436 results about "Roller screw" patented technology

Provided is an electric heavy-load push-pull tool including a power input unit, a power conversion unit and a power output unit. Through the transmission design of multiple stages of reducers and a planetary roller screw of a downhole operation tool, low-speed and high-torque power output of the motor is realized. The heavy-load push-pull tool provided by the present disclosure can not only provide large-torque thrust force, but also provide large-torque pulling force. A forward direction of a transmission nut is based on a rotation direction of a motor. By controlling the forward rotation or reverse rotation of a transmission shaft of the motor, the forward or backward movement of an operation tool can be realized at low cost through power transmission.

The invention discloses a reverse type annular tooth groove planetary roller screw which comprises a nut, a screw rod, a plurality of rollers and a retainer, a multi-head internal thread is arranged in the nut, the rollers and the screw rod are both of an annular tooth groove structure without a helix angle, and the annular tooth grooves of the rollers are meshed with the internal thread of the nut and the annular tooth grooves of the screw rod respectively; first gears are machined at the two ends of the annular tooth groove of the lead screw, second gears are machined at the two ends of the annular tooth groove of the roller, and the first gears are meshed with the multiple second gears at the same time. The retainer is of an integral flexible retainer structure, and the pin rollers have the self-adaptive capacity in multiple directions in the circumferential direction and the radial direction through the retainer. And an arc-shaped roller path is designed on the screw rod and is matched with the ball spline housing to play a linear rolling guiding and rotation stopping role on the screw rod. The reverse lead screw has the advantages of being large in transmission ratio, compact in structure, easy to machine and assemble, low in cost, good in self-adaptive performance, high in positioning precision, good in reliability and the like.

The invention relates to the technical field of high-precision transmission, and particularly discloses a retainer and a circulating type planetary roller lead screw pair. Wherein the retainer comprises a circular ring-shaped main body, a plurality of pin roller guide grooves which are uniformly distributed in the circumferential direction are formed in the circular ring-shaped main body, the pin roller guide grooves extend in the radial direction of the circular ring-shaped main body, and openings penetrating to an inner hole in the circular ring-shaped main body are formed in the radial inner ends of the pin roller guide grooves; the two sides of the opening are shrunk inwards to form shrunk openings, and the shrunk openings are elastic. According to the structure, the retainer is in the shape of the circular ring and is arranged on the side face of the internal thread section of the nut, so that the overall radial size of the circulating type planetary roller screw pair can be reduced, and a reliable structural foundation is provided for achieving miniaturization and microminiaturization of the circulating type planetary roller screw pair; the roller guide grooves are provided with the openings, the radial size of the retainer can be made smaller, and therefore the overall radial size of the circulating type planetary roller lead screw pair is made smaller.

The invention discloses a roller screw external thread grinding force measuring method. The method comprises the steps that a to-be-measured screw is installed on an external thread grinding machine tool in the mode that the to-be-measured screw is clamped by tips at the two ends of the machine tool; the two mechanical sensors are installed at the center position right facing the lead screw to be measured and face the normal grinding force direction and the tangential grinding force direction respectively; a to-be-measured lead screw clamped by double tips is regarded as a simply supported beam structure of which one end is fixed and hinged and the other end is movable and hinged, a mechanical sensor is regarded as an elastic support, a mechanical model is established, and the relationship among the measurement result of the mechanical sensor, an actual method and tangential grinding force at different grinding positions is obtained; and according to the measurement result of the mechanical sensor, the actual method and the tangential grinding force are obtained by utilizing the relation between the measurement result of the mechanical sensor at different grinding positions and the actual method and the tangential grinding force, and the actual grinding force is obtained after vector superposition. The device has the characteristics of clear and definite measurement principle, accurate and reliable measurement result, simple structure and convenience in assembly.

