An electric cylinder with radial self-locking drive

Abstract

An electric cylinder with radial self-locking and integrated drive and electricity relates to the technical field of electric drive equipment. It comprises a cylinder body, in which an inverted ball screw pair is rotatably installed, the front end of the screw of the inverted ball screw pair extends forward from the cylinder body, and a stator winding installed in the cylinder body is arranged outside the inverted ball screw pair, and a circle of magnets is fixedly arranged on the inverted ball screw pair in the stator winding. The magnetic encoder controller of the present invention is integrated with the circuit board of the motor driver as a whole, with a high degree of integration, and is arranged on the rear side of the electric cylinder, and the volume of the whole machine is further reduced, which is conducive to the debugging and maintenance of the motor driver, and has higher maintainability and reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of electric drive equipment, in particular to an electric cylinder with radial self-locking function and integrated drive and electricity. Background Art

[0002] The existing integrated servo electric cylinder structure has areas that can be further optimized and improved, specifically: 1) The driver is externally connected or fixed on the housing. When using an external driver, it is inconvenient to operate, requires connection and debugging, is large in size, and has cumbersome procedures; 2) The installation process requirements for the front-end angular contact ball bearing are high, and an additional locking nut is required to prevent the bearing from loosening during repeated rotation. There are many links and low reliability; 3) Both the brake installation and the encoder installation require additional installation shafts to be connected to the transmission structure. There are many intermediate transfer processes, complex processes, high processing accuracy requirements, high installation difficulty, and poor reliability; 4) There is no mechanical limit at the maximum and minimum strokes. When running to the maximum and minimum strokes, the lead screw will continue to perform axial linear motion, causing friction with the front cover or transmission pair. Relying solely on the encoder is not enough to ensure reliability. Usually, there are two ways: a. Add a buffer pad. This method is prone to damage in the long run and has poor reliability; b. Add an external or built-in sensor rod to achieve position parameter feedback. This structure will increase the size and weight of the integrated servo electric cylinder, increase the cost, and the process is complex, the processing accuracy requirements are high, and the installation is difficult. Summary of the invention

[0003] The purpose of the present invention is to provide a drive-electric integrated electric cylinder with radial self-locking, which can effectively solve the problems in the background technology.

[0004] The technical solution to achieve the above-mentioned purpose is: an integrated drive-electric electric cylinder with radial self-locking, including a cylinder body, characterized in that: an inverted ball screw pair is rotatably installed in the cylinder body, the front end of the screw of the inverted ball screw pair extends forward from the cylinder body, a stator winding installed in the cylinder body is arranged outside the inverted ball screw pair, and a circle of magnetic steel is fixedly arranged on the inverted ball screw pair in the stator winding.

[0005] Furthermore, the inverted ball screw pair includes a nut sleeve with an opening at the front end and a screw coaxially inserted into the nut sleeve, a plurality of balls are arranged on the threaded groove between the nut sleeve and the screw, a circulator is arranged in the nut sleeve and the circulator is connected to the threaded groove, and the circulator is used to realize the circulation of each ball in the nut sleeve.

[0006] Furthermore, the screw rod includes an expanding section with a threaded groove and a reducing section connected to the front end center of the expanding section. The expanding section and the nut sleeve are rotated together by balls. The front end side wall and the rear end side wall of the nut sleeve are respectively connected with limiting columns extending radially into the nut sleeve. The limiting column located at the front end of the nut sleeve is gap-fitted with the reducing section of the screw rod. The end outer walls of the expanding section are respectively provided with arc-shaped grooves for forming radial limitations with the limiting columns on the corresponding side, and the arc-shaped grooves are open on the side facing the corresponding limiting column.

[0007] Furthermore, the cylinder body includes a casing with openings at both ends, the front end of the casing is connected to a front end cover, the rear end is connected to a rear end cover, the front end of the screw rod extends forward from the front end cover, a dust ring and a piston rod sealing ring are arranged between the screw rod and the front end cover, and the dust ring is arranged on the front side of the sealing ring.

