CN220210159U

CN220210159U - Variable electromechanical servo actuator of helical pitch

Info

Publication number: CN220210159U
Application number: CN202321738837.7U
Authority: CN
Inventors: 乔冠; 刘付乐; 卢哲龙; 高阳; 罗宇; 陈佳琪; 张智杰
Original assignee: Inner Mongolia University of Technology
Current assignee: Inner Mongolia University of Technology
Priority date: 2023-07-05
Filing date: 2023-07-05
Publication date: 2023-12-19
Anticipated expiration: 2033-07-05

Abstract

The utility model belongs to the technical field of electromechanical actuators, in particular to an electromechanical servo actuator with a variable lead, wherein the outer surface of a shaft body of a screw rod is provided with meshing external threads, a telescopic component comprises a roller retainer, rollers, a piezoelectric actuator, a guide nut, a front guide rod, a mounting head and a control unit, the rollers are mounted on the roller retainer, meshing external threads are arranged at the middle part of the rollers, the rollers can rotate on the roller retainer, the pitches of the meshing external threads of all the rollers are identical to those of the meshing external threads of the shaft body of the screw rod, the roller retainer grooves in the same radial plane are one group, all the parameters of the rollers in the same group of roller retainer grooves are identical, and the other parameters except the pitches of the rollers in different groups of roller retainer grooves are different, and the control unit controls the piezoelectric actuator to drive the roller retainer to move so that the rollers in each group of roller retainer grooves are respectively meshed with the screw rod, so that the problems of single lead and incapability of changing different leads according to actual working conditions in the prior art are solved.

Description

Variable electromechanical servo actuator of helical pitch

Technical Field

The utility model relates to the technical field of electromechanical actuators, in particular to an electromechanical servo actuator with a variable lead.

Background

The electromechanical servo actuator is an electromechanical integrated device, and converts output command signals of a servo controller/driver into mechanical quantities such as speed, displacement, load and the like so as to realize the purposes of speed driving, displacement driving and load driving of a control object, and the conventional electromechanical servo actuator is single in lead, so that the output speed cannot be changed under the condition of unchanged input rotating speed, and the beat is influenced; meanwhile, the existing small-lead electromechanical servo actuator generally has higher positioning precision, but has smaller output speed; the existing large-lead electromechanical servo actuator has low positioning accuracy although the output speed is high. Therefore, how to replace different leads of the electromechanical servo actuator according to actual working conditions so as to meet field requirements is one of the technical difficulties to be overcome.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, an object of the present utility model is to provide an electromechanical servo actuator with a variable lead, which is used for solving the problem that in the prior art, different leads cannot be replaced according to actual working conditions.

To achieve the above and other related objects, the present utility model provides an electromechanical servo actuator with a variable lead, comprising: the telescopic assembly, the cylinder body assembly, the driver and the screw rod;

the inside of the cylinder body assembly is communicated in the axial direction, and one end of the cylinder body assembly is connected with a driver;

the screw rod is rotationally connected in the cylinder body assembly, one end of the screw rod penetrates out of the cylinder body assembly and is in transmission connection with the driver,

the telescopic assembly comprises a guide nut which is arranged along the axial direction of the cylinder assembly and is sequentially far away from the driver, the guide nut is connected in the cylinder assembly in a sliding way along the axial direction of the guide nut, and the guide nut is sleeved on the outer surface of the screw rod; the guide nut is internally provided with a plurality of roller retainer grooves which are sequentially arranged along the axial direction of the guide nut, each roller retainer groove is respectively and radially connected with a roller retainer in a sliding manner, each roller retainer groove is fixedly connected with a piezoelectric actuator, a plurality of rollers are rotatably arranged in each roller retainer groove, the rollers in the same radial plane are arranged in a group, the rollers in the same group of roller retainer grooves are the same, the rollers in different groups of roller retainer grooves are different, the piezoelectric actuators are used for controlling the roller retainers to radially move so as to select the roller in one roller retainer groove to be engaged with a screw rod, and the outer surface of the guide nut is provided with a control unit which is used for controlling the on-off of the piezoelectric actuator.

