A linear actuator that is easy to maintain

Abstract

The utility model discloses a linear actuator convenient to maintain relates to actuator technical field, and includes: casing, stator, rotor, planetary screw rod, connecting piece and screw rod nut, be provided with oil injection channel in planetary screw rod, and the one end away from connecting piece of planetary screw rod is provided with oil injection hole, and oil injection hole is linked together with oil injection channel, be provided with oil inlet hole in connecting piece, and the plug is set up at oil inlet hole, the utility model discloses when using, motor stator drive rotor drives planetary screw rod nut rotation to drive planetary screw rod moves back and forth, when needing oil injection lubrication, the plug is taken off from oil inlet hole, and the grease is injected into oil injection channel from oil inlet hole, then overflows to the tail of planetary screw rod from oil injection hole through oil injection channel, then rotates planetary screw rod, makes the grease even adhesion on the ring side of planetary screw rod and the screw thread of screw rod nut inner wall to complete maintenance, and the whole oil injection process is simple and convenient, need not to dismount spare part.

Description

Technical Field

[0001] This utility model relates to the field of actuator technology, specifically to a linear actuator that is easy to maintain. Background Technology

[0002] Linear actuators can be used as one of the drive units for humanoid robots, or as servo pressure cylinders in industry. Because they use planetary screws as the main transmission component, their advantages include high thrust and small size.

[0003] Since planetary screws are generally used in medium- to heavy-duty applications with frequent movement, regular lubrication is crucial. However, lubrication of existing linear actuators using planetary screws is relatively cumbersome, requiring the disassembly of some parts.

[0004] Therefore, a linear actuator that is easy to maintain is needed. Utility Model Content

[0005] To address the problems existing in the prior art, this utility model solves the problem using the following technical structure.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A maintainable linear actuator includes: a housing, a stator, a rotor, a planetary screw, a connector, and a screw nut. The planetary screw passes through the housing, and the stator, rotor, and screw nut are disposed within the housing. The screw nut is sleeved on the annular side of the planetary screw, the rotor is sleeved on the annular side of the screw nut, the stator is sleeved on the annular side of the rotor, and the connector is disposed on the outer side of the housing and connected to one end of the planetary screw.

[0008] The planetary screw is provided with an oil injection channel, and an oil injection hole is provided at the end of the planetary screw away from the connector. The oil injection hole is connected to the oil injection channel, and the oil outlet of the oil injection hole is located on the ring side of the planetary screw.

[0009] The connector is provided with an oil inlet hole, which is connected to the oil injection channel, and a plug is provided at the oil inlet hole.

[0010] The plug is a screw, and the oil inlet hole is threaded. The plug is threadedly connected to the connector.

[0011] The oil injection holes are provided in multiple locations, which are distributed at different positions on the annular side of the planetary screw.

[0012] The multiple oil injection holes are evenly distributed circumferentially on the annular side of the planetary screw.

[0013] The connecting component is a first fisheye bearing.

[0014] An angular contact bearing is provided inside the housing, and one end of the lead screw nut is located inside the angular contact bearing.

[0015] A second fisheye bearing is provided on the side of the housing away from the connector.

[0016] A pressure sensor is provided on the side of the housing away from the connector.

[0017] The housing is equipped with a rotary encoder for detecting the rotational speed of the lead screw and nut.

[0018] The planetary screw is provided with a number of magnets, which are arranged sequentially along the axial direction of the planetary screw. The magnetic poles of two adjacent magnets are opposite. A magnetic encoder is provided on the side of the housing near the connector.

[0019] The above-described structure of this utility model can achieve the following beneficial effects:

[0020] In use, the motor stator drives the rotor to rotate the planetary screw nut, thereby driving the planetary screw to move back and forth. When lubrication is required, remove the plug from the oil inlet and inject grease into the oil injection channel through the oil inlet. The grease then overflows from the oil injection hole to the tail of the planetary screw through the oil injection channel. Then, rotate the planetary screw to make the grease evenly adhere to the ring side of the planetary screw and the threads on the inner wall of the screw nut, thus completing the maintenance. The entire lubrication process is simple and convenient, and does not require disassembly of parts. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this embodiment.