The invention discloses a planetary roller screw dynamic modeling method based on a generalized finite element method, and belongs to the field of dynamic characteristic analysis of planetary roller screws. The method comprises the following steps: carrying out unit division on a planetary roller screw finite element model; constructing a dynamic model of each type of unit; respectively establishing mass matrixes, stiffness matrixes, damping matrixes and load column vectors of the shaft section unit, the lead screw-roller contact side thread meshing unit, the nut-roller contact side thread meshing unit and the roller tooth-inner gear ring gear meshing unit; and assembling a system dynamics model to complete planet roller screw dynamics modeling. According to the method, the dynamic characteristics of the real physical model can be accurately analyzed, and an effective means is provided for analyzing the vibration response of the system.

The invention relates to a special machining device for a reverse nut of a planetary roller screw, which is characterized by comprising a workbench, and a workpiece clamping center, a grinding unit and a turning unit which are arranged on the workbench, a grinding wheel dressing unit is arranged on one side of the workpiece clamping center, a workpiece is clamped on a workpiece clamp assembly in advance, and the grinding wheel dressing unit is arranged on the other side of the workpiece clamping center. Then an electric tool turret of a turning unit is made to be coaxial with the workpiece, the electric tool turret firstly turns an inner hole of the reverse nut semi-finished product, then a grinding component is adjusted to be coaxial with the turned reverse nut semi-finished product, a grinding electric spindle is driven, the grinding component grinds the inner hole of the reverse nut semi-finished product, and the inner hole of the reverse nut semi-finished product is ground. And finally, the dressing motorized spindle is driven, and the dressing grinding wheel is used for dressing the grinding component. According to the turning and grinding integrated technology, the reverse nut is machined in the mode that turning is conducted firstly and then grinding is conducted, the machining efficiency is high, and the production cost is greatly reduced.

The invention relates to a reverse toothless planetary roller screw, and belongs to the technical field of roller screws, the reverse toothless planetary roller screw comprises a screw rod, a long nut, a planet carrier assembly and a plurality of rollers, and the periphery of the screw rod is sequentially provided with a front optical axis section, an external thread section and a rear optical axis section; internal threads are arranged on the inner wall of the nut; each roller comprises a threaded part in the middle and polished shaft parts at the two ends; the thread part of the roller and the external thread section of the lead screw are opposite in rotation direction and equal in lead angle; the planet carrier assembly comprises a middle retainer and end covers at the two ends, at least three opening grooves used for assembling the pin rollers in the radial direction are formed in the outer side of the middle retainer, and positioning holes in clearance fit with the optical axis parts of the pin rollers are formed in the end covers. By canceling a screw rod gear / ring groove and pin roller gear / ring groove structure and combining a double matching mechanism of the planet carrier assembly, the machining bottleneck of a composite structure is thoroughly eliminated, the axial parallelism and the constant lead characteristic of the pin rollers are guaranteed, meanwhile, vibration noise is remarkably reduced, and high-precision and large-scale mass production is achieved.

The invention discloses a hyperbolic tangent and algebraic sine coupled nut-driven ball screw pair which comprises a ball screw and a ball nut, an inner hole of the ball nut is provided with an inner spiral raceway, the outer cylindrical surface of the ball screw is provided with an outer spiral raceway, and the inner spiral raceway and the outer spiral raceway are matched with each other to form a spiral raceway; the outer cylindrical surface of the ball screw is provided with a ball return channel which is sunken towards the center of the ball screw between two adjacent outer spiral raceways, the ball return channel and the outer spiral raceways of the ball screw are integrally designed, and the ball return channel and the outer spiral raceways form a circulating raceway; according to the internal circulation roller screw pair, the ball screw outer spiral raceway and the ball return channel are integrally designed, the ball screw pair is compact in structure and smooth in operation, the uniformity and consistency of the ball screw and the ball nut are better, meanwhile, the reliability and operation stability of the ball screw pair are improved, and the service life of the ball screw pair is prolonged. And the noise and vibration phenomena during high-speed operation of the ball screw pair are greatly reduced.

