Driving and control integrated electric actuating device in industrial manufacturing field

Abstract

The invention relates to a drive and control integrated electric actuating device in the field of industrial manufacturing, a servo driver is integrated in a drive control box, and the drive control box is mounted at the top of a motor shell; the upper computer is connected; the planetary roller lead screw is of a cantilever type structure supported by a single-end supporting bearing, and the supporting bearing is installed at the tail of the rotor supporting frame. The brake and the encoder are mounted at the tail end of the planetary roller screw; the rotor supporting frame is connected with the motor rotor and the planetary roller lead screw, the planetary roller lead screw is connected with the push rod through the nut, and the push rod penetrates through the front end cover and extends to the outside. The space size of the electromechanical actuating device is reduced, the power density of the device is improved, external connecting lines are reduced, the system complexity is reduced, the control precision is finer, the system response speed is higher, and the stability is higher; the system has the comprehensive advantages of good control characteristics, high-precision control, easy maintenance, low total weight, small occupied space, low environmental pollution, low noise and the like.

Description

Technical Field

[0001] The present invention belongs to the fields of industrial manufacturing and electromechanical actuation, and specifically relates to an integrated drive and control electric actuation device, which is suitable for scenarios such as industrial automation production lines and precision manufacturing equipment, and realizes high-precision linear drive functions. Background Art

[0002] Electromechanical actuators are core actuators in the industrial manufacturing field. Their performance directly affects the accuracy, efficiency, and reliability of the equipment. In the existing technology, the development of electromechanical actuators has gone through two stages: split design and mechatronic design:

[0003] 1. Split design:

[0004] Early electromechanical actuators typically adopted a split design with a clear physical boundary between the motor and the lead screw. Although this structure facilitates assembly and maintenance, it has limitations in terms of compactness and efficiency.

[0005] 2. Mechatronics design:

[0006] With the advancement of technology, the mechatronic design has been achieved by directly combining the motor rotor of the electromechanical actuator with the lead screw or nut, which improves the space utilization within the system and enhances the power density of the system. However, the device system still has problems such as too many external connections and insufficient spatial integration to meet the integrated drive requirements in the field of intelligent manufacturing.

[0007] In the existing related technologies, there is an integrated highly integrated electromechanical actuator disclosed in patent document (CN106787412A), which has a structure including a long nut rotor assembly, a servo motor stator, a screw actuator, etc., and is characterized by the integration of a motor and a screw, angular velocity and linear displacement sensors, and a dual-redundancy design. However, there is no integrated drive, and it belongs to electromechanical integration, but the drive and control are separated, there are many external connections, the system complexity is high, and there is no brake, which cannot prevent the push rod from wandering, and the locking measures are insufficient. The high-power density integrated electromechanical servo actuator disclosed in patent document (CN106787414A) integrates a motor and a planetary roller screw, uses linear bearings and encoders, but also does not mention the integration of the drive. In addition, there is no brake, and the protection is insufficient, especially in industrial environments. Therefore, both of the existing technologies do not integrate a drive control module and require an external driver, resulting in multiple system connections, high complexity, and limited response speed; due to the lack of a brake, the planetary roller screw cannot self-lock, and the push rod position is prone to wandering; the locking structure design is simple and easy to loosen under impact and vibration conditions, affecting reliability; the sealing protection design is not optimized for the industrial environment and is difficult to adapt to harsh conditions such as dust and moisture; there is no manual control structure, the push rod cannot be operated after a power outage, and the maintenance convenience is poor. Summary of the Invention

[0008] In response to the problems of high system complexity, slow response speed, poor stability and low control accuracy in existing electromechanical actuators, the present invention proposes an integrated drive and control electric actuator in the field of industrial manufacturing. By embedding the motor drive control module into the mechatronic actuator, an integrated drive and control electromechanical actuator is formed, which promotes the deep integration of the motor driver and the mechatronic actuator, reduces external connections, reduces system complexity, improves system integration and compatibility, achieves finer control accuracy, enhances the system's response speed and stability, and at the same time has the comprehensive advantages of good control characteristics, high-precision control, easy maintainability, low total weight, small footprint, low environmental pollution and low noise.

