CN117856523B - Compact integrated telescopic rotary electric cylinder - Google Patents

Abstract

A compact integrated telescopic rotary electric cylinder comprises a cylinder body, a first motor assembly, a second motor assembly, a reverse planetary roller screw subassembly, and a ball spline subassembly; the present invention utilizes two frameless torque motors arranged coaxially to drive a long nut and a spline shaft respectively, and all components are inside the electric cylinder, thereby minimizing the axial dimension and the radial dimension, so that the structure of the electric cylinder is simple and compact, meeting the installation requirements in a small space, and meeting the demand for high precision at the same time; the present invention utilizes a reverse planetary roller screw subassembly to improve the load force and rigidity, stable power transmission, low heat generation, and long service life, and the low friction loss of the ball spline subassembly during axial movement helps to improve the overall efficiency.

Description

A compact integrated telescopic rotary electric cylinder

Technical Field

The invention belongs to the field of rotary electric cylinders, and in particular relates to a compact integrated telescopic rotary electric cylinder.

Background technique

The electric cylinder is a modular product that integrates a servo motor and a lead screw. It converts the rotational motion of the servo motor into linear motion. Based on the precise control characteristics of the servo motor, it achieves precise control of the position, speed and thrust of the electric cylinder output shaft. It is a high-precision linear motion product.

Some existing telescopic rotating electric cylinders use a ball screw pair. An external motor drives the screw shaft to rotate, which is converted into linear motion of the piston rod. Another motor is placed on the side of the cylinder body to drive the spline shaft and spline nut to rotate, and the gear on one side of the spline nut drives the turntable with an internal gear on the top of the piston rod to rotate.

Some existing telescopic rotary electric cylinders adopt a double cylinder setting, where the main cylinder drives a telescopic rotating shaft, and the auxiliary cylinder outputs linear motion. The auxiliary cylinder shaft is connected to the main cylinder shaft through a connecting plate, and the main cylinder shaft can rotate and move linearly.

The existing telescopic rotary electric cylinder has large axial or lateral dimensions and a complex overall structure, which makes it difficult to meet installation requirements when space dimensions are limited.

Summary of the invention

The purpose of the present invention is to provide a compact integrated telescopic rotary electric cylinder in order to solve the problems existing in the existing telescopic rotary electric cylinder.

A compact integrated telescopic rotary electric cylinder comprises a cylinder body, a first motor assembly, a second motor assembly, a reverse planetary roller screw subassembly, and a ball spline subassembly;

The cylinder body part comprises an intermediate cylinder body, a front end cover, a rear end cover, a first bearing, a second bearing, a third bearing, and a fourth bearing;

The first motor assembly comprises a first frameless torque motor stator, a first frameless torque motor rotor, a first annular magnetic encoder stator, a first annular magnetic encoder rotor and a first stator clamping ring;

The second motor assembly comprises a second frameless torque motor stator, a second frameless torque motor rotor, a second annular magnetic encoder stator, a second annular magnetic encoder rotor and a second stator clamping ring;

The reverse planetary roller screw subassembly comprises a hollow screw, a roller, a retaining frame, a first retaining ring, a long nut and a sleeve;

The ball spline subassembly comprises a ball spline shaft, a spline sleeve, a ball spline nut in the spline sleeve and a second retaining ring;

The front end cover is connected to the middle cylinder body by four screws, and the rear end cover is connected to the middle cylinder body by four screws. A flange is provided on the connection side of the front end cover and the rear end cover. The front end cover, the rear end cover and the middle cylinder body are embedded and connected to ensure the coaxiality with the middle cylinder body. The middle cylinder body is provided with a radial hole.

The outer walls of the first bearing, the second bearing, the third bearing and the fourth bearing are matched and connected with the inner wall of the middle cylinder body part, the first bearing and the second bearing are symmetrically arranged at both ends of the spline sleeve, and the inner walls are matched and connected with the outer walls at both ends of the spline sleeve, and the third bearing and the fourth bearing are symmetrically arranged at both ends of the long nut for support and positioning;

The first frameless torque motor stator is fixed inside the front end of the intermediate cylinder body by screws and a first stator clamping ring, the inner wall of the first frameless torque motor rotor is fixed to the outer wall of the middle part of the spline sleeve by structural adhesive, the first annular magnetic encoder stator is installed on the outside of the front end cover by screws, and the first annular magnetic encoder rotor is fixedly connected to the spline sleeve by a set screw;

The second frameless torque motor stator is fixed inside the rear end of the intermediate cylinder body by screws and a second stator clamping ring, the inner wall of the second frameless torque motor rotor is fixed to the outer wall of the middle part of the long nut by structural adhesive, the second annular magnetic encoder stator is fixedly installed on the outer side of the rear end cover by screws, and the second annular magnetic encoder rotor is fixedly connected to the outer wall of the sleeve by a set screw;

