve efficient and precise transmission control in a limited space. Specifically, the present invention can limit the rotation of the movable teeth within a limited area by providing a motion groove, so that the driven bearing can move precisely under the guidance of the cam. This design effectively limits the rotation range of the movable teeth, and at the same time limits the active area of ​​the movable teeth to be consistent with the motion profile of the cam, thereby avoiding transmission errors or mechanical failures caused by excessive rotation of the movable teeth.

[0025] According to a preferred embodiment, there is a gap between the movable components, and the size of the gap is adapted to the meshing position of the inner gear ring, so that the movable component and the inner gear ring form a differential gear transmission, and the movable components do not interfere with each other, thereby reducing the damage rate of each movable component.

[0026] According to a preferred embodiment, the retainer is provided with two rows of tooth holes, and the movable teeth in the two transmission assemblies are in corresponding contact with the rows of tooth holes on the retainer. This arrangement ensures that the movable components on different cams are at a fixed distance in the axial direction, further avoiding the situation where the two gear rings are offset due to vibration.

[0027] According to a preferred embodiment, a deep groove ball bearing and a lip seal are arranged between the inner gear ring and the retaining frame, and a deep groove ball bearing is arranged between the cam and the retaining frame, so that the cam and the retaining frame can rotate relative to each other, so that the retaining frame is not affected by the rotation of the cam and maintains a stable state.

[0028] According to a preferred embodiment, the device includes a first transmission assembly and a second transmission assembly; the first transmission assembly includes a first cam, a first movable assembly and a first inner gear ring; the second transmission assembly includes a second cam, a second movable assembly and a second inner gear ring; when the initial positions of the first cam and the second cam differ by 180°, the first inner gear ring is connected to the second inner gear ring, and the first cam is connected to the second cam, so that the rotation speed of the first movable assembly and the second movable assembly are the same, and the power transmitted to the retaining frame by the first movable assembly and the second movable assembly is the same, so that the first transmission assembly and the second transmission assembly form a differential gear transmission. Such a connection can ensure the synchronous rotation of the two movable assemblies.

[0029] According to a preferred embodiment, the inner gear ring end cover is arranged at the end of the first inner gear ring that is not connected to the second inner gear ring to fix and support the first inner gear ring; the cam end cover is arranged at the outer end of the second cam to stabilize the circumferential position of the second cam; in the assembled state, a third lip seal is arranged between the inner gear ring end cover and the first cam in the first transmission assembly; the cam end cover is connected to the second cam in the second transmission assembly and rotates with the second cam, and a first lip seal is arranged between the retaining frame and the cam end cover.

[0030] Lip seals can reduce lubricant loss and prevent the intrusion of contaminants. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the exploded structure of the logarithmic spiral movable tooth transmission precision speed reducer provided by the present invention;

[0032] Figure 2 It is a schematic diagram of the exploded structure of the movable component provided by the present invention;

[0033] Figure 3 It is a schematic diagram of the cross-sectional structure of the moving pair provided by the present invention;

[0034] Figure 4 It is an enlarged schematic diagram of the configuration of the movable component provided by the present invention;

[0035] Figure 5 It is a schematic diagram of the assembly structure of the first cam and the second cam provided by the present invention;

[0036] Figure 6 It is a schematic diagram of the planar structure of the first cam and the second cam provided by the present invention;

[0037] Figure 7 It is a schematic cross-sectional structural diagram of the first cam and the second cam provided by the present invention when they are assembled;

[0038] Figure 8 is a schematic structural diagram of a retaining frame provided by the present invention;

[0039] Fig. 9 is a schematic structural diagram of a first inner gear ring and a second inner gear ring provided by the present invention;

[0040] Fig.10 is a schematic diagram of a profile curve of a cam provided by the present invention;

[0041] Fig.11 It is a schematic cross-sectional structure diagram of the logarithmic spiral movable tooth transmission precision reduction device provided by the present invention in an assembled state.