[0009] To achieve the above-mentioned purpose, the technical solution of the present invention is: an integrated drive and control electric actuator in the field of industrial manufacturing, comprising a drive control box, a servo driver, a front end cover, a motor housing, a push rod, a planetary roller screw, a motor stator and rotor, a rotor support frame, a support bearing, a brake, and an encoder; the servo driver is integrated into the drive control box, and the drive control box is installed on the top of the motor housing; and is connected to the host computer; the planetary roller screw adopts a cantilever structure supported by a single-end support bearing, and the support bearing is installed at the tail of the rotor support frame; the brake and encoder are installed at the tail end of the planetary roller screw; the rotor support frame connects the motor rotor and the planetary roller screw, and the planetary roller screw is connected to the push rod through a nut, and the push rod extends to the outside through the front end cover.

[0010] Furthermore, the support bearing is an angular contact ball bearing.

[0011] Furthermore, a locking nut is provided between the planetary roller screw and the rotor support frame, and a high-strength thread fastening glue is applied to the locking nut during installation; the rotation direction of the screw is opposite to the thread rotation direction of the locking nut.

[0012] Furthermore, the rotor support frame is provided with a toothed structure for manual control after the actuator is powered off; a double-row angular contact ball bearing is installed at the rear of the rotor support frame, and the front end is connected to the deep groove ball bearing of the motor.

[0013] Furthermore, the front end cover is provided with an anti-rotation device, and the connecting surfaces of the motor housing, the front end cover and the drive control box are all provided with a sealing structure.

[0014] Furthermore, the anti-rotation device includes a sliding bearing installed on the side wall of the front end cover and a slender polished rod connected to the front end of the push rod. The slender polished rod cooperates with the sliding bearing to limit the rotational movement of the push rod.

[0015] Furthermore, the sealing structure includes: radial O-ring static seals are used on the fitting surfaces between the motor housing and the front end cover, and between the motor housing and the bearing seat; end face O-ring static seals are used on the fitting surfaces between the bearing seat and the drive control box, and the tail box; an annular seal and a dust seal are provided on the inner side of the front end cover; and radial O-ring static seals are used on the connecting surfaces between the push rod connector and the push rod sleeve.

[0016] Furthermore, the drive control box is also provided with a filter unit and an encoder battery box. The mating surface between the drive control box and the bearing seat is provided with a wire hole. The outer ring of the wire hole is statically sealed with an end face O-ring. The box body and the box cover are statically sealed with an end face O-ring. The electrical connector is a high-protection aviation plug.

[0017] Furthermore, the motion limit of the drive-control integrated electric actuator includes an electrical limit and a mechanical limit, and the mechanical limit includes the electrical limit. The mechanical limit position can be reached only when the electrical limit is exceeded.

[0018] Furthermore, the host computer sends the control signal to the servo driver through the CAN bus, and the power signal is connected to the servo driver through the filtering unit. The servo driver converts the control and power signals into voltage and current signals of the motor, drives the motor to rotate, and drives the planetary roller screw to rotate through the rotor support frame, so that the nut moves along the axial direction of the screw, and then drives the push rod to output linear motion.

[0019] The present invention has the following beneficial effects by realizing the integrated design of the lead screw, motor and driver:

[0020] The space size of the electromechanical actuator is reduced, the power density is improved, the external connections are reduced, the system complexity is reduced, and it has finer control accuracy, faster system response speed and stronger stability.

[0021] 1. Improve control accuracy and stability:

[0022] Due to the high transmission accuracy and long service life of the servo motor and planetary roller screw, the control accuracy and stability of the integrated drive and control electric actuator are significantly improved.

[0023] 2. Reduce maintenance costs:

[0024] Compared with worm gears, planetary roller screws have higher working efficiency and lifespan. After one installation, they can work stably for a long time and do not require regular maintenance, which significantly reduces maintenance costs.

