CN209245180U - Double flex spline harmonic reducer with limitable deformation - Google Patents

Abstract

A double flex spline harmonic reducer with limitable deformation is characterized in that: the double flex spline harmonic reducer with limitable deformation includes strong flex splines, weak flex splines, wave generators and strong flex splines As a limiting part, the strong and soft wheel and the weak and soft wheel are coaxially fixed axially and radially fixed, the strong and soft wheel and the weak and soft wheel are respectively provided with teeth that can mesh with each other, and there is a difference in the number of teeth between the strong and soft wheel and the weak and soft wheel , the wave generator causes the weak and flexible wheel to undergo non-circular elastic deformation and meshes with the strong and flexible wheel part, and the contact part between the strong and soft wheel and the weak and flexible wheel is subjected to the radial pressure of the weak and flexible wheel to produce non-circular elastic deformation, and the strong and flexible wheel The non-toothed side of the flexible tubular wall is processed with a limited contact surface. The deformation limit part of the strong and flexible wheel is relatively fixed with the strong and flexible wheel. The deformation limit part of the strong and flexible wheel is processed with an annular limit surface. The limiting contact surface of the flexible wheel deformed by the radial pressure of the weak flexible wheel is in contact with the annular limiting surface on the deformation limiting part of the strong flexible wheel.

Description

Double flex spline harmonic reducer with limitable deformation

technical field

The invention relates to the field of reducers, in particular to a double flexspline harmonic reducer with limitable deformation.

Background technique

Harmonic gear transmission was invented by American inventor C.W.Musser in 1955. It is a new type of transmission method that uses elastic deformation of flexible working components for motion or power transmission. It breaks through the rigid component mechanism of mechanical transmission. Mode, using a flexible component to achieve mechanical transmission, thus obtaining a series of special functions that other transmissions are difficult to achieve. Because the deformation process of the middle flexible member is basically a symmetrical harmonic, it gets its name. Except that the former Soviet Union called this kind of transmission wave transmission or flexible wheel transmission, the United States, Britain, Germany, Japan and other countries all call it "harmonic transmission".

The principle of harmonic gear transmission deceleration refers to the use of the relative motion of the flex spline, rigid spline and wave generator, mainly the controllable elastic deformation of the flex spline to realize motion and power transmission. The elliptical cam in the wave generator rotates in the flexspline to deform the flexspline. When the flexible spline teeth at the two ends of the long axis of the wave generator and the rigid spline teeth are engaged, the flexible spline teeth at the two ends of the short axis are disengaged from the rigid spline teeth. For the teeth between the long axis and the short axis of the wave generator, the teeth in different sections along the circumference of the flexible spline and the rigid spline are in a semi-meshed state that gradually enters into mesh, which is called meshing; in a semi-meshed state that gradually exits mesh, called gnawing. When the wave generator rotates continuously, the flexspline continuously deforms, so that the two gear teeth change their original working states continuously in the four movements of meshing, meshing, meshing and disengagement, resulting in staggered tooth movement, realizing the active wave Motion transfer from generator to flexspline.

Composition of the existing harmonic gear transmission ① Rigid gear: Rigid internal gear, generally 2 teeth more than the flex spline, usually fixed on the casing; ② Flex spline: thin cup with gears on the outer ring of the opening Shaped metal elastic parts, which deform with the rotation of the wave generator, are usually connected to the output shaft; ③ wave generator: composed of an elliptical cam and a flexible bearing, usually connected to the input shaft. The inner ring of the flexible bearing is fixed on the cam, and the outer ring can be elastically deformed into an ellipse through balls.

However, the hysteresis of the current harmonic reducer depends on the degree of meshing tightness between the teeth of the ellipse major axis and the teeth of the steel wheel after the elliptical deformation of the flexspline under the action of the wave generator. If the meshing is not tight, the hysteresis will be large. Yinghui will not be able to assemble or rotate difficult. Whether the flexible wheel and the steel wheel can be accurately meshed depends on the production accuracy of the harmonic reducer. Higher precision requirements increase the production cost and limit some relatively cheap materials and processing techniques. At the same time, the flexspline, steel wheel and wave generator will be worn to a certain extent during operation, and the wear will also cause the meshing tightness between the flexspline and the steel wheel to gradually decrease, and the hysteresis of the reducer will gradually increase. Large, which determines that the precision life of the reducer cannot be too long.

Contents of the invention

In order to solve the above problems, the present invention proposes a double flexspline harmonic reducer with limitable deformation.

The technical scheme adopted in the present invention is.

