Forward integrated electric cylinder structure

Abstract

The utility model relates to the technical field of electric cylinders, and discloses a forward type integrated electric cylinder structure. According to the forward type integrated electric cylinder structure, a motor assembly comprises a motor shell, a motor stator and a motor rotor which are arranged from outside to inside; the lead screw assembly comprises a lead screw nut sleeve, a lead screw and a nut, a rotor shaft sleeve is arranged on the inner wall of the motor rotor, the rotor shaft sleeve and the motor rotor rotate synchronously, and the lead screw nut sleeve is connected with a piston rod. One end of the screw rod is connected with a rear bearing inner sleeve, and the other end extends into the piston rod inner cavity; the rear bearing inner sleeve is connected with the rotor shaft sleeve; the motor rotor rotates to sequentially drive the rotor shaft sleeve, the rear bearing inner sleeve and the lead screw to rotate, the nut is driven to move back and forth along the lead screw, and then the piston rod is driven to stretch out or retract from the cylinder barrel assembly. The electric cylinder can meet the working condition requirement of a small space, due to the fact that the forward lead screw is adopted, the size of the nut is not changed, the size of the electric cylinder is only related to the stroke, and the electric cylinder is more compact in structure, higher in power density and larger in selectable stroke range.

Description

Technical Field

[0001] The utility model relates to the technical field of electric cylinders, in particular to a forward integrated electric cylinder structure. Background Art

[0002] The electric cylinder is a device that converts electrical energy into mechanical energy. It is a modular product that integrates the functions of a servo motor and a lead screw. It converts the rotational motion of the servo motor into the linear motion of the nut and outputs thrust. As an actuator, the electric cylinder usually converts the rotational motion output by the motor into the linear motion of the lead screw pair through a reducer and a gearbox. The integrated electric cylinder is a modular product that integrates the servo motor and the transmission mechanism. It converts the rotational motion of the servo motor into the linear motion of the actuator and accurately controls the speed and position. It is generally composed of a servo motor, a synchronous conveyor belt, a lead screw and a cylinder body. Compared with traditional electric cylinders, the power density of integrated electric cylinders can be increased by more than 1 times.

[0003] In the prior art, most electric cylinders use reverse integrated electric cylinders, with a structure such as Figure 1 The structure of this reverse integrated electric cylinder is as follows: the motor stator 1' is located outside the motor rotor 2', the screw nut 3' is sleeved outside the screw 4', and the motor rotor 2' drives the screw nut 3' to rotate; the working process of the above structure is: the motor rotor 2' rotates, driving the screw nut 3' to rotate, thereby driving the internal screw 4' to make a linear motion, and the screw 4' is connected to the piston rod, which can drive the piston rod to extend or retract. The motor torque transmission process in the reverse integrated electric cylinder is: motor rotor 1'-screw nut 3'-screw 4'-piston rod. Under this structure, the stroke of the electric cylinder is determined by the length of the screw nut 3', and the structure of the reverse screw determines that the longer the screw nut 3' is, the greater the processing difficulty is, and there is a corresponding size restriction. This also limits the optional stroke range of the electric cylinder and the application scenarios. For the reverse structure, because the stroke of the electric cylinder is related to the screw structure, after the stroke increases, the installation size of the screw will also increase accordingly. The size of the electric cylinder is related to the increased stroke and the size of the screw nut, the size will be larger, and the corresponding power density will decrease. Utility Model Content

[0004] The technical problem to be solved by the utility model is: to overcome the deficiencies in the prior art and provide a forward integrated electric cylinder structure, which can meet the working requirements of a small space. Since a forward-type lead screw is adopted, the size of the lead screw nut sleeve remains unchanged, and the size of the electric cylinder is only related to the stroke. The structure of the electric cylinder is more compact and the power density is higher. At the same time, the stroke of the forward integrated electric cylinder structure is not affected by the lead screw nut sleeve structure, and the optional stroke range is larger.

