CN112706187B - Normally open pneumatic flexible spherical brake - Google Patents

Abstract

The invention relates to a normally open pneumatic flexible spherical brake, which belongs to a mechanical brake device and is used for a robot joint or a small brake device; the brake can solve the problems of large volume, inflexibility, single braking direction and the like of the traditional mechanical, hydraulic, electromagnetic and combined braking systems; the brake is structurally characterized in that the brake is provided with a left hemispherical ball seat and a right hemispherical ball seat which share the center of a sphere, a spherical brake framework, a mandrel, a drum-shaped driving air bag, a floating brake plate and other parts; the brake force is generated by the pressure fluid filled in the drum-shaped driving air bag; the drum-shaped driving air bag pushes the floating braking plate and the ball seat to generate acting force, so that the multi-directional space braking purpose is achieved; the braking force is determined by the pressure of the filling fluid when the brake brakes; the brake is in a non-braking state when not in operation; the joint moment can be preset through the adjustment of the braking moment.

Description

Normally open pneumatic flexible spherical brake

Technical Field

The invention relates to a pneumatic flexible brake with a pose maintaining function, which is used on a wrist and a joint of a robot.

Background

The robot technology is widely applied in the fields of industry, military, medical treatment and the like, and is one of the important strategic technologies in the country; the flexibility and accuracy of the robot operation are determined by the robot arm and the joints, and the positioning accuracy and the pose maintaining capacity of the end effector are affected by the braking performance of the robot arm and the joints; the current driving modes of the robot joint brake mainly comprise: hydraulic, electromagnetic, pneumatic, etc.; the hydraulic brake has larger braking moment and is mainly used on the joints of the heavy robot, but has larger volume and needs huge hydraulic systems and equipment; the electromagnetic brake has larger volume, difficult brake moment adjustment and inflexible application; the pneumatic brake has compact structure, convenient control and cleaning, and is widely used at present; the brake with the space pose maintaining capability and the adjustable braking moment can realize multidirectional space braking, so that the special requirements of the brake structure, the braking performance and the control requirement of the robot joint are met.