A double flex spline harmonic reducer with limitable deformation is characterized in that: the double flex spline harmonic reducer with limitable deformation includes strong flex splines, weak flex splines, wave generators and strong flex splines As a limiting part, the strong and soft wheel and the weak and soft wheel are coaxially fixed axially and radially fixed, the strong and soft wheel and the weak and soft wheel are respectively provided with teeth that can mesh with each other, and there is a difference in the number of teeth between the strong and soft wheel and the weak and soft wheel , the wave generator causes the weak and flexible wheel to undergo non-circular elastic deformation and meshes with the strong and flexible wheel part, and the contact part between the strong and soft wheel and the weak and flexible wheel is subjected to the radial pressure of the weak and flexible wheel to produce non-circular elastic deformation, and the strong and flexible wheel The non-toothed side of the flexible tubular wall is processed with a limited contact surface. The deformation limit part of the strong and flexible wheel is relatively fixed with the strong and flexible wheel. The deformation limit part of the strong and flexible wheel is processed with an annular limit surface. The limit contact surface of the soft wheel deformed by the radial pressure of the weak wheel is in contact with the annular limit surface on the deformation limit part of the strong and soft wheel, and the deformation of the strong and soft wheel is due to the deformation of the strong and soft wheel. The amount of wheel deformation limiting parts contact and limited. The double flexible wheel harmonic reducer with limited deformation is to replace the steel wheel of the existing harmonic reducer with a strong flexible wheel whose rigidity is greater than that of the existing harmonic reducer flexible wheel, so the strong flexible wheel is different from the existing steel wheel A notable feature of the wheel is that the strong and flexible wheel has a flexible and thin wall similar to the existing harmonic reducer flexible wheel, that is to say, the strong and flexible wheel includes a connection method between the elastically deformable ring gear structure and the non-elastically deformable A section of thin-walled structure that can be elastically deformed between the blue plate structures, which can facilitate the non-circular elastic deformation of the ring gear structure surface, usually adopts a thin-walled tubular structure; the double flexwheel harmonic reducer with limited deformation Another notable feature is that the radius of the index circle of the tooth farthest from the axis of the reducer after the weak and flexible gear undergoes non-circular deformation under the action of the wave generator is larger than that of the circular ring gear before the strong and flexible gear is assembled. The radius of the circle; it is said that the weak and flexible wheel undergoes non-circular elastic deformation under the action of the wave generator and the strong and flexible wheel undergoes non-circular elastic deformation under the radial pressure of the teeth of the meshing part after the non-circular deformation of the weak and flexible wheel, so The weak and flexible gear always keeps some teeth continuously meshing in and out of the teeth of the strong and flexible gear along with the rotation direction of the wave generator. Due to the difference in the number of teeth between the strong and flexible gear and the weak and flexible gear, it shows that the rotation and rotation drive of the wave generator is strong. The flexible wheel and the weak flexible wheel will rotate relative to each other to achieve the effect of the speed reducer for deceleration and torque increase. The wave generator is provided with a shaft hole or a flange connected to the input power source. Flange and output flange; of course, the double flex spline harmonic reducer with limited deformation also has the reversible output characteristics of the existing harmonic reducer; in practical applications, most of the wave generators use elliptical cams and The outer ring is equipped with a rolling bearing structure. The elliptical cam is a 2-headed cam that can cause two teeth on the weak and soft wheel to mesh with the strong and soft wheel. The difference in the number of teeth between the strong and soft wheel and the weak and soft wheel should be the cam of the wave generator. Integer multiples of the number of heads. In theory, a single-head cam or a multi-head cam with more than three heads can be used to mesh the weak and soft wheels with one or more places. Use cams with different numbers of heads to match the strong and soft wheels There are corresponding requirements for the number of teeth and tooth shape of the wheel; strong and soft wheels can use cycloid teeth, involute teeth, triangular teeth, trapezoidal teeth and circular cycloid teeth, etc., because strong and soft wheels can have certain deformation It is equivalent to setting a certain controllable range of tooth surface meshing pressure, and the degree of meshing is also improved, which can facilitate the use of smaller tooth heights, which are conducive to reducing the elastic deformation of weak flex gears and thus The deceleration material is fatigued, and the smaller tooth height is also more conducive to the miniaturization of the reducer. The purpose of using double flexible gears is to allow the strong flexible gears to have a small or slight amount of non-circular elastic deformation along with the weak flexible gears when the harmonic reducer is running; This can not only increase the fault tolerance of the harmonic reducer to parts, but also improve the wear resistance of the harmonic reducer to prolong the precision life, so it also allows the use of cheaper materials and processing technology to produce better manufacturing accuracy Harmonic reducer, thereby greatly reducing the cost of harmonic reducer. The double flexible wheel harmonic reducer with limitable deformation is to use a part with a ring contact surface to limit the deformation of the strong and flexible wheel, or to limit the maximum value of the long axis of the ellipse after the deformation of the strong and soft wheel, and the deformation of the strong and soft wheel The limit part and the strong and flexible wheel are relatively fixed in the adjusted installation position coaxial with the strong and flexible wheel; the flexible tubular wall of the strong and flexible wheel is divided into the inner surface of the tubular wall and the outer surface of the tubular wall. If the inner surface has teeth, the toothless side refers to Outside the tubular wall, if the outer surface is processed with teeth that mesh with the weak and flexible wheel, the toothless side refers to the inner surface of the tubular wall; in order to reduce the contact pressure of the limit surface, the limit contact surface on the strong and flexible wheel and the limit parts of the strong and flexible wheel The surface in contact with the flexible wheel is processed into a surface that matches each other when in contact, such as a chamfered surface with an approximate angle or a rounded surface with an approximate fillet radius; The tooth profile of flex splines and weak splines can be involute profile trapezoidal profile, etc. However, it is the same as most tooth profile gear transmissions, keeping the tooth surface as the contact force surface is the basic common sense of tooth profile design , as far as the present invention is concerned, it should be considered that the teeth of the weak and strong gears maintain the contact force on the tooth surface of the weak and strong gears in the whole wear and adjustment deformation state, rather than other parts such as the tip of the tooth.

The annular limiting surface on the deformation limiting part of the strong and flexible wheel is an annular limiting surface with a gradually changing diameter. The annular limiting surface with a gradually changing diameter can be fixed axially by changing the deformation limiting part of the strong and flexible wheel The position realizes the difference in the deformation limit of the strong and flexible wheel, because the ellipse major axis of the limit contact surface after the deformation of the strong and flexible wheel cannot be greater than the diameter of the limit contact surface of the deformation limit part of the strong and flexible wheel in contact with it, Therefore, changing the diameter of the annular limit surface where the deformation limit part of the strong and soft wheel is in contact with the strong and soft wheel can change the limit value of the deformation of the strong and soft wheel; Filleted faces.

The deformation limit part of the strong and flexible wheel can realize that the diameter of the annular limit surface in contact with the limit contact surface of the strong and flexible wheel is different through the adjustable axial fixed position, so as to realize the control of the deformation limit value of the strong and flexible wheel. adjust. That is to say, by adjusting the axial fixed position of the deformation limit part of the strong and flexible wheel, the limit value of the deformation of the strong and flexible wheel can be adjusted, thus a mechanism for adjusting the deformation of the strong and flexible wheel is proposed.

The deformation limiting part of the strong and flexible wheel is directly fixed to the axial direction of the strong and flexible wheel through threads or indirectly through other parts of the reducer, and the axial position adjustment is realized through the relative rotation of the threads. Use threads to connect the deformation limiting part of the strong and flexible wheel with the strong wheel, or use threads to connect the deformation limiting part of the strong and flexible wheel and any parts that are relatively fixed with the strong and flexible wheel, and then rotate the deformation limiting part of the strong and flexible wheel Realize the change of the axially relatively fixed position between the deformation limit part of the strong and soft wheel and the strong and soft wheel; usually the axis line of the thread is coaxial with the strong and soft wheel; usually because the surface of the strong and soft wheel is not suitable for processing threads, so A connection part is required to be fixed with the strong wheel and processed with threads. The thread of the connection part is connected with the deformation limit part of the strong wheel. Of course, the connection part may be directly fixed with the flanging of the strong wheel or may be fixed with the The flanging of the strong and flexible wheels is fixed on the same outer ring of the bearing or on the same casing; the double-flexible wheel harmonic reducer with limitable deformation can also be processed on the main bearing parts of the reducer to match the strong and flexible The thread that the wheel deformation limiting parts match, the strong and flexible wheel deformation limiting parts are directly fixed on the bearing parts fixed with the strong and flexible wheels by threads.

The way that the deformation amount limiting part of the strong and flexible wheel is fixed to the strong and flexible wheel by threads also includes a thread anti-loosening mechanism, and the thread anti-loosening mechanism is a top screw or a spline. There are a large number of anti-loosening mechanisms in the prior art. At first, there are various top screws, some of which withstand the thread and the surface of the workpiece. On another part; there are many kinds of anti-loosening methods such as elastic sun washers using splines, or using detachable spline washers to realize anti-loose fixation by disassembling the spline washers each time, which is proposed in the present invention In the technical solution, it is not an ideal choice to use a one-time anti-loosening mechanism or an irreversible anti-loosening mechanism such as glue because adjustment is required.

