104results about How to "Eliminate transmission backlash" patented technology

The invention relates to a large precise numerical control rotating table. The large precise numerical control rotating table comprises a table base, a table spindle, worms and worm gears which are mounted in both sides of the table base and a reducer and a servo motor which are connected with the worm in one side of the table base. The large precise numerical control rotating table is characterized in that the worm in the other side of the table base is connected with the reducer and the servo motor by a coupling so as to form a driven worm gear pair for providing a resistance moment for the table base; and the outer circumference of the table base is provided with a plurality of static pressure support pads, a clearance is left between the lower end surface of the table spindle and the static pressure support pads, three rows of cylindrical roller rotating table bearings are mounted between the table spindle and the table base, and the inner rings of the three rows of cylindrical roller rotating table bearings are provided with steel scales. The invention solves the problems that the rotary positioning accuracy is low, the table runout of the rotating table can not meet the accuracy requirements, the supported workpiece can not bear a large impact force as a result of restricted eccentric center and the like. Besides, the invention greatly improves the transmission smoothness of the rotating table and prolongs the service life of the bearing.

The invention relates to a two-motor drive modular joint. According to the two-motor drive modular joint, an output shaft is rotationally connected with a shell and fixedly connected with an output gear; the output shaft comprises a through hole extending in the axial direction; the shell comprises a penetrating hole corresponding to the through hole, and the through hole and the penetrating holeare used for storing a line; the output shaft further comprises a radial channel which cooperates with a zero-bit detection module to determine the zero bit; a first gear and a second gear are engagedwith the output gear and are free of interference; a first servo motor is connected with the first gear and a first motor encoder; and a second servo motor is connected with the second gear and a second motor encoder. The two-motor drive modular joint can eliminate the gap between the output gear and a drive device, so that transmission is more precise, and the joint can still run in a gapless mode even when the gears are abraded. The zero-bit detection module is used for determining the zero bit of the output shaft. Through cooperation of the penetrating hole and the through hole, various cables can be arranged inside the joint, and thus the joint is simple and compact as a whole.

The invention relates to the technical field of industrial robots, in particular to a two-degree-of-freedom joint structure. The two-degree-of-freedom joint structure comprises a first rack, a first driving device, a first gear shaft, a first bevel gear, a second rack, a second driving device, a second gear shaft, a second bevel gear, a third rack, an output gear shaft, an output bevel gear, a clearance-elimination driving device, a clearance-elimination gear shaft and a clearance-elimination bevel gear. The first bevel gear is arranged on the first gear shaft, and the first driving device drives the first gear shaft to rotate. The second bevel gear is arranged on the second gear shaft, and the second driving device drives the second gear shaft to rotate. The output bevel gear is arranged on the output gear shaft. The clearance-elimination gear is arranged on the clearance-elimination gear shaft, and the clearance-elimination driving device drives the clearance-elimination gear shaft to rotate. The output bevel gear and the clearance-elimination bevel gear are engaged with the first bevel gear and the second bevel gear correspondingly at the same time. By adoption of the two-degree-of-freedom joint structure, the pitching motion can be achieved, the revolving motion and the pitching and revolving combined motion can also be achieved, and the transmission precision is higher.

The invention provides a planetary gear transmission mechanism which comprises a sun wheel, planet wheels and a few-tooth-difference transmission mechanism. In order to improve the precision, gear teeth of two inner gear rings and gear teeth of two few-tooth-difference gears are variable-tooth-thickness involute gear teeth; the rotation directions of the helix angles of the two inner gear rings are opposite, and a clearance-eliminating elastic body is arranged between a pair of few-tooth-difference gears. The planetary gear transmission mechanism has the advantages of being high in rigidity and precision, large in transmission ratio and torque, and capable of greatly lowering machining difficulty. The invention further provides a robot joint reducer which comprises the planetary gear transmission mechanism. The robot joint reducer has the advantages of being scientific in design, small in size, high in precision, large in transmission ratio and torque, and capable of greatly lowering machining difficulty. The invention further provides a robot which comprises the robot joint reducer. The robot has the advantages of being scientific in design, high in precision, large in transmission ratio and torque, and capable of greatly lowering machining difficulty.

The invention relates to a two-degree-of-freedom joint structure driven by three motors. The two-degree-of-freedom joint structure comprises a first motor reducer, a second motor reducer, a third motor reducer, a first transmission system, a second transmission system, a third transmission system, an output system, an intermediate connector, a rack and a housing, wherein the rack is connected withthe housing through the intermediate connector; the first motor reducer, the second motor reducer and the third motor reducer are mounted on the rack; the output system comprises a third supporting frame and an output bevel gear; the output bevel gear is connected with the third supporting frame in a sleeving manner; the first motor reducer drives, through the transmission of the first transmission system, the output bevel gear to rotate; the second motor reducer drives, through the transmission of the second transmission system, the output bevel gear to rotate; and the third motor reducer drives, through the transmission of the third transmission system, the third supporting frame to act. The two-degree-of-freedom joint structure can realize autoroatation and pitching motion and meanwhile eliminate the transmission return difference of reverse motion, thereby finally improving the transmission accuracy greatly.