[0008] Furthermore, the rear end of the nut sleeve is a closed structure, and a fixed shaft is connected to the center position. The rear end cover is provided with a center hole. The rear end of the fixed shaft is rotatably installed in the center hole through a bearing, and a magnetic encoder is connected to the end.

[0009] Furthermore, the outer end of the rear end cover is detachably connected to a driver cover for enclosing the magnetic encoder.

[0010] Furthermore, sealing rings are respectively arranged between the housing and the front end cover, between the housing and the rear end cover, and between the rear end cover and the driver cover.

[0011] Further, the driver cover is provided with a motor driver and a magnetic encoder controller connected to the rear end cover, the motor driver and the magnetic encoder controller are electrically connected;

[0012] The circuit boards of the motor driver and the magnetic encoder controller are integrated as a whole, a socket strip is installed on the driver cover, the magnetic encoder controller is connected to the magnetic encoder, the motor driver is connected to the stator winding, and the motor driver is also connected to the socket strip for external wiring.

[0013] Furthermore, a thermistor connected to the motor driver is installed at the end of the stator winding.

[0014] Furthermore, the front end of the nut sleeve is installed in the cylinder body through a paired angular contact ball bearing, and the paired angular contact ball bearing uses the nut sleeve as an inner ring of the bearing.

[0015] Beneficial effects of the present invention: The magnetic encoder controller of the present invention is integrated with the circuit board of the motor driver into a whole with a high degree of integration and is arranged on the rear side of the electric cylinder. The volume of the whole machine is further reduced, which is conducive to the debugging and maintenance of the motor driver, and has higher maintainability and reliability.

[0016] The paired angular contact ball bearings and the nut sleeve of the present invention adopt an integrated design, which reduces the bearing installation process, eliminates the locking nut, shortens the length of the nut sleeve, further reduces the volume of the whole machine, simplifies the process, and improves the overall reliability.

[0017] The nut sleeve adopts a front and back integrated structure, and the magnetic encoder is directly installed on the nut sleeve. Different magnetic encoders or brakes can be selected according to working conditions. It is only necessary to process the nut sleeve to match the installation dimensions. The number of parts is reduced, the process is streamlined, the processing is simple, and the installation is convenient, which improves the overall reliability and improves the accuracy.

[0018] When the lead screw runs to the maximum stroke or the minimum stroke, the limit column enters the arc-shaped groove of the lead screw. Under the limiting action of the limit column, the lead screw blocks the rotation of the nut sleeve, causing the nut sleeve to stop rotating and generate a large current. The driver module stops the motor after receiving the high current signal, avoiding the friction between the lead screw and the front cover or the nut sleeve. The whole machine is smaller in size, streamlined in process, easy to install and highly reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention;

[0020] Figure 2 It is a structural schematic diagram of an inverted ball screw pair;

[0021] Figure 3 It is a structural diagram of the screw rod. DETAILED DESCRIPTION

[0022] like Figure 1-3 As shown, the present invention discloses an electric cylinder with radial self-locking drive integration, including a cylindrical cylinder body 1, the cylinder body 1 including a casing 2 with openings at both ends, the front end of the casing 2 is connected to a front end cover 3, and the rear end is connected to a rear end cover 4, a coaxially arranged inverted ball screw pair 5 is rotatably installed in the cylinder body 1, the inverted ball screw pair 5 is a commercially available mature product, including a nut sleeve 6 with an opening at the front end and a screw 7 coaxially inserted into the nut sleeve 6, a plurality of balls (not shown in the figure) are arranged on the threaded groove between the nut sleeve 6 and the screw 7, a circulator (not shown in the figure) is arranged in the nut sleeve 6 and the circulator is connected to the threaded groove, and the circulator is used to realize the circulation of each of the balls in the nut sleeve 6.