There is a gear on the deformation limiting part of the strong and flexible wheel, and the outside world can push the gear through the gear or worm parts, thereby pushing the deformation limiting part of the strong and flexible wheel to rotate, and the outer diameter can pass through the non-rotating gear or worm The part locks the gear on the deformation limiting part of the strong and flexible wheel to realize the locking of the relative axial position of the deformation limiting part of the strong and flexible wheel and the strong and flexible wheel. In the description in this paragraph, the external parts are not part of the double flex wheel harmonic reducer with limitable deformation, but refer to all the rotation or locking forces that can form the transmission pair with the gears on the deformation limit parts of the strong flex wheel The input part of the input part is provided with a gear coaxial with the adjusting thread on the deformation limiting part of the strong and flexible wheel. The external part can be another gear that forms a gear transmission pair with this gear, and the external part can also be a gear that forms a gear transmission pair with this gear. The worm of the helical gear worm transmission pair, of course, when the gear or worm as an external part rotates, it can drive the deformation limit part of the strong and soft wheel to rotate and tighten or loosen the thread fixed with the axial position of the strong and soft wheel to realize the deformation of the strong and soft wheel Adjustment of the axial position of the quantity limiting part; similarly, when the gear or worm as an external part is fixed and does not rotate, it also plays the role of locking the deformation limit part of the strong and flexible wheel, which is to lock the deformation limit of the strong and flexible wheel The axial position of the part and the flex wheel.

It also includes an elastic part that applies axial force to the deformation limiting part of the strong and flexible wheel, and the deformation limiting part of the strong and flexible wheel can move axially under the force of the elastic part. The elastic parts can be springs or rubber pads, and the elastic parts are compressed and installed. When the amount of deformation decreases due to tooth surface wear and other reasons, the deformation limiting part of the strong and soft wheel will move axially under the force of the elastic part, and the angle between the limit contact surface on the strong and soft wheel and the axis of the strong and soft wheel should be less than 20 degrees , even less than 10 degrees is better, so that the axial component of the contact pressure between the strong and soft wheel and the deformation limit part of the strong and soft wheel is as small as possible, and the deformation limit part of the strong and soft wheel caused by this pressure is reduced or avoided as much as possible Compressing the elastic element produces axial movement.

The deformation limiting part of the flexspline can be processed into a flexspline protective shell or a part of the flexspline protective shell. Protect the strong and flexible wheel from the interference caused by the installation of external parts while maintaining the upper limit of the deformation of the strong and flexible wheel.

The double-flex wheel harmonic speed reducer with limitable deformation also includes a connecting part, which is relatively fixed with the strong-flex wheel, and the deformation-limiting part of the strong-flex wheel is connected and fixed with this part to realize the connection with the strong The flexible spline is relatively fixed. The connecting parts are usually provided with flanging, and the flanging and the flanging of the strong and flexible wheel are provided with corresponding bolt holes, which can be fixed to each other by bolts or fixed to bearings or equipment housings by bolts. Relative fixation with the strong wheel.

The double flex spline harmonic reducer whose deformation can be limited also includes a gear or worm, and the gear or worm can form a gear transmission pair or a worm helical gear with the gear processed on the deformation limiting part of the flex spline Transmission pair, the axis of rotation of described gear and worm is relatively fixed with strong and flexible wheel. The gear and worm can be used as a set together with the double flex spline harmonic reducer with limitable deformation. The structure of fixed gear or worm rotation shaft can be processed on the reducer body, or the reducer can be installed The structure of the rotation shaft of the fixed gear or worm is processed on the equipment shell; the structure of the rotation shaft of the fixed gear or worm is usually a bearing seat and is inlaid with sliding or rolling bearings.

In the double flexspline harmonic reducer with limited deformation, the flexspline includes an elastically deformable thin-walled structure between the ring gear structure and the connecting flange structure. The strong flexible wheel has a flexible thin wall similar to the existing harmonic reducer flexible wheel, that is to say, the strong flexible wheel contains a section between the ring gear structure that can be elastically deformed and the connecting flange structure that cannot be elastically deformed The thin-walled structure that can be elastically deformed, the structure that can facilitate the non-circular elastic deformation of the structural surface of the ring gear is usually a thin-walled tubular structure.

For the double flex gear harmonic reducer whose deformation can be limited, the index circle radius of the teeth farthest from the axis of the reducer after the weak flex gear undergoes non-circular deformation under the action of the wave generator is larger than that of the strong flex gear The pitch circle radius of the unassembled circular ring gear. The strong and soft wheel guaranteed by the larger quantity will produce a certain amount of elastic deformation after assembly. This greater than the amount is the elastic deformation of the strong and soft wheel. The strong and soft wheel can only achieve this under the basic premise of maintaining a certain amount of elastic deformation. The technical effect of the invention; the above-mentioned size relationship is based on the fact that the weak and flexible wheels are inside the strong and flexible wheels. inner wall of the wheel.

The pitch circle radius of the circular ring gear of the strong flexible gear before being assembled is greater than the pitch circle radius of the tooth closest to the axis of the reducer after the weak flexible gear undergoes non-circular deformation under the action of the wave generator. Theoretically, there is another kind of harmonic reducer structure in which the soft wheel is provided with the internal gear ring outside and the strong wheel is provided with the external tooth ring. The wave generator acts on the outer wall of the weak wheel. The wheel squeezes the strong and soft wheel inward. This structure requires that the index circle radius of the circular ring gear of the strong and soft wheel before assembly is greater than the distance of the weak and soft wheel after non-circular deformation under the action of the wave generator. The radius of the pitch circle of the tooth closest to the center of the machine shaft. In general, it is recommended that the greater value be at least 0.05mm. In some cases, the greater value is even required to be 0.1mm or 1mm. The greater value It is the flexible deformation of the assembled strong and soft wheel. The flexible deformation of the strong and soft wheel is related to the radius of the strong and soft wheel, the material of the strong and soft wheel, and the level of processing accuracy. The larger the radius of the strong and soft wheel, the theoretically the design deformation of the strong and soft wheel The larger the amount of deformation should be, the softer the material, the larger the above-mentioned deformation should be designed theoretically, and the lower the processing accuracy requirements should be, the larger the above-mentioned deformation should be designed theoretically. If the wave generator with an elliptical hole is used, the above-mentioned deformation The quantity is the difference between the radius of the major axis of the ellipse and the radius of the minor axis of the ellipse after the deformation of the ellipse of the strong and flexible wheel.