[0025] 3. Safety of lifting device:

[0026] The integrated servo drive includes multiple safety protections that can monitor the working status of the device in real time. Once an abnormal situation is detected, such as overload or overheating, the operation of the device can be stopped immediately to ensure the safety of the device and personnel.

[0027] 4. Improve system integration:

[0028] The integrated servo drive designed for electric actuators reduces external interfaces and system complexity, allowing operators to adjust working conditions and parameters more conveniently and perform real-time control and adjustment of electric actuators, greatly improving system integration, operation and maintenance efficiency, and system response speed, reducing the space size of electromechanical actuators and increasing power density. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a structural diagram of the drive-control integrated electric actuator of the present invention;

[0030] In the figure: 1-drive control box, 2-servo drive, 3-aviation plug, 4-front end cover, 5-push rod connector, 6-motor housing, 7-push rod, 8-planetary roller screw, 9-motor stator and rotor, 10-rotor support frame, 11-support bearing, 12-brake, 13-encoder. DETAILED DESCRIPTION

[0031] The present invention is further described below with reference to the accompanying drawings and examples.

[0032] The present invention adopts a fusion design of a servo motor and an electromechanical actuator. At the same time, in order to ensure the precise position control of the electromechanical actuator, the drive unit of the integrated electromechanical actuator needs to be equipped with a rotary encoder, that is, the position closed loop can be achieved through a small closed loop of the motor rotation position; the mechanical part of the electromechanical actuator does not need to be closed-loop controlled, and the position is guaranteed only by mechanical transmission. The positioning accuracy of the electromechanical actuator consists of two parts: one is the control accuracy of the motor, and the other is the mechanical transmission accuracy of the electromechanical actuator. Under the premise of the machining and assembly accuracy of the mechanical part of the electromechanical actuator, the control accuracy of the motor determines the control accuracy of the entire electromechanical actuator. The encoder is crucial to the motor control accuracy, and each position determined by the mechanical position of the absolute encoder is unique. It does not need to be memorized, does not need to find a reference point, and does not need to be counted all the time. When the position needs to be known, it is read. In this way, the anti-interference characteristics of the encoder and the reliability of the data are greatly improved.

[0033] The planetary roller screw pair is a key core component of the drive and control integrated electromechanical actuator. Its performance determines the load-bearing capacity, transmission efficiency, precision, life and reliability of the mechanical part of the entire electromechanical actuator. Since the planetary roller screw cannot be self-locked, a brake is configured in the integrated electromechanical actuator to prevent the position of the electromechanical actuator push rod from wandering during use. In addition, during the operation of the planetary roller screw pair, on the one hand, the screw must rotate at high speed, and on the other hand, it must withstand axial loads and radial loads. Therefore, the planetary roller screw of the present invention adopts a cantilever structure supported by a single-end bearing. Therefore, an angular contact ball bearing is selected to support the screw so that it can rotate freely, while limiting the axial movement of the screw, thereby ensuring the life of the planetary roller screw pair and the reliability of its operation.

[0034] Furthermore, through analysis of the structural stress of the present invention, it is known that when the push rod is subjected to tension, the locking nut acts as an axial fixation for the lead screw. Once the locking nut thread becomes loose due to impact and vibration (such as repeated starting and stopping, or reversing), causing the locking nut to fall off, the lead screw pair, push rod assembly, etc. will be completely pulled out. Therefore, to prevent the occurrence of such problems, the present invention adopts the following two measures to prevent the locking nut from loosening: first, during installation, the locking nut is loosened and protected with a high-strength thread fastener to ensure the reliability of the connection under impact and vibration conditions; second, the rotation direction of the lead screw and the locking nut thread are opposite. When the two have the same rotation direction and the actuator is subjected to tension, if the actuator stops suddenly, the locking nut tends to loosen. If the rotation direction is opposite, the locking nut tends to tighten.