[0023] The front end of the screw rod 7 of the inverted ball screw pair 5 extends forward from the front end cover 3, and a dust ring 8 and a piston rod sealing ring 9 are arranged between the screw rod 7 and the front end cover 3. The dust ring 8 is arranged on the front side of the piston rod sealing ring 9. A stator winding 10 installed in the cylinder body 1 is arranged outside the nut sleeve 6. A circle of magnetic steel 11 set in a gap with the stator winding 10 is fixed on the nut sleeve 6 in the stator winding 10. In order to ensure a tight installation, a circle of Kevlar fiber film is also wrapped around the outside of the magnetic steel 11 for fixing.

[0024] The screw rod 7 includes an expanding section 12 with a threaded groove and a reducing section 13 connected to the front end center of the expanding section 12. The expanding section 12 and the nut sleeve 6 are rotated in cooperation with each other through balls. The front end side wall and the rear end side wall of the nut sleeve 6 are respectively connected with limiting columns 14 extending radially into the nut sleeve 6. The limiting columns 14 located at the front end of the nut sleeve 6 are clearance-matched with the reducing section 13 of the screw rod. The end outer walls of the expanding section 12 are respectively provided with arcuate notches 15 for forming radial limiting with the limiting columns 14 on the corresponding side, and the arcuate notches 15 are open toward the side of the corresponding limiting columns 14.

[0025] In this embodiment, the front end of the nut sleeve 6 is installed in the cylinder body 1 through a pair of angular contact ball bearings 16. The angular contact ball bearings 16 use the nut sleeve 6 as the inner ring of the bearing. The rear end of the nut sleeve 6 is a closed structure, and a fixed shaft 17 is connected to the center position. The rear end cover 4 is provided with a center hole. The rear end of the fixed shaft 17 is rotatably installed in the center hole through a bearing 18, and a magnetic encoder 19 is connected to the end.

[0026] The outer end of the rear end cover 4 is detachably connected to a driver cover 20 for enclosing the magnetic encoder 19, and sealing rings 21 are respectively provided between the housing 2 and the front end cover 3, between the housing 2 and the rear end cover 4, and between the rear end cover 4 and the driver cover 20.

[0027] The driver cover 20 is provided with a motor driver 23 and a magnetic encoder controller connected to the rear end cover 4. The magnetic encoder controller is electrically connected to the driver module 23, and the circuit boards of the magnetic encoder controller and the driver module 23 are integrated as a whole. The magnetic encoder controller is connected to the magnetic encoder 19, and the motor driver 23 is connected to the stator winding 10. The end of the stator winding 10 is equipped with a thermistor 25 electrically connected to the motor driver 23. A socket strip 24 is installed on the driver cover 20, and the driver module 23 is also connected to the socket strip 24 for external wiring.

[0028] The magnetic encoder controller of the present invention is integrated with the circuit board of the motor driver 23 as a whole, with a high degree of integration, and is arranged at the rear side of the electric cylinder, so that the volume of the whole machine is further reduced, which is conducive to the debugging and maintenance of the driver, and has higher maintainability and reliability;

[0029] The paired angular contact ball bearings 16 and the nut sleeve 6 of the present invention are designed in an integrated manner, which reduces the bearing installation process, eliminates the locking nut, shortens the length of the nut sleeve 6, further reduces the volume of the whole machine, simplifies the process, and improves the overall reliability.

[0030] The nut sleeve 6 adopts a front and rear integrated structure, and the magnetic encoder 19 is directly installed on the nut sleeve 6. Different magnetic encoders or brakes can be selected according to working conditions. It is only necessary to process the nut sleeve 6 to match the installation dimensions. The number of parts is reduced, the process is streamlined, the processing is simple, and the installation is convenient, which improves the overall reliability and improves the accuracy.