The double flex spline harmonic reducer with limitable deformation also includes a reducer main bearing, and the strong and weak splines are coaxially and axially fixed and radially fixed through the reducer main bearing. The main bearing of the reducer must be able to withstand the axial moment, radial moment and overturning moment. The main bearing of the reducer usually adopts cross roller bearings or double row angular contact bearings, and can also choose a pair of angular contact bearings or a pair of tapered contact bearings installed separately. Roller bearings can be any bearing or bearing combination that can bear axial moment, radial moment and overturning moment equally in the specific reducer structure; and all or part of the bearing inner ring and bearing outer ring of the main bearing of the reducer can be directly It is processed on the strong and soft wheels and the weak and soft wheels respectively, and can also be fixed on the strong and soft wheels and the weak and soft wheels by bolt fixing and other methods; the output flange and fixing method of the double-flex wheel harmonic reducer with limited deformation The blue can be processed on the strong and soft wheels and the weak and soft wheels respectively, and can also be processed on the bearing inner ring and bearing outer ring of the main bearing of the reducer. In some special cases, the main bearing of the reducer can be realized in the form of a sliding bearing. It is even possible to process all or part of the inner ring and outer ring of the sliding bearing directly on the strong and soft wheels and the weak and soft wheels.

The double flexspline harmonic reducer with limitable deformation also includes a wave generator positioning bearing, and the wave generator is axially fixed and radially fixed with the strong flex spline or the weak flex spline through the wave generator positioning bearing. Since there is no steel wheel of the existing harmonic reducer, better fixing the axis of the wave generator so that it is coaxial with the strong or weak wheel can effectively reduce the slight amount of different shaft pairs when the wave generator is connected to the motor Influenced by the service life of the reducer and the transmission efficiency, the positioning bearing of the wave generator mentioned above should not be confused with the non-circular bearing contained in the wave generator in the existing harmonic reducer, it is an additional circular bearing; if in the actual structure such as If the driving shaft of the wave generator such as the motor shaft and the main bearing of the reducer are well coaxial and radially fixed, the positioning bearing of the wave generator may not be needed. Concentric and radially fixed with the weak flexible wheel.

The radius of the pitch circle of the tooth farthest from the axis of the reducer after the weak and flexible gear undergoes non-circular deformation under the action of the wave generator is preferably greater than the pitch circle of the circular ring gear before the strong and flexible gear is assembled The radius is above 0.2mm.

The above-mentioned dimensional difference is the flexible deformation of the assembled strong and soft wheel. The flexible deformation of the strong and soft wheel is related to the radius of the strong and soft wheel, the material of the strong and soft wheel, and the level of processing accuracy. The larger the radius of the strong and soft wheel In theory, the design deformation of the strong and flexible wheel should be larger. The softer the material, the larger the above deformation should be designed. The lower the machining accuracy requirements, the larger the above deformation should be. If the elliptical wave is used Generator, above-mentioned deformation amount is exactly the difference of the ellipse major axis radius and the ellipse minor axis radius after the ellipse deformation of strong and flexible wheel.

The wall thickness of the strong and flexible wheel is greater than 1.2 times of the wall thickness of the weak and flexible wheel and less than 4 times of the wall thickness of the weak and flexible wheel. The wall thickness of the strong and soft wheel or the wall thickness of the weak and soft wheel refers to the wall thickness of the tubular part of the main flexible non-circular deformation of the soft wheel. The above-mentioned limitation is mainly because the elastic On the premise of materials with similar or the same modulus, if a material with a large difference in elastic modulus is selected for the strong and soft wheels and the weak and soft wheels, the above wall thickness limit range should be converted according to the difference in the elastic modulus of the materials.

The strong and flexible wheel is a tubular elastic part with inner flanging or outer flanging. The inner ring or outer ring of the main bearing of the reducer is processed on the flange, or the screw holes are processed on the flange and the inner ring or outer ring of the main bearing of the reducer is fixed by bolts. The inner flange type is usually also Known as cupped.

The weak flexible wheel is a thin-walled tubular elastic part with inward or outward flanging. The inner ring or outer ring of the main bearing of the reducer is processed on the flange, or the screw holes are processed on the flange and the inner ring or outer ring of the main bearing of the reducer is fixed by bolts. The inner flange type is usually also Known as cupped.

Usually, the existing harmonic reducer has a flex spline with the inner steel wheel outside. At this time, the flex spline is processed with external teeth, and the steel wheel is processed with internal teeth; but theoretically speaking, the flex spline is outside the outer steel wheel. At this time, internal teeth are processed on the flexspline, and external teeth are processed on the steel wheel. At the same time, it is also feasible to cooperate with the inner ring of the non-circular bearing of the wave generator to squeeze the flexspline inward to mesh with the steel wheel. This is more The structural form of the harmonic reducer that is conducive to the hollowing of the structure. Of course, if it is for better hollowing, the rotation power of the wave generator at this time may come from the same hollow outer rotor motor or from the gear or the outer ring of the wave generator. Synchronous belt transmission; similarly, the double-flexible wheel harmonic speed reducer with limited deformation of the present invention usually adopts the structural form of the strong flexible wheel inside the outer weak flexible wheel. At this time, the soft wheel is processed with an outer The strong and soft wheel is processed with internal teeth, but in the same theory, the form of the strong and soft wheel inside the weak and soft wheel can also be used. The strong and soft wheel has external teeth and the weak and soft wheel has internal teeth. The weak and soft wheel can be The outer flanging tubular shape is selected, the strong and soft wheel adopts the inner flanging tubular shape, and the wave generator adopts a hollow form. The inner ring of the non-circular bearing of the wave generator is used to squeeze the weak and soft wheel to produce non-circular deformation, and the weak and soft wheel Squeeze the strong wheel further to cause a slight non-circular deformation. At this time, the rotation power of the wave generator may come from the same hollow outer rotor motor or from the gear or synchronous belt drive on the outer ring of the wave generator. According to the description in this paragraph In the structure of the double-flex wheel harmonic reducer whose deformation can be limited, the deformation limiting part of the strong wheel should be located in the strong wheel, and what is limited is no longer the maximum value of the long axis of the elliptical deformation of the strong wheel. is the minimum value of the minor axis that limits the elliptical deformation of the strong wheel.

The double flexspline harmonic speed reducer with limitable deformation also includes an outer flexspline protective case, and the flexspline protective case is fixed to the inner ring or outer ring of the main bearing of the reducer. The strong flexible spline and the weak flexible spline are both flexible and can be collectively referred to as the flexible spline. Since the outer side of the reducer is not a steel wheel but a flexible spline, the protection of the outer flexible spline of the reducer is very important. It is necessary to ensure that the transportation and installation process If the outer flexible spline is damaged, it is also necessary to ensure that there is enough space for the deformation of the outer flexible spline when the reducer is installed, so the flexible spline protective shell can provide effective protection; The parts that limit parts are connected by threads can be used as a part of the soft wheel protective shell, and also a part of the adjustment mechanism of the deformation limit parts of the strong wheel. At this time, the parts fixed with the strong wheel and the deformation limit of the strong wheel The two parts together play the function of the flexspline protective shell; at the same time, the flexspline protective shell and the coaxial fixed connection that can be used as the main bearing of the reducer and the positioning bearing of the wave generator, the positioning bearing of the wave generator connects with the reducer through the flexible spline protective shell The main bearing is coaxially fixed.