The invention relates to a gear and rack transmission anti-backlash mechanism. The gear and rack transmission anti-backlash mechanism comprises a gear and a rack. The rack is formed by stacking a first rack body and a second rack body and is meshed with the gear. The anti-backlash mechanism further comprises a lead screw shaft, a bearing support, needle bearings, a nut, a nut support and a plane spiral spring which are placed in a cavity formed in the first rack body and the second rack body. The two ends of the lead screw shaft are installed on the bearing support through the needle bearings, and the bearing support is fixed to the second rack body. The lead screw shaft is matched with the nut, and the nut is installed on the first rack body through the nut support. The two ends of the plane spiral spring are fixed to the lead screw shaft and the second rack body respectively. According to the anti-backlash mechanism, when a transmission backlash occurs between the gear and the rack, teeth of the two rack bodies are staggered under the elasticity effect of the spiral spring, the equivalent tooth thickness is increased, the transmission backlash between the gear and the rack is eliminated, transmission torque is large, the structure is simple, work is reliable, and the gear and rack transmission anti-backlash mechanism is suitable for the field of numerical control without backlash transmission, and especially for high-accuracy numerical control machine tools and robots.

The invention relates to a metal powder electron beam melting lamination layer shaping workbench z-axis movement system, and belongs to the field of three-dimensional rapid forming and manufacturing. The top of a second-stage speed change mechanism is fixedly connected with a supporting mechanism, a first-stage speed change mechanism is fixedly connected with the supporting mechanism, and a worm gear of the first-stage speed change mechanism is connected with a lower screw nut of the second-stage speed change mechanism through a key. The metal powder electron beam melting lamination layer shaping workbench z-axis movement system has the advantages that the structure is novel; a servo motor, a worm and gear and a ball screw serve as key parts, the transmission accuracy of the whole system is remarkably improved compared with transmission accuracy of an existing transmission system, and therefore powder material and workpiece vibration can be reduced, the manufacturing accuracy of a workpiece is improved, and the system is suitable for high-precision electron beam melting forming systems for manufacturing heavy test pieces.

The invention relates to a gear rack drive revolving worktable. The gear rack drive revolving worktable comprises a working table, a box, a lifting driving mechanism, a revolving driving mechanism and a gap eliminating mechanism, wherein the revolving driving mechanism is driven by a gear and a rack; the rack is formed by laminating two racks; and the gap eliminating mechanism comprises a lead screw shaft, a bearing bracket, a rolling needle bearing, a nut, a nut bracket and a plane scroll spring placed in a cavity formed in the two racks. The revolving worktable is driven by a hydraulic cylinder, can realize 180 degrees of fixed-angle transposition, can automatically eliminate the gap, and is large in transfer torque, simple in structure and reliable in operation.

The invention relates to the field of gear design, in particular to a gear assembly capable of eliminating transmission gaps. The gear assembly comprises a gear shaft, a first helical gear, a second helical gear, a spring and an adjusting mechanism. The gear shaft is sleeved with the first helical gear, and the first helical gear is in interference fit with the gear shaft. The gear shaft is sleeved with the second helical gear in a clearance fit mode. The spring and the adjusting mechanism are installed on the gear shaft. The spring is arranged between the second helical gear and the adjusting mechanism, one end of the spring is made to abut against the right end face of the second helical gear, and the other end of the spring is made to abut against the adjusting mechanism. According to the technical scheme, when the gears are meshed, the transmission gaps between gear teeth can be eliminated, in this way, transmission precision and stability are improved, meanwhile, the abrasion speed of the gear teeth is decreased, the service life of the gears is prolonged, and noise is lowered.

The present invention provides a quad redundant angular displacement sensor. The sensor comprises a hollow U-shaped housing (2), the U-shaped housing (2) and a cover plate (3) are connected with each other through two screws to form the support structure of the whole sensor; a gear shaft (4) is installed on the U-shaped housing (2) and the cover plate (3) through inter-axis bearing (5) and a axis-end bearing (7), and the angular displacement sensors (9) of the four angular displacement sensor assemblies (1) are symmetrically installed at the bottom of the U-shaped housing (2) through a small pressing plate (8); and the gears (10) of the four angular displacement sensor assemblies (1) and anti-backlash gears (11) are symmetrically installed in the cavity of the U-shaped housing (2), and the gears (10) and the anti-backlash gears (11) re engaged with the gear of the gear shaft (4). The quad redundant angular displacement sensor is small in size, compact in structure, light in quality and high in reliability.