[0035] The support unit is the supporting structure of the entire actuator, including: rotor bracket, front end cover, bearing seat, junction box and other parts. The main functions of the rotor bracket include: installing the motor rotor and transmitting torque to the screw; providing a mounting interface for the support bearing, with a double-row angular contact ball bearing installed at the tail of the rotor bracket, and the front end connected to the deep groove ball bearing of the motor; a toothed structure is designed on the rotor bracket, which can be used for manual control after the actuator is powered off, ensuring that the actuator push rod can be extended or retracted even after power off.

[0036] The main functions of the front end cover include: providing an installation position for the dustproof seal for the dynamic seal of the actuator front end push rod to ensure the sealing reliability of the equipment; providing positioning and support for the installation of the push rod wear ring and the front buffer pad, the push rod guide sleeve is installed in the front end cover by a threaded connection, and the front buffer pad is connected by screws and positioned on the inner end face of the front end cover; providing an installation interface for the integrated electromechanical actuator, which is connected and fixed through the threaded holes on the side wall of the front end cover.

[0037] The brake mounting plate and encoder mounting plate are used to mount the brake and encoder, respectively. One side of the brake mounting plate is connected to the bearing housing, while the other end secures the brake stator via a flange. The brake rotor is mounted on the lead screw. A fan-shaped slot is provided on one side of the brake mounting plate to facilitate motor threading. A shoulder on the inner hole of the brake mounting plate positions the lip seal of the rotating shaft and prevents grease from the bearing from flowing into the tail housing. The encoder mounting plate is connected to the tail housing via a flange. The encoder stator is mounted on the encoder mounting plate via a connector, and the rotor is connected to the end of the lead screw.

[0038] The tail housing and end cover primarily provide sealing protection for the encoder and brake. The tail housing also provides a mounting location for the encoder mounting plate. They also provide space for encoder and brake wiring. Mounting bolts are installed in the flange holes on the rear of the end cover, pass through the through-holes in the tail housing, and secure to the threaded holes in the bearing housing.

[0039] The guide unit of the present invention comprises a screw guide, a push rod guide, and an anti-rotation structure. The planetary roller screw pair is supported by a cantilevered input end fixation method. One end of the screw extends into the push rod sleeve. Since the screw only rotates, while the push rod assembly moves linearly relative to the screw, that is, the inner circle of the push rod sleeve slides linearly relative to the screw, a guide head is designed to be installed at the end of the screw to reduce friction on the one hand and provide sliding support on the other hand. Since one end of the push rod is connected to the nut by a thread and the other end is suspended in the air, it is necessary to design a support structure to ensure that the screw is not subjected to excessive additional bending moment. On the other hand, since the push rod sleeve is in a linear motion state during operation and has relative motion with the structure, the support structure should have a good wear-reducing effect. The electromechanical actuator guides and supports the push rod assembly through a wear-resistant ring in the front end cover. Therefore, the concentricity of the front end cover wear-resistant ring and the push rod sleeve is crucial to its support and guidance function. At the same time, to ensure that the rotational motion of the screw is converted into the linear motion of the push rod assembly, the rotational motion of the nut and the push rod must be constrained and the linear motion guidance of the push rod must be guaranteed. This functionality is ensured by an externally mounted anti-rotation device. This device is screwed to the sidewall of the front cover. The front end of the push rod is connected to a slender polished rod via a clamp. When the push rod moves back and forth, it drives the polished rod along the sliding bearing, while rotational movement is restricted by the polished rod.

[0040] In order to facilitate the disassembly, maintenance and upkeep of the drive control unit, the drive control unit is integrated into the drive control box, and the drive control box is installed on the top of the actuator, away from the brake, which effectively improves electromagnetic compatibility. The drive control unit mainly consists of a drive control box, a servo driver, a filter unit, an encoder battery box, an aviation plug, etc. Among them, the drive control box is used to provide an installation location and sealing protection for the internal electronic components. There are mounting earrings on the side of the box body to fix the drive control box on the bearing seat. In order to facilitate the threading of the motor, encoder and brake, a wire hole is designed on the side that is close to the bearing seat. In this design scheme, the driver is integrated and installed inside the drive control box, so the driver has the characteristics of small size, high integration, low power consumption, high efficiency, high reliability, quietness and low vibration.