The invention discloses an electrically-driven mechanical tread brake unit which comprises an electric brake cylinder, a hoisting arm, a brake-shoe hoist, a brake-shoe holder and a brake-shoe, the electric brake cylinder is provided with a motor located in a shell, and further provided with a planetary gear assembly connected with an output shaft of the motor and a planetary roller screw rod driven by the planetary gear assembly; the planetary gear assembly comprises a sun gear coaxially connected with an output shaft of the motor, an inner gear ring fixed to the shell, a planet gear meshed between the sun gear and the inner gear ring in a tooth meshing mode and a planet carrier connected with the planet gear, the planet roller lead screw comprises a lead screw shaft, a roller and a nut, and the planet carrier is provided with an outer gear ring. A transmission gear is fixed to a nut of the planetary roller lead screw, and an outer gear ring on the planet carrier is meshed with the transmission gear. The planetary gear and the planetary roller lead screw are arranged to replace a traditional force amplification mechanism, low-power output and large torque are achieved, and meanwhile the functions of manually resetting the lead screw and preventing the lead screw from being stuck in the fault state can be achieved.

The invention relates to a multistage planetary roller lead screw pair structure, and belongs to the technical field of electromechanical servo transmission. The linear actuator comprises a first-stage lead screw, a first-stage pin roller, a first-stage nut, an angular contact bearing II, a first-stage actuator cylinder, a second-stage lead screw, a second-stage pin roller, a second-stage nut, a shell and an adapter shaft. Therefore, a nested structure of the first-stage planetary roller screw pair and the second-stage planetary roller screw pair is formed. The large working stroke can be provided within the small retraction size, and the large bearing capacity can be provided through the small radial size; meanwhile, the linear motion speed ratio of different graded lead screw pairs is controlled by adjusting the thread lead of the first-stage lead screw and the second-stage lead screw, accurate control over the motion speed of the tail end effective load is achieved, a guide structure within the stroke range is designed for each stage of nut, and high stability of the tail end output load of the structure can be achieved.

The utility model relates to the technical field of planetary roller screws, in particular to a gearless planetary roller screw, which comprises a nut, a screw and a plurality of rollers. Assembling sections are arranged on the pin rollers; when the lead screw is a driving part, one of the assembling section and the nut is provided with annular teeth, the other one of the assembling section and the nut is provided with an annular groove, and the annular groove is matched with the annular teeth in a meshed mode so that no relative axial displacement exists between the pin rollers and the nut. When the nut is a driving part, one of the assembling section and the lead screw is provided with annular teeth, the other one of the assembling section and the lead screw is provided with annular grooves, and the annular grooves are matched with the annular teeth in a meshed mode so that no relative axial displacement exists between the pin rollers and the lead screw. Aiming at the defects of the existing planetary roller screw, a gear structure is eliminated, burrs generated by gear machining are eliminated, the cleanliness level of the roller is improved, the influence of the burrs on thread meshing is reduced, and the overall service life of the planetary roller screw is prolonged; impact and noise caused by gear meshing are avoided, and the overall NVH level of the planetary roller screw is improved.

A planetary roller screw adapted for solving insufficient structural strength of the conventional planetary roller screw while proceeding with precise motion control is disclosed. The planetary roller screw includes a main screw having an external thread, a nut having an internal thread, and a planetary assembly having rollers. Each roller includes an outer periphery having an external thread. The pitches of the external thread of the main screw, the internal thread of the nut, and the external thread of each roller are identical. The helix direction of the external thread of the main screw is opposite to that of the internal thread of the nut. When one of the main screw, the nut, and the planetary assembly acting as a driving member rotates, a linear displacement direction of the planetary assembly relative to the nut is opposite to that of the main screw relative to the planetary assembly.

The invention discloses a planetary roller screw high-speed operation vibration detection device, and relates to the technical field of planetary roller screw detection, the planetary roller screw high-speed operation vibration detection device comprises a device main body, a mounting seat and a movable seat, the mounting seat is movably mounted at one end of the device main body, the movable seat is movably mounted in the device main body, and two groups of limiting plates are movably mounted at the upper end of the movable seat. Second movable grooves are symmetrically formed in the opposite ends of the two sets of limiting plates, first mounting columns are movably mounted in the multiple sets of second movable grooves, and first clamping plates are mounted at one ends of the multiple sets of first mounting columns. By arranging the movable seat, the limiting plate, the first clamping plates and the second clamping plates, the lead screw drives the roller to vibrate, and the roller transmits the vibration frequency to the sensors in the first mounting columns and the sensors in the second mounting columns through the first clamping plates and the second clamping plates. And the multiple groups of sensors transmit vibration data to the control screen, and the data are collected, so that the accuracy of the vibration detection data of the lead screw is improved.