[0042] List of reference numerals:

[0043] 101: first lip seal; 102: first deep groove ball bearing; 103: second lip seal; 104: second deep groove ball bearing; 105: first movable component; 106: first cam; 107: first locking retaining ring; 108: second locking retaining ring; 109: third lip seal; 110: inner gear ring end cover; 111: third deep groove ball bearing; 112: fourth deep groove ball bearing; 113: first inner gear ring; 114: second inner gear ring; 115: retaining frame; 116: second cam; 117: cam end cover; 118: tooth hole; 119: second movable component; 120: inner teeth; 121: moving groove; 122: first countersunk screw; 123: first movable member; 124: movable teeth; 125: second countersunk screw; 126: nut; 127: second movable member; 128: screw; 129: driven bearing. DETAILED DESCRIPTION

[0044] The following is a detailed description with reference to the accompanying drawings.

[0045] At present, precision reducers have some common shortcomings, including:

[0046] (1) The load-bearing capacity of the harmonic reducer is weak, fatigue damage is prone to occur, and the transmission process is not very stable.

[0047] (2) The transmission ratio of the planetary gear reducer is relatively small when single-stage reduction is used, and the use scenarios of multi-stage reduction are also limited.

[0048] (3) The reduction ratio of the new movable tooth transmission reducer is also subject to certain limitations.

[0049] Therefore, how to increase the reduction ratio while keeping the reducer small and achieve single-wave cam force balance so that the reducer can be suitable for various industrial scenarios is a technical problem that has not yet been solved.

[0050] In view of the shortcomings of the prior art, the present invention provides a logarithmic spiral movable tooth transmission precision reduction device, also known as a logarithmic spiral movable tooth transmission precision reducer. The present invention can also provide an assembly method for the logarithmic spiral movable tooth transmission precision reducer.

[0051] The present invention explains some of the noun terms.

[0052] Active components: Figure 2 As shown, the movable member is composed of a driven bearing 129, a movable tooth 124 and a nut 126. The driven bearing 129 passes through the through hole on the movable tooth 124 from one side of the movable tooth 124. The nut 126 is screwed to the driven bearing 129 on the other side of the movable tooth 124, so that the movable tooth 124 can rotate on the driven bearing 129. The driven bearing 129 limits the rotational freedom of the movable tooth 124.

[0053] Active components: e.g. Figure 3 As shown, a plurality of movable components are mounted on the cam in a circumferential arrangement to form a movable assembly. Specifically, the driven bearing 129 is in rotatable contact with the first cam 106 .

[0054] Mobile vice: Figure 3 and Figure 8 As shown, the movable teeth 124 on the movable assembly are in contact with and matched with the tooth holes 118 on the retaining frame 115 to form a moving pair.

[0055] Transmission assembly: The movable teeth 124 on the movable assembly penetrate the tooth holes 118 on the retainer 115. The tooth profile part on the movable teeth 124 contacts with the inner teeth 120 on the inner gear ring and realizes meshing motion.

[0056] Cam: The cam used in the present invention is a single-wave cam, also known as a single-peak cam, which is a mechanical cam designed so that the cam profile has only one bulge or "wave". The cam profile is designed in a single bulge shape, and the bulge is usually circular or elliptical. When the cam rotates, its bulge pushes the follower (such as a push rod or slider) to make it move linearly or oscillatingly. Fig.10 The cam profile curve in a single wave form is shown. Each time the cam rotates one circle, the movable member and the inner gear ring complete a cycle of meshing, rotating from the long semi-axis to the short semi-axis to complete the meshing process, and then rotating from the short semi-axis to the long semi-axis to complete the meshing process, and so on.

[0057] Lip seal: The sealing principle of the lip seal is mainly to use the interference between the seal lip and the mating surface and the pressure of the working medium to cause the seal ring to produce elastic deformation, thereby blocking the gap between the two relatively moving parts to achieve the sealing effect.