[0041] To prevent the integrated electromechanical actuator from exceeding its range of motion and causing damage to the equipment, it is necessary to specify its position range. This design incorporates two types of limits during the actuator's motion: electrical and mechanical. To conserve overall housing space, the mechanical limit incorporates the electrical limit, meaning the mechanical limit position can only be reached after exceeding the electrical limit.

[0042] In order to ensure that the main motion and guide components of the electromechanical actuator can operate reliably throughout its life, they need to be lubricated. The specific locations that need lubrication are: screw pair, support bearing, copper guide head and push rod sleeve, etc.

[0043] In order to make the electromechanical actuator adapt to various usage scenarios, the sealing protection and anti-corrosion design of the equipment are crucial, and it is necessary to carefully consider the sealing protection and anti-corrosion of the equipment separately.

[0044] a) Sealing protection of the motor housing mainly includes: to prevent leakage of the seals at both ends of the housing, a radial O-ring static sealing structure is used on the fitting plane between the motor housing and the front cover, and between the motor housing and the bearing seat; and efforts are made to avoid designing a wall-breaking structure on the motor housing to avoid affecting the overall protection performance of the motor housing.

[0045] b) Sealing protection of the bearing seat mainly includes: using an end face O-ring static sealing structure on the fitting surface where the bearing seat is connected to the drive control box and the housing, and using a radial O-ring static sealing structure on the fitting surface with the motor housing; installing a sealing screw plug at the manual control hole.

[0046] c) The sealing protection of the box body and the tail end cover mainly includes: using an end face O-ring static sealing structure on the fitting surface where the box body, bearing seat and tail end cover are connected.

[0047] d) Dynamic sealing protection of the front cover. In order to ensure the dynamic sealing protection performance of the equipment here, an annular step seal and dust seal structure are designed on the inside of the front cover.

[0048] e) Push rod seal, mainly including: a radial O-ring static sealing structure is adopted on the cylindrical surface where the push rod connector and the push rod sleeve are connected.

[0049] f) The drive control box seal mainly includes: an end face O-ring static sealing structure is adopted on the outer ring of the wire hole on the surface fitting with the bearing seat, an end face O-ring static sealing structure is adopted between the box body and the box cover, and the electrical connector adopts a highly protective aviation plug.

[0050] All housings are made of 7075 aluminum alloy and hard-anodized. Specific parts include the rear end cover, housing, bearing housing, motor housing, front end cover, drive control box, and drive control box cover. The push rod sleeve and push rod connector are passivated 316L stainless steel. All fasteners are A4L-80 austenitic stainless steel.

[0051] In summary, if Figure 1 As shown, the drive-control integrated electric actuator of the present invention mainly includes a drive control box 1, a servo driver 2 system, an aviation plug 3, a front end cover 4, a push rod connector 5, a motor housing 6, a push rod 7, a planetary roller screw 8, a motor stator and rotor 9, a rotor support frame 10, a support bearing 11, a brake 12, an encoder 13 and other accessories.

[0052] The drive control box 1 is bolted to the top of the motor housing 6. It integrates the servo driver 2, filter unit, and encoder battery box. The motor stator and rotor 9 are mounted within the motor housing 6. A rotor support frame 10 connects the motor rotor to the planetary roller screw 8. The left end of the planetary roller screw 8 is cantilevered by a support bearing 11. The right end is connected to the push rod 7 via a nut. The push rod 7 extends through the front cover 4 to the outside. A brake 12 and encoder 13 are mounted at the rear end of the planetary roller screw 8. The front cover 4 is equipped with an anti-rotation device and a sealing structure.

[0053] The upper computer is electrically connected to the servo driver 2 and sends the control signal to the servo driver 2 through the CAN bus. The power signal is connected to the servo driver 2 through the filter unit. The servo driver 2 converts the control and power signals into voltage and current signals of the motor. The motor rotates according to the instructions, driving the connecting frame of the motor stator and rotor 9 to rotate, and then drives the planetary roller screw 8 to rotate. The rotation of the planetary roller screw 8 causes the nut to move back and forth along the axis of the screw: the push rod 7 fixed to the nut outputs the back and forth movement along the axis to the external load, thereby realizing the linear actuation function.

