An integrated electric cylinder

Abstract

This utility model relates to the field of electric cylinder technology. More specifically, this utility model relates to an integrated electric cylinder, comprising: a cylinder body, in which an encoder assembly, a brake assembly, a reducer, and a motor assembly are sequentially arranged along the axial direction; a rotor shaft, which is hollow inside, passing through and connected to the motor assembly, with its front end rotatably connected to the cylinder body and its rear end connected to the reducer; a piston rod, coaxially disposed within the rotor shaft, with its front end extending out of the cylinder body; and a lead screw, passing through and connecting to the brake assembly and the reducer, with its rear end connected to the encoder assembly and its front end coaxially extending into the piston rod, a lead screw nut mounted on the lead screw, the lead screw nut being slidably connected to the rotor shaft along its axis, and the lead screw nut being connected to the piston rod. This utility model integrates the motor, driver, and reducer, reducing the space occupied by the electric cylinder, miniaturizing the electric cylinder while ensuring performance, and reducing the later maintenance costs of the electric cylinder.

Description

Technical Field

[0001] This utility model relates to the field of electric cylinder technology. More specifically, this utility model relates to an integrated electric cylinder. Background Technology

[0002] Electric cylinders are devices that convert electrical energy into mechanical energy to achieve linear reciprocating motion, enabling precise control of object movement in engineering applications. Compared to traditional hydraulic drives, they offer lower noise levels and more stable operating accuracy. Furthermore, they boast advantages such as rapid response, superior accuracy, and repeatability, simplifying the programming of complex motions and allowing equipment to quickly adapt to different process requirements.

[0003] Currently, commercially available electric cylinders have limited load-bearing capacity and are relatively bulky in engineering applications. In daily production, they suffer from large footprints and high maintenance costs. They also present certain usage barriers in high-speed, high-load, and rapid-response scenarios, and cannot accurately achieve closed-loop position control. Therefore, it is necessary to provide a new electric cylinder structure to solve these technical problems. Utility Model Content

[0004] The purpose of this invention is to address the above-mentioned problems by providing an integrated electric cylinder that combines the motor, driver, and reducer into one unit, thereby reducing the space occupied by the electric cylinder, miniaturizing the electric cylinder while ensuring performance, and reducing the later maintenance costs of the electric cylinder.

[0005] To achieve these objectives and other advantages according to the present invention, an integrated electric cylinder is provided, comprising:

[0006] The cylinder body contains, along the axial direction, an encoder assembly, a brake assembly, a reducer, and a motor assembly.

[0007] The rotor shaft is hollow inside, passes through and is connected to the motor assembly, the front end of the rotor shaft is rotatably connected to the cylinder body, and the rear end is connected to the reducer;

[0008] A piston rod is coaxially disposed inside the rotor shaft, and its front end extends out of the cylinder body;

[0009] A lead screw passes through and connects to the brake assembly and the reducer. The rear end of the lead screw is connected to the encoder assembly, and its front end extends coaxially into the piston rod. A lead screw nut is installed on the lead screw, and the lead screw nut is slidably connected to the rotor shaft along the axis of the rotor shaft. The lead screw nut is connected to the piston rod.

[0010] Furthermore, in the aforementioned integrated electric cylinder, the motor assembly includes:

[0011] Stator windings are disposed within the cylinder body;

[0012] A rotor permanent magnet is disposed within the stator winding, and the rotor shaft passes through and is connected to the rotor permanent magnet.

[0013] Furthermore, in the aforementioned integrated electric cylinder, the cylinder body includes:

[0014] The cylinder has a front end cover at its front end, the piston rod passes through the front end cover and slides and seals with it, the rear end of the cylinder is connected to the front end of the reducer housing, and the reducer and motor assembly are disposed inside the cylinder;

[0015] The transition section has its front end connected to the rear end of the reducer housing, and its rear end is provided with a rear end cover. The encoder assembly and the brake assembly are disposed in the transition section.

