CN118793747B

CN118793747B - Precise speed reducer for logarithmic spiral oscillating tooth transmission

Info

Publication number: CN118793747B
Application number: CN202411274102.2A
Authority: CN
Inventors: 邓星桥; 王博文; 王世松; 董成龙
Original assignee: Chengdu Univeristy of Technology
Current assignee: Chengdu Univeristy of Technology
Priority date: 2024-09-12
Filing date: 2024-09-12
Publication date: 2024-12-10
Anticipated expiration: 2044-09-12
Also published as: CN118793747A

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

Precise speed reducer for logarithmic spiral oscillating tooth transmission

Technical Field

The invention relates to the technical field of industrial transmission machinery, in particular to a logarithmic spiral movable tooth transmission precise speed reducing device.

Background

Currently, the commonly used precision speed reducers mainly comprise harmonic speed reducers, planetary gear speed reducers and the like. The harmonic reducer is a flexible transmission structure and consists of three components of a wave generator, a flexible gear and a rigid gear. Along with the continuous progress of technology and the reduction of cost, the harmonic reducer is gradually and widely applied to the fields of industrial robots, precise instruments, medical instruments and the like. The working principle is that the gear engagement between the flexible gear and the rigid gear is driven by the elliptic deformation generated by the wave generator to generate relative motion, so that the transmission effect of high reduction ratio, high precision and low return difference is realized. Although the harmonic reducer is susceptible to fatigue and wear under high-speed operation and high-load conditions, durability and reliability are significantly improved by using high-strength materials and advanced manufacturing processes.

The planetary gear reducer is a compact and high-efficiency transmission device and consists of a sun gear, a planetary gear, an inner gear ring and a retainer. The speed reducer realizes speed reduction by rotating the planetary gears around the sun gear, and has high bearing capacity, high transmission efficiency and compact volume. The planetary gear reducer is widely applied to the fields of automation equipment, engineering machinery, automobile transmission systems and the like, can adapt to different input and output configurations, and realizes various types of speed reduction or speed increase transmission. With the development of material science and manufacturing technology, the performance of the planetary gear reducer is continuously improved, such as adopting high-strength alloy materials, precision machining technology and advanced lubrication systems, so as to improve the working efficiency and service life of the planetary gear reducer.

In addition, the novel oscillating tooth transmission speed reducer is a novel transmission form evolving from K-H-V type differential tooth planetary gear transmission, and the planetary gear teeth are made into a group of independent moving bodies capable of circularly moving by converting rigid connection of the planetary gear teeth and the hub into flexible hinge. The design improves the flexibility and adaptability of transmission, reduces the mutual interference between gears, and improves the transmission efficiency and stability. The novel movable tooth transmission speed reducer has wide application prospect in the fields of precise speed reducing devices, robot joints, precise positioning systems and the like. The characteristics of high precision and high reliability make the device an important development direction of future precise transmission technology. However, the design and manufacturing process of the novel oscillating tooth transmission reducer still face technical challenges, such as how to ensure that the independent motion characteristics of the oscillating tooth can be kept stable and efficient under various working conditions.

CN113503353a discloses a logarithmic spiral conjugate tooth profile harmonic reducer, comprising a rigid gear, a flexible gear, a wave generator and a flexible bearing. The tooth profiles of the rigid gear and the flexible gear in the meshing state are designed by adopting curves of two sections of different sections on the same logarithmic spiral line, the origin of the logarithmic spiral line coincides with the rotation center of the flexible gear, and complete conjugation is realized in the meshing transmission process.

CN117588529a discloses a cycloid-like precision reducer for an industrial robot, which has a compact structure, and is driven by two stages, wherein the first stage is involute gear with an internal gear, the second stage is cycloid gear meshing transmission, an input central gear is an integrated structure of an input shaft and a gear, a planetary gear set is meshed between the central gear and the internal gear, a planetary carrier pin shaft for the planetary gear set is connected with a planetary carrier, the planetary carrier is connected with an eccentric shaft, the eccentric shaft is connected with the cycloid gear, a needle roller on the cycloid gear and a needle roller on a machine shell are driven by small teeth difference intermeshing, and an output disc connected on the cycloid gear performs output motion.

CN116816896a relates to a movable tooth reducer with logarithmic spiral tooth profile, comprising an external gear ring, a cam and a retainer, wherein a transmission ratio is generated between the external gear ring and the retainer and a torque is transmitted by the cam driving a plurality of movable teeth arranged on the cam and movable radially through the retainer, the movable teeth are divided into at least two groups, the two groups of movable teeth are mutually spaced in the axial direction of the cam, and at least one group of movable teeth is used as a compensating mechanism for harmonic transmission shake to compensate vibration induced by load borne by the retainer as an output shaft.

