Multi-motor redundancy synchronous drive electric cylinder

Abstract

The invention relates to a multi-motor redundant synchronous driving electric cylinder which comprises a transmission box, a ball screw pair assembly, a cylinder barrel assembly and a plurality of motor driving assemblies, a lower supporting lug is fixed to the lower side of the transmission box, and a driven gear and a plurality of driving gears are installed in the transmission box through ball bearings; the multiple driving gears are meshed with the driven gear and evenly distributed in the circumferential direction, the lower end of the ball screw pair assembly is coaxially and fixedly connected with the driven gear, the lower end of the cylinder barrel assembly is fixed to the upper side of the transmission box and matched with the ball screw pair assembly to conduct telescopic motion, and an upper supporting lug is fixed to the upper end of the cylinder barrel assembly. The motor driving assemblies and the driving gears are arranged in a one-to-one correspondence mode, each motor driving assembly comprises a speed reducer fixed to the transmission box and a servo motor fixed to the speed reducer, the output end of each speed reducer is coaxially and fixedly connected with the corresponding driving gear, and the input end of each speed reducer is connected with an output shaft of the corresponding servo motor. The device has the advantages of compact structure, small size, safety, reliability and high practicability.

Description

Technical Field

[0001] The invention relates to an electric cylinder, in particular to an electric cylinder based on redundant synchronous driving of multiple motors. Background Art

[0002] With the rapid development of automation technology, electric cylinders have been widely used as a mechatronics product that can achieve precise control. Compared with hydraulic cylinders, electric cylinders have the following advantages: the rigidity of the cylinder body will not be affected by the compressibility of the transmission medium; no additional auxiliary devices such as hydraulic pipelines and control valves are required. Not only are they compact and pollution-free, but they also have good controllability. Therefore, it has become a trend for electric cylinders to gradually replace hydraulic cylinders within a certain output thrust range. Based on the urgent need for full electrification of ground equipment drive in the aerospace field, heavy-duty electric cylinders have been promoted and applied on launch platforms. However, the heavy-duty electric cylinders currently used in this field usually use a single motor drive mode. Because a single motor needs to have sufficient power, the overall volume is large, which increases the difficulty of layout on the heavy-duty launch platform. In addition, once the motor fails in the single motor drive mode, the electric cylinder cannot achieve telescopic action, affecting work efficiency and safety and reliability. Summary of the invention

[0003] The object of the present invention is to provide a multi-motor redundant synchronous drive electric cylinder, which has the advantages of compact structure, small size, safety, reliability and strong practicality.

[0004] In order to solve the above-mentioned problems existing in the prior art, the present invention provides a multi-motor redundant synchronous drive electric cylinder, including a transmission box, a ball screw subassembly, a cylinder assembly and multiple motor drive assemblies, a lower support ear is fixed on the lower side of the transmission box, a driven gear and multiple driving gears are installed in the transmission box through ball bearings, the multiple driving gears are respectively meshed with the driven gears and are evenly distributed along the circumferential direction, the lower end of the ball screw subassembly is coaxially fixedly connected with the driven gear, the lower end of the cylinder assembly is fixed on the upper side of the transmission box and cooperates with the ball screw subassembly to perform telescopic movements, an upper support ear is fixed on the upper end of the cylinder assembly, the multiple motor drive assemblies are arranged in a one-to-one correspondence with the driving gears, the motor drive assembly includes a reducer fixed on the transmission box and a servo motor fixed on the reducer, the output end of the reducer is coaxially fixedly connected with the driving gear, and the input end of the reducer is connected to the output shaft of the servo motor.

[0005] Furthermore, the present invention provides a multi-motor redundant synchronous drive electric cylinder, wherein the ball screw subassembly includes a primary screw, a secondary screw and a tertiary screw which are sequentially sleeved from the inside to the outside, the lower end of the primary screw is clamped in a through hole set along the axis of the driven gear and a flat key is provided between the two, a push-pull bearing is clamped between the primary screw and the transmission box, a transmission torque rod is provided in a guide hole set along the axis of the primary screw, a guide piece in the tertiary screw is fixed to the upper end of the transmission torque rod, a primary ball is provided between the lower end of the secondary screw and the primary screw, a secondary ball is provided between the lower end of the tertiary screw and the secondary screw, The cylinder assembly is sleeved on the outside of the ball screw sub-assembly, and the cylinder assembly includes a first-stage cylinder, a second-stage cylinder, a third-stage cylinder and a fourth-stage cylinder which are sleeved in sequence from the outside to the inside. The lower end of the first-stage cylinder is fixed on the transmission box, and the lower end of the second-stage cylinder is fixedly connected to the lower end of the second-stage screw through an adapter. A third-stage ball is arranged between the lower end of the fourth-stage cylinder and the third-stage screw, and the upper support ear is fixed to the upper end of the fourth-stage cylinder, wherein an axial guide mechanism is arranged between the transmission torque rod and the first-stage screw, between the guide member and the third-stage screw, between the second-stage cylinder and the first-stage cylinder, between the third-stage cylinder and the second-stage cylinder, and between the fourth-stage cylinder and the third-stage cylinder.

[0006] Furthermore, the present invention provides a multi-motor redundant synchronously driven electric cylinder, wherein the transmission box includes an upper box body and a