The invention provides a differential roller screw transmission assembly, which comprises a nut, a screw, a plurality of rollers and a retainer group, the nut is provided with an inner hole penetrating in the axial direction, and an annular tooth section is arranged on the inner circumferential face. The threaded rod is arranged in the inner hole in a penetrating mode, a thread structure is arranged on the peripheral face of the threaded rod, the thread structure is provided with M thread lines, and M is an integer larger than one. The plurality of rollers are arranged between the nut and the screw. Each roller has a uniform pitch diameter, the periphery of each roller is provided with an annular tooth groove structure with a plurality of tooth grooves, and the annular tooth groove structures are meshed with the thread structure of the screw rod and the annular tooth section of the nut. The number of the plurality of rollers is N, and N is a factor greater than one of M. The retainer group is arranged at two ends of the roller. And the spiral angle of each thread line of the screw is matched with the circumferential distance of the plurality of rollers, so that the axial distance between any thread line and the corresponding tooth groove between the two adjacent rollers is equal to the pitch of the annular tooth groove structure. Therefore, the part design and the manufacturing process are simplified, and the load sharing effect is improved.

The invention relates to a reverse toothless planetary roller screw, and belongs to the technical field of roller screws, the reverse toothless planetary roller screw comprises a screw rod, a long nut, a planet carrier assembly and a plurality of rollers, and the periphery of the screw rod is sequentially provided with a front shaft section, an external thread section and a rear shaft section; internal threads are arranged on the inner wall of the nut; each roller comprises a threaded part in the middle and polished shaft parts at the two ends; the thread part of the roller and the external thread section of the lead screw are opposite in rotation direction and equal in lead angle; the planet carrier assembly comprises a middle retainer, and the middle retainer is provided with at least three open grooves used for assembling the pin rollers in the radial direction. By canceling a screw rod gear / ring groove and pin roller gear / ring groove structure and combining a double matching mechanism of the planet carrier assembly, the machining bottleneck of a composite structure is thoroughly eliminated, the axial parallelism and the constant lead characteristic of the pin rollers are guaranteed, meanwhile, vibration noise is remarkably reduced, and high-precision and large-scale mass production is achieved.

Provided are a micro-lead differential-type planetary roller screw and an electric cylinder. A part of an area in a screw (1) engaged with a first roller threaded zone (201) has the same pitch, the same spiral lifting angle, and opposite spiral direction as the first roller threaded zone (201); alternatively, a part of an area in an outer sleeve (g) engaged with a second roller thread zone (b01) has the same pitch, the same spiral lifting angle, and opposite spiral direction as the second roller thread zone (b01). Thus, a constant output lead that is much smaller than the screw thread lead is achieved, expanding the application range of micro-lead differential planetary roller screws to the micro-lead field.

The invention provides a planetary roller screw transmission assembly. The planetary roller screw transmission assembly comprises a nut, a screw, a plurality of rollers, a retainer group and a friction elastic piece, the nut is provided with an axially penetrating inner hole, and the inner circumferential surface of the nut is provided with at least one annular groove section and at least one non-tooth-shaped section adjacent to the annular groove section. The screw rod is arranged in the inner hole in a penetrating mode and extends out of the nut. A plurality of rollers are arranged in an inner hole of the nut and arranged on the periphery of the screw in a surrounding mode, each roller is provided with at least one large-pitch-diameter section and at least one small-pitch-diameter section with a smooth face in the axial direction, the large-pitch-diameter sections are provided with annular teeth used for being meshed with the screw in a rolling mode, and the small-pitch-diameter sections are provided with annular teeth used for being meshed with the nut in a rolling mode. The retainer group is arranged at the axial end parts of the plurality of rollers. The friction elastic piece is arranged on the non-tooth-shaped section of the inner circumferential face of the nut and makes interference contact with the smooth face of the small-pitch-diameter section of the multiple pin rollers.