[0005] The technical solution adopted by the utility model to solve its technical problems is:

[0006] A forward integrated electric cylinder structure, wherein a cylinder bottom, a motor assembly and a cylinder barrel assembly are arranged along the central axis of the electric cylinder, the motor assembly is located between the cylinder bottom and the cylinder barrel assembly, and a screw assembly is built into the motor assembly;

[0007] The motor assembly includes a motor housing, a motor stator and a motor rotor arranged from the outside to the inside; the screw assembly includes a screw nut sleeve, a screw and a nut, the nut sleeve is arranged outside the screw, and the screw nut sleeve is arranged outside the nut; the inner wall of the motor rotor is provided with a rotor sleeve and the rotor sleeve rotates synchronously with the motor rotor, and the screw nut sleeve is connected to a piston rod;

[0008] One end of the screw rod is connected to a rear bearing inner sleeve, and the other end of the screw rod extends into the inner cavity of the piston rod; the rear bearing inner sleeve is connected to the rotor sleeve; the rotation of the motor rotor drives the rotor sleeve, the rear bearing inner sleeve and the screw rod to rotate in turn, driving the nut to move back and forth along the screw rod, thereby driving the piston rod to extend or retract from the cylinder assembly.

[0009] Furthermore, the rotor sleeve is arranged outside the screw nut sleeve and there is a gap between the rotor sleeve and the screw nut sleeve.

[0010] Furthermore, the screw nut sleeve and the piston rod are threadedly connected, the inner wall of the screw nut sleeve is provided with a first step, the inner wall of the piston rod is provided with a second step, the first step and the second step are respectively clamped at both ends of the nut to limit the nut; the piston rod is connected to the piston head.

[0011] Furthermore, the cylinder assembly includes an inner cylinder member, an outer cylinder member and a cylinder end cover, the outer cylinder member is sleeved on the outside of the inner cylinder member, and the cylinder end cover is arranged on one end of the inner cylinder member and the outer cylinder member; the inner cylinder member is connected to the rotor sleeve and the inner cylinder member and the rotor sleeve rotate synchronously; a second deep groove ball bearing is installed on the inner wall of the cylinder end cover, and the second deep groove ball bearing is sleeved on the outside of the inner cylinder member.

[0012] Furthermore, a front bearing assembly is provided between the motor assembly and the cylinder assembly, and the front bearing assembly includes a front bearing seat and an angular contact ball bearing, one end of the front bearing seat is connected to the motor housing, and the other end of the front bearing seat is connected to the outer cylinder member; the front bearing seat is installed on the outside of the angular contact ball bearing, and the angular contact ball bearing is sleeved on the outside of the inner cylinder member.

[0013] Furthermore, a support ring is installed at the end of the screw rod extending into the inner cavity of the piston rod, and the outer wall of the support ring contacts the inner wall of the piston rod to support the screw rod.

[0014] Furthermore, a rear bearing assembly is provided at one end of the motor assembly away from the cylinder assembly, and the rear bearing assembly includes a rear bearing seat and a first deep groove ball bearing, and the rear bearing seat is connected to the motor housing; the rear bearing seat is installed on the outside of the first deep groove ball bearing, and the first deep groove ball bearing sleeve is arranged on the outside of the rear bearing inner sleeve.

[0015] Furthermore, the forward integrated electric cylinder structure also includes a brake assembly for braking the inner sleeve of the rear bearing. The brake assembly includes a brake housing and an electromagnetic brake. The electromagnetic brake is installed on the inner sleeve of the rear bearing, and a brake housing is provided on the outside of the electromagnetic brake.

[0016] Furthermore, the outer wall of the inner sleeve of the rear bearing is provided with a first shaft elastic retaining ring and a second shaft elastic retaining ring, and the first shaft elastic retaining ring and the second shaft elastic retaining ring are respectively clamped on both sides of the electromagnetic brake.