The strong and weak wheels of the double-flex wheel harmonic speed reducer with limitable deformation are injection molded from plastic materials or undergo a small amount of processing after injection molding of plastic materials. The accuracy of the injection molding process is lower than that of precision metal processing, and the plastic parts have the disadvantages of water absorption and thermal deformation. If the existing harmonic reducer structure uses the injection molding process to process the flexible wheel, it is difficult to achieve high-efficiency transmission with minimal hysteresis. , if the structure of the double flex wheel harmonic reducer with limitable deformation is used, the precision harmonic reduction transmission can be realized if the injection molding process difference is less than the elastic deformation of the preset soft wheel; POM material and nylon material are both Potentially suitable for injection molding processing as flexspline materials, such as PA66, PA6, PA601 and other nylon materials are very suitable for direct injection molding processing or injection molding and then through a small amount of machining to manufacture the flexspline parts of the technical solution of the present invention; with the development of polymer injection molding materials Development, new composite polymer materials are constantly being developed, such as PEEK and other new generation polymer materials with better mechanical properties, as long as the hardness, wear resistance, toughness and fatigue resistance meet the requirements of polymer injection molding materials can be It is used to injection mold the flexible spline parts and the hard spline deformation limit parts of the double flexspline harmonic reducer whose deformation can be limited, which can greatly reduce the cost of the precision reducer and reduce the weight of the reducer.

The weak and strong splines of the double flex spline harmonic reducer with limited deformation are directly injection molded into parts including the inner ring and outer ring of part of the main bearing. Because of the convenience of injection molding, from the perspective of simplifying the structure and reducing costs, part of the inner ring or outer ring of the main bearing is directly integrally injected on the parts of the weak and strong wheels. Of course, the part processing process can include injection molding. After a small amount of post-machining.

The flexspline of the double flexspline harmonic reducer whose deformation can be limited is directly processed with a ball rolling groove of a wave generator. When plastic materials are used to injection mold the soft wheel, the wave generator can also be injection molded, and the rolling elements of the bearing are filled into the pre-processed bearing inner ring and bearing outer ring on the wave generator and the soft wheel respectively during assembly. Among them, especially when filling with full balls, forming a full ball bearing is more conducive to simplifying the structure and reducing the cost.

The teeth of the double flexspline harmonic reducer with limitable deformation can be processed by laser engraving or etching. The existing harmonic reducer is inconvenient to use very small teeth due to the limitation of work tolerance, but the double flex spline harmonic reducer with limited deformation can use very small teeth due to its good tolerance of work tolerance. The harmonic reducer can be designed so that the soft wheel can run with only a small non-circular deformation, which can effectively improve the life of the weak wheel and reduce heat and improve transmission efficiency. Therefore, laser engraving or etching process can be considered. The processing of the teeth of strong and soft wheels and weak wheels improves processing efficiency and reduces processing costs.

A significant advantage of the double flex spline harmonic reducer with limitable deformation is that it is more inclusive of processing tolerances, and can use parts with lower level of tolerance requirements to achieve high-precision harmonics with small backlash or even zero backlash Reducer; at the same time, the inclusiveness of the parts tolerance is equal to the inclusiveness of the wear of the parts. The wear of the parts within a certain range will not affect the precision of the reducer, and the parts can also be limited by further adjusting the deformation of the strong and flexible wheel. To restore the accuracy of the reducer to the load torque, this can effectively improve the service life of the reducer; since the requirements for the processing of parts are reduced, the selection of materials and processing technology is greatly expanded, which means that it can be used Cheaper materials and processing technology realize the production and manufacture of precision harmonic reducers, which reduces the cost of harmonic reducers of the same precision. The wave reducer requires the heat treatment process of the flexspline teeth, because the heat treatment of the flexspline teeth will reduce the material fatigue life of the flexspline against elastic deformation; the double flexspline harmonic reducer with limited deformation is also conducive to the selection of smaller tooth heights The use of a smaller tooth height is beneficial to reduce the elastic deformation of the weak spline, thereby reducing material fatigue, and at the same time, a smaller tooth height is also more conducive to the miniaturization of the reducer.

Although the strengths of the above-mentioned strong and weak wheels are different, they all belong to soft wheels, and like wave generators, bearings and other components, they are familiar to the general technicians in the field of harmonic reducer and the general technicians in the field of transmission technology. Detailed technical indicators, processing technology and common materials will not be explained in detail in this article; for the common structure of the double flex spline harmonic reducer with limited deformation, this patent will also give implementation for several typical structures below. For example, it is believed that those skilled in the art understand that the core invention of this patent is "a kind of flexible spline with strong elastic modulus to replace the steel wheel in the existing harmonic reducer and to replace the flexible spline with the steel wheel. Adjustable harmonic reducer that allows maximum deformation limitation", it can be fully understood that the present invention can be applied to the structures of all existing harmonic reducers.

Description of drawings

Fig. 1 Front view of double flexspline harmonic reducer with limitable deformation in Embodiment 1.

Figure 2 is a sectional view of the double flexspline harmonic reducer with limitable deformation in Embodiment 1.

Figure 3 is a perspective view of the double flexspline harmonic reducer with limitable deformation in Embodiment 1.

Fig. 4 The exploded view of the double flexspline harmonic reducer with limitable deformation in Embodiment 1.

Figure 5 is the front view of the double flexspline harmonic reducer with limitable deformation in Embodiment 2.

Figure 6 is a sectional view of the double flexspline harmonic reducer with limitable deformation in Embodiment 2.

Figure 7 is a three-dimensional view of the double flexspline harmonic reducer with limitable deformation in Embodiment 2.

Figure 8 is an exploded view of the double flexspline harmonic reducer with limitable deformation in Embodiment 2.

Figure 9 is the front view of the double flexspline harmonic reducer with limitable deformation in Embodiment 3.

Fig. 10 is a sectional view of the double flexspline harmonic reducer with limitable deformation in Embodiment 3.

Figure 11 is a three-dimensional view of the double flexspline harmonic reducer with limitable deformation in Embodiment 3.

Fig. 12 The exploded view of the parts of the double flexspline harmonic reducer with limitable deformation in Embodiment 3.

Fig. 13 Front view of double flexspline harmonic reducer with limitable deformation in Embodiment 4.