The invention discloses a planetary roller screw multi-dimensional detection device based on bearing and wear characteristics, and relates to the technical field of planetary roller screw detection, the planetary roller screw multi-dimensional detection device comprises a device main body, a turntable and a mounting seat, the bottom end of the mounting seat is movably provided with a telescopic column, and the bottom end of the telescopic column is provided with a mounting hole; a plurality of sets of mounting blocks are symmetrically mounted in the mounting hole, sensing devices are arranged in the multiple sets of mounting blocks, two sets of movable columns are movably mounted in the mounting hole, movable heads are mounted at one ends of the two sets of movable columns, and limiting rods are symmetrically mounted on the outer walls of the two sets of movable columns. By arranging the mounting base, the telescopic column, the movable columns and the movable heads, the telescopic column moves downwards, one end of the telescopic column enters the threaded groove in the outer wall of the lead screw, the two movable heads are connected with the inner walls of the two sides of the threaded groove correspondingly, and the sensing device reads the distance between the two movable columns; the detection cost and convenience of screw thread pitch detection are reduced, and the requirement for workers is reduced.

The invention discloses a roller screw milling forming device with an anti-deviation function, and relates to the technical field of milling machine tools, the milling device comprises a seating machine tool body, a sliding rail is arranged on the seating machine tool body, a machining table is slidably connected to the sliding rail, a milling main body is arranged in the machining table, an auxiliary closing frame is slidably connected to the seating machine tool body, and the auxiliary closing frame is slidably connected to the machining table. The auxiliary closing frame is fixedly connected with the machining table, a deviation rectifying frame and an adjusting frame are arranged on the auxiliary closing frame, the adjusting frame is slidably connected with the seating bed body and comprises an adjusting steering engine and an adjusting wedge column arranged on the adjusting steering engine, a compensation closing table is slidably connected into the auxiliary closing frame, and a compensation wedge column is arranged on the compensation closing table. And a speed measuring sensor corresponding to the speed measuring wheel is arranged in the auxiliary closing frame, the speed measuring sensor is electrically connected with the adjusting steering engine, and the functions of automatic correction machining of the lead screw and fine adjustment of the milling cutter are achieved.

A detection device for detecting a spindle displacement of a roller screw motor of a robot, characterized in that the roller screw motor comprises a motor stator, a motor rotor, an internal support structure, a motor housing, and a motor spindle, wherein the motor stator is fixedly connected to the internal support structure, wherein the motor housing encloses the internal support structure, wherein the motor rotor is movably connected to the internal support structure, wherein the motor rotor can rotate relative to the motor stator, wherein the motor rotor, when rotating, sets the motor spindle into a linear movement, wherein the detection device comprises a first gear, a second gear, a first magnetic encoder and a second magnetic encoder, wherein the first gear is fixedly connected to an end piece of the motor rotor, wherein the first gear rotates with the motor rotor, wherein the second gear is arranged on the motor housing, wherein the second gear is in engagement with the first gear, wherein the second gear is driven for rotation by the first gear; wherein the first magnetic encoder is arranged on the first gear to detect a first angle of the first gear; wherein the second magnetic encoder is arranged on the second gear to detect a second angle of the second gear; wherein the number of teeth of the first gear is not equal to the number of teeth of the second gear; and wherein the first angle, the second angle and the difference between the number of teeth of the first gear and the number of teeth of the second gear are used to determine the spindle displacement.

The invention discloses a device for detecting the rolling-sliding ratio of a planetary roller lead screw pair. The device comprises a roller simulation part and a columnar lead screw simulation part, a circular truncated cone is processed at one end of the lead screw simulation part, and the side surface of the circular truncated cone is a lead screw tooth-shaped contour surface; the roller simulation part comprises a roller thread section simulation circular ring; a pin roller thread simulation surface is arranged between the outer circumferential surface of the pin roller thread section simulation circular ring and each of the two end surfaces of the pin roller thread section simulation circular ring, and an included angle beta formed between each pin roller thread simulation surface and the outer circumferential surface is greater than 90 degrees and less than 180 degrees. The device provided by the invention can simulate the friction state and the rolling-sliding ratio of the contact position of the pin roller and the lead screw in the star pin roller lead screw pair, and allows the detection of the friction wear conditions of lead screws and pin rollers made of different materials through the arrangement of the replaceable pin roller threaded section simulation circular ring and the lead screw simulation part.