[0022] Figure 2 This is a cross-sectional view of the structure in this embodiment.

[0023] In the diagram: 1. Housing; 11. Angular contact bearing; 12. Second fisheye bearing; 13. Pressure sensor; 2. Stator; 3. Rotor; 4. Planetary screw; 41. Oil filling channel; 42. Oil filling hole; 5. Connector; 51. Oil inlet; 52. Plug; 6. Screw nut; 7. Rotary encoder; 8. Magnet; 9. Magnetic grid encoder. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0025] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this utility model are intended to cover non-exclusive inclusion. For example, a process, method, apparatus, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products or devices.

[0026] The following is in conjunction with the appendix Figures 1-2 This application will be described in further detail.

[0027] refer to Figures 1-2 The linear actuator shown is easy to maintain and includes: a housing 1, a stator 2, a rotor 3, a planetary screw 4, a connecting piece 5, and a screw nut 6. The planetary screw 4 is inserted into the housing 1. The stator 2, rotor 3, and screw nut 6 are disposed inside the housing 1. The screw nut 6 is sleeved on the annular side of the planetary screw 4. The rotor 3 is sleeved on the annular side of the screw nut 6. The stator 2 is sleeved on the annular side of the rotor 3. The connecting piece 5 is disposed on the outer side of the housing 1 and is connected to one end of the planetary screw 4.

[0028] The planetary screw 4 is provided with an oil injection channel 41. An oil injection hole 42 is provided at the end of the planetary screw 4 away from the connector 5. The oil injection hole 42 is connected to the oil injection channel 41. The oil outlet of the oil injection hole 42 is located on the ring side of the planetary screw 4.

[0029] The connector 5 is provided with an oil inlet hole 51, which is connected to the oil injection channel 41, and a plug 52 is provided at the oil inlet hole 51.

[0030] Based on the above structure, during use, the motor stator 2 drives the rotor 3 to rotate the planetary screw nut 6, thereby driving the planetary screw 4 to move back and forth. When oil lubrication is required, the plug 52 is removed from the oil inlet 51, and the grease is injected into the oil injection channel 41 from the oil inlet 51. Then, the grease overflows from the oil injection hole 42 through the oil injection channel 41 to the tail of the planetary screw 4. Then, the planetary screw 4 is rotated to make the grease evenly adhere to the ring side of the planetary screw 4 and the threads on the inner wall of the screw nut 6, thereby completing the maintenance. The entire oiling process is simple and convenient, and there is no need to disassemble parts (except for the plug 52).

[0031] A further optimization is that the plug 52 can be a screw, and the oil inlet hole 51 is threaded. The plug 52 is threadedly connected to the connector 5. In this way, the oil inlet hole 51 can be opened and closed by screwing the plug 52.

[0032] Further optimization involves providing multiple oil injection holes 42 to improve lubrication efficiency. These multiple oil injection holes 42 are distributed at different positions on the annular side of the planetary screw 4. The optimal configuration is that the multiple oil injection holes 42 are evenly distributed circumferentially on the annular side of the planetary screw 4, so that the grease can be evenly overflowed onto the annular side of the planetary screw 4.

[0033] like Figure 1 As shown, the connector 5 can be a first fisheye bearing, and a second fisheye bearing 12 is provided on the side of the housing 1 away from the connector 5. By providing fisheye bearings on both sides of the housing 1, it is convenient to connect with other components.

[0034] like Figure 2 As shown, an angular contact bearing 11 is provided inside the housing 1, and one end of the lead screw nut 6 is located inside the angular contact bearing 11. The lead screw nut 6 is supported and assembled by the angular contact bearing 11, so that the lead screw thread 6 can rotate more stably.

[0035] like Figure 2 As shown, a rotary encoder 7 for detecting the rotational speed of the lead screw nut 6 is installed inside the housing 1. The position of the planetary lead screw 4 is fed back through the rotary encoder 7 at the tail end. A pressure sensor 13 is installed on the side of the housing 1 away from the connecting member 5. By installing the pressure sensor 13 on one side, the thrust of the planetary lead screw 4 can be adjusted in real time through pressure sensing.