[0054] In summary, the present invention significantly improves the comprehensive performance of the electromechanical actuator through structural innovation and system optimization, and is suitable for high-precision driving scenarios in the industrial manufacturing field.

Claims

1. An integrated drive and control electric actuator in the field of industrial manufacturing, characterized by: It includes a drive control box, a servo driver, a front end cover, a motor housing, a push rod, a planetary roller screw, a motor stator and rotor, a rotor support frame, a support bearing, a brake, and an encoder; the servo driver is integrated into the drive control box, and the drive control box is installed on the top of the motor housing; and is connected to the host computer; the planetary roller screw adopts a cantilever structure supported by a single-end support bearing, and the support bearing is installed at the tail of the rotor support frame; the brake and encoder are installed at the tail end of the planetary roller screw; the rotor support frame connects the motor rotor and the planetary roller screw, and the planetary roller screw is connected to the push rod through a nut, and the push rod extends to the outside through the front end cover.

2. The drive-control integrated electric actuator for industrial manufacturing according to claim 1, characterized in that: The support bearing adopts an angular contact ball bearing.

3. The drive-control integrated electric actuator for industrial manufacturing according to claim 1, characterized in that: A locking nut is provided between the planetary roller screw and the rotor support frame, and the locking nut is coated with high-strength thread fastening glue when installed; the rotation direction of the screw is opposite to the thread rotation direction of the locking nut.

4. The drive-control integrated electric actuator for industrial manufacturing according to claim 1, characterized in that: The rotor support frame is provided with a toothed structure for manual control after the actuator is powered off; a double-row angular contact ball bearing is installed at the tail of the rotor support frame, and the front end is connected to the deep groove ball bearing of the motor.

5. The drive-control integrated electric actuator for industrial manufacturing according to claim 1, characterized in that: The front end cover is provided with an anti-rotation device, and the connecting surfaces of the motor housing, the front end cover and the drive control box are all provided with a sealing structure.

6. The drive-control integrated electric actuator for industrial manufacturing according to claim 5, characterized in that: The anti-rotation device includes a sliding bearing installed on the side wall of the front end cover and a slender polished rod connected to the front end of the push rod. The slender polished rod cooperates with the sliding bearing to limit the rotational movement of the push rod.

7. The drive-control integrated electric actuator for industrial manufacturing according to claim 5, characterized in that: The sealing structure includes: radial O-ring static seals are used on the fitting surfaces between the motor housing and the front end cover, and between the motor housing and the bearing seat; end face O-ring static seals are used on the fitting surfaces between the bearing seat and the drive control box and the tail box; an annular step seal and a dust seal are provided on the inner side of the front end cover; and radial O-ring static seals are used on the fitting surfaces between the push rod connector and the push rod sleeve.

8. The drive-control integrated electric actuator for industrial manufacturing according to claim 1, characterized in that: The drive control box is also provided with a filter unit and an encoder battery box. The mating surface between the drive control box and the bearing seat is provided with a wire hole. The outer ring of the wire hole is statically sealed with an end face O-ring. The box body and the box cover are statically sealed with an end face O-ring. The electrical connector is a high-protection aviation plug.

9. The drive-control integrated electric actuator for industrial manufacturing according to claim 1, characterized in that: The motion limit of the drive-control integrated electric actuator includes electrical limit and mechanical limit. The mechanical limit includes the electrical limit. The mechanical limit position can be reached only when the electrical limit is exceeded.

10. The drive-control integrated electric actuator in the industrial manufacturing field according to claim 1, characterized in that: The host computer sends the control signal to the servo driver through the CAN bus, and the power signal is connected to the servo driver through the filtering unit. The servo driver converts the control and power signals into voltage and current signals of the motor, drives the motor to rotate, and drives the planetary roller screw to rotate through the rotor support frame, so that the nut moves along the axial direction of the screw, and then drives the push rod to output linear motion.

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