However, the precision reducers described above all have some common drawbacks, including:

(1) The bearing capacity of the harmonic reducer is weak, fatigue damage is easy to occur, and the transmission process is unstable. The harmonic reducer transmits torque through deformation of the flexspline, which results in an increased risk of fatigue damage to the material. In addition, as the service time increases, the accuracy of the movement may also decrease significantly.

(2) The planetary gear reducer has smaller transmission in single-stage reduction, and the use scene of multi-stage reduction is limited. The single stage reduction ratio of the planetary gear reducer is at least 3 and generally not more than 10. When the larger reduction ratio is needed, the single-stage planetary gear transmission system cannot meet the requirement, and the 2-3-stage reduction is needed to realize the larger reduction ratio. This increases the number of drive stages and gears, which in turn increases the length and weight of the reducer, limiting its use.

(3) The reduction ratio of the novel oscillating tooth transmission speed reducer is also limited to a certain extent. In order to keep the force of the motion of the input parts parallel, the novel oscillating tooth transmission speed reducer adopts a double wave cam with symmetrical shape. There are two profile periods around the double wave cam, which limits the upper limit of the reduction ratio to some extent.

Therefore, how to improve the reduction ratio under the condition of keeping the small volume of the speed reducer and realize the stress balance of the single-wave cam, so that the speed reducer is applicable to various industrial scenes, and is a technical problem which is not solved yet.

Furthermore, since the applicant has studied numerous documents and patents on the one hand, and since the applicant has made the present invention, the text is not to be limited to all details and matters of detail, but this is by no means the present invention does not feature these prior art features, but rather the present invention has features of all prior art, and the applicant has remained in the background art to which this invention pertains.

Disclosure of Invention

Currently, precision reducers suffer from a number of common disadvantages, including:

(1) The bearing capacity of the harmonic reducer is weak, fatigue damage is easy to occur, and the transmission process is unstable.

(2) The planetary gear reducer has smaller transmission in single-stage reduction, and the use scene of multi-stage reduction is limited.

(3) The reduction ratio of the novel oscillating tooth transmission speed reducer is also limited to a certain extent.

Technical solutions for realizing a stable transmission process based on a cam structure for logarithmic spiral oscillating tooth transmission have been disclosed in the prior art. For example, patent document with publication No. CN118100515A discloses a driving and transmitting integrated device based on logarithmic spiral oscillating tooth transmission, which comprises a driving part, a transmission part and a driven part which are coaxially connected, wherein a rotor in the driving part is arranged on a central shaft of a cam in the transmission part in a circumferential arrangement manner to form a driving and transmitting integrated mechanism, the driving part and the transmission part are connected by the driving and transmitting integrated mechanism, the transmission part is connected with the driven part, and the transmission part transmits power of the driving part to the driven part under the condition that the driving and transmitting integrated mechanism rotates based on the action of a magnetic field. According to the technical scheme, the driving and transmitting integrated mechanism is arranged, so that the integrated design of the driving part and the transmission part is realized, and the redundant transmission chain is reduced. However, this solution involves only a single conventional cam structure having two different base diameters and tip diameters, forming two major axes and two minor axes, which design allows the cam profile to exhibit two different movement cycles, enabling more complex movement patterns, such cams belonging to a multi-wave form of cam, or more specifically to a dual-wave form of cam. Double wave cams are commonly used in mechanical devices that require relatively high frequency reciprocating motion, or when single wave cams are unable to meet specific motion requirements. For example, double wave cams are very useful in high speed presses, certain types of internal combustion engines (e.g., two-stroke engines) and other automated equipment requiring continuous or high frequency action. As previously mentioned, this limits the upper limit of the reduction ratio due to its two profile periods, which makes it impossible to meet the higher demands on the reduction ratio in certain specific applications. In contrast, the cam of the present invention is a single wave cam having only one long axis and one short axis, which not only reduces the size of the reducer, reduces the cost and complexity of manufacture, but more importantly, provides a wider range of reduction ratio settings, which allows the single wave cam to accommodate a wider variety of motion control requirements, particularly in those applications where finer speed and range of motion are desired.

The invention provides a logarithmic spiral movable tooth transmission precise speed reducing device, which aims at the defects of the prior art and comprises two transmission components, wherein the transmission components comprise a cam in a single wave form, a movable component and an inner gear ring, the cam is arranged in the movable component comprising a plurality of movable components, the cam is contacted with the movable components in a relatively rotatable manner, the inner gear ring is sleeved on the outer side of the movable component and meshed with the movable components, so that the inner gear ring and the movable components are meshed for 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 initial positions are different by 180 degrees, so that the two cams form a relatively balanced stressed movement structure. The initial positions of the two cams rotated are 180 degrees different, the initial positions of the movable components and the inner gear rings matched with the cams are 180 degrees different, the instantaneous speeds of the cams rotated are identical, and the speeds transmitted to the inner gear rings on the two sides are identical, so that the stability of the whole structure is ensured. Unlike the prior art, the present invention replaces the conventional monoblock cam configuration by providing two sets of connected single wave form 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 accurate deceleration effect while ensuring the transmission efficiency. Specifically, the invention adopts the movable teeth with logarithmic spiral shape, realizes the uniform distribution of force in the transmission process, reduces the impact and vibration caused by torque fluctuation, and improves the transmission stability. In addition, the two transmission components are connected in opposite directions, so that the initial positions of the single-wave cam and the inner gear ring are different by 180 degrees, the force balance is realized through the layout, structural deformation or abrasion caused by uneven stress in the transmission process is reduced through the symmetrical design, and the stability and durability of the speed reducer are further improved.