The invention relates to the field of mechanical transmission parts, and particularly discloses an integrated reverse planetary roller screw structure which comprises a transmission roller, a moving screw and a retainer, the transmission roller comprises a transmission part and a limiting part, the transmission part is a cylinder with threads distributed on the peripheral surface, the limiting part is a cylinder with the peripheral surface arranged smoothly, the retainer is a hollow cylinder, and the moving screw is arranged on the transmission part. The holder comprises a holding end, a transmission area and a movement area, the transmission area is arranged on the peripheral face of the holder, the movement area penetrates through the axial center of the holder, the movement lead screw rotates in the movement area in a limited mode, the transmission part rotates in the transmission area in a limited mode, the holding end is provided with a limiting groove, and the limiting part rotates in the limiting groove in a limited mode. Straight teeth of the transmission pin roller are omitted, the transmission pin roller is integrally limited through the retainer, the synchronism of the two ends of the transmission pin roller is guaranteed, slight clamping stagnation of the pin roller during rotation is avoided, the transmission stability is improved, and the overall structure is simplified.

The invention discloses an automatic assembling method and system for a standard planetary roller lead screw pair based on SolidWorks secondary development, and relates to the technical field of automatic assembling of mechanical parts. Comprising the steps of newly creating an assembly file; the parts are guided in; assembling characteristics are obtained; adding a matching relationship; parameterized driving assembly is carried out; and assembling is completed. According to the method, by extracting assembly features (such as a reference surface and a reference axis) in a part model and using an API function command to write a program (such as AddCompent5 and AddMate5), automatic import, feature matching and matching relation adding of parts are achieved, and the problem of complexity of multi-roller thread meshing assembly is solved.

The invention discloses an optimal design method for a circulating type planetary roller screw structure. The method comprises the following steps: firstly, establishing a multi-body contact mathematical model of a circulating type planetary roller screw; constructing a Bayesian learning model based on variational inference in combination with an active learning Kriging strategy; constructing a multi-objective optimization model, and determining design structure parameters, optimization objectives and constraint conditions; and solving the multi-objective optimization model by combining a Bayesian learning model and an NSGA-III algorithm, so as to obtain an optimal parameter combination when the contact points among the structures of the circulating planetary roller screw are constrained in a given range and the contact stress is minimized at the same time. According to the invention, the contact stress can be effectively reduced, the contact fatigue can be delayed, the transmission reliability can be improved, and the requirements of high-precision and high-load application can be met.

The invention belongs to the technical field of detection devices, particularly relates to a detection device based on distribution uniformity of rollers of a planetary roller screw, and provides the following scheme: the detection device comprises a base; a rotary driving module, an optical detection module, a contact stress detection module, a high-precision capacitive displacement sensor array mechanism and a mobile detection mechanism are sequentially arranged at the top of the base, the rotary driving module comprises a servo motor, an encoder and an air bearing, and the servo motor is fixedly connected with a coupler; and the coupler is in transmission connection with the planetary roller screw. The three-dimensional scanning assembly reconstructs the surface appearance of the roller through the line laser transmitter and the area-array camera, the thin film pressure sensor is embedded into a nut raceway to collect contact pressure, the strain gauge array is pasted to a lead screw shaft neck to monitor deformation, and the multiple sensors work cooperatively to comprehensively evaluate the distribution state of the roller from the dimensions of optical tracks, mechanical response and the like. And the one-sidedness problem of a traditional single detection means is solved.