[0058] Countersunk screw: Its head is a 90-degree cone, similar to common wood screws, with a tool tightening groove on the head, which can be flat, cross, hexagonal, etc. The notable feature of countersunk screws is that they can keep the surface flat after installation, so that the surface of the connected object does not lose its flatness. Example 1

[0059] In view of the deficiencies of the prior art, the present invention provides a logarithmic spiral movable tooth transmission precision reduction device, including two transmission components. The transmission component includes a single-wave cam, a movable component and an inner gear ring. The cam is arranged in a movable component including a plurality of movable components, and the cam and the movable component are in contact in a relatively rotatable manner. The inner gear ring is sleeved on the outer side of the movable component and meshes with the movable component, so that the inner gear ring and the movable component perform meshing movement. The two transmission components are connected in opposite directions, and the two cams in the two transmission components are arranged in a manner that the initial positions differ by 180°, so that the two cams form a motion structure with relatively balanced forces. The initial positions of the two cams rotate by 180°, and the initial positions of the movable components and the inner gear rings that cooperate with them also differ by 180°, but the instantaneous rotation speed of the cams is exactly the same, and the speed transmitted to the inner gear rings on both sides is also exactly the same, thus ensuring the stability of the overall structure.

[0060] Figure 1 The exploded diagram of the parts of the logarithmic spiral movable tooth transmission precision reduction device is shown. Figure 1 and Fig.11 As shown, the logarithmic spiral movable tooth transmission precision reduction device includes a first transmission assembly and a second transmission assembly. The first transmission assembly and the second transmission assembly are combined in such a way that the initial positions of the first cam 106 and the second cam 116 differ by 180°, so that the first transmission assembly and the second transmission assembly form a differential gear transmission.

[0061] like Fig.10 As shown in the figure, the cam is a symmetrical eccentric structure, and its contour curve has a long semi-axis and a short semi-axis. When the cam rotates one circle, the movable component and the inner gear ring complete a cycle of meshing motion. There is only one motion cycle when the two cams rotate one circle, which further increases the reduction ratio of the reducer.

[0062] like Figure 1 and Fig.11 As shown, the logarithmic spiral movable tooth transmission precision reduction device includes a first transmission assembly and a second transmission assembly. The first transmission assembly and the second transmission assembly are combined in such a way that the initial positions of the first cam 106 and the second cam 116 differ by 180°, so that the first transmission assembly and the second transmission assembly form a differential gear transmission.

[0063] Figure 3The schematic diagram of the structure of the moving pair of the present invention is shown. The moving pair includes a first transmission assembly. The structure of the second transmission assembly is the same as that of the first transmission assembly, so it is not shown.

[0064] like Figure 3 As shown, the first transmission assembly includes a first cam 106, a first movable assembly 105, a retainer 115 and a first inner gear ring 113. The first cam 106 is disposed in the first movable assembly 105 including a plurality of movable components, and the first cam 106 is in contact with the movable components in a relatively rotatable manner. The first inner gear ring 113 is sleeved on the outer side of the first movable assembly 105 and meshes with the movable components, so that the first inner gear ring 113 and the first movable assembly 105 perform meshing motion.

[0065] like Figure 3 As shown, the first movable assembly 105 includes a retaining frame 115 and a plurality of first movable components 123. Figure 2 As shown, the first movable component 123 includes a driven bearing 129 and a movable tooth 124. The driven bearing 129 passes through the through hole of the movable tooth 124 and is rotatably connected to the movable tooth 124. The tooth profile portion of the movable tooth 124 is inserted into the tooth hole 118 on the retaining frame 115, so that the movable tooth 124 is circumferentially distributed on the retaining frame 115, and the driven bearing 129 is in contact with the cam surface. In the overall precision reduction device, there are a total of two groups of movable components. Each group of movable components includes 24 movable components. The two groups of movable components have a total of 48 identical movable components.

[0066] When the cam rotates, the cam drives the movable component to move according to its profile. When the cam rotates one circle, the movable component and the inner gear ring complete a cycle of meshing, rotating from the long semi-axis to the short semi-axis to complete the meshing process, and then rotating from the short semi-axis to the long semi-axis to complete the meshing process, and so on. Compared with the structure of the prior art that uses needle rollers, sliding shoes and movable teeth, the movable component has fewer overall parts, a simple and compact structure, and does not need to consider the problem of contact surface curvature matching.