[0017] Furthermore, an encoder assembly is provided on the cylinder bottom, and the encoder assembly includes an encoder and an encoder housing. The encoder housing is provided on the outside of the encoder, and a screw is provided in the center of the encoder. The screw is connected to the inner sleeve of the rear bearing to realize that the encoder and the inner sleeve of the rear bearing are assembled into a whole.

[0018] The beneficial effects of the utility model are as follows: the utility model has a simple structure, a reasonable design, and has the following advantages:

[0019] (1) The motor stator and motor rotor are integrated inside the electric cylinder, with a compact structure and a high degree of integration;

[0020] (2) The motor rotor rotates, driving the lead screw to rotate, so that the inner cylinder barrel, the rotor sleeve, the rear bearing inner sleeve and the lead screw rotate synchronously, driving the nut to rotate, and the nut moves linearly along the lead screw to push the piston rod to extend or retract; the structure of the utility model is adjusted from the reverse type to the forward type, the nut size remains unchanged, the size of the electric cylinder is only related to the stroke, the structure of the electric cylinder is more compact, and the power density is higher;

[0021] (3) The forward structure of the utility model ensures that the stroke of the electric cylinder is not affected by the nut structure, and the optional stroke range is larger, which is suitable for more production conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a schematic diagram of the mechanism of a reverse integrated electric cylinder in the prior art;

[0024] Figure 2 It is a structural schematic diagram of the utility model;

[0025] Figure 3 yes Figure 2 A partial enlarged view of point Ⅰ in the middle.

[0026] In the figure: 1'. A motor stator of the prior art, 2'. A motor rotor of the prior art, 3'. A screw nut of the prior art, 4'. A screw of the prior art;

[0027] 1. Cylinder bottom, 2. Encoder, 3. Encoder housing, 4. Screws, 5. Brake housing, 6. Elastic circlip for the first shaft, 7. Electromagnetic brake, 8. Elastic circlip for the second shaft, 9. Rear bearing seat, 10. First deep groove ball bearing, 11. Rear bearing inner sleeve, 12. Rotor sleeve, 13. Screw nut sleeve, 14. Motor stator, 15. Motor housing, 16. Front bearing seat, 17. Inner cylinder barrel, 18. Angular contact ball bearing, 19. Piston rod, 20. Screw, 21. Support ring, 22. Second deep groove ball bearing, 23. Piston rod head, 24. Motor rotor, 25. Outer cylinder barrel, 26. Cylinder end cover, 27. Nut. DETAILED DESCRIPTION

[0028] It should be noted that the following detailed descriptions are all illustrative and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0029] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form also includes the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this description, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0030] The technical solution of the utility model will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0031] like Figure 2 and Figure 3The structure of a forward integrated electric cylinder shown in the figure has a cylinder bottom 1, a motor assembly and a cylinder barrel assembly arranged along the central axis of the electric cylinder. The motor assembly is located between the cylinder bottom 1 and the cylinder barrel assembly, and a screw assembly is built into the motor assembly; the motor assembly includes a motor housing 15, a motor stator 14 and a motor rotor 24 arranged from the outside to the inside; the screw assembly includes a screw nut sleeve 13, a screw 20 and a nut 27, the nut 27 is sleeved on the outside of the screw 20, the screw nut sleeve 13 is sleeved on the outside of the nut 27; the motor rotor 24 is inside A rotor sleeve 12 is provided on the wall and the rotor sleeve 12 rotates synchronously with the motor rotor 24; the screw nut sleeve 13 is connected to the piston rod 19; one end of the screw 20 is connected to the rear bearing inner sleeve 11, and the other end of the screw 20 extends into the inner cavity of the piston rod 19; the rear bearing inner sleeve 11 is connected to the rotor sleeve 12; the rotation of the motor rotor 24 drives the rotor sleeve 12, the rear bearing inner sleeve 11 and the screw 20 to rotate in turn, and the driving nut 27 moves back and forth along the screw 20, thereby driving the piston rod 19 to extend or retract from the cylinder assembly.