Figure 14 is a sectional view of a double flexspline harmonic reducer with limitable deformation in Embodiment 4.

Figure 15 is a perspective view of a double flexspline harmonic reducer with limitable deformation in Embodiment 4.

Fig. 16 Exploded view of parts of double flexspline harmonic reducer with limitable deformation in embodiment 4.

The meanings of the marks in the figure are as follows: 1. Wave generator; 2. Weak and soft wheel; 3. Strong and soft wheel; 4. Deformation limit part of strong and soft wheel; 5. Main bearing of reducer; 6. Elastic part.

Detailed ways

Examples of specific implementation methods are provided below in conjunction with the accompanying drawings.

Embodiment 1: As shown in Figures 1 to 4, the double-flexible-wheel harmonic reducer with limitable deformation includes strong-flexible wheels, weak-flexible wheels, wave generators, deformation-limiting parts of strong-flexible wheels and reducer main body Bearings, the main bearing of the reducer adopts cross roller bearings, and the strong and soft wheels and the weak and soft wheels are equipped with mounting flanges, and the strong and soft wheels and the weak and soft wheels are respectively connected to the reducer by bolts through the flanges. The outer ring and inner ring of the main bearing are fixed, and the strong and weak wheels are processed by using the processing technology of the existing harmonic reducer soft wheels and the steel materials commonly used for the soft wheels. The teeth that can mesh with each other are processed separately. The weak and flexible gears are external teeth and the strong and flexible gears are internal teeth. The involute tooth shape is selected. The weak and flexible gears use the same thin-walled cup as most existing harmonic reducer flex gears. The strong and soft wheel is in the shape of the flanging soft wheel and the wall thickness is 2.5 times that of the weak and soft wheel. The number of teeth of the strong and soft wheel is 2 more than that of the weak and soft wheel. The wave generator uses the elliptical cam outer commonly used in the existing harmonic reducer. A wave generator with a ball bearing is provided. The wave generator is provided with a keyway shaft hole connected to the input torque. The wave generator is installed in the weak and flexible wheel so that the weak and flexible wheel undergoes non-circular elastic deformation and partially meshes with the strong and flexible wheel. After the flexible spline undergoes elliptical elastic deformation under the action of the wave generator, the radius of the index circle of the teeth at both ends of the ellipse's major axis is 0.1 mm larger than that of the teeth of the strong and flexible spline parts, and the contact part of the strong and weak spline The radial pressure of the weak and flexible wheel produces non-circular elastic deformation; the deformation limiting part of the strong and flexible wheel is made of steel, and the deformation limiting part of the strong and flexible wheel has a flanging, and the flanging is provided with The hole corresponding to the screw hole of the strong and flexible wheel, the flange of the deformation limiting part of the strong and flexible wheel and the flange of the strong and flexible wheel are fixed on the outer ring of the same bearing by bolts through the above screw holes. The lower edge of the outer wall of the wheel is processed with a chamfered surface with an angle of 10 degrees, and the inner wall of the deformation limiting part of the strong and flexible wheel is also processed with a chamfered surface with an angle of 10 degrees. When fixed, the radial distance between the above two 10-degree chamfered surfaces is 0.1mm. When the weak and flexible wheel and the wave generator are assembled with the strong and flexible wheel, the strong and soft wheel will undergo elliptical deformation, and the long axis of the ellipse after the deformation of the strong and flexible wheel The radial distance between the two 10-degree chamfer surfaces and the 10-degree chamfer surface of the deformation limiting part of the strong and flexible wheel tends to 0; The teeth of the strong and soft wheel are continuously engaged and meshed, so it shows that the wave generator rotates to drive the strong and soft wheels to rotate relative to each other, achieving the effect of a reducer that reduces speed and increases torque; the deformation of the strong and soft wheels in the figure is small , it is not easy to visually see the elliptical deformation of the strong and soft wheel, so please read and understand the fact that the strong and soft wheel has deformation according to the manual; the wave generator, bearing and other components in the figure are multi-entity components, and the markings in the figure point to Annotate any part of the body contained in the part; some connecting bolts and washers are hidden in the exploded view.

Embodiment 2: As shown in Figures 5 to 8, the double flex wheel harmonic reducer with limitable deformation includes strong flex wheel, weak flex wheel, wave generator, deformation limiting parts of strong flex wheel and reducer main body Bearings, the main bearing of the reducer adopts cross roller bearings, and the strong and soft wheels and the weak and soft wheels are equipped with mounting flanges, and the strong and soft wheels and the weak and soft wheels are respectively connected to the reducer by bolts through the flanges. The outer ring and inner ring of the main bearing are fixed, and the strong and weak wheels are processed by using the processing technology of the existing harmonic reducer soft wheels and the steel materials commonly used for the soft wheels. The teeth that can mesh with each other are processed separately. The weak and flexible gears are external teeth and the strong and flexible gears are internal teeth. The involute tooth shape is selected. The weak and flexible gears use the same thin-walled cup as most existing harmonic reducer flex gears. The strong and soft wheel is in the shape of the flanging soft wheel and the wall thickness is 2.5 times that of the weak and soft wheel. The number of teeth of the strong and soft wheel is 2 more than that of the weak and soft wheel. The wave generator uses the elliptical cam outer commonly used in the existing harmonic reducer. A wave generator with a ball bearing is provided. The wave generator is provided with a keyway shaft hole connected to the input torque. The wave generator is installed in the weak and flexible wheel so that the weak and flexible wheel undergoes non-circular elastic deformation and partially meshes with the strong and flexible wheel. After the flexible spline undergoes elliptical elastic deformation under the action of the wave generator, the radius of the index circle of the teeth at both ends of the ellipse's major axis is 0.1 mm larger than that of the teeth of the strong and flexible spline parts, and the contact part of the strong and weak spline The radial pressure of the weak and flexible wheel produces non-circular elastic deformation; the deformation limiting part of the strong and flexible wheel is made of steel, and the deformation limiting part of the strong and flexible wheel is processed with internal threads, and the deformation can be The limited double flex wheel harmonic reducer also includes a connecting part with flanging and external thread, which is also made of metal through machining, and the deformation limiting part of the strong flex wheel is connected to the above-mentioned thread through the above-mentioned Parts are connected, the above-mentioned connecting parts have flanging, and holes corresponding to the screw holes of the strong and flexible wheel are provided on the flanging, and the flanging of the connecting parts and the flanging of the strong and flexible wheel are fixed on the same On the outer ring of the bearing, the deformation limit part of the strong and flexible wheel is also provided with a threaded hole for a top screw, and the deformation limit part of the strong and flexible wheel is realized by screwing the top screw in the threaded hole and fixing the top screw on the connecting part. The anti-loosening effect of screw fixing between connecting parts; the lower edge of the outer wall of the strong and flexible wheel is processed with a chamfered surface with an angle of 10 degrees, and the inner wall of the deformation limit part of the strong and flexible wheel is also processed with a chamfered angle of 10 degrees On the surface, when the deformation limiting part of the strong and flexible wheel and the strong and flexible wheel are fixed, the radial distance between the above two 10-degree chamfered surfaces is 0.1mm. When the weak and flexible wheel and the wave generator are assembled with the strong and flexible wheel, Elliptical deformation of the strong and soft wheel occurs, and the radial distance between the two 10-degree chamfers of the long axis of the ellipse and the 10-degree chamfer of the deformation limit part of the strong and soft wheel approaches 0 after the deformation of the strong and soft wheel; The flexible gear always maintains some teeth that continuously mesh in and out of the teeth of the strong flexible gear along with the rotation direction of the wave generator, so it shows that the rotation of the wave generator drives the strong flexible gear and the weak flexible gear to rotate relative to each other, realizing deceleration and increasing speed. Twisted reducer effect; the deformation of the strong and soft wheel in the picture is small, and it is not easy to see the elliptical deformation of the strong and soft wheel intuitively, so please read and understand the strong and soft wheel according to the manual The wheel is a fact of deformation; the wave generator, bearing and other components in the figure are multi-body components, and the labels in the figure point to any part of the entity contained in the marked components; some connecting bolts and gaskets are hidden in the exploded view.