This utility model relates to the field of wood processing and discloses a high-efficiency wood surface treatment roller, including an operating table. A positioning component is provided at the front of the operating table, and a mounting frame is fixedly connected to the top surface of the operating table. Two electric rods are fixedly connected to the upper part of the mounting frame, and a sanding component is provided at the lower part of the mounting frame. An installation opening is provided in the middle of the operating table, and an auxiliary roller is rotatably connected to the center of the installation opening. The positioning component includes a housing, with a control rod rotatably connected through the center of the housing. Sliding blocks are slidably connected to the left and right sides inside the housing, and the control rod and the sliding blocks are threaded together. In this utility model, by setting up the cooperation between components such as the housing, control rod, sliding blocks, mounting frame, support, roller screw, and limiting rod, the device can restrict the wood more stably and prevent tilting, making it more practical.

The embodiment of the utility model provides a joint driving device, and belongs to the technical field of joint driving. The transmission sleeve is installed on the driving body, the driving body drives the transmission sleeve to rotate so as to drive the planetary roller assembly to move in the axial direction of the transmission shaft along with the transmission shaft, the transmission sleeve is provided with internal threads, and the end, away from the limiting section, of the installation section extends out of the driving body. The planetary roller assembly is provided with transition threads meshed with the internal threads and the external threads and located on the side, away from the installation section, of the limiting section, the meshing section limits the planetary roller assembly to move relative to the meshing section in the axial direction of the installation section, and the limiting section at least partially protrudes out of the installation section in the radial direction of the installation section. The limiting part is located on the side, facing the mounting section, of the limiting section, and the limiting section can move to make contact with or be disengaged from the limiting part. According to the joint driving device, the possibility that the planetary roller lead screw is damaged can be reduced.

The application relates to the field of high-precision transmission technology, and particularly discloses a retainer and a circulating planetary roller screw pair. The retainer comprises a circular ring body, a plurality of roller guide grooves are arranged on the circular ring body and are uniformly distributed in the circumferential direction, the roller guide grooves extend along the radial direction of the circular ring body, an opening penetrating through an inner hole of the circular ring body is arranged at the radial inner end of the roller guide groove, the two sides of the opening are inwardly contracted to form a contraction opening, and the contraction opening is elastic. In the above structure, the retainer is circular ring-shaped and is arranged on the side surface of the inner threaded section of the nut, so that the overall radial size of the circulating planetary roller screw pair can be reduced, and a reliable structural basis is provided for realizing the miniaturization and micro-miniaturization of the circulating planetary roller screw pair; the roller guide groove is provided with the opening, the radial size of the retainer can be made smaller, and the overall radial size of the circulating planetary roller screw pair is smaller.

The invention relates to a standard toothless planetary roller screw, and belongs to the technical field of roller screws, the standard toothless planetary roller screw comprises a screw rod, a nut, a planet carrier assembly and a plurality of rollers, and the periphery of the screw rod is provided with external threads; internal threads are arranged on the inner wall of the nut, and unthreaded hole parts are arranged at the two ends of the internal threads; each roller comprises a threaded part in the middle and polished shaft parts at the two ends; the thread part of the roller and the internal thread of the nut have the same screwing direction and the same lead angle; the planet carrier assembly comprises a middle retainer, and the middle retainer is provided with at least three open grooves used for assembling the pin rollers in the radial direction. By canceling nut gear ring / ring groove and pin roller gear / ring groove structures and combining a double matching mechanism of the planet carrier assembly, the machining bottleneck of a composite structure is thoroughly eliminated, the axial parallelism and the constant lead characteristic of the pin rollers are guaranteed, meanwhile, vibration noise is remarkably reduced, and high-precision and large-scale mass production is achieved.

The utility model discloses a retainer of a planetary roller lead screw pair, which comprises a retainer body, the center of the retainer body is provided with a through accommodating cavity for a lead screw to pass through for installation, and the retainer is characterized in that the retainer body is made of a non-metal material with high strength, high rigidity and light weight, and a plurality of elastic buffer parts are arranged in the accommodating cavity at intervals in a protruding manner. The retainer has the advantages of low cost and light weight, and the operation stability and the service life of the planetary roller screw pair can be ensured when the retainer is applied to the corresponding planetary roller screw pair.