[0036] like Figure 2 As shown, several magnets 8 are arranged on the planetary screw 4, and the magnets 8 are arranged sequentially along the axial direction of the planetary screw 4. The magnetic poles of two adjacent magnets 8 are opposite. A magnetic encoder 9 is arranged on the side of the housing 1 near the connecting member 5. The interior of the planetary screw 4 is composed of N-pole and S-pole magnets 8 stacked sequentially. When the planetary screw 4 moves back and forth, the magnetic encoder 9 reads the magnetic poles on the output shaft of the planetary screw 4, and can feed back the real-time position to the driver. The position feedback result of the magnetic encoder 9 can be compared with the position feedback result of the rotary encoder 7 at the tail to detect whether the actual linear displacement is in place and perform closed-loop compensation. The advantage of this design is that it improves the positioning accuracy of the linear actuator (accurately feeding back the linear movement of the planetary screw 4), and the magnetic encoder 9 eliminates part of the backlash of the planetary screw 4 from the control perspective, reducing the problem that the rotor rotational inertia is relatively large due to rapid acceleration and deceleration, thus causing the planetary screw 4 to continue to move.

[0037] The above are merely preferred embodiments of this application, and the present invention is not limited to the above embodiments. It is understood that other improvements and variations that can be directly derived or conceived by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included within the protection scope of the present invention.

Claims

1. A linear actuator that is easy to maintain, characterized in that, include: The assembly comprises a housing (1), a stator (2), a rotor (3), a planetary screw (4), a connector (5), and a screw nut (6). The planetary screw (4) is inserted into the housing (1). The stator (2), rotor (3), and screw nut (6) are disposed within the housing (1). The screw nut (6) is fitted onto the annular side of the planetary screw (4). The rotor (3) is fitted onto the annular side of the screw nut (6). The stator (2) is fitted onto the annular side of the rotor (3). The connector (5) is disposed on the outer side of the housing (1) and is connected to one end of the planetary screw (4). The planetary screw (4) is provided with an oil injection channel (41), and an oil injection hole (42) is provided at the end of the planetary screw (4) away from the connector (5). The oil injection hole (42) is connected to the oil injection channel (41), and the oil outlet of the oil injection hole (42) is located on the ring side of the planetary screw (4). The connector (5) is provided with an oil inlet hole (51), which is connected to the oil injection channel (41), and a plug (52) is provided at the oil inlet hole (51).

2. The easy-to-maintain linear actuator according to claim 1, characterized in that: The plug (52) is a screw, and the oil inlet (51) is threaded. The plug (52) is threadedly connected to the connector (5).

3. The easy-to-maintain linear actuator according to claim 1, characterized in that: Multiple oil injection holes (42) are provided, and the multiple oil injection holes (42) are distributed at different positions on the annular side of the planetary screw (4).

4. The easy-to-maintain linear actuator according to claim 3, characterized in that: Multiple oil injection holes (42) are evenly distributed circumferentially on the annular side of the planetary screw (4).

5. The easy-to-maintain linear actuator according to claim 1, characterized in that: The connector (5) is a first fisheye bearing.

6. The easy-to-maintain linear actuator according to claim 1, characterized in that: An angular contact bearing (11) is provided inside the housing (1), and one end of the lead screw nut (6) is located inside the angular contact bearing (11).

7. The linear actuator for easy maintenance according to claim 1, characterized in that: A second fisheye bearing (12) is provided on the side of the housing (1) away from the connector (5).

8. The linear actuator that is easy to maintain according to claim 1, characterized in that: A pressure sensor (13) is provided on the side of the housing (1) away from the connector (5).

9. The linear actuator for easy maintenance according to claim 1, characterized in that: The housing (1) is equipped with a rotary encoder (7) for detecting the rotational speed of the lead screw nut (6).

10. A linear actuator that is easy to maintain according to claim 9, characterized in that: The planetary screw (4) is provided with a plurality of magnets (8), which are arranged sequentially along the axial direction of the planetary screw (4). The magnetic poles of two adjacent magnets (8) are opposite. A magnetic encoder (9) is provided on the side of the housing (1) near the connector (5).

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