[0016] Furthermore, the integrated electric cylinder further includes:

[0017] A rotor transition shaft is coaxially disposed at the front end of the rotor shaft, and the piston rod coaxially passes through the rotor transition shaft and is slidably connected to it.

[0018] The first bearing is used to rotatably connect the rotor transition shaft to the front end cover.

[0019] Furthermore, the integrated electric cylinder further includes:

[0020] A bearing mounting seat is slidably disposed within the piston rod;

[0021] The second bearing is used to rotatably connect the front end of the lead screw to the bearing mounting seat.

[0022] Furthermore, in the aforementioned integrated electric cylinder, the encoder assembly includes:

[0023] An encoder rotor, which is connected to the rear end of the lead screw;

[0024] The encoder stator is connected to the brake assembly via a mounting bracket.

[0025] Furthermore, in the aforementioned integrated electric cylinder, a guide key is provided on the outer side of the piston rod, and a limiting groove parallel to its axial direction is provided on the inner wall of the rotor shaft, with the guide key slidably disposed in the limiting groove.

[0026] Furthermore, in the aforementioned integrated electric cylinder, the brake assembly includes:

[0027] Brake;

[0028] A brake mounting plate is provided, through which the brake is connected to the cylinder body.

[0029] Furthermore, the integrated electric cylinder further includes:

[0030] A servo driver that is electrically connected to the motor assembly.

[0031] Furthermore, in the integrated electric cylinder, the reducer is a harmonic reducer, with its input end connected to the rear end of the rotor shaft and its output end connected to the lead screw.

[0032] The beneficial effects of this utility model are:

[0033] 1. Compared with traditional electric cylinders, the integrated electric cylinder of this utility model, by integrating the reducer and driver onto the electric cylinder, results in a smaller overall size, higher integration, and wider applicability. Because the stator windings on the cylinder are designed independently, and further adjustments to the reducer's reduction ratio allow for better adaptation to the electric cylinder's output, thus enabling the electric cylinder to be used in high-speed, high-load, and fast-response scenarios within a limited size.

[0034] 2. Because the stator winding of this invention adopts a modular design, it can be easily replaced with a dual-winding method in certain applications where redundancy is required for electric cylinders. Compared with the dual-input single-output reducer used in traditional electric cylinders, this invention further reduces the overall size and weight of the electric cylinder under the same working mode.

[0035] 3. By directly mounting the encoder on the lead screw, this utility model can directly detect the absolute position parameters of the lead screw in real time, avoiding the errors caused by gear transmission, motor speed fluctuations and other factors in traditional electric cylinders, and can achieve high-precision closed-loop position control.

[0036] 4. By directly mounting the brake onto the lead screw, this utility model avoids the braking delay caused by the excessively long transmission chain in traditional electric cylinders, enabling faster and safer braking and ensuring the safety of the load and personnel.

[0037] Other advantages, objectives and features of this invention will be partly apparent from the following description, and partly understood by those skilled in the art through study and practice of this invention. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the integrated electric cylinder described in this utility model;

[0039] Figure 2 This is a schematic diagram of the encoder assembly described in this utility model.

[0040] The reference numerals in the attached figures are as follows:

[0041] 1. Rear end cover; 2. Transition section; 3. Encoder; 4. Mounting bracket; 5. Brake; 6. Brake mounting plate; 7. Reducer; 8. Cylinder; 9. Stator winding; 10. Guide key; 11. Rotor permanent magnet; 12. Rotor shaft; 13. Piston rod; 14. Lead screw; 15. Second bearing; 16. Rotor transition shaft; 17. First bearing; 18. Front end cover; 19. Lead screw nut; 20. Servo driver; 21. Bearing holder. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the embodiments of this application, so that those skilled in the art can implement them based on the description.