[0032] The rotor sleeve 12 is arranged outside the screw nut sleeve 13 and there is a gap between the rotor sleeve 12 and the screw nut sleeve 13 .

[0033] The screw nut sleeve 13 and the piston rod 19 are threadedly connected, the inner wall of the screw nut sleeve 13 is provided with a first step, the inner wall of the piston rod 19 is provided with a second step, the first step and the second step are respectively clamped at both ends of the nut 27 to limit the nut 27; the piston rod 19 is connected to the piston head 23.

[0034] The cylinder assembly includes an inner cylinder member 17, an outer cylinder member 25 and a cylinder end cover 26. The outer cylinder member 25 is sleeved on the outside of the inner cylinder member 17, and the cylinder end cover 26 is arranged on one side end of the inner cylinder member 17 and the outer cylinder member 25; the inner cylinder member 17 is connected to the rotor sleeve 12 and the inner cylinder member 17 and the rotor sleeve 12 rotate synchronously; a second deep groove ball bearing 22 is installed on the inner wall of the cylinder end cover 26, and the second deep groove ball bearing 22 is sleeved on the outside of the inner cylinder member 17.

[0035] A front bearing assembly is provided between the motor assembly and the cylinder assembly, and the front bearing assembly includes a front bearing seat 16 and an angular contact ball bearing 18. One end of the front bearing seat 16 is connected to the motor housing 15, and the other end of the front bearing seat 16 is connected to the outer cylinder member 25; the front bearing seat 16 is installed on the outside of the angular contact ball bearing 18, and the angular contact ball bearing 18 is sleeved on the outside of the inner cylinder member 17.

[0036] A support ring 21 is installed at the end of the screw rod 20 extending into the inner cavity of the piston rod 19 , and the outer wall of the support ring 21 contacts the inner wall of the piston rod 19 to support the screw rod 20 .

[0037] A rear bearing assembly is provided at one end of the motor assembly away from the cylinder assembly, and the rear bearing assembly includes a rear bearing seat 9 and a first deep groove ball bearing 10. The rear bearing seat 9 is connected to the motor housing 15; the rear bearing seat 9 is installed on the outside of the first deep groove ball bearing 10, and the first deep groove ball bearing 10 is sleeved on the outside of the rear bearing inner sleeve 11.

[0038] This forward integrated electric cylinder structure also includes a brake assembly for braking the rear bearing inner sleeve 11 , the brake assembly includes a brake housing 5 and an electromagnetic brake 7 , the electromagnetic brake 7 is mounted on the rear bearing inner sleeve 11 , and a brake housing 5 is provided on the outer side of the electromagnetic brake 7 .

[0039] The outer wall of the rear bearing inner sleeve 11 is provided with a first shaft circlip 6 and a second shaft circlip 8, which are respectively clamped on both sides of the electromagnetic brake 7. The first shaft circlip 6 prevents the electromagnetic brake 7 from moving, and the second shaft circlip 8 is used to fix the first deep groove ball bearing 10.

[0040] An encoder assembly is provided on the cylinder bottom 1, and the encoder assembly includes an encoder 2 and an encoder housing 3. The encoder housing 3 is provided on the outside of the encoder 2. A screw 4 is provided in the center of the encoder 2. The screw 4 is connected to the rear bearing inner sleeve 11 to realize that the encoder 2 and the rear bearing inner sleeve 11 are assembled into a whole.