Embodiment 3: As shown in Figures 9 to 12, the double flex wheel harmonic reducer with limitable deformation includes strong flex wheel, weak flex wheel, wave generator, deformation limit parts of strong flex wheel and reducer main body Bearings, the main bearing of the reducer adopts cross roller bearings, and the strong and soft wheels and the weak and soft wheels are equipped with mounting flanges, and the strong and soft wheels and the weak and soft wheels are respectively connected to the reducer by bolts through the flanges. The outer ring and inner ring of the main bearing are fixed, and the strong and weak wheels are processed by using the processing technology of the existing harmonic reducer soft wheels and the steel materials commonly used for the soft wheels. The teeth that can mesh with each other are processed separately. The weak and flexible gears are external teeth and the strong and flexible gears are internal teeth. The involute tooth shape is selected. The weak and flexible gears use the same thin-walled cup as most existing harmonic reducer flex gears. The strong and soft wheel is in the shape of the flanging soft wheel and the wall thickness is 2.5 times that of the weak and soft wheel. The number of teeth of the strong and soft wheel is 2 more than that of the weak and soft wheel. The wave generator uses the elliptical cam outer commonly used in the existing harmonic reducer. A wave generator with a ball bearing is provided. The wave generator is provided with a keyway shaft hole connected to the input torque. The wave generator is installed in the weak and flexible wheel so that the weak and flexible wheel undergoes non-circular elastic deformation and partially meshes with the strong and flexible wheel. After the flexible spline undergoes elliptical elastic deformation under the action of the wave generator, the radius of the index circle of the teeth at both ends of the ellipse's major axis is 0.1 mm larger than that of the teeth of the strong and flexible spline parts, and the contact part of the strong and weak spline The radial pressure of the weak and flexible wheel produces non-circular elastic deformation; the deformation limiting part of the strong and flexible wheel is made of steel, and the deformation limiting part of the strong and flexible wheel is processed with internal threads, and the deformation can be The limited double flex wheel harmonic reducer also includes a connecting part with flanging and external thread, which is also made of metal through machining, and the deformation limiting part of the strong flex wheel is connected to the above-mentioned thread through the above-mentioned Parts are connected, the above-mentioned connecting parts have flanging, and holes corresponding to the screw holes of the strong and flexible wheel are provided on the flanging, and the flanging of the connecting parts and the flanging of the strong and flexible wheel are fixed on the same On the outer ring of the bearing, the deformation limiting part of the strong and flexible wheel is also provided with an external gear, which is a rotation force input structure for rotating and adjusting the deformation limiting part of the strong and flexible wheel, and is also used to lock its position. The input structure of the anti-loosening fixing force of the anti-loosening effect; the lower edge of the outer wall of the strong and flexible wheel is processed with a chamfered surface with an angle of 10 degrees, and the inner wall of the deformation limit part of the strong and flexible wheel is also processed with an angle of 10 degrees. For the corner surface, when the deformation limit part of the strong and flexible wheel and the strong and flexible wheel are fixed, the radial distance between the above two 10-degree chamfered surfaces is 0.1mm. When the weak and flexible wheel and the wave generator are assembled with the strong and flexible wheel , the elliptical deformation of the strong and soft wheel occurs, and the radial distance between the two 10-degree chamfers of the long axis of the ellipse and the 10-degree chamfer of the deformation limit part of the strong and soft wheel approaches 0 after the deformation of the strong and soft wheel; The weak and flexible gear always maintains some teeth that continuously mesh in and out of the strong and flexible gear along with the rotation direction of the wave generator, so it shows that the rotation of the wave generator drives the strong and weak gear to rotate relative to each other to achieve deceleration The effect of the reducer with increased torque; the deformation of the strong and soft wheel in the picture is small, and it is not easy to see the elliptical deformation of the strong and soft wheel intuitively, so please interpret it according to the manual And understand the fact that the strong and flexible wheel has deformation; the wave generator, bearing and other components in the figure are multi-entity components, and the markings in the figure point to any part of the entity contained in the marked components; some connecting bolts and gaskets are hidden in the exploded view.