[0043] Obviously, the described embodiments are only some, not all, of the embodiments in this application. In the description of this utility model, the terms "lateral," "longitudinal," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0044] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0045] First, a brief introduction to the design concept of the embodiments of this application:

[0046] When the servo driver 20 is powered on, its output power supplies the stator winding 9. After power-on, the stator winding 9 drives the permanent magnet rotor to rotate. The permanent magnet is connected to the rotor via an interference fit, which in turn drives the rotor shaft 12 to rotate. The rotor shaft 12 is connected to the input end of the reducer 7, and the output end of the reducer 7 is connected to the lead screw 14. The rotational motion of the rotor shaft 12 is then transmitted to the lead screw 14 via the reducer 7. The piston rod 13 is connected to the lead screw nut 19, and the piston rod 13 is connected to the guide key 10. Due to the transmission from the reducer 7, the rotor shaft 12 and the lead screw 14 rotate at different speeds, resulting in relative rotation between them. The guide key 10 can only move along the length of the rotor shaft 12, thus restricting the rotation of the lead screw nut 19. This allows the lead screw nut 19 to move only along the length of the rotor shaft 12, driving the piston rod 13 to move along the length of the rotor shaft 12, thereby converting the rotational motion of the lead screw 14 into the reciprocating linear motion of the piston rod 13. During the rotation of the lead screw 14, the rotor of the encoder 3, installed at the rear end of the lead screw 14, rotates along with it, thereby achieving real-time monitoring of the position information of the piston rod 13. This avoids errors caused by gear transmission and motor speed fluctuations in traditional electric cylinders, enabling high-precision closed-loop position control. By directly mounting the brake 5 on the lead screw 14, braking delays caused by excessively long transmission chains in traditional electric cylinders are avoided, achieving faster and safer braking and ensuring the safety of the load and personnel. Because the stator winding 9 adopts a modular design, it can be easily replaced with a dual-winding configuration in applications requiring redundancy. Compared to the dual-input single-output reducer used in traditional electric cylinders, this further reduces the overall size and weight of the electric cylinder under the same operating conditions.

[0047] like Figure 1 As shown, an embodiment of this utility model provides an integrated electric cylinder, comprising:

[0048] The cylinder body contains, along the axial direction, an encoder assembly 3, a brake assembly 5, a reducer 7, and a motor assembly.

[0049] The rotor shaft 12 is hollow inside. The rotor shaft 12 passes through and is connected to the motor assembly. The front end of the rotor shaft 12 is rotatably connected to the cylinder body, and its rear end is connected to the reducer 7.

[0050] The piston rod 13 is coaxially disposed inside the rotor shaft 12, and its front end extends out of the cylinder body;

[0051] A lead screw 14 passes through and connects to the brake 5 assembly and the reducer 7. The rear end of the lead screw 14 is connected to the encoder 3 assembly, and its front end extends coaxially into the piston rod 13. A lead screw nut 19 is installed on the lead screw 14. The lead screw nut 19 is slidably connected to the rotor shaft 12 along its axis. The lead screw nut 19 is connected to the piston rod 13.

[0052] In this embodiment, the motor assembly drives the rotor shaft 12 to rotate, and the rotor shaft 12 drives the lead screw 14 to rotate through the reducer 7. However, the rotational speed of the lead screw 14 is less than that of the rotor shaft 12, and the lead screw nut 19 on the lead screw 14 can only slide along the axis of the rotor shaft 12. Therefore, the lead screw nut 19 will move along the length of the lead screw 14 and drive the piston rod 13 to slide, extending into or out of the cylinder, ultimately converting the rotation of the rotor into the linear reciprocating motion of the piston rod 13. Compared with traditional electric cylinders, this embodiment integrates the reducer 7 and the driver into the electric cylinder, making the overall size of the electric cylinder smaller, more integrated, and adaptable to a wider range of scenarios. Since the stator winding 9 on the cylinder adopts an independent design, further adjustment of the reduction ratio of the reducer 7 can better adapt the output of the electric cylinder, thereby realizing the application of the electric cylinder in high-speed, high-load, and fast-response scenarios within a limited size.