Preferably, the piezoelectric actuators in the roller retainer grooves are in a plurality of and one-to-one correspondence with the roller retainers.

Preferably, the cylinder body assembly comprises a rear end cover, a shell and a front end cover, wherein the rear end cover and the front end cover are fixedly connected to two ends of the shell respectively, the guide nut is axially and slidably connected in the shell along the screw rod, one end of the front guide rod is fixedly connected with the guide nut, the other end of the front guide rod penetrates out of the front end cover, a convex ring used for being plugged into the shell is integrally arranged on the front end cover, and a buffer pad is fixedly arranged on the radial end face of the convex ring.

Preferably, the outer surface of the guide nut is provided with a semi-cylindrical boss extending along the axial direction of the guide nut, the shell is internally provided with a semi-cylindrical groove, and the semi-cylindrical boss is slidingly connected in the semi-cylindrical groove.

Preferably, the front guide rod is further provided with a front guide rod, the outer diameter of the front guide rod is smaller than that of the guide nut, one end of the front guide rod is fixedly connected with the guide nut, and the other end of the front guide rod penetrates out of the front end cover and is in sliding sealing connection with the front end cover.

Preferably, the outer surface of the guide nut is provided with a groove for embedding the control unit, and the control unit is connected in the groove in a bolt way.

Preferably, the shell is rectangular in shape, a cylindrical through hole is formed in the inner side of the shell, a bearing mounting surface and an end cover mounting surface are arranged on the inner surface of one end, close to the rear end cover, of the shell, the bearing mounting surface is used for mounting a bearing, the bearing inner ring is fixed on the outer surface of the screw rod, and the end cover mounting surface is in threaded connection with the rear end cover.

Preferably, sliding grooves are formed in two side faces of the roller retainer groove of the guide nut, and two ends of the roller retainer slide in the sliding grooves along the radial direction of the guide nut.

Preferably, one end of the front guide rod, which is far away from the guide nut, is fixedly connected with a mounting head.

Preferably, the two ends of the mounting head are provided with external threads, a flange boss is arranged between the two ends, the two ends of the whole outline of the flange boss are semicircular, and the middle of the outline of the flange boss is rectangular.

The utility model has the beneficial effects that:

the utility model relates to the technical field of electromechanical actuators, in particular to an electromechanical servo actuator with a variable lead. Compared with the traditional electromechanical actuator, the utility model has multiple leads, and can switch rollers with different parameters according to actual working conditions, so that the leads of the rollers are changed to generate the effect of high positioning precision or high output speed, and the roller parameters can be automatically designed according to requirements, so that the application range of the electromechanical servo actuator is wider.

Drawings

FIG. 1 is a schematic diagram of the internal composition principle of an electromechanical actuator according to an embodiment of the present utility model;

FIG. 2 is a schematic view of the overall appearance of an electromechanical actuator according to an embodiment of the present utility model;

fig. 3 is a cross-sectional view of a screw provided by an embodiment of the present utility model.

Fig. 4 is a schematic view of the appearance of a guide nut according to an embodiment of the present utility model.

Fig. 5 is a schematic half-sectional view of a guide nut according to an embodiment of the present utility model.

Fig. 6 is an enlarged view at a of fig. 1.

Fig. 7 is a schematic view of the appearance of a roller according to an embodiment of the present utility model.

Description of element reference numerals

1. A motor; 2. a speed reducer; 3. a flexible coupling; 4. a connecting flange; 5. angular contact ball bearings;

6. a screw rod; 61. a shaft head; 62. a stepped shaft portion; 63. a collar portion; 64. a boss; 65. a groove; 66. a shaft body;

67. shaft shoulder

7. Roller cage groove

10. A telescoping assembly; 101. a roller holder; 102. a roller; 103. a piezoelectric actuator; 104. a guide nut; 105. a front guide bar; 106. a mounting head; 107. a control unit; 108. semi-cylindrical boss

20. A cylinder assembly; 200. a housing; 201. a front end cover; 202. a rear end cover; 203. and (3) sealing rings.

Detailed Description

Further advantages and effects of the present utility model will become apparent to those skilled in the art from the disclosure of the present utility model, which is described by the following specific examples.