Disclosure of Invention

The invention aims to solve the problems of uncontrollable braking moment and multidirectional space braking of the current brake, and provides a brake capable of realizing joint space pose maintenance and braking functions; the brake consists of a spherical floating brake device and a drum-shaped driver; the spherical floating brake device is characterized in that a spherical floating brake device is arranged between the upper flange and the lower flange of the brake, and the central axis of the spherical floating brake device is positioned on the connecting line of the geometric centers of the upper flange and the lower flange of the brake; the spherical floating braking device consists of a plurality of adjusting bolts, nuts, a left hemispherical ball seat, a right hemispherical ball seat, an upper limiting end cover, a lower limiting end cover, a fixing nut, a gasket, a mandrel, a floating braking plate and a spherical braking framework; uniformly distributed through holes are reserved at the geometric center position of the lower flange of the brake, and are fixedly connected to uniformly distributed threaded holes at the bottom of the spherical brake framework by bolts, so that the central axis of the spherical brake framework coincides with the geometric center connecting lines of the upper flange and the lower flange; the spherical brake framework is a plurality of hollow hemispheres, the upper edge positions of the spherical brake framework are annular platforms for positioning the assembly positions of the upper limit end covers, four identical trapezoid windows are uniformly and symmetrically distributed on the hemispheres, and arc-shaped stand columns are formed between adjacent windows; the cross section of the arc-shaped upright post is a T-shaped cross section; the narrow face end of the arc-shaped upright post faces outwards, and the wide face end faces inwards; a floating brake plate with the same shape as the trapezoid window is arranged between two adjacent arc T-shaped upright posts; two adjacent arc-shaped T-shaped stand columns can limit the floating brake plates to move towards the sphere center along the radial direction, so that the floating brake plates can only move away from the sphere center along the radial direction; the shape of the floating brake plate is consistent with the shape of uniformly distributed windows on the spherical brake skeleton, the body structure of the thin-sheet spherical surface body is a part of a spherical surface, and the diameter of the thin-sheet spherical surface body is identical with the diameter of the spherical brake skeleton; the position of the sphere center of the floating brake plate is overlapped with that of the framework of the spherical brake after the floating brake plate is installed; the central position of the lower end of the spherical brake skeleton is provided with a threaded hole, a mandrel is fixedly connected with threads, the central axis of the mandrel coincides with the central axis of the spherical brake skeleton, the mandrel is provided with threads at two ends of a stepped shaft, and the threads at the lower end are connected with the threaded hole at the center of the spherical brake skeleton and limit the axial movement of the mandrel; the mandrel is fixed on the spherical brake framework; a lower limiting end cover is arranged on a shaft shoulder at the lower end of the mandrel, and the lower limiting end cover is parallel to the lower flange after the lower limiting end cover is arranged; an upper limit end cover is arranged on a shaft shoulder at the upper end of the mandrel, and the upper limit end cover is parallel to the lower flange after the upper limit end cover is arranged; the drum-shaped driving air bag is arranged between the upper limit end cover and the lower limit end cover, and is characterized in that the drum-shaped driving air bag is structurally a drum-shaped thin-wall hollow high-elasticity bag body, the end faces of the upper end face and the lower end face of the drum-shaped driving air bag are parallel, four grooves are formed in the radial direction, and the width and the phase of the grooves are the same as the width of the inner side of the arc-shaped upright post; when the drum-shaped driving air bag is installed, the groove is assembled on the arc-shaped upright post, and the arc-shaped upright post is used for limiting the circumferential deformation and displacement of the drum-shaped driver; the outer sides of the floating brake plate and the spherical brake framework are provided with brake ball seats, and the brake ball seats are formed by left and right hemispherical brake ball seats; the left hemisphere brake ball seat and the right hemisphere brake ball seat are provided with adjusting gaskets and bolts; the brake ball seat is in clearance fit with the spherical brake framework, and a movement clearance is reserved between the floating brake plate and the left and right hemispherical brake ball seats; the upper end of the left hemispherical brake ball seat is fixedly provided with an upper flange of the actuator; a gas inlet is arranged at the bottom of the drum-shaped driving air bag; when the pressure of the filled gas is increased, the drum-shaped driving air bag expands and deforms, the axial deformation of the drum-shaped driving air bag is restrained, and only radial expansion and deformation are realized; the radial expansion deformation pushes the floating brake plate to move along the radial outward brake ball seat; when the pressure reaches a certain value, the floating brake plate is contacted with the left hemispherical brake ball seat on the outer side; when the filling pressure continues to increase, the positive pressure of the floating braking plate to the left hemispherical braking ball seat and the right hemispherical braking ball seat at the outer side increases, the friction between the floating braking plate and the ball seat increases, and the braking force increases; the normally open pneumatic flexible spherical brake has good braking effect on the axial moment and the radial moment which are applied when the normally open pneumatic flexible spherical brake is in a working state and the resultant moment thereof; when the pressure of the filled gas is reduced, the drum-shaped driving air bag resets under the elastic acting force of the drum-shaped driving air bag; therefore, the positive pressure of the left hemispherical brake ball seat and the right hemispherical brake ball seat on the outer side of the floating brake plate is reduced, the friction force between the floating brake plate and the ball seat is reduced, the braking force is reduced until the braking force is reduced to zero, and the braking function is lost; according to the working requirement, the braking torque of the brake can be adjusted by adjusting the input air pressure of the drum-shaped driving air bag; the invention has the advantages that the size of the brake is small, the movement is flexible, the braking torque is adjustable, and the multi-directional braking can be realized; the working states of different loads can be adapted; has great popularization and application value in the application fields of bionic robots, special equipment and the like and has good development prospect.

Drawings

FIG. 1 is a cross-sectional view of the general structure of a normally open pneumatic flexible ball brake;

FIG. 2 is an exploded schematic view of a normally open pneumatic flexible ball brake;

Detailed Description

The invention is described in further detail below with reference to the attached drawing figures and specific examples:

as shown in fig. 1, the normally open pneumatic flexible spherical brake is provided with a left hemispherical brake ball seat 3, a right hemispherical brake ball seat 6, an upper limit end cover 10, a drum-shaped driving air bag 11, a lower limit end cover 12, a mandrel 13, a floating brake plate 14, a spherical brake framework 15 and a plurality of connecting bolts, nuts and gaskets; connecting a threaded shaft at the bottom end of the mandrel 13 to a central threaded hole at the lower end of the spherical brake framework 15, so that the spherical center of the spherical brake framework 15 coincides with the central axis of the mandrel 13; the central hole of the lower limit end cover 12 passes through the mandrel 13 and is assembled on the bottom shaft shoulder of the mandrel 13; the end face of the lower limit end cover 12 is ensured to be parallel to the end face of the bottom of the spherical brake skeleton 15; the drum-shaped driving air bag 11 is arranged at the middle position of the mandrel 13 through the central hole of the drum-shaped driving air bag 11, and the drum-shaped driving air bag 11 is arranged on the lower limit end cover 12; four grooves which are uniformly distributed on the drum-shaped driving air bag 11 are respectively arranged on four arc-shaped stand columns of the spherical brake skeleton 15, and the arc-shaped stand columns limit the drum-shaped driving air bag 11 to be incapable of rotating circumferentially; the upper limit end cover 10 is arranged above the drum-shaped driving air bag 11, so that the shoulder surface of the upper limit end cover 10 coincides with the cross section of the upper end surface of the spherical brake skeleton 15; the bottom surface of the boss of the upper limit end cover 10 sinks below the cross section of the upper end surface of the spherical brake framework 15; the gasket 9 is assembled on the mandrel 13 and is arranged above the upper limit end cover 10; a nut 8 is used for locking and fixing a gasket 9 and an upper limit end cover 10; the floating brake plate 14 is arranged in a groove formed by assembling the spherical brake skeleton 15 and the drum-shaped driving air bag 11 by adopting a clearance fit method; the left hemispherical brake ball seat 3, the right hemispherical brake ball seat 6, the positioning pin 5, the adjusting bolt 7 and the adjusting gasket 4 form a brake ball seat; the brake ball seat is arranged on the outer sides of the spherical brake framework 15 and the floating brake plate 14, and the brake ball seat is assembled with the spherical brake framework 15 and the floating brake plate 14 in a clearance fit manner; the adjusting bolt 7 and the adjusting gasket 4 can adjust the gap between the ball seat and the spherical brake skeleton 15; when the ball seat is assembled, the ball centers of the left hemispherical brake ball seat 3 and the right hemispherical brake ball seat 6 and the spherical brake skeleton 15 are required to be coincident; bolts are used to connect the upper flange 2 and the lower flange 16 of the actuator.