According to a preferred embodiment, the cam is of symmetrical eccentric construction, the profile curve of which presents a major and a minor half axis, the movable member completing a cycle of meshing movement with the ring gear when the cam makes one revolution. Only one movement period exists when the two cams rotate for one circle, and the reduction ratio of the speed reducer is further increased.

According to a preferred embodiment, the movable assembly comprises a holder and a number of movable members, the movable members comprising a follower bearing and movable teeth, the follower bearing penetrating through the through-holes of the movable teeth and being rotatably connected to the movable teeth, the profile portions of the movable teeth being inserted into the holes in the holder such that the movable teeth are circumferentially distributed on the holder and the follower bearing being in contact with the cam surface, the cam driving the movable assembly to move according to its profile in the event of rotation of the cam. Compared with the structure of the prior art that the roller pin and the sliding shoe are matched with the movable teeth, the movable component has fewer parts, simple and compact structure and no need of considering the problem of curvature matching of the contact surface.

According to a preferred embodiment, the tooth profile portions of the movable teeth extend through the tooth holes in the holder and engage with the inner teeth on the inner gear ring, and in the event of a cam rotation, the cam drives the movable assembly to rotate the inner gear ring. In this way, the cam pushes the inner gear ring to rotate through the movable teeth, so that the two gear rings synchronously rotate.

According to a preferred embodiment, the cams are provided with movement grooves, and in the case of the two cams being connected in opposite directions, the two movement grooves are penetrated, and the follower bearings in the movable members are in contact fit with the cams in the movement grooves. Unlike the prior art, the present invention provides a motion slot on the cam to allow the follower bearing in the movable member to contact and mate with the cam within the motion slot, thereby achieving a more accurate and controlled transmission motion. Based on the above-mentioned distinguishing technical features, the problem to be solved by the present invention may include how to achieve efficient and accurate transmission control in a limited space. In particular, the invention can limit the movable teeth to rotate in a limited area by arranging the movement groove, so that the driven bearing can accurately move under the guidance of the cam, this design effectively limits the range of rotation of the movable teeth while limiting the movable area of the movable teeth to conform to the motion profile of the cam, thereby avoiding transmission errors or mechanical failure due to excessive rotation of the movable teeth.

According to a preferred embodiment, a space exists between the movable members, the size of the space is matched with the meshing position of the inner gear ring, so that the movable members and the inner gear ring form differential gear transmission, the movable members do not interfere with each other, and the damage rate of each movable member is reduced.

According to a preferred embodiment, the cage is provided with two rows of teeth holes, the movable teeth of the two transmission assemblies being in corresponding contact with the rows of teeth holes of the cage. The arrangement is such that the movable members on the different cams are axially fixed in distance, further avoiding the situation that the middle of the two gear rings is offset due to vibration.

According to a preferred embodiment, a deep groove ball bearing and a lip seal are arranged between the annular gear and the retainer, and a deep groove ball bearing is arranged between the cam and the retainer, so that the cam and the retainer can rotate relatively, and the retainer can be not influenced by the rotation of the cam and can maintain a stable state.

According to a preferred embodiment, the device comprises a first transmission assembly and a second transmission assembly, wherein the first transmission assembly comprises a first cam, a first movable assembly and a first annular gear, the second transmission assembly comprises a second cam, a second movable assembly and a second annular gear, the first annular gear is connected with the second annular gear under the condition that the initial positions of the first cam and the second cam are different by 180 degrees, the first cam is connected with the second cam, the rotation speed of the first movable assembly is the same as that of the second movable assembly, the power transmitted to the retainer by the first movable assembly is the same as that of the second movable assembly, and therefore differential gear transmission is formed by the first transmission assembly and the second transmission assembly. In this way, the synchronous rotation of the two movable components can be ensured.

According to a preferred embodiment, the ring gear end cover is arranged at one end of the first ring gear, which is not connected with the second ring gear, to fix and support the first ring gear, the cam end cover is arranged at the outer end of the second cam to stabilize the circumferential position of the second cam, a third lip seal is arranged between the ring gear end cover and the first cam in the first transmission assembly in the assembled state, and the cam end cover is connected with the second cam in the second transmission assembly and rotates together with the second cam, and a first lip seal is arranged between the retainer and the cam end cover.