Please refer to fig. 1 to 7. It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for illustration purposes only and should not be construed as limiting the utility model to the extent that it can be practiced, since modifications, changes in the proportions, or adjustments of the sizes, which are otherwise, used in the practice of the utility model, are included in the spirit and scope of the utility model which is otherwise, without departing from the spirit or scope thereof. Also, the terms such as "upper," "lower," "left," "right," "middle," and "a" and the like recited in the present specification are merely for descriptive purposes and are not intended to limit the scope of the utility model, but are intended to provide relative positional changes or modifications without materially altering the technical context in which the utility model may be practiced.

A variable lead electromechanical servo actuator comprising: the telescopic assembly 10, the cylinder assembly 20, the driver and the screw rod 6; the driver comprises a motor 1, a speed reducer 2, a flexible coupling 3 and a connecting flange 4.

The inside of the cylinder body assembly is communicated in the axial direction, and one end of the cylinder body assembly is connected with a driver. In this embodiment, the cylinder assembly 20 includes inside casing 200, front end housing 201, rear end housing 202 and sealing washer 203 that link up along the axial, the one end and the front end housing 201 fixed connection of casing 200, the other end and rear end housing 202 solid connection, front end housing 201 with all be equipped with the sealed annular groove that is used for installing sealing washer 203 on the inner circle surface of rear end housing 202, sealing washer 203 cup joints on the lead screw 6 that passes cylinder assembly 20, the one end fixedly connected with flange 4 of keeping away from casing 200 of rear end housing 202, flange 4's inside has set firmly flexible coupling 3, motor 1 is connected with speed reducer 2, speed reducer 2 with flange 4 connects, speed reducer 2's output pass through flexible coupling 3 with lead screw 6's one end transmission is connected.

The telescopic assembly 10 is located in the cylinder assembly 20, the telescopic assembly 10 comprises a guide nut 104 and a front guide rod 105 which are arranged along the axial direction of the cylinder assembly 20 and are sequentially far away from the driver, a plurality of groups of roller retainer grooves 7 which are sequentially arranged along the axial direction of the guide nut 104 are formed in the guide nut 104, and each group of roller retainer grooves comprises a plurality of roller retainer grooves 7 which are located on the same radial plane and are uniformly distributed. As shown in fig. 5, an annular groove may be formed on the inner wall surface of the guide nut 104, then one set of roller cage grooves or a plurality of sets of roller cage grooves may be formed on the wall surface of the annular groove, for mounting the rollers 102 with different radial dimensions, when the radial dimensions of the rollers 102 are larger, the rollers 102 do not interfere with the inner wall of the guide nut 104 when radially extending and retracting through the action of the annular groove, and two sets of roller cage grooves are formed in the embodiment, wherein one set of roller cage grooves 7 is directly formed on the inner wall surface of the guide nut 104, and the other set of roller cage grooves 7 is formed on the wall surface of the annular groove. The roller holders 101 are respectively arranged in the roller holder grooves 7, the piezoelectric actuators 103 are arranged in the roller holders 101, the piezoelectric actuators 103 in the roller holder grooves 7 are fixedly connected with the roller holders 101 in a plurality of one-to-one correspondence manner, a plurality of rollers 102 are rotatably arranged in the roller holders 101, the roller holder grooves 7 in the same radial plane are formed into one group, the rollers 102 in the same group of roller holder grooves 7 are identical, the rollers 102 in different groups of roller holder grooves 7 are different, the piezoelectric actuators 103 are used for driving the roller holders 101 to move radially so as to select the roller 102 in one group of roller holder grooves 7 to be meshed with the screw rod 6, the outer surface of the guide nut 104 is provided with a control unit 107, and the control unit 107 is used for controlling the on-off of the piezoelectric actuators 103; as shown in fig. 5, preferably, each roller holder 101 is provided with a small hole for installing a roller 102, two ends of each roller 102 are smooth cylinders, the two cylinders are respectively rotatably installed in the small holes of the roller holder 101, the middle part of each roller 102 is provided with meshing external threads, the rollers 102 can rotate on the roller holder 101, the pitch of the meshing external threads of all the rollers 102 is the same as that of the screw rod 6, the rollers 102 can be meshed with the screw rod 6, the piezoelectric actuator 103 is an element for generating displacement by applying voltage by utilizing the reverse piezoelectric effect (this is the prior art and is not repeated), the roller holder 101 can be driven to move by controlling the on-off of the voltage of the piezoelectric actuator 103 so that each group of rollers 102 can be meshed with the screw rod respectively, the control unit 107 (this is the prior art and is not repeated) controls the piezoelectric actuator 103, and the control unit 107 is fixedly connected to the outer surface of the guide nut 104;