[0067] The movable component reduces the overall mass and size of the device by reducing the number of parts and simplifying the combination. The simple design not only reduces manufacturing costs, but also improves the reliability of the device, because fewer parts mean a lower failure rate. The movable component directly contacts the cam surface, reducing the energy loss caused by indirect drive. Compared with the traditional design of force transmission through needle rollers and sliding shoes, direct contact transmission is more efficient, while also reducing wear and extending the service life of the equipment. Due to the simple structure and the need to consider the matching of the contact surface curvature, the maintenance and replacement of the movable component becomes simpler and faster. This is especially important for precision devices that need to run for a long time, which can significantly reduce downtime and improve production efficiency. The design of the movable component allows the reduction gear to control the speed and position more accurately during the rotation process. The design of the movable component allows it to adapt to different working environments and conditions, including temperature differences, vibrations, etc. Its structural stability and reliability enable the reduction gear to work stably under a variety of complex external conditions.

[0068] like Figure 3 and Figure 4 As shown, there is a gap between the movable components, and the size of the gap is adapted to the meshing position of the inner gear ring, so that the movable component and the inner gear ring form a differential gear transmission, and the movable components do not interfere with each other, thereby reducing the damage rate of each movable component.

[0069] By setting the appropriate interval, the meshing between the moving components and the inner gear ring is more precise, reducing the sliding friction when the gears mesh, thereby improving the transmission efficiency. This differential gear transmission method makes energy transmission more direct and efficient. Since the moving components do not interfere with each other, the wear of each component is more uniform, reducing local stress concentration and excessive wear. This not only reduces the damage rate of each moving component, but also extends the service life of the entire device. The setting of the interval makes the arrangement of the moving components on the cage more compact and optimizes the space utilization. The size of the interval can be adjusted according to actual needs, which provides flexibility for the adjustment and optimization of the device. Under different working conditions, the transmission performance can be optimized by adjusting the interval to meet specific application requirements. Appropriate interval design can reduce the noise and vibration of the moving components when they are running at high speed. By avoiding direct collision and friction between components, the noise level during operation can be significantly reduced, and the comfort of the working environment can be improved.

[0070] like Figure 3 As shown, the tooth profile of the movable tooth 124 passes through the tooth hole 118 on the retainer 115 and meshes with the inner tooth 120 on the first inner gear ring 113. When the cam rotates, the cam drives the movable assembly to push the inner gear ring to rotate. In this way, the cam pushes the inner gear ring to rotate through the movable tooth 124, so that the two gear rings rotate synchronously.

[0071] Similarly, the second transmission assembly includes a second cam 116, a second movable assembly 119, a retainer 115, and a second inner gear ring 114. The second cam 116 is disposed in the second movable assembly 119 including a plurality of movable components, and the second cam 116 is in contact with the movable components in a relatively rotatable manner. The second inner gear ring 114 is sleeved on the outer side of the second movable assembly 119 and meshes with the movable components, so that the second inner gear ring 114 and the second movable assembly 119 perform meshing motion.

[0072] The second movable assembly 119 includes a retainer 115 and a plurality of second movable members 127. The second movable member 127 has the same structure as the first movable member 123, and includes a driven bearing 129 and a movable tooth 124. The driven bearing 129 passes through the through hole of the movable tooth 124 and is rotatably connected to the movable tooth 124. The tooth profile of the movable tooth 124 is inserted into the tooth hole 118 on the retainer 115, so that the movable teeth 124 are circumferentially distributed on the retainer 115, and the driven bearing 129 is in contact with the cam surface. When the cam rotates, the cam drives the movable assembly to move according to its profile.

[0073] In the second transmission assembly, the tooth profile of the movable tooth 124 passes through the tooth hole 118 on the retainer 115 and meshes with the inner tooth 120 on the second inner gear ring 114. When the cam rotates, the cam drives the movable assembly to push the inner gear ring to rotate. In this way, the cam pushes the inner gear ring to rotate through the movable tooth 124, so that the first inner gear ring 113 and the second inner gear ring 114 rotate synchronously.

[0074] When the initial positions of the first cam 106 and the second cam 116 differ by 180°, the first inner gear ring 113 is connected to the second inner gear ring 114. The first cam 106 and the second cam 116 are connected, preferably connected by shafts, so that the rotation speed of the first movable assembly 105 and the second movable assembly 119 are the same, and the power transmitted to the retaining frame 115 by the first movable assembly 105 and the second movable assembly 119 is the same, so that the first transmission assembly and the second transmission assembly form a differential gear transmission. In this way, the synchronous rotation of the two movable assemblies is achieved.