The lip seal can reduce the loss of lubricant and avoid the invasion of pollutants.

Drawings

FIG. 1 is a schematic diagram of an explosion structure of a logarithmic spiral oscillating tooth transmission precision speed reducer provided by the invention;

FIG. 2 is a schematic view of an exploded construction of a movable member provided by the present invention;

FIG. 3 is a schematic cross-sectional view of a mobile pair according to the present invention;

FIG. 4 is an enlarged schematic view of the configuration of the movable member provided by the present invention;

FIG. 5 is a schematic diagram of an assembly structure of a first cam and a second cam according to the present invention;

FIG. 6 is a schematic view of the plane structures of the first cam and the second cam according to the present invention;

FIG. 7 is a schematic cross-sectional view of a first cam and a second cam provided by the present invention when assembled;

FIG. 8 is a schematic view of the structure of the cage provided by the present invention;

fig. 9 is a schematic structural view of a first ring gear and a second ring gear provided by the present invention;

FIG. 10 is a schematic illustration of a profile curve of a cam provided by the present invention;

fig. 11 is a schematic sectional view of the logarithmic spiral oscillating tooth transmission precision speed reducer in the assembled state.

List of reference numerals:

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 retainer, 108 second locking retainer, 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 retainer, 116 second cam, 117 cam end cover, 118 tooth hole, 119 second movable component, 120 inner gear, 121 moving groove, 122 first countersunk screw, 123 first movable component, 124 movable tooth, 125 second countersunk screw, 126 nut, 127 second movable component, 128 screw, 129 driven bearing.

Detailed Description

The following detailed description refers to the accompanying drawings.

Aiming at the defects of the prior art, the invention provides a logarithmic spiral movable tooth transmission precise speed reducer, which is also called a logarithmic spiral movable tooth transmission precise speed reducer. The invention also provides an assembling method of the logarithmic spiral oscillating tooth transmission precision speed reducer.

The invention is described in terms of partial terminology.

Movable member as shown in fig. 2, the movable member is composed of a driven bearing 129, movable teeth 124, and a nut 126. The driven bearing 129 passes through a through hole in 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 is rotatable on the driven bearing 129. The driven bearing 129 restricts the rotational freedom of the movable teeth 124.

The movable components are formed by arranging a plurality of movable components on the cam in a circumferential arrangement manner as shown in figure 3. Specifically, the driven bearing 129 is in rotatable contact with the first cam 106.

As shown in fig. 3 and 8, the movable teeth 124 of the movable assembly are in contact with and matingly mounted to the teeth holes 118 of the cage 115 to form a kinematic pair.

The drive assembly, the movable teeth 124 on the movable assembly extend through the perforations 118 in the cage 115. The tooth profile portions on the movable teeth 124 contact the internal teeth 120 on the internal gear ring and effect meshing movement.

Cam the cam used in the present invention is a cam in the form of a single wave, also known as a unimodal cam, and is a mechanical cam designed such that there is only one lobe or "wave" in the profile of the cam. The cam profile is designed as a single convex shape, with the convex portion being generally circular or elliptical. When the cam rotates, the convex portion pushes the follower (such as a push rod or a slide block) to make the follower perform linear or swinging motion. Fig. 10 shows a cam profile curve in the form of a single wave. When the cam rotates for one circle, the movable component and the annular gear are meshed for one period, the meshing process is completed from the rotation of the long half shaft to the completion of the short half shaft, and then the meshing process is completed from the rotation of the short half shaft to the completion of the long half shaft, so that the cam is reciprocated.

The sealing principle of the lip seal ring is mainly that the sealing ring generates elastic body deformation through the interference between the lip of the sealing piece and the matching surface and the pressure of the working medium, thereby sealing the gap between the two parts which relatively move and achieving the sealing effect.

Countersunk head screw, its head is a 90 degree cone, similar to common wood screw, its head has tool tightening groove, and has straight line, cross shape, internal hexagon, etc. The countersunk head screw has the remarkable characteristics that the surface can be kept flat after installation, so that the surface of a connected object does not lose flatness.

Example 1

Aiming at the defects of the prior art, the invention provides a logarithmic spiral movable tooth transmission precision speed reducing device which comprises two transmission components. The transmission assembly comprises a cam in a single wave form, a movable assembly and an annular gear, wherein the cam is arranged in the movable assembly comprising a plurality of movable members, and the cam is contacted with the movable members in a relatively rotatable manner. The inner gear ring is sleeved on the outer side of the movable assembly and meshed with the movable member, so that the inner gear ring and the movable assembly 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 mode that initial positions are 180 degrees different, so that the two cams form a motion structure with relatively balanced stress. The initial positions of the two cams rotated are 180 degrees different, the initial positions of the movable components and the inner gear rings matched with the cams are 180 degrees different, the instantaneous speeds of the cams rotated are identical, and the speeds transmitted to the inner gear rings on the two sides are identical, so that the stability of the whole structure is ensured.