The inner wall of the hollow screw is fixedly connected to the outer wall of one end of the ball spline shaft, a retaining frame is respectively arranged at both ends of the hollow screw, and both ends of the roller are respectively connected to the two retaining frames, and the first retaining ring is fixedly arranged on the outer wall of the hollow screw to fix the retaining frame, and the thread on the roller matches the inner thread of the long nut and the outer thread of the hollow screw respectively;

The inner wall of the sleeve is connected with the outer wall of one end of the long nut, and the outer wall of the sleeve is connected with the inner wall of the fourth bearing installed in the rear end cover. The sleeve is fixedly arranged on the long nut to rotate together, and is supported and positioned by the third bearing and the fourth bearing.

The outer wall of the ball spline shaft and the inner wall of the ball spline nut are connected by sliding and interlacing.

The ball spline nut is bonded and fixed in the spline sleeve by the second retaining ring.

The first bearing, the second bearing and the fourth bearing are single-row angular contact ball bearings.

The third bearing is a double-row angular contact ball bearing.

Working principle and working process of the present invention:

The first frameless torque motor stator and the first frameless torque motor rotor constitute a first frameless torque motor; the second frameless torque motor stator and the second frameless torque motor rotor constitute a second frameless torque motor.

The first annular magnetic encoder stator and the first annular magnetic encoder rotor form a first annular magnetic encoder; the second annular magnetic encoder stator and the second annular magnetic encoder rotor form a second annular magnetic encoder.

When the present invention is in use, the second frameless torque motor drives the long nut to rotate, the second annular magnetic encoder is used to feed back the angle, angular velocity and angular acceleration of the motor, the first frameless torque motor drives the spline sleeve to rotate, and can drive the spline shaft to rotate, the first annular magnetic encoder is used to feed back the angle, angular velocity and angular acceleration of the motor; when the present invention needs to output linear motion, the first frameless torque motor is enabled, the rotation angle is controlled to be zero, the second frameless torque motor rotates, and after the motion conversion of the reverse planetary roller screw subassembly, it is converted into the linear motion of the spline shaft (501); when the present invention needs to output rotational motion, the first frameless torque motor rotates to control the second frameless torque motor and the first frameless torque motor to move synchronously; when the present invention needs to output linear and rotational mixed motion, according to the motion conversion relationship, the first frameless torque motor and the second frameless torque motor are respectively rotated at a certain angular velocity; the spline sleeve and the shaft sleeve respectively limit the front and rear limit positions of the present invention.

Beneficial effects of the present invention:

1. The present invention utilizes two frameless torque motors arranged coaxially to drive the long nut and the spline shaft respectively. All components are inside the electric cylinder, which minimizes the axial dimension and the radial dimension, making the structure of the electric cylinder simple and compact, meeting the installation requirements in a small space and meeting the demand for high precision.

2. The present invention adopts a reverse planetary roller screw pair to improve load capacity and rigidity, stable power transmission, low heat generation, and long service life. The low friction loss of the ball spline pair during axial movement helps to improve the overall efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of an embodiment of the present invention.

FIG. 2 is an axial view of the spline shaft and spline nut in accordance with an embodiment of the present invention.

Detailed ways

Please refer to FIG. 1 and FIG. 2 , which are embodiments of the present invention.

A compact integrated telescopic rotary electric cylinder comprises a cylinder body 1, a first motor assembly 2, a second motor assembly 3, a reverse planetary roller screw subassembly 4, and a ball spline subassembly 5;

The cylinder body part 1 comprises a middle cylinder body 101, a front end cover 102, a rear end cover 103, a first bearing 104, a second bearing 105, a third bearing 106, and a fourth bearing 107;

The first motor assembly 2 comprises a first frameless torque motor stator 201, a first frameless torque motor rotor 202, a first annular magnetic encoder stator 203, a first annular magnetic encoder rotor 204 and a first stator clamping ring 205;

The second motor assembly 3 comprises a second frameless torque motor stator 301, a second frameless torque motor rotor 302, a second annular magnetic encoder stator 303, a second annular magnetic encoder rotor 304 and a second stator clamping ring 305;

The reverse planetary roller screw subassembly 4 comprises a hollow screw 401, a roller 402, a retaining frame 403, a first retaining ring 404, a long nut 405 and a sleeve 406;

The ball spline subassembly 5 comprises a ball spline shaft 501, a spline sleeve 502, a ball spline nut 503 in the spline sleeve 502 and a second retaining ring 504;

The front end cover 102 is connected to the middle cylinder body 101 by four screws, and the rear end cover 103 is also connected to the middle cylinder body 101 by four screws. A flange is provided on the connection side of the front end cover 102 and the rear end cover 103;