the screw rod 6 sequentially comprises a shaft head 61, a stepped shaft 62, a shaft neck 63, a shaft shoulder 67, a boss 64, a groove 65 and a shaft body 66 from left to right in fig. 3, the shaft head 61 is in transmission connection with the speed reducer 2, the screw rod 6 passes through a rear end cover 202, a shell 200, a guide nut 104 and a front guide rod 105, and one end of the front guide rod 105 far away from the motor 1 passes through the front end cover 201; the outer surface of the shaft body 66 of the screw rod 6 is provided with meshing external threads, and the part of the shaft body 66 with the meshing external threads is positioned in the front guide rod 105 and the guide nut 104 and can be connected with threads of the rollers 102 in a certain group of roller retainer grooves 7; the pitch of the engaging external threads of all the roller 102 surfaces is the same as the pitch of the engaging external threads of the screw 6. In this embodiment, the shaft head 61 is provided with a key slot, the shaft head 61 is fixedly connected with the connecting flexible coupling 3 through the key slot and the key, the shaft neck 63 passes through the rear end cover 202 and is in sealing connection with the sealing ring 203 in the rear end cover 202, the outer ring of the angular ball bearing 5 is fixed on the inner wall of the housing 200 facing the motor 1, and the inner ring of the angular ball bearing 5 is fixed on the outer surface of the shaft neck 63. The radial dimension of the shaft shoulder 67 is larger than that of the shaft neck 63, and the shaft shoulder 67 is used for limiting the rear end cover 202 and the angular contact ball bearing 5 to move along the axial direction;

further, the piezoelectric actuators 103 in the roller holder grooves 7 are plural and in one-to-one correspondence with the roller holders 101. In this embodiment, the piezoelectric actuator 103 can realize independent corresponding adjustment on the roller holder 101, so that the stress of the roller holder 101 is more uniform, the roller 102 on the roller holder 101 operates more stably, and the abrasion between the roller 102 and the screw rod 6 is smaller.

Further, the guide nut 104 is axially slidably connected in the housing 200 along the screw rod 6, one end of the front guide rod 105 is fixedly connected with the guide nut 104, the other end of the front guide rod 105 penetrates out of the front end cover 201, the front end cover 201 is integrally provided with a convex ring for being plugged into the housing 200, and a cushion pad is fixedly arranged on the radial end face of the convex ring. In this embodiment, the cushion pad of the convex ring may be made of polyethylene, and when the guide nut 104 extends axially to reach the radial end surface of the convex ring of the front end cover 201, the cushion pad protects the guide nut 104, so that a large impact is not caused to the front end cover 201, and the service life of the device is prolonged.

Further, the outer surface of the guide nut 104 is provided with a plurality of semi-cylindrical bosses 108, the housing 200 is internally provided with semi-cylindrical grooves with the same specifications as the semi-cylindrical bosses 108 on the outer surface of the guide nut 104, and the plurality of semi-cylindrical bosses 108 of the guide nut 104 are installed in the semi-cylindrical grooves of the housing 200. In this embodiment, the guide nut 104 and the housing 200 form a sliding connection relationship, the guide nut 104 can move left and right in the housing 200 along the axial direction, and meanwhile, the semi-cylindrical boss 108 of the guide nut 104 and the semi-cylindrical groove in the housing 200 form a circumferential limiting relationship, so that the guide nut 104 cannot rotate during the left and right movement, and the semi-cylindrical shape is more convenient to install.