Fig. 1 shows an exploded view of a logarithmic spiral oscillating tooth drive precision reduction gear. As shown in fig. 1 and 11, the logarithmic spiral oscillating tooth transmission precision speed reducing device comprises a first transmission assembly and a second transmission assembly. The first and second drive assemblies are combined in a manner such that the initial positions of the first and second cams 106, 116 are 180 degrees apart, such that the first and second drive assemblies form a differential gear.

As shown in fig. 10, the cam is a symmetrical eccentric structure with a profile curve having a major half axis and a minor half axis. When the cam rotates for one circle, the movable component and the inner gear ring complete one cycle of meshing movement. Only one movement period exists when the two cams rotate for one circle, and the reduction ratio of the speed reducer is further increased.

As shown in fig. 1 and 11, the logarithmic spiral oscillating tooth transmission precision speed reducing device comprises a first transmission assembly and a second transmission assembly. The first and second drive assemblies are combined in a manner such that the initial positions of the first and second cams 106, 116 are 180 degrees apart, such that the first and second drive assemblies form a differential gear.

Fig. 3 shows a schematic diagram of the structure of the mobile pair of the present invention. The mobile pair comprises a first transmission assembly. The structure of the second transmission assembly is the same as that of the first transmission set and is therefore not shown.

As shown in fig. 3, the first transmission assembly includes a first cam 106, a first movable assembly 105, a cage 115, and a first ring gear 113. The first cam 106 is disposed within a first movable assembly 105 comprising a plurality of movable members, and the first cam 106 is in relatively rotatable contact with the movable members. The first ring gear 113 is sleeved on the outer side of the first movable assembly 105 and is engaged with the movable member, so that the first ring gear 113 performs an engaging motion with the first movable assembly 105.

As shown in fig. 3, the first movable assembly 105 includes a holder 115 and a number of first movable members 123. As shown in fig. 2, the first movable member 123 includes a driven bearing 129 and movable teeth 124. The driven bearing 129 penetrates through the through hole of the movable tooth 124 and is rotatably coupled with the movable tooth 124. The tooth profile portion of the movable tooth 124 is inserted into the tooth aperture 118 in the cage 115 such that the movable tooth 124 is circumferentially distributed on the cage 115 and the follower bearing 129 is in contact with the cam surface. In the integral precision speed reducer, there are two movable components in total. Each set of movable assemblies includes 24 movable members. The two sets of movable components have 48 identical movable members.

In the case of cam rotation, the cam drives the movable assembly to move according to its profile. The cam rotates for one circle, the movable component and the annular gear are meshed for one period, the meshing process is completed from the rotation of the long half shaft to the completion of the short half shaft, and then the meshing process is completed from the rotation of the short half shaft to the completion of the long half shaft, so that the cam is reciprocated. Compared with the structure of the prior art that the roller pin and the sliding shoe are matched with the movable teeth, the movable component has fewer parts, simple and compact structure and no need of considering the problem of curvature matching of the contact surface.

The movable member reduces the overall mass and volume of the device by reducing the number of parts and simplifying the assembly. The compact design not only reduces manufacturing costs but also improves reliability of the device, as fewer parts means a lower failure rate. The movable member directly contacts the cam surface, reducing energy losses from indirect drive. Compared with the traditional design of force transmission through the roller pin and the sliding shoe, the direct contact transmission efficiency is higher, the abrasion is reduced, and the service life of the equipment is prolonged. Because the structure is simple, and the matching problem of the curvature of the contact surface is not needed to be considered, the maintenance and replacement of the movable component become simpler and quicker. This is particularly important for precision devices that require long runs, and can significantly reduce downtime and increase production efficiency. The design of the movable member allows the speed reducing device to control the speed and position more precisely during rotation. The design of the movable member allows it to accommodate different operating environments and conditions, including temperature differentials, vibrations, and the like. The structural stability and reliability of the speed reducer enables the speed reducer to stably operate under various complex external conditions.

As shown in fig. 3 and 4, a space exists between the movable members, and the size of the space is matched with the meshing position of the inner gear ring, so that the movable members and the inner gear ring form differential gear transmission, the movable members do not interfere with each other, and the damage rate of each movable member is reduced.

By setting proper intervals, the engagement between the movable component and the inner gear ring is more accurate, and the sliding friction during gear engagement is reduced, so that the transmission efficiency is improved. This differential gearing makes the energy transfer more direct and efficient. Because the movable components do not interfere with each other, the abrasion of each component is more uniform, and the conditions of local stress concentration and excessive abrasion are reduced. This not only reduces the rate of damage to the individual moving parts, but also extends the useful life of the overall device. The arrangement of the interval makes the arrangement of the movable components on the retainer more compact, and the space utilization rate is optimized. The size of the interval can be adjusted according to actual needs, which provides flexibility for adjustment and optimization of the device. Under different working conditions, the transmission performance can be optimized by adjusting the interval, so that the specific application requirements are met. Proper spacing design can reduce noise and vibration of the movable member during high speed operation. By avoiding direct collisions and friction between the components, the noise level during operation can be significantly reduced, improving the comfort of the working environment.