[0075] like Figure 6 As shown, the cam is provided with a motion groove 121. Figure 7 As shown, when the first cam 106 and the second cam 116 are connected to each other, the two motion grooves 121 are connected. The driven bearing 129 in the movable member contacts and cooperates with the cam in the motion groove 121. The motion groove 121 can limit the rotation of the movable tooth 124 in a limited area, and at the same time limit the movable area of ​​the movable tooth 124 to be consistent with the motion profile of the cam.

[0076] like Figure 8As shown, two rows of tooth holes 118 are provided on the retainer 115, and the movable teeth 124 in the two transmission components are in corresponding contact with the rows of tooth holes 118 on the retainer 115. This arrangement ensures that the movable components on different cams are at a fixed distance in the axial direction, further avoiding the situation where the two gear rings are offset due to vibration.

[0077] like Fig.11 As shown, a deep groove ball bearing and a lip seal are provided between the inner gear ring and the retainer 115. A deep groove ball bearing is provided between the cam and the retainer 115, so that the cam and the retainer 115 can rotate relative to each other, so that the retainer 115 can be not affected by the rotation of the cam and maintain a stable state.

[0078] like Fig.11 As shown, in the assembled state, the inner gear end cover 110 is arranged at one end of the first inner gear 113 that is not connected to the second inner gear 114 to fix and support the first inner gear 113. A third lip seal 109 is arranged between the inner gear end cover 110 and the first cam 106.

[0079] like Fig.11 As shown, in the assembled state, the cam cover 117 is arranged at the outer end of the second cam 116 to stabilize the circumferential position of the second cam 116. The cam cover 117 is connected to the second cam 116 in the second transmission assembly and rotates together with the second cam 116. A first lip seal 101 is arranged between the retainer 115 and the cam cover 117.

[0080] like Fig.11 As shown, there is a second deep groove ball bearing 104 and a second lip seal 103 between the second inner gear ring 114 and the retainer 115. The second inner gear ring 114 blocks the outer ring of the second deep groove ball bearing 104. The retainer 115 blocks the inner ring of the second deep groove ball bearing 104. The first deep groove ball bearing 102 is disposed between the second cam 116 and the retainer 115. The cam end cover 117 is connected to the second cam 116 by screws 128. The retainer 115 blocks the outer ring of the first deep groove ball bearing 102, and the cam end cover 117 blocks the inner ring of the first deep groove ball bearing 102. Providing a lip seal can reduce the loss of lubricant and prevent the invasion of pollutants.

[0081] like Figure 2 , Figure 5 , Figure 7 and Fig.11As shown, the first movable member 123 on the left cooperates with the first cam 106, the retainer 115, and the first inner gear ring 113, and the structure is exactly the same as the second movable member 127 on the right. The contact and cooperation of multiple movable members and the first cam 106 form the first movable assembly 105. The first cam 106 and the second cam 116 are connected by the first countersunk screw 122. The first inner gear ring 113 and the second inner gear ring 114 are connected by the second countersunk screw 125. There is a fourth deep groove ball bearing 112 between the first inner gear ring 113 and the retainer 115. The first inner gear ring 113 blocks the outer ring of the fourth deep groove ball bearing 112, the first locking retainer 107 is connected to the retainer 115 to block the inner ring of the fourth deep groove ball bearing 112, and there is a third deep groove ball bearing 111 between the retainer 115 and the first cam 106. The retainer 115 blocks the outer ring of the third deep groove ball bearing 111. The second locking retaining ring 108 is connected to the first cam 106 to block the inner ring of the third deep groove ball bearing 111. The inner gear ring end cover 110 and the first inner gear ring 113 are connected by screws 128.