Claims (4)

1. A normally open pneumatic flexible spherical brake is characterized in that spherical floating brake devices are arranged on central axes of an upper flange and a lower flange; the spherical floating braking device consists of a ball seat and a ball head; the ball seat consists of a spherical thin-wall left half ball seat, a spherical thin-wall right half ball seat, a plurality of bolts and an adjusting gasket; the ball head consists of an upper limit end cover, a drum-shaped driving air bag, a lower limit end cover, a step-shaped mandrel, a floating brake plate and a spherical brake framework; the central hole of the drum-shaped driving air bag penetrates into a stepped mandrel, an upper limit end cover and a lower limit end cover are respectively arranged at the upper end and the lower end of the drum-shaped driving air bag, the top of the upper limit end cover is fastened by a gasket and a nut, the other end of the mandrel is fixed on a central threaded hole at the bottom of a cavity in the spherical brake skeleton by threads, the spherical brake skeleton is a hemispherical hollowed-out metal piece, the top of the spherical brake skeleton is a circular ring surface, a plurality of arc-shaped stand columns are uniformly distributed below the circular ring surface, the cross sections of the arc-shaped stand columns are of T-shaped structures, the narrow surface ends of the arc-shaped stand columns are positioned on the peripheral surface of the spherical brake skeleton, the wide surface ends of the arc-shaped stand columns are positioned on the inner side surface of the spherical brake skeleton, a plurality of trapezoid windows with the same shape as the trapezoid windows are arranged between the arc-shaped stand columns and the upper end surface and the lower end surface of the spherical brake skeleton, a plurality of floating brake plates are uniformly distributed at the windows of the spherical brake skeleton, the floating brake plates are sheet-shaped spherical surface bodies, the shapes of the floating brake plate bodies have the same shape as the windows on the spherical brake skeleton, and the spherical surfaces have the same radius as the spherical surfaces; the ball seat is arranged on the outer sides of the spherical brake framework and the floating brake plate, is assembled with the ball head in a clearance fit manner, and is overlapped with the ball center of the ball head after assembly and is positioned on the central axes of the upper flange and the lower flange; the end faces of the upper end and the lower end of the drum-shaped driving air bag are parallel, four grooves are formed in the radial direction, and the grooves are assembled on the arc-shaped upright posts when the drum-shaped driving air bag is installed; the gap between the ball seat and the ball head can be adjusted through the adjusting gasket and the adjusting bolt; after the driving air bag is filled with pressure gas, the driving air bag radially expands to push the floating brake plate to press the ball seat, and braking force is generated.

2. The normally open pneumatic flexible spherical brake according to claim 1, wherein the spherical brake skeleton is provided with a threaded hole at the bottom, and the central axis of the threaded hole coincides with the central axis of the spherical brake skeleton and is used for connecting the threads at the bottom of the mandrel; mounting threaded holes are distributed around the central threaded holes and are used for connection and fixation; a through hole is arranged at the middle position of the two fixed threaded holes and is used for penetrating through the fluid pipeline; the spherical brake skeleton is made of carbon steel, aluminum alloy, engineering plastic or composite material.

3. A normally open pneumatic flexible ball brake according to claim 1, wherein the floating brake plates are made of carbon steel, aluminum alloy, engineering plastic or composite materials.

4. The normally open pneumatic flexible spherical brake according to claim 1, wherein the drum-shaped driving air bag is a pressure-resistant drum-shaped hollow thin-wall high-elasticity single bag body, the appearance of the drum-shaped driving air bag is the same as the inner cavity of the spherical brake skeleton, and the bottom of the drum-shaped driving air bag is provided with a vent hole; through holes are arranged between the upper end face and the lower end face of the drum-shaped driving air bag, and the diameter of the through holes is the same as that of the mandrel; the drum-shaped driving air bag is made of latex, rubber, silica gel and AB glue.

Images