As shown in fig. 3, the tooth profile portions of the movable teeth 124 penetrate through the tooth holes 118 of the cage 115 and mesh with the inner teeth 120 of the first ring gear 113. Under the condition that the cam rotates, the cam drives the movable assembly to push the annular gear to rotate. In this way, the cam pushes the ring gear to rotate through the movable teeth 124, so that the two ring gears rotate synchronously.

Similarly, the second drive assembly includes a second cam 116, a second movable assembly 119, a cage 115, and a second ring gear 114. The second cam 116 is disposed within a second movable assembly 119 that includes a plurality of movable members, and the second cam 116 is in relatively rotatable contact with the movable members. The second ring gear 114 is sleeved on the outer side of the second movable assembly 119 and is engaged with the movable member, so that the second ring gear 114 and the second movable assembly 119 perform engagement movement.

The second movable assembly 119 includes a cage 115 and a number of second movable members 127. The second movable member 127 has the same constituent structure as the first movable member 123, including the driven bearing 129 and the movable teeth 124. The driven bearing 129 penetrates through the through hole of the movable tooth 124 and is rotatably coupled with the movable tooth 124. The tooth profile portion of the movable tooth 124 is inserted into the tooth aperture 118 in the cage 115 such that the movable tooth 124 is circumferentially distributed on the cage 115 and the follower bearing 129 is in contact with the cam surface. In the case of cam rotation, the cam drives the movable assembly to move according to its profile.

In the second drive assembly, the tooth profile portions of the movable teeth 124 extend through the tooth holes 118 in the cage 115 and engage the inner teeth 120 on the second ring gear 114. Under the condition that the cam rotates, the cam drives the movable assembly to push the annular gear to rotate. In this way, the cam pushes the ring gear to rotate through the movable teeth 124, so that the first ring gear 113 and the second ring gear 114 rotate synchronously.

In the case that the initial positions of the first cam 106 and the second cam 116 differ by 180 °, the first ring gear 113 is connected with the second ring gear 114. The first cam 106 is connected, preferably axially connected, to the second cam 116 such that the rotational speeds of the first movable assembly 105 and the second movable assembly 119 are the same, and the power transmitted to the cage 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. This achieves a synchronous rotation of the two movable assemblies.

As shown in fig. 6, the cam is provided with a movement groove 121. As shown in fig. 7, when the first cam 106 and the second cam 116 are connected to each other, the two movement grooves 121 penetrate. The follower bearing 129 in the movable member is in contact engagement with the cam in the movement slot 121. The provision of the movement slots 121 can limit the movement of the movable teeth 124 in a limited area while limiting the movement area of the movable teeth 124 to conform to the movement profile of the cam.

As shown in fig. 8, the retainer 115 is provided with two rows of tooth holes 118, and the movable teeth 124 in the two transmission assemblies are correspondingly contacted with the rows of tooth holes 118 on the retainer 115. The arrangement is such that the movable members on the different cams are axially fixed in distance, further avoiding the situation that the middle of the two gear rings is offset due to vibration.

As shown in fig. 11, a deep groove ball bearing and a lip seal are provided between the ring gear and the cage 115. A deep groove ball bearing is provided between the cam and the cage 115 so that the cam and the cage 115 can relatively rotate, so that the cage 115 can be kept in a stable state without being affected by the rotation of the cam.

As shown in fig. 11, in the assembled state, the ring gear end cap 110 is disposed at one end of the first ring gear 113 that is not connected with the second ring gear 114 to fix and support the first ring gear 113. A third lip seal 109 is provided between the ring gear end cap 110 and the first cam 106.

As shown in fig. 11, in the assembled state, a cam end cover 117 is provided at the outer end of the second cam 116 to stabilize the circumferential position of the second cam 116. The cam end cap 117 is connected to the second cam 116 in the second drive assembly and rotates with the second cam 116. A first lip seal 101 is disposed between the cage 115 and the cam end cap 117.

As shown in fig. 11, there is a second deep groove ball bearing 104 and a second lip seal 103 between the second ring gear 114 and the cage 115. The second ring gear 114 blocks the outer race of the second deep groove ball bearing 104. The cage 115 retains the inner race of the second deep groove ball bearing 104. A first deep groove ball bearing 102 is present between the second cam 116 and the cage 115. The cam cap 117 is connected to the second cam 116 by a screw 128. The cage 115 retains the outer race of the first deep groove ball bearing 102 and the cam cap 117 retains the inner race of the first deep groove ball bearing 102. The lip seal can reduce the loss of lubricant and avoid the invasion of pollutants.