[0053] In this embodiment, during the rotation of the lead screw 14, the encoder 3 rotor installed at the rear end of the lead screw 14 rotates along with it, thereby realizing real-time monitoring of the position information of the piston rod 13. By directly mounting the encoder 3 on the lead screw, the absolute position parameters of the lead screw can be directly detected in real time, avoiding the errors caused by gear transmission, motor speed fluctuations, and other factors in traditional electric cylinders, and achieving high-precision closed-loop position control.

[0054] In this embodiment, by directly mounting the brake 5 onto the lead screw, the braking delay caused by the excessively long transmission chain in traditional electric cylinders can be avoided, enabling faster and safer braking and ensuring the safety of the load and personnel.

[0055] Preferably, in another embodiment of the present invention, the motor assembly includes:

[0056] Stator winding 9 is disposed within the cylinder body;

[0057] A rotor permanent magnet 11 is disposed within the stator winding 9, and the rotor shaft 12 passes through and is connected to the rotor permanent magnet 11.

[0058] In this embodiment, the rotor shaft 12 passes through the rotor permanent magnet 11, and the two are connected by an interference fit.

[0059] Preferably, in another embodiment of the present invention, the cylinder body includes:

[0060] The cylinder 8 has a front end cover 18 at its front end. The piston rod 13 passes through the front end cover 18 and slides and seals with it. The rear end of the cylinder 8 is connected to the front end of the housing of the reducer 7. The reducer 7 and the motor assembly are disposed inside the cylinder 8.

[0061] The transition section 2 has its front end connected to the rear end of the housing of the reducer 7, and its rear end is provided with a rear end cover 1. The encoder 3 assembly and the brake 5 assembly are disposed in the transition section 2.

[0062] In this embodiment, such as Figure 1 As shown, cylinder 8 and transition section 2 are respectively located at the front and rear ends of reducer 7 and connected to it. The front end of cylinder 8 is sealed by front end cover 18, and piston rod 13 passes through front end cover 18 and slides to seal with it. The rear end of transition section 2 is sealed by rear end cover 1.

[0063] Preferably, as another embodiment of the present invention, it further includes:

[0064] The rotor transition shaft 16 is coaxially disposed at the front end of the rotor shaft 12, and the piston rod 13 coaxially passes through the rotor transition shaft 16 and is slidably connected to it.

[0065] The first bearing 17 is used to rotatably connect the rotor transition shaft 16 to the front end cover 18.

[0066] In this embodiment, the rotor transition shaft 16 is connected to the inner ring of the first bearing 17, and the outer ring of the first bearing 17 is connected to the front end cover 18, so as to realize the rotational connection between the rotor shaft 12 and the cylinder body. Since the rotor shaft 12 is relatively long, the rotor shaft 12 can be supported by the first bearing 17, so that the rotation of the rotor shaft 12 is more stable.

[0067] Preferably, as another embodiment of the present invention, it further includes:

[0068] The bearing mounting seat 21 is slidably disposed within the piston rod 13;

[0069] The second bearing 15 is used to rotatably connect the front end of the lead screw 14 to the bearing mounting base 21.

[0070] In this embodiment, the front end of the lead screw 14 is connected to the inner ring of the second bearing 15, the outer ring of the second bearing 15 is connected to the bearing fixing seat 21, and the bearing fixing seat 21 is slidably connected to the piston rod 13. This does not affect the rotation of the lead screw 14, and the bearing fixing seat 21 can support the lead screw 14 when it rotates, making the rotation of the lead screw 14 more stable.

[0071] Preferably, as another embodiment of this utility model, such as Figure 2As shown, the encoder 3 component includes:

[0072] The encoder 3 rotor is connected to the rear end of the lead screw 14;

[0073] The encoder 3 stator is connected to the brake 5 assembly via a mounting bracket 4.

[0074] Preferably, in another embodiment of the present invention, a guide key 10 is provided on the outer side of the piston rod 13, and a limiting groove parallel to its axial direction is provided on the inner wall of the rotor shaft 12, and the guide key 10 is slidably disposed in the limiting groove.

[0075] In this embodiment, the guide key 10 is limited by the limiting groove, so that the guide key 10 can only move in the length direction of the limiting groove, thereby limiting the lead screw nut 19, so that the lead screw nut 19 can only move along the length direction of the limiting groove.