[0082] The working principle of the present invention is:

[0083] The first cam 106 and the second cam 116 are connected by the first countersunk screw 122 and serve as input, and the retainer 115 serves as output. The first inner gear ring 113 and the second inner gear ring 114 are connected and fixed by the second countersunk screw 125. First, the motor drives the first cam 106 and the second cam 116 to rotate on a fixed axis, and then the first cam 106 and the second cam 116 respectively contact the outer ring surface of the driven bearing 129 connected to the first movable member 123 and the second movable member 127 through the inner and outer contour surfaces of their motion grooves 121, and push the movable teeth 124 on the first movable member 123 and the second movable member 127 to move radially along the tooth holes 118 of the retainer 115, and then the tooth profile parts of the movable teeth 124 on the first movable member 123 and the second movable member 127 respectively mesh with the inner teeth 120 of the first inner gear ring 113 and the second inner gear ring 114. Since the first inner gear ring 113 and the second inner gear ring 114 are fixed, the meshing movement of the first movable member 123 and the second movable member 127 finally drives the retaining frame 115 to rotate. Example 2

[0084] This embodiment is a further improvement on Embodiment 1, and the repeated contents will not be repeated here.

[0085] The first inner gear ring 113 in the first transmission assembly is connected to the second inner gear ring 114 in the second transmission assembly, so that the first movable assembly 105 and the second movable assembly 119 rotate at the same speed. The first movable assembly 105 and the second movable assembly 119 transmit the same power to the retaining frame 115. Such a connection can ensure the synchronous rotation of the two movable assemblies.

[0086] like Figure 7 As shown, the first cam 106 and the second cam 116 are connected via a first countersunk screw 122 as input. Fig. 9 As shown, the first inner gear ring 113 and the second inner gear ring 114 are connected as outputs through the second countersunk screw 125. The retainer 115 is fixed. First, the motor drives the first cam 106 and the second cam 116 to rotate on a fixed axis, and then the first cam 106 and the second cam 116 contact the outer ring surface of the driven bearing 129 connected to the first movable member 123 and the second movable member 127 through the inner and outer contour surfaces of the motion groove 121, pushing the movable teeth 124 on the first movable member 123 and the second movable member 127 to move radially along the tooth holes 118 of the retainer 115. Afterwards, the tooth profiles of the movable teeth 124 of the first movable member 123 and the second movable member 127 mesh with the inner teeth 120 of the first inner gear ring 113 and the second inner gear ring 114. Since the retainer 115 is fixed, the first inner gear ring 113 and the second inner gear ring 114 rotate.

[0087] The present invention uses the first countersunk screw 122 to connect the first cam 106 and the second cam 116, and uses the second countersunk screw 125 to connect the first inner gear ring 113 and the second inner gear ring 114, so that the reduction device can be divided into two parts for assembly.

[0088] The first cam 106 and the second cam 116 adopt a single wave form, and there is only one long semi-axis and one short semi-axis in one rotation, that is, one cycle. The reduction ratio of the reducer is increased while keeping the size of the reducer small.

[0089] By adopting an assembly connection method in which the long semi-axis of the first cam 106 and the short semi-axis of the second cam 116 correspond to each other, the overall force of the single-wave cam is relatively more balanced, thereby improving the stability of the reducer.

[0090] The present invention reduces the number of parts of the movable component by connecting the driven bearing 129 with the movable tooth 124, and the structure is simpler. A gap is left between the two movable components in the first movable assembly 105, such as the position gap of one movable component, to form a differential gear transmission to avoid mutual interference between the movable components. In the present invention, the first locking ring 107 is connected to the retaining frame 115 and blocks the inner ring of the fourth deep groove ball bearing 112. The second locking ring 108 is connected to the first cam 106 and blocks the inner ring of the corresponding third deep groove ball bearing 111, thereby fixing it.

[0091] It should be noted that the above-mentioned specific embodiments are exemplary, and those skilled in the art can come up with various solutions inspired by the disclosure of the present invention, and these solutions also belong to the disclosure scope of the present invention and fall within the protection scope of the present invention. Those skilled in the art should understand that the present invention specification and its drawings are illustrative and do not constitute a limitation on the claims. The scope of protection of the present invention is defined by the claims and their equivalents. The present invention specification contains multiple inventive concepts, such as "preferably" and "according to a preferred embodiment", which means that the corresponding paragraph discloses an independent concept, and the applicant reserves the right to file a divisional application based on each inventive concept.