[0031] The present invention drives the nut sleeve 6 to rotate through the stator winding 10, and the nut sleeve 6 drives the lead screw 7 to move linearly. When the lead screw 7 runs to the maximum stroke or the minimum stroke, the limit column 14 enters the arc-shaped groove 15 of the lead screw 7. Under the limiting action of the limit column 14, the lead screw 7 forms a barrier to the rotation of the nut sleeve 6, so that the nut sleeve 6 stops rotating and generates a large current. The driver module 23 stops the motor after receiving the large current signal, thereby avoiding the friction between the lead screw 7 and the front cover 3 or the nut sleeve 6. The whole machine is smaller in size, streamlined in process, easy to install, and highly reliable.

Claims

1. An electric cylinder with radial self-locking drive and electricity integration, comprising a cylinder body, characterized in that: An inverted ball screw pair is rotatably installed in the cylinder body, the front end of the screw of the inverted ball screw pair extends forward from the cylinder body, a stator winding installed in the cylinder body is arranged outside the inverted ball screw pair, and a circle of magnetic steel is fixedly arranged on the inverted ball screw pair in the stator winding; The screw rod includes an expanding section with a threaded groove and a reducing section connected to the front end center of the expanding section. The expanding section and the nut sleeve are rotated together by balls. The front end side wall and the rear end side wall of the nut sleeve are respectively connected with limiting columns extending radially into the nut sleeve. The limiting column located at the front end of the nut sleeve is gap-fitted with the reducing section of the screw rod. The end outer walls of the expanding section are respectively provided with arc-shaped grooves for forming radial limitation with the limiting column on the corresponding side, and the arc-shaped grooves are open on the side facing the corresponding limiting column.

2. The drive-electric integrated electric cylinder with radial self-locking according to claim 1, characterized in that: The inverted ball screw pair includes a nut sleeve with an opening at the front end and a screw rod coaxially inserted into the nut sleeve, a plurality of balls are arranged on the thread groove between the nut sleeve and the screw rod, a circulator is arranged in the nut sleeve and the circulator is connected with the thread groove, and the circulator is used to realize the circulation of each ball in the nut sleeve.

3. The drive-electric integrated electric cylinder with radial self-locking according to claim 1, characterized in that: The cylinder body includes a casing with openings at both ends. The front end of the casing is connected to a front cover and the rear end is connected to a rear cover. The front end of the screw rod extends forward from the front cover. A dust ring and a piston rod sealing ring are arranged between the screw rod and the front cover. The dust ring is arranged on the front side of the sealing ring.

4. The drive-electric integrated electric cylinder with radial self-locking according to claim 3, characterized in that: The rear end of the nut sleeve is a closed structure, and a fixed shaft is connected to the center position. The rear end cover is provided with a center hole. The rear end of the fixed shaft is rotatably installed in the center hole through a bearing, and a magnetic encoder is connected to the end.

5. The drive-electric integrated electric cylinder with radial self-locking according to claim 4, characterized in that: The outer end of the rear end cover is detachably connected with a driver cover for enclosing the magnetic encoder.

6. The drive-electric integrated electric cylinder with radial self-locking according to claim 3, characterized in that: Sealing rings are respectively arranged between the casing and the front end cover, between the casing and the rear end cover, and between the rear end cover and the driver cover.

7. The drive-electric integrated electric cylinder with radial self-locking according to claim 5, characterized in that: A motor driver and a magnetic encoder controller connected to the rear end cover are arranged in the driver cover, and the motor driver and the magnetic encoder controller are electrically connected; the circuit boards of the motor driver and the magnetic encoder controller are integrated as a whole, a socket strip is installed on the driver cover, the magnetic encoder controller is connected to the magnetic encoder, the motor driver is connected to the stator winding, and the motor driver is also connected to the socket strip for external wiring.

8. The drive-electric integrated electric cylinder with radial self-locking according to claim 7, characterized in that: The end of the stator winding is provided with a thermistor connected to the motor driver.

9. The drive-electric integrated electric cylinder with radial self-locking according to claim 2, characterized in that: The front end of the nut sleeve is installed in the cylinder body through a paired angular contact ball bearing, and the paired angular contact ball bearing uses the nut sleeve as the inner ring of the bearing.

Images