Embodiment 4: As shown in Figures 13 to 16, the double flex wheel harmonic reducer with limitable deformation includes strong and soft wheels, weak and soft wheels, wave generators, deformation limiting parts of strong and flexible wheels, elastic parts and The main bearing of the reducer, the main bearing of the reducer is a cross roller bearing, and the strong and soft wheels and the weak and soft wheels are equipped with mounting flanges, and the strong and soft wheels and the weak and soft wheels are bolted respectively through the flanges. It is fixed with the outer ring and inner ring of the main bearing of the reducer. The strong and weak wheels are processed using the processing technology of the existing harmonic reducer soft wheels and the steel materials commonly used for the soft wheels. The strong and soft wheels and the weak The soft splines are respectively processed with teeth that can mesh with each other. The weak splines are external teeth and the strong splines are internal teeth. The involute tooth shape is selected. The weak splines are the same as most existing harmonic reducer flexsplines. The thin-walled cup shape, the strong and soft wheel adopts the shape of the flanging soft wheel and the wall thickness is 2.5 times that of the weak and soft wheel. The number of teeth of the strong and soft wheel is 2 more than that of the weak and soft wheel. The wave generator uses the ellipse commonly used in existing harmonic reducers. A wave generator with ball bearings on the periphery of the shaped cam. The wave generator is provided with a keyway shaft hole connected to the input torque. The wave generator is installed in the weak wheel to make the soft wheel non-circular elastic deformation and connect with the strong wheel part. Meshing, after the weak and flexible wheel undergoes elliptical elastic deformation under the action of the wave generator, the radius of the index circle of the teeth at both ends of the ellipse's major axis is 0.1mm larger than that of the teeth of the strong and soft wheel. The contact part of the wheel is subjected to the radial pressure of the weak and flexible wheel to produce non-circular elastic deformation; the deformation limiting part of the strong and flexible wheel is made of high-hardness copper by machining, and the deformation limiting part of the strong and flexible wheel is an annular part , the elastic part is an elastic washer constructed of a steel frame apron, and the double flexspline harmonic reducer with limitable deformation also includes a connecting part with an inner flange, and the elastic part is mounted on the connecting part. Between the edge and the deformation limiting part of the strong and flexible wheel, and the compression assembly always has an axial thrust on the deformation limiting part of the strong and flexible wheel, and the deformation limiting part of the strong and flexible wheel is always under the action of the thrust of the elastic part To maintain contact with the strong and flexible wheel, the above-mentioned connecting parts have flanges, and the flanges are provided with holes corresponding to the screw holes of the strong and flexible wheels, and the flanges of the connecting parts and the flanges of the strong and flexible wheels pass through the above screw holes It is fixed on the outer ring of the same bearing by bolts; the lower edge of the outer wall of the strong and flexible wheel is processed with a chamfered surface with an angle of 10 degrees, and the inner wall of the deformation limit part of the strong and flexible wheel is also processed with a chamfered angle of 10 degrees On the surface, when the deformation limiting part of the strong and flexible wheel and the strong and flexible wheel are fixed, the radial distance between the above two 10-degree chamfered surfaces is 0.1mm. When the weak and flexible wheel and the wave generator are assembled with the strong and flexible wheel, Elliptical deformation of the strong and soft wheel occurs, and after the deformation of the strong and soft wheel, the two 10-degree chamfers of the long axis of the ellipse keep in contact with the 10-degree chamfers of the deformation limit part of the strong and soft wheel; the weak and soft wheel always maintains a part The teeth of the strong and flexible gear are continuously meshed with the rotation direction of the wave generator, so it shows that the rotation of the wave generator drives the strong and flexible gear and the weak and flexible gear will rotate relative to each other, realizing the reducer effect of deceleration and torque increase; The deformation of the strong and soft wheel in the picture is small, and it is not easy to see the elliptical deformation of the strong and soft wheel intuitively, so please read and understand the existence of the strong and soft wheel according to the manual. Facts about the amount of deformation; components such as wave generators and bearings in the figure are multi-body components, and the labels in the figure point to any part of the entity contained in the marked components; some connecting bolts and gaskets are hidden in the exploded view.

Claims (10)

1. A double flex spline harmonic reducer with limitable deformation, characterized by: a double flex spline harmonic reducer with limitable deformation, including strong and soft wheels, weak and soft wheels, wave generators and strong and soft wheels Deformation limiting parts, the strong and flexible wheels and the weak and flexible wheels are coaxially fixed axially and radially fixed, the strong and soft wheels and the weak and soft wheels are respectively provided with teeth that can mesh with each other, the strong and soft wheels and the weak and flexible wheels exist The number of teeth is poor, and the wave generator causes the weak and flexible wheel to undergo non-circular elastic deformation and meshes with the strong and flexible wheel. The non-toothed side of the flexible tubular wall of the wheel is processed with a limited contact surface. The deformation limit part of the strong and flexible wheel is relatively fixed with the strong and flexible wheel. The deformation limit part of the strong and flexible wheel is processed with an annular limit surface. The limit contact surface of the strong and soft wheel deformed by the radial pressure of the weak and soft wheel is in contact with the annular limit surface on the deformation limit part of the strong and soft wheel. The deformation of the strong and soft wheel is due to the deformation of the strong and soft wheel. The flexspline deformation limit part is limited by contact. 2. A double flex wheel harmonic reducer with limitable deformation according to claim 1, characterized in that: the annular limit surface on the deformation limit part of the strong flex wheel is a ring limit with a gradual diameter change. plane. 3. A double-flexible wheel harmonic reducer with limitable deformation according to claim 2, characterized in that: the deformation limit part of the strong flexible wheel can realize its connection with the adjustable axial fixed position The diameters of the annular limit surfaces contacted by the limit contact surface of the strong and flexible wheel are different, so as to realize the adjustment of the limit value of the deformation amount of the strong and flexible wheel. 4. A double-flexible wheel harmonic reducer with limitable deformation according to claim 3, characterized in that: the deformation limit part of the strong flexible wheel is directly connected with the strong wheel through the thread or indirectly through other parts of the reducer. The flexspline is fixed in the axial direction, and the axial position can be adjusted through the relative rotation of the thread. 5. A double-flexible-wheel harmonic reducer with limitable deformation according to claim 4, characterized in that: the deformation limiting part of the strong-flexible wheel is fixed to the strong-flexible wheel by threads and also includes threads An anti-loosening mechanism, the threaded anti-loosening mechanism is a top screw or a spline. 6. A double flex spline harmonic reducer with limitable deformation according to claim 4, characterized in that: a gear is provided on the deformation limiting part of the flex spline, and the outside world can pass through the gear or worm The part pushes the gear, thereby pushing the deformation limiting part of the strong and flexible wheel to rotate, and the outer diameter can lock the gear on the deformation limiting part of the strong and flexible wheel through the non-rotating gear or worm parts, so as to realize the deformation limit of the strong and flexible wheel The locking of the relative axial position of the bit part and the strong wheel. 7. A double flexspline harmonic reducer with limitable deformation according to claim 1, characterized in that: said double flexspline harmonic reducer with limitable deformation also includes a strong The flex wheel deformation limit part is an elastic part that exerts axial force, and the strong flex wheel deformation limit part can move axially under the force of the elastic part. 8. A double flexspline harmonic reducer with limitable deformation according to claim 1, characterized in that: the deformation limiting part of the strong flexspline can be processed into a flexspline protective shell or a flexspline protective shell a part of. 9. A double flexspline harmonic reducer with limitable deformation according to claim 1, characterized in that: said double flexspline harmonic reducer with limitable deformation also includes a connecting part, The connecting part is relatively fixed with the strong and flexible wheel, and the deformation limit part of the strong and flexible wheel is connected and fixed with this part to realize relative fixing with the strong and flexible wheel. 10. A double flexspline harmonic reducer with limitable deformation according to claim 6, characterized in that: said double flexspline harmonic reducer with limitable deformation further includes a gear or worm , the gear or worm can form a gear transmission pair or a worm helical gear transmission pair with the gear processed on the deformation limiting part of the strong and flexible wheel, and the rotation axis of the gear and the worm is relatively fixed with the strong and flexible wheel.