As shown in fig. 2,5, 7 and 11, the first movable member 123 on the left side is engaged with the first cam 106, the cage 115 and the first ring gear 113, and the structure is identical to the second movable member 127 on the right side. The contact of the plurality of movable members with the first cam 106 cooperates to form the first movable assembly 105. The first cam 106 and the second cam 116 are connected by a first countersunk screw 122. The first ring gear 113 and the second ring gear 114 are connected by a second countersunk head screw 125. A fourth deep groove ball bearing 112 is present between the first ring gear 113 and the cage 115. The first annular gear 113 is used for blocking the outer ring of the fourth deep groove ball bearing 112, the first locking retainer ring 107 is connected with the retainer 115 to block the inner ring of the fourth deep groove ball bearing 112, and a third deep groove ball bearing 111 is arranged between the retainer 115 and the first cam 106. The cage 115 retains the outer race of the third deep groove ball bearing 111. The second locking retainer 108 is connected with the first cam 106 to block the inner ring of the third deep groove ball bearing 111. The ring gear end cap 110 and the first ring gear 113 are connected by screws 128.

The working principle of the invention is as follows:

The first cam 106 and the second cam 116 are connected by a first countersunk screw 122 and serve as inputs, and the cage 115 serves as an output. The first ring gear 113 and the second ring gear 114 are connected and fixed by the second countersunk screws 125. First, the motor drives the first cam 106 and the second cam 116 to rotate on the fixed shaft, then the first cam 106 and the second cam 116 are respectively contacted with the outer ring surfaces of the driven bearings 129 connected to the first movable member 123 and the second movable member 127 through the inner and outer contour surfaces of the movement grooves 121, the movable teeth 124 on the first movable member 123 and the second movable member 127 are pushed to move radially along the tooth holes 118 of the retainer 115, and then the tooth contour portions of the movable teeth 124 on the first movable member 123 and the second movable member 127 are respectively engaged with the inner teeth 120 of the first inner gear ring 113 and the second inner gear ring 114. Since the first ring gear 113 and the second ring gear 114 are fixed, finally the meshing movement of the first movable member 123 and the second movable member 127 rotates the cage 115.

Example 2

This embodiment is a further improvement of embodiment 1, and the repeated contents are not repeated.

The first ring gear 113 in the first transmission assembly is connected to the second ring gear 114 in the second transmission assembly such that the rotational speeds of the first movable assembly 105 and the second movable assembly 119 are the same. The power transmitted to the cage 115 by the first movable assembly 105 and the second movable assembly 119 is the same. In this way, the synchronous rotation of the two movable components can be ensured.

As shown in fig. 7, the first cam 106 and the second cam 116 are connected as inputs by a first countersunk screw 122. As shown in fig. 9, the first ring gear 113 and the second ring gear 114 are connected as an output by the second countersunk head screw 125. The holder 115 is fixed. First, the motor drives the first cam 106 and the second cam 116 to rotate on the fixed shaft, and then the first cam 106 and the second cam 116 contact with 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 movement groove 121, so that the movable teeth 124 on the first movable member 123 and the second movable member 127 are pushed to move radially along the tooth holes 118 of the holder 115. Thereafter, the movable teeth 124 of the first movable member 123 and the second movable member 127 are tooth-profile-meshed with the internal teeth 120 of the first ring gear 113 and the second ring gear 114. Since the holder 115 is fixed, the first ring gear 113 and the second ring gear 114 are rotated.

The first countersunk head screw 122 is used for connecting the first cam 106 and the second cam 116, and the second countersunk head screw 125 is used for connecting the first annular gear 113 and the second annular gear 114, so that the whole speed reducer is conveniently divided into two parts for assembly respectively.

The first cam 106 and the second cam 116 take the form of a single wave, with only one major half axis and one minor half axis, i.e., one cycle, being present for one revolution. The reduction ratio of the speed reducer is increased while keeping the speed reducer small.

The assembly connection mode of the long half shaft of the first cam 106 and the short half shaft of the second cam 116 is adopted, so that the whole stress of the single-wave cam is relatively balanced, and the stability of the speed reducer is improved.

The invention reduces the parts of the movable component by the movable component connected with the movable teeth 124 through the driven bearing 129, and has simpler structure. The first movable component 105 has a space between two movable components, such as a space between the positions of one movable component, so as to form a differential gear transmission, and avoid mutual interference between the movable components. In the present invention, the first locking collar 107 is connected to the cage 115 and blocks the inner race of the fourth deep groove ball bearing 112. The second locking retainer 108 is connected with the first cam 106 and retains the inner ring of the corresponding third deep groove ball bearing 111, thereby being fixed.