Claims

1. A logarithmic spiral movable tooth transmission precision reduction device, characterized in that: It includes two transmission components, wherein the transmission component includes a single-wave cam, a movable component and an inner gear ring. The cam is arranged in the movable assembly including a plurality of movable components, and the cam is in contact with the movable components in a relatively rotatable manner. The inner gear ring is sleeved on the outer side of the movable component and meshes with the movable member, so that the inner gear ring and the movable component perform meshing movement; The two transmission assemblies are connected to each other, and the two cams in the two transmission assemblies are arranged in a manner that the initial positions differ by 180°, so that the two cams form a motion structure with relatively balanced forces; The device comprises a first transmission assembly and a second transmission assembly; The first transmission assembly comprises a first cam (106), a first movable assembly (105) and a first inner gear ring (113); The second transmission assembly comprises a second cam (116), a second movable assembly (119) and a second inner gear ring (114); When the initial positions of the first cam (106) and the second cam (116) differ by 180°, the first inner gear ring (113) is connected to the second inner gear ring (114), and the first cam (106) is connected to the second cam (116), so that the rotation speeds of the first movable component (105) and the second movable component (119) are the same, and the power transmitted to the retaining frame (115) by the first movable component (105) and the second movable component (119) is the same, so that the first transmission component and the second transmission component form a differential gear transmission.

2. The logarithmic spiral movable tooth transmission precision reduction device according to claim 1 is characterized in that: The cam is a symmetrical eccentric structure, and its contour curve has a major semi-axis and a minor semi-axis. When the cam rotates one circle, the movable member and the inner gear ring complete one cycle of meshing motion.

3. The logarithmic spiral movable tooth transmission precision reduction device according to claim 2 is characterized in that: The movable assembly comprises a retaining frame (115) and a plurality of movable components. The movable component comprises a driven bearing (129) and movable teeth (124). The driven bearing (129) passes through the through hole of the movable tooth (124) and is rotatably connected to the movable tooth (124); The tooth profile portion of the movable tooth (124) is inserted into the tooth hole (118) on the retaining frame (115), so that the movable teeth (124) are distributed circumferentially on the retaining frame (115), and the driven bearing (129) is in contact with the cam surface; When the cam rotates, the cam drives the movable component to move according to its contour.

4. The logarithmic spiral movable tooth transmission precision reduction device according to claim 3 is characterized in that: The tooth profile portion of the movable tooth (124) passes through the tooth hole (118) on the retaining frame (115) and meshes with the inner tooth (120) on the inner gear ring. When the cam rotates, the cam drives the movable component to push the inner gear ring to rotate.

5. The logarithmic spiral movable tooth transmission precision reduction device according to claim 3 or 4, characterized in that: The cam is provided with a movement groove (121). When the two cams are connected toward each other, the two motion grooves (121) are connected. The driven bearing (129) in the movable component is in contact with the cam in the moving groove (121).

6. The logarithmic spiral movable tooth transmission precision reduction device according to claim 5, characterized in that: There is a gap between the movable components. The size of the interval is matched with the meshing position of the inner gear ring, so that the movable member and the inner gear ring form a differential gear transmission, and the movable members do not interfere with each other.

7. The logarithmic spiral movable tooth transmission precision reduction device according to claim 5, characterized in that: The retaining frame (115) is provided with two rows of tooth holes (118). The movable teeth (124) in the two transmission assemblies are in corresponding contact with each row of the tooth holes (118) on the retaining frame (115).

8. The logarithmic spiral movable tooth transmission precision reduction device according to claim 5, characterized in that: A deep groove ball bearing and a lip seal are provided between the inner gear ring and the retaining frame (115). A deep groove ball bearing is arranged between the cam and the retaining frame (115).

9. The logarithmic spiral movable tooth transmission precision reduction device according to claim 5, characterized in that: The inner gear ring end cover (110) is arranged at an end of the first inner gear ring (113) that is not connected to the second inner gear ring (114) to fix and support the first inner gear ring (113); the cam end cover (117) is arranged at the outer end of the second cam (116) to stabilize the circumferential position of the second cam (116); In the assembled state, a third lip seal (109) is provided between the inner gear ring end cover (110) and the first cam (106) in the first transmission assembly; the cam end cover (117) is connected to the second cam (116) in the second transmission assembly and rotates together with the second cam (116); and a first lip seal (101) is provided between the retaining frame (115) and the cam end cover (117).

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