Further, the outer diameter of the front guide rod 105 is smaller than the outer diameter of the guide nut 104, one end of the front guide rod 105 is fixedly connected with the guide nut 104, and the other end of the front guide rod 105 penetrates out of the front end cover 201 and is in sliding sealing connection with the front end cover. In this embodiment, one end of the front guide rod 105 is fixedly connected with the guide nut 104 by a bolt, so that the installation and the disassembly are convenient, the sliding sealing connection between the front guide rod 105 and the front end cover 201 is used for enabling the front guide rod 105 to slide relative to the front end cover 201, and meanwhile, the connection part of the front guide rod 105 and the front end cover 201 is in a sealing state, so that dust is prevented from entering the housing 200 to cause the sliding blockage of the guide nut 104 and the front guide rod 105, and when the guide nut 104 is driven by the roller 102 to axially move, the front guide rod 105 is driven to axially move at the same time as the front end cover.

Further, the outer surface of the guide nut 104 is provided with a groove for embedding the control unit 107, a plurality of threaded holes are distributed on the inner bottom surface of the groove, through holes are formed in the piezoelectric actuator 103, and bolts penetrate through the through holes of the piezoelectric actuator 103 to be fixedly connected with the threaded holes of the groove of the guide nut 104. In this embodiment, the control unit 107 is embedded in the outer surface of the guide nut 104, so that the space occupied by the control unit 107 is saved.

Further, the casing 200 is rectangular in shape, a cylindrical through hole is formed in the inner side of the casing 200, a bearing mounting surface and an end cover mounting surface are arranged on the inner surface of one end of the casing 200, which is close to the rear end cover 202, the bearing mounting surface is used for mounting a bearing, the bearing inner ring is fixed on the outer surface of the screw rod 6, and the end cover mounting surface is in threaded connection with the rear end cover. In this embodiment, the rectangular housing 200 is convenient to transport and place, four threaded mounting holes are uniformly distributed on end surfaces of two ends of the housing 200, a bearing mounting surface and an end cover mounting surface are arranged on an inner surface of one end, connected with the rear end cover 202, of the housing 200, the bearing mounting surface is used for mounting the angular contact ball bearing 5 to form a rolling bearing, the end cover mounting surface is used for mounting the rear end cover 202, the rear end cover 202 axially compresses the angular contact ball bearing 5 and enables the angular contact ball bearing to be fixedly connected with the housing 200 by using bolts, a sliding surface of the guide nut 104 is arranged on an inner side of one end, connected with the front end cover 201, of the housing 200, an annular boss retaining shoulder is arranged between the bearing mounting surface and the sliding surface of the housing 200, one side surface of the annular boss retaining shoulder is in contact with the guide nut 104, the other side surface of the annular boss retaining shoulder is in contact with the thrust bearing, a buffer pad is fixedly connected with one surface, the buffer pad is made of polyethylene, the height of the annular boss retaining shoulder protrudes out of the height of the inner ring after the thrust bearing is mounted, and the inner ring is ensured not to be in contact with the housing 200 during operation.

Further, both side surfaces of the roller cage groove 7 of the guide nut are provided with sliding grooves (not shown in the figure), and both ends of the roller cage slide in the sliding grooves along the radial direction of the guide nut. In this embodiment, the shape of the sliding grooves on both side surfaces of the ball retainer groove of the guide nut may be T-shaped, and both ends of the ball retainer may slide radially in the T-shaped sliding grooves.

Further, as shown in fig. 1-2, a mounting head 106 is fixedly connected to an end of the front guide rod 105 away from the guide nut 104. In this embodiment, the mounting head 106 can be externally connected with a driven device, so that the device has rich expansibility.

Further, external threads are arranged at two ends of the mounting head 106, a flange boss is arranged between the two ends, two ends of the whole outline of the flange boss are semicircular, and the middle of the outline of the flange boss is rectangular. In this embodiment, external threads are provided at two ends of the mounting head 106, one end of the mounting head 106 is in threaded fixed connection with the front guide rod 105, the other end of the mounting head 106 can be in threaded fixed connection with an external device, a flange boss is provided between the two ends, two ends of the whole outline of the flange boss are semicircular, the middle of the whole outline of the flange boss is rectangular, one end, far away from the guide nut 104, of the front guide rod 105 is abutted on the radial end face of the flange boss, so that the mounting depth of the mounting head 106 screwed into the front guide rod 105 is limited, and the rectangular part is convenient for wrench installation.