An airborne photoelectric-platform outer frame elimination clearance torque motor driving shafting module belongs to a torque motor driving shafting module in an aviation optoelectronics technology field. The invention aims at providing a photoelectric-platform outer frame elimination clearance torque motor driving shafting module. In a technical scheme, a torque motor base, a torque motor stator, a torque motor shaft, a harmonic reducer input shaft, a bearing, a harmonic reducer, a torque motor rotor, an outer orientation frame, an outer high-low frame and the like are comprised. The torque motor base is fixed on the outer orientation frame. The harmonic reducer is fixed on the torque motor base. The harmonic reducer input shaft is connected with a wave generator of the harmonic reducer.The torque motor shaft is connected with the harmonic reducer input shaft. The torque motor rotor forms interference fit with the torque motor shaft. The torque motor stator is fixed on the torque motor base. The outer high-low frame is connected with a flexible gear of the harmonic reducer. By using the torque motor driving shafting module, gear transmission clearance can be eliminated and resetting is easy.

The invention discloses an automatic welding machine and a welding method for steel structural parts. The automatic welding machine for the steel structural parts comprises a portal frame which spans on a steel structural part to be welded and can longitudinally move along the steel structural part, and a welding arm which is arranged in the portal frame; and the welding arm comprises a mechanical arm, a mounting plate fixedly arranged at the upper end of the mechanical arm, a transverse moving device arranged at the top of the portal frame and used for driving the mounting plate to transversely move, a connecting plate fixedly arranged at the lower end of the mechanical arm, a welding gun fixedly arranged on the connecting plate and a three-dimensional imaging device arranged beside the welding gun and fixedly connected with the connecting plate. According to the automatic welding machine for the steel structural parts provided by the invention, manual welding of the steel structural parts is replaced, normal welding is guaranteed, and the welding efficiency is improved. A turnover device enables the steel structural parts to be turned over automatically, manual participation is not needed, the efficiency is further improved, and the labor intensity is reduced.

The invention relates to the technical field of mechanical transmission manufacturing, in particular to a clearance eliminating device for a gear pair. The clearance eliminating device for the gear pair comprises a transmission shaft, a driven gear fixedly arranged on the transmission shaft, and a hydraulic system. A frictional damping disc and a rear cover are sequentially arranged on the left side of the driven gear. An oil cavity is formed between the frictional damping disc and the rear cover. A gearbox casing is located on the outer circumferential walls of the frictional damping disc and the rear cover. An oil port connected with the oil cavity is formed in the gearbox casing. According to the clearance eliminating device for the gear pair, hydraulic damping force is generated by the hydraulic system, and the driven gear in the gear pair is under the effect of frictional resistance in the transmission process, so that additional force is generated between tooth sides of the gear pair, and it is guaranteed that meshing teeth can be kept in the pressed state at all transmission moments in the transmission process of the gear pair.

The invention discloses a zero-return-difference harmonic gear transmission device. The zero-return-difference harmonic gear transmission device comprises a rigid gear, a flexible gear and a wave generator; the wave generator is composed of a flexible bearing and an elastic cam; the flexible gear is located in the rigid gear; the upper end and the lower end of the flexible gear mesh with the upper end and the lower end of the rigid gear; the flexible bearing is located between the elastic cam and the flexible gear; the shape of the elastic cam is oval; a shaft hole is formed in the center of the elastic cam; and two structural holes used for forming thin walls of the cam at the two ends in the long axis direction of the elastic cam are formed in the positions, located on the two sides of the shaft hole, in the long axis direction of the elastic cam respectively. The zero-return-difference harmonic gear transmission device is simple in structure, reasonable in design and convenient to implement, backlash in circular teeth can be effectively eliminated, the transmission return difference can be effectively eliminated, in addition, the torsional rigidity can be guaranteed, the service life can be long, the application range can be wide, the practicability can be high, and the popularization and application values can be high.

The invention discloses a liquid-level variable and gear variable combined high-precision measuring and metering method and a device. The device comprises three parts of a hydraulic container or cylinder liquid-level variable precise measuring and metering device, a gear variable combiner and an electronic information control device. The bottom of the large-aperture hydraulic container or cylinder provided with a piston is communicated with a small-aperture measurement pipe. The gear variable combiner is as follows: a plurality of meshed large gears and small gears are installed in a gearbox;and the gear perimeter transmission ratio is the magnifying power and the reducing power of the gear variable count. The electronic information control device comprises a computer, a controller, an infrared electronic measurement ruler and a stepping motor which are mutually and electrically connected. An output gear rack or a measurement head of the gear variable combiner and a piston connectingrod of the hydraulic container or cylinder are tightly matched with an object to be measured so that the object to be measured is located and measured accurately. The device disclosed by the invention has the advantages of high measuring and metering precision and accurate zero point location and can be widely applicable in the fields, such as numerical control machines, sighting devices, preciseinstruments, balanced pressures, standard length weights and the like. A novel measuring and metering instrument and a tool for agricultural and industrial production, national defence construction and scientific research are provided.