[0041] The working process of this forward integrated electric cylinder structure is as follows: the motor stator 14 is fixed by the motor housing 15, and is axially pressed by the front bearing seat 16 and the rear bearing seat 9 to prevent the motor stator 14 from axial movement; the rotor sleeve 12 is connected to the motor rotor 24 after being threadedly locked with the inner cylinder member 17, and the rotor sleeve 12 is simultaneously connected to the rear bearing inner sleeve 11 with screws, and the rear bearing inner sleeve 11 is threadedly locked with the lead screw 20, so that when the motor rotor 24 rotates, the lead screw 20 can be driven to rotate together, thereby driving the nut 27 to move forward and backward, thereby driving the lead screw nut sleeve 13 and the piston rod 19 to move forward and backward, and at this time the piston rod 19 extends or retracts from the cylinder assembly.

[0042] In the brake assembly, the rotor of the electromagnetic brake 7 is directly connected to the shaft of the rear bearing inner sleeve 11. When power is on, the electromagnetic brake 7 is opened, and the rotor of the electromagnetic brake 7 rotates together with the shaft of the bearing inner sleeve 11. After power is off, the friction plate of the electromagnetic brake 7 is sucked, and the friction force of the contact surface prevents the rotor from rotating together with the shaft of the bearing inner sleeve 11. The rear bearing inner sleeve 11 is locked, and the screw rod 20 is also locked at the same time, so that the nut 27 is locked in the original position, the piston rod 19 also stops working, and the electric cylinder structure remains in the corresponding position.

[0043] In the encoder assembly, the encoder 2 is installed on the encoder housing 3, and a small section of the shaft of the rear bearing inner sleeve 11 is extended to connect with the encoder 2. During the rotation of the rear bearing inner sleeve 11, the encoder 2 can be driven to move, and the corresponding position information can be recorded in time and transmitted to the control device.

[0044] This type of forward integrated electric cylinder has a simple structure and reasonable design, and has the following advantages:

[0045] (1) The motor stator 14 and the motor rotor 24 are integrated inside the electric cylinder, with a compact structure and a high degree of integration;

[0046] (2) The motor rotor 24 rotates, driving the lead screw 20 to rotate, so that the inner cylinder member 17, the rotor sleeve 12, the rear bearing inner sleeve 11 and the lead screw 20 rotate synchronously, driving the nut 27 to move linearly along the lead screw 20, pushing the piston rod 19 to extend or retract; the structure of the utility model is adjusted from the reverse type to the forward type, the size of the nut 27 remains unchanged, the size of the electric cylinder is only related to the stroke, the structure of the electric cylinder is more compact, and the power density is higher;

[0047] (3) The electric cylinder structure is a forward structure, so that the electric cylinder stroke is not affected by the structure of the nut 27, the optional stroke range is larger, and it is suitable for more production conditions.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in the field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.

Claims

1. A forward integrated electric cylinder structure, characterized in that: A cylinder bottom (1), a motor assembly and a cylinder barrel assembly are arranged along the central axis of the electric cylinder, the motor assembly is located between the cylinder bottom (1) and the cylinder barrel assembly, and a screw assembly is built into the motor assembly; The motor assembly comprises a motor housing (15), a motor stator (14) and a motor rotor (24) arranged from outside to inside; the screw rod assembly comprises a screw rod nut sleeve (13), a screw rod (20) and a nut (27), the nut (27) is sleeved outside the screw rod (20), and the screw rod nut sleeve (13) is sleeved outside the nut (27); the inner wall of the motor rotor (24) is provided with a rotor sleeve (12), and the rotor sleeve (12) rotates synchronously with the motor rotor (24), and the screw rod nut sleeve (13) is connected to a piston rod (19); One end of the screw rod (20) is connected to the rear bearing inner sleeve (11), and the other end of the screw rod (20) extends into the inner cavity of the piston rod (19); the rear bearing inner sleeve (11) is connected to the rotor shaft sleeve (12); the rotation of the motor rotor (24) drives the rotor shaft sleeve (12), the rear bearing inner sleeve (11) and the screw rod (20) to rotate in turn, and the driving nut (27) moves forward and backward along the screw rod (20), thereby driving the piston rod (19) to extend or retract from the cylinder assembly.