In this embodiment, the lead calculation formula:

wherein, l-lead, p-pitch, D-lead screw diameter, D-roller diameter, S-lead screw head number, S-roller head number.

Description: in order to ensure that the screw rod and the roller threads are meshed correctly, the screw pitches of the screw rod and the roller threads are required to be the same; the method comprises the steps that positive directions are set when the screw rod and the roller rotate in the right direction, negative signs are required to be added before the number of heads when the screw rod and the roller rotate in the left direction; when the thread lead angle is not provided, the number of the screw and the roller heads is 0.

According to the lead calculation formula, the electromechanical servo actuator with different leads is obtained by adopting a plurality of groups of rollers and different design forms of roller parameters of each group.

Examples:

when the number of screw heads is s=1, the screw pitch is p, and the diameter is d;

the number of roller heads s=1, pitch p, diameter d=d, at which time the lead l=2p, in a certain set of roller cage grooves 7;

the number of roller heads in the other set of roller cage grooves 7 s=1, the pitch is p, the diameter d=2d, at which time the lead l=1.5p;

according to the actual working condition, the piezoelectric actuator 103 can be controlled by the control unit 107 to enable the rollers 102 positioned in the same group of roller retainer grooves 7 to be meshed with the screw rod 6, and at the moment, the number of screw heads is s=1, the screw pitch is p, and the diameter is d; the roller 102 has a roller head number s=1, a pitch p, a diameter d=d, and a lead l=2p; meanwhile, the engagement of the rollers 102 in the other group of roller retainer grooves 7 and the screw rod 6 is disconnected, after the roller 102 is engaged with the screw rod 6, the screw rod 6 rotates under the combined action of the motor 1, the speed reducer 2 and the flexible coupling 3, the roller 102 obtains axial force from the rotation process of the screw rod 6, and at the moment, the telescopic assembly 10 can obtain telescopic movement with high output speed, but the positioning accuracy is lower. When another movement effect is needed, the engagement of the group of rollers 102 with the screw rod 6 is cut off, so that the roller heads S=1, the screw pitch is p, the rollers 102 with the diameter D=2d are engaged with the screw rod 6, and the screw lead l=1.5p; the telescopic assembly 10 can achieve telescopic movement with high positioning precision, but the output speed is low. And in combination with the actual working condition of the site, a certain group of rollers 102 in the roller retainer groove 7 are selected to be meshed with the screw rod 6, so that the lead of the electromechanical servo actuator reaches the purpose of variability.

Working principle:

the roller 102 is arranged on the roller retainer 101, the roller retainer 101 is fixedly arranged in a roller retainer groove 7 of a guide nut 104 through a piezoelectric actuator 103, a front guide rod 105 is embedded into the guide nut 104 from right to left and fixedly connected through countersunk bolts, the guide nut 104 is arranged in a shell 200 from right to left, a thrust bearing is arranged in the shell 200 from left to right, a screw rod 6 is arranged from left to right, a front section cover 201 is sealed and annular groove is put into a sealing ring 203, the front guide rod 105 passes through the front end cover 201 to finish the installation, the screw rod 6 is put into an angular contact ball bearing 5 from left to right, one end of the screw rod 6 passes through a rear end cover 202 after the rear end cover 202 is sealed and annular groove is put into the sealing ring 203, the rear end cover 202 is fixedly connected with the shell 200 to finish axial limiting and fixing of the angular contact ball bearing 5 of the rear end cover 202, the screw rod 6 is connected with a flexible coupling 3 through a key groove, the flexible coupling 3 is fixedly connected with a speed reducer 2, and the speed reducer 2 is fixedly connected with a motor 1. When the motor 1 is started, the speed of the motor 1 is correspondingly decelerated by the speed reducer 2 to obtain larger torque, the torque on the speed reducer 2 is transmitted to the screw rod 6 through the flexible coupling 3, the screw rod 6 rotates, the piezoelectric actuator 103 is enabled to act under the control of the control unit 107, and when the rollers 102 in the same group of ball retainer grooves 7 are meshed with the screw rod 6, at the moment: the number of screw heads is s=1, the screw pitch is p, and the diameter is d; the number of roller heads s=1, the pitch is p, the diameter d=d, and the lead l=2p; when the meshing of the rollers 102 in the other group of roller retainer grooves 7 and the screw rod 6 is disconnected, the telescopic component can extend and retract under the rotation of the screw rod 6, the positioning precision of the telescopic component is high, the output speed is low, when the meshing of the rollers 102 in the other group of roller retainer grooves 7 and the screw rod 6 is disconnected by controlling the piezoelectric actuator 103, the rollers 102 in the other group of roller retainer grooves 7 are meshed with the screw rod 6, the roller heads S=1, the screw pitch is p, the diameter D=2d, the screw lead l=1.5p at the moment, the telescopic component can obtain the transmission effect of low positioning precision and high output speed, and therefore the aim of switching different screw leads according to different working conditions is fulfilled.