The outer walls of the first bearing 104, the second bearing 105, the third bearing 106 and the fourth bearing 107 are matched and connected with the inner wall of part of the intermediate cylinder body 101, the first bearing 104 and the second bearing 105 are symmetrically arranged at both ends of the spline sleeve 502, and the inner walls are matched and connected with the outer walls at both ends of the spline sleeve 502, and the third bearing 106 and the fourth bearing 107 are symmetrically arranged at both ends of the long nut 502 for support and positioning;

The first frameless torque motor stator 201 is fixed inside the front end of the intermediate cylinder body 101 by screws and a first stator clamping ring 205, the inner wall of the first frameless torque motor rotor 202 is fixed to the outer wall of the middle part of the spline sleeve 502 by structural adhesive, the first annular magnetic encoder stator 203 is installed on the outside of the front end cover 102 by screws, and the first annular magnetic encoder rotor 204 is fixedly connected to the spline sleeve 502 by a set screw; the first annular magnetic encoder is used as feedback for the first frameless torque motor.

The second frameless torque motor stator 301 is fixed inside the rear end of the intermediate cylinder 101 by screws and the second stator clamping ring 305, the inner wall of the second frameless torque motor rotor 302 and the outer wall of the middle part of the long nut 405 are fixed by structural adhesive, the second annular magnetic encoder stator 303 is fixedly installed on the outside of the rear end cover 103 by screws, and the second annular magnetic encoder rotor 304 is fixedly connected to the outer wall of the sleeve 406 by set screws; the second annular magnetic encoder is used as feedback for the second frameless torque motor.

The inner wall of the hollow screw 401 is fixedly connected to the outer wall of one end of the ball spline shaft 501, and a retaining frame 403 is respectively provided at both ends of the hollow screw 401. Both ends of the roller 402 are respectively connected to the two retaining frames 403. The first retaining ring 404 is fixedly provided on the outer wall of the hollow screw 401 to fix the retaining frame 403. The threads on the roller 402 match the inner threads of the long nut 405 and the outer threads of the hollow screw 401 respectively.

The inner wall of the sleeve 406 is cooperated and connected with the outer wall of one end of the long nut 405, and the outer wall of the sleeve 406 is cooperated and connected with the inner wall of the fourth bearing 107 installed in the rear end cover 103. The sleeve 406 is fixedly arranged on the long nut 405 for common rotation, and is supported and positioned by the third bearing 106 and the fourth bearing 107; it is necessary to ensure the axial relative position and radial clearance between the second frameless torque motor rotor 302 and the second frameless torque motor stator 301, and ensure the relative position and radial clearance between the second annular magnetic encoder stator 303 and the second annular magnetic encoder rotor 304, so that the frameless torque motor and the second annular magnetic encoder can work normally, and the long nut 405 is driven to rotate by the second frameless torque motor.

The outer wall of the ball spline shaft 501 and the inner wall of the ball spline nut 503 are slidably connected.

The ball spline nut 503 is bonded and fixed in the spline sleeve 502 by the second retaining ring 504; the spline sleeve 502 is driven to rotate by the first frameless torque motor, and the spline sleeve 502 is supported and positioned by the first bearing 104 and the second bearing 105, so as to ensure the axial relative position and radial clearance between the first frameless torque motor rotor 202 and the first frameless torque motor stator 201, and ensure the relative position and radial clearance between the first annular magnetic encoder stator 203 and the first annular magnetic encoder rotor 204, so that the first frameless torque motor and the first annular magnetic encoder can work normally.

The first bearing 104, the second bearing 105 and the fourth bearing 107 are single-row angular contact ball bearings; the third bearing 106 is a double-row angular contact ball bearing.

The working principle and working process of this embodiment:

When the present embodiment is in use, the second frameless torque motor drives the long nut 405 to rotate, the second annular magnetic encoder is used to feedback the angle, angular velocity and angular acceleration of the motor, the first frameless torque motor drives the spline sleeve 502 to rotate, and can drive the spline shaft 501 to rotate, and the first annular magnetic encoder is used to feedback the angle, angular velocity and angular acceleration of the motor; when the present invention needs to output linear motion, the first frameless torque motor is enabled, the control angle is zero, the second frameless torque motor rotates, and after the motion conversion of the reverse planetary roller screw subassembly 4, it is converted into the linear motion of the spline shaft (501); when the present invention needs to output rotational motion, the first frameless torque motor rotates to control the second frameless torque motor and the first frameless torque motor to move synchronously; when the present invention needs to output linear and rotational mixed motion, according to the motion conversion relationship, the first frameless torque motor and the second frameless torque motor are respectively rotated at a certain angular velocity; the spline sleeve 502 and the shaft sleeve 406 respectively limit the front and rear limit positions of the present invention.