[0076] Preferably, in another embodiment of the present invention, the brake 5 assembly includes:

[0077] Brake 5;

[0078] Brake mounting plate 6, the brake 5 is connected to the cylinder body through the brake mounting plate 6.

[0079] Preferably, as another embodiment of the present invention, it further includes:

[0080] Servo driver 20, which is electrically connected to the motor assembly.

[0081] In this embodiment, the servo driver 20 is a DC servo driver 20 or an AC servo driver 20, which can be installed outside or inside the cylinder 8, such as... Figure 1 As shown, the servo driver 20 is mounted outside the cylinder 8.

[0082] Preferably, in another embodiment of the present invention, the reducer 7 is a harmonic reducer 7, the input end of which is connected to the rear end of the rotor shaft 12, and the output end of which is connected to the lead screw 14.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application do not depart from the spirit and scope of the technical solutions of this application, and should all be covered within the scope of the claims of this application.

Claims

1. An integrated electric cylinder characterized by comprising: include: The cylinder body contains, along the axial direction, an encoder assembly, a brake assembly, a reducer, and a motor assembly. The rotor shaft is hollow inside, passes through and is connected to the motor assembly, the front end of the rotor shaft is rotatably connected to the cylinder body, and the rear end is connected to the reducer; A piston rod is coaxially disposed inside the rotor shaft, and its front end extends out of the cylinder body; A lead screw passes through and connects to the brake assembly and the reducer. The rear end of the lead screw is connected to the encoder assembly, and its front end extends coaxially into the piston rod. A lead screw nut is installed on the lead screw, and the lead screw nut is slidably connected to the rotor shaft along the axis of the rotor shaft. The lead screw nut is connected to the piston rod.

2. An integrated electric cylinder as claimed in claim 1, characterized in that The motor assembly includes: Stator windings are disposed within the cylinder body; A rotor permanent magnet is disposed within the stator winding, and the rotor shaft passes through and is connected to the rotor permanent magnet.

3. The integrated electric cylinder of claim 1, wherein The cylinder body includes: The cylinder has a front end cover at its front end, the piston rod passes through the front end cover and slides and seals with it, the rear end of the cylinder is connected to the front end of the reducer housing, and the reducer and motor assembly are disposed inside the cylinder; The transition section has its front end connected to the rear end of the reducer housing, and its rear end is provided with a rear end cover. The encoder assembly and the brake assembly are disposed in the transition section.

4. The integrated electric cylinder as described in claim 3, characterized in that, Also includes: A rotor transition shaft is coaxially disposed at the front end of the rotor shaft, and the piston rod coaxially passes through the rotor transition shaft and is slidably connected to it. The first bearing is used to rotatably connect the rotor transition shaft to the front end cover.

5. The integrated electric cylinder as described in claim 3, characterized in that, Also includes: A bearing mounting seat is slidably disposed within the piston rod; The second bearing is used to rotatably connect the front end of the lead screw to the bearing mounting seat.

6. The integrated electric cylinder as described in claim 3, characterized in that, The encoder component includes: An encoder rotor, which is connected to the rear end of the lead screw; The encoder stator is connected to the brake assembly via a mounting bracket.

7. The integrated electric cylinder as described in claim 1, characterized in that, The piston rod is provided with a guide key on its outer side, and the inner wall of the rotor shaft is provided with a limiting groove parallel to its axial direction. The guide key is slidably disposed in the limiting groove.

8. The integrated electric cylinder as described in claim 1, characterized in that, The brake assembly includes: Brake; A brake mounting plate is provided, through which the brake is connected to the cylinder body.

9. The integrated electric cylinder as described in claim 1, characterized in that, Also includes: A servo driver that is electrically connected to the motor assembly.

10. The integrated electric cylinder as described in claim 1, characterized in that, The reducer is a harmonic reducer, with its input end connected to the rear end of the rotor shaft and its output end connected to the lead screw.

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