The above embodiments are merely illustrative of the principles of the present utility model and its effectiveness, and are not intended to limit the utility model. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the utility model. Accordingly, it is intended that all equivalent modifications and variations of the utility model be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims

1. An electro-mechanical servo actuator having a variable lead, comprising: the telescopic assembly, the cylinder body assembly, the driver and the screw rod;

2. The variable lead electromechanical servo actuator according to claim 1, wherein: the piezoelectric actuators in the roller retainer grooves are in a plurality of one-to-one correspondence with the roller retainers.

3. The variable lead electromechanical servo actuator according to claim 1, wherein: the cylinder body assembly comprises a rear end cover, a shell and a front end cover, wherein the rear end cover and the front end cover are fixedly connected to the two ends of the shell respectively, a guide nut is axially and slidably connected in the shell along a screw rod, one end of a front guide rod is fixedly connected with the guide nut, the other end of the front guide rod penetrates out of the front end cover, a convex ring used for being plugged into the shell is integrally arranged on the front end cover, and a buffer pad is fixedly arranged on the radial end face of the convex ring.

4. The variable lead electromechanical servo actuator according to claim 1, wherein: the guide nut is characterized in that a semi-cylindrical boss extending along the axial direction of the guide nut is arranged on the outer surface of the guide nut, a semi-cylindrical groove is formed in the shell, and the semi-cylindrical boss is slidably connected in the semi-cylindrical groove.

5. A variable lead electromechanical servo actuator according to claim 3, wherein: the front guide rod is smaller than the guide nut in outer diameter, one end of the front guide rod is fixedly connected with the guide nut, and the other end of the front guide rod penetrates out of the front end cover and is in sliding sealing connection with the front end cover.

6. The variable lead electromechanical servo actuator according to claim 1, wherein: the surface of the guide nut is provided with a groove for embedding the control unit, and the control unit is connected in the groove by bolts.

7. A variable lead electromechanical servo actuator according to claim 3, wherein: the shell is rectangular in appearance, the inner side of the shell is provided with a cylindrical through hole, the inner surface of one end of the shell, which is close to the rear end cover, is provided with a bearing mounting surface and an end cover mounting surface, the bearing mounting surface is used for mounting a bearing, a bearing inner ring is fixed on the outer surface of the screw rod, and the end cover mounting surface is in threaded connection with the rear end cover.

8. A variable lead electromechanical servo actuator according to claim 3, wherein: sliding grooves are formed in two side faces of the roller retainer groove of the guide nut, and two ends of the roller retainer radially slide along the guide nut in the sliding grooves.

9. A variable lead electromechanical servo actuator according to claim 3, wherein: one end of the front guide rod, which is far away from the guide nut, is fixedly connected with a mounting head.

10. The variable lead electromechanical servo actuator according to claim 9, wherein: external threads are arranged at two ends of the mounting head, flange bosses are arranged between the two ends, two ends of the whole outline of each flange boss are semicircular, and the middle of each flange boss is rectangular.