It should be noted that the above-described embodiments are exemplary, and that a person skilled in the art, in light of the present disclosure, may devise various solutions that fall within the scope of the present disclosure and fall within the scope of the present disclosure. It should be understood by those skilled in the art that the present description and drawings are illustrative and not limiting to the claims. The scope of the invention is defined by the claims and their equivalents. The description of the invention includes various inventive concepts such as "preferably", "according to a preferred embodiment" each meaning that the corresponding paragraph discloses a separate concept, and applicant reserves the right to filed a divisional application according to each inventive concept.

Claims

1. The logarithmic spiral oscillating tooth transmission precise speed reducing device is characterized by comprising two transmission components, wherein the transmission components comprise a cam in a single wave form, a movable component and an inner gear ring,

The cam is arranged in the movable assembly comprising a plurality of movable components, and the cam is contacted with the movable components in a relatively rotatable manner,

The inner gear ring is sleeved on the outer side of the movable assembly and meshed with the movable member, so that the inner gear ring and the movable assembly perform meshing movement;

the two transmission assemblies are connected in opposite directions, and the two cams in the two transmission assemblies are arranged in a mode that initial positions are 180 degrees different, so that the two cams form a motion structure with relatively balanced stress;

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 annular gear (113);

the second transmission assembly comprises a second cam (116), a second movable assembly (119) and a second annular gear (114);

Under the condition that the initial positions of the first cam (106) and the second cam (116) are different by 180 degrees, the first annular gear (113) is connected with the second annular gear (114), the first cam (106) is connected with the second cam (116), so that the rotation speed of the first movable assembly (105) is the same as that of the second movable assembly (119), the power transmitted to the retainer (115) by the first movable assembly (105) is the same as that of the second movable assembly (119), and the first transmission assembly and the second transmission assembly form differential gear transmission.

2. The logarithmic spiral oscillating tooth transmission precision speed reducing device according to claim 1, wherein the cam is of symmetrical eccentric structure, the profile curve of the cam has a long half shaft and a short half shaft,

When the cam rotates for one circle, the movable component and the inner gear ring complete one cycle of meshing movement.

3. The logarithmic spiral oscillating tooth transmission precision reducing apparatus according to claim 2, wherein the movable assembly comprises a holder (115) and a plurality of movable members,

The movable member includes a driven bearing (129) and movable teeth (124),

The driven bearing (129) penetrates through the through hole of the movable tooth (124) and is rotatably connected with the movable tooth (124);

-the tooth profile portion of the movable tooth (124) is inserted into a tooth aperture (118) in the cage (115) such that the movable tooth (124) is circumferentially distributed on the cage (115) and the follower bearing (129) is in contact with the cam surface;

In the case of rotation of the cam, the cam drives the mobile assembly to move according to its profile.

4. The logarithmic spiral oscillating tooth transmission precision reducing apparatus according to claim 3, wherein a tooth profile portion of said movable tooth (124) penetrates said tooth hole (118) of said holder (115) and meshes with internal teeth (120) on said internal tooth ring,

And under the condition that the cam rotates, the cam drives the movable assembly to push the annular gear to rotate.

5. The logarithmic spiral oscillating tooth transmission precision speed reducing device according to claim 3 or 4, wherein the cam is provided with a movement groove (121),

In the case of two cams connected in opposite directions, two movement grooves (121) are formed through each other,

A follower bearing (129) in the movable member is in contact engagement with the cam within the movement groove (121).

6. The logarithmic spiral oscillating tooth transmission precision speed reducing device according to claim 5, wherein a space exists between the movable members,

The size of the interval is matched with the meshing position of the inner gear ring, so that the movable component and the inner gear ring form differential gear transmission, and the movable components do not interfere with each other.

7. The logarithmic spiral oscillating tooth transmission precision speed reducing device according to claim 5, wherein the retainer (115) is provided with two rows of the tooth holes (118),

The movable teeth (124) in the two transmission assemblies are correspondingly contacted with the rows of the tooth holes (118) on the retainer (115).

8. The logarithmic spiral oscillating tooth transmission precision speed reducing device according to claim 5, wherein a deep groove ball bearing and a lip seal are provided between the ring gear and the retainer (115),

A deep groove ball bearing is arranged between the cam and the retainer (115).

9. The logarithmic spiral oscillating tooth transmission precision speed reducing device according to claim 5, wherein a ring gear end cap (110) is provided at one end of the first ring gear (113) which is not connected with the second ring gear (114) to fix and support the first ring gear (113), a cam end cap (117) is provided at an outer side end of the second cam (116) to stabilize a circumferential position of the second cam (116);

in an assembled state, a third lip seal (109) is arranged between the annular gear end cover (110) and a first cam (106) in the first transmission assembly, a cam end cover (117) is connected with a second cam (116) in the second transmission assembly and rotates together with the second cam (116), and a first lip seal (101) is arranged between the retainer (115) and the cam end cover (117).