2. The forward integrated electric cylinder structure according to claim 1, characterized in that: The rotor shaft sleeve (12) is arranged outside the screw nut sleeve (13), and a gap exists between the rotor shaft sleeve (12) and the screw nut sleeve (13).

3. The forward integrated electric cylinder structure according to claim 1, characterized in that: The screw nut sleeve (13) and the piston rod (19) are threadedly connected, the inner wall of the screw nut sleeve (13) is provided with a first step, and the inner wall of the piston rod (19) is provided with a second step, and the first step and the second step are respectively clamped at two ends of the nut (27) to limit the position of the nut (27); the piston rod (19) is connected to the piston head (23).

4. The forward integrated electric cylinder structure according to claim 1 is characterized in that: The cylinder assembly comprises an inner cylinder member (17), an outer cylinder member (25) and a cylinder end cover (26); the outer cylinder member (25) is sleeved on the outer side of the inner cylinder member (17); the cylinder end cover (26) is arranged at one end of the inner cylinder member (17) and the outer cylinder member (25); the inner cylinder member (17) is connected to the rotor sleeve (12), and the inner cylinder member (17) and the rotor sleeve (12) rotate synchronously; a second deep groove ball bearing (22) is installed on the inner wall of the cylinder end cover (26), and the second deep groove ball bearing (22) is sleeved on the outer side of the inner cylinder member (17).

5. The forward integrated electric cylinder structure according to claim 4 is characterized in that: A front bearing assembly is provided between the motor assembly and the cylinder assembly, and the front bearing assembly comprises a front bearing seat (16) and an angular contact ball bearing (18). One end of the front bearing seat (16) is connected to the motor housing (15), and the other end of the front bearing seat (16) is connected to the outer cylinder member (25). The front bearing seat (16) is installed on the outside of the angular contact ball bearing (18), and the angular contact ball bearing (18) is sleeved on the outside of the inner cylinder member (17).

6. The forward integrated electric cylinder structure according to claim 1, characterized in that: The end of the screw rod (20) extending into the inner cavity of the piston rod (19) is provided with a support ring (21), and the outer wall of the support ring (21) contacts the inner wall of the piston rod (19) to support the screw rod (20).

7. The forward integrated electric cylinder structure according to claim 1 is characterized in that: A rear bearing assembly is provided at one end of the motor assembly away from the cylinder assembly, the rear bearing assembly comprising a rear bearing seat (9) and a first deep groove ball bearing (10), the rear bearing seat (9) being connected to the motor housing (15); the rear bearing seat (9) is mounted on the outside of the first deep groove ball bearing (10), and the first deep groove ball bearing (10) is sleeved on the outside of the rear bearing inner sleeve (11).

8. The forward integrated electric cylinder structure according to claim 1, characterized in that: It also includes a brake assembly for braking the rear bearing inner sleeve (11), the brake assembly includes a brake housing (5) and an electromagnetic brake (7), the electromagnetic brake (7) is installed on the rear bearing inner sleeve (11), and the brake housing (5) is arranged outside the electromagnetic brake (7).

9. The forward integrated electric cylinder structure according to claim 8, characterized in that: The outer wall of the rear bearing inner sleeve (11) is provided with a first shaft elastic retaining ring (6) and a second shaft elastic retaining ring (8), and the first shaft elastic retaining ring (6) and the second shaft elastic retaining ring (8) are respectively clamped on both sides of the electromagnetic brake (7).

10. The forward integrated electric cylinder structure according to claim 1, characterized in that: An encoder assembly is provided on the cylinder bottom (1), the encoder assembly comprising an encoder (2) and an encoder housing (3), the encoder housing (3) being arranged outside the encoder (2), a screw (4) being provided at the center of the encoder (2), the screw (4) being connected to the rear bearing inner sleeve (11) so that the encoder (2) and the rear bearing inner sleeve (11) are assembled into a whole.

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