Claims (3)

1. A compact integrated telescopic rotary electric cylinder, comprising a cylinder body (1), a first motor assembly (2), a second motor assembly (3), a reverse planetary roller screw subassembly (4), and a ball spline subassembly (5), characterized in that: The cylinder part (1) comprises an intermediate cylinder (101), a front end cover (102), a rear end cover (103), a first bearing (104), a second bearing (105), a third bearing (106), and a fourth bearing (107); The first motor assembly (2) comprises a first frameless torque motor stator (201), a first frameless torque motor rotor (202), a first annular magnetic encoder stator (203), a first annular magnetic encoder rotor (204) and a first stator clamping ring (205); The second motor assembly (3) comprises a second frameless torque motor stator (301), a second frameless torque motor rotor (302), a second annular magnetic encoder stator (303), a second annular magnetic encoder rotor (304) and a second stator clamping ring (305); The reverse planetary roller screw subassembly (4) comprises a hollow screw (401), a roller (402), a retaining frame (403), a first retaining ring (404), a long nut (405) and a shaft sleeve (406); The ball spline subassembly (5) comprises a ball spline shaft (501), a spline sleeve (502), a ball spline nut (503) in the spline sleeve (502), and a second retaining ring (504); The front end cover (102) is connected to the middle cylinder body (101) by four screws, and the rear end cover (103) is also connected to the middle cylinder body (101) by four screws. A flange is provided on the connection side of the front end cover (102) and the rear end cover (103). The front end cover (102), the rear end cover (103) and the middle cylinder body (101) are embedded and connected to ensure coaxiality with the middle cylinder body (101). The middle cylinder body (101) is provided with a radial hole. The outer walls of the first bearing (104), the second bearing (105), the third bearing (106) and the fourth bearing (107) are matched and connected with the inner wall of part of the intermediate cylinder body (101); the first bearing (104) and the second bearing (105) are symmetrically arranged at both ends of the spline sleeve (502); the inner walls are matched and connected with the outer walls at both ends of the spline sleeve (502); the third bearing (106) and the fourth bearing (107) are symmetrically arranged at both ends of the long nut (405) for support and positioning; The first frameless torque motor stator (201) is fixed inside the front end of the intermediate cylinder body (101) by means of screws and a first stator clamping ring (205); the inner wall of the first frameless torque motor rotor (202) and the middle outer wall of the spline sleeve (502) are fixed by means of structural adhesive; the first annular magnetic encoder stator (203) is mounted on the outside of the front end cover (102) by means of screws; and the first annular magnetic encoder rotor (204) is fixedly connected to the spline sleeve (502) by means of a set screw; The second frameless torque motor stator (301) is fixed inside the rear end of the intermediate cylinder (101) by means of screws and a second stator clamping ring (305); the inner wall of the second frameless torque motor rotor (302) and the outer wall of the middle portion of the long nut (405) are fixed by means of structural adhesive; the second annular magnetic encoder stator (303) is fixedly mounted on the outside of the rear end cover (103) by means of screws; and the second annular magnetic encoder rotor (304) is fixedly connected to the outer wall of the shaft sleeve (406) by means of set screws; The inner wall of the hollow screw (401) is fixedly connected to the outer wall of one end of the ball spline shaft (501), a retaining frame (403) is respectively provided at both ends of the hollow screw (401), and both ends of the roller (402) are respectively connected to the two retaining frames (403), and the first retaining ring (404) is fixedly arranged on the outer wall of the hollow screw (401) to fix the retaining frame (403), and the thread on the roller (402) matches the inner thread of the long nut (405) and the outer thread of the hollow screw (401) respectively. The inner wall of the shaft sleeve (406) is matched and connected with the outer wall of one end of the long nut (405); the outer wall of the shaft sleeve (406) is matched and connected with the inner wall of the fourth bearing (107) installed in the rear end cover (103); the shaft sleeve (406) is fixedly arranged on the long nut (405) to rotate together, and is supported and positioned by the third bearing (106) and the fourth bearing (107); The outer wall of the ball spline shaft (501) and the inner wall of the ball spline nut (503) are connected in a sliding and interlaced manner. The ball spline nut (503) is bonded and fixed in the spline sleeve (502) by a second retaining ring (504), and the spline sleeve (502) is supported and positioned by a first bearing (104) and a second bearing (105); The outer wall of the ball spline shaft (501) and the inner wall of the ball spline nut (503) are connected in a sliding and interlaced manner. The ball spline nut (503) is bonded and fixed in the spline sleeve (502) by a second retaining ring (504). 2. A compact integrated telescopic rotary electric cylinder according to claim 1, characterized in that: the first bearing (104), the second bearing (105) and the fourth bearing (107) are single-row angular contact ball bearings. 3. The compact integrated telescopic rotary electric cylinder according to claim 1, characterized in that: the third bearing (106) is a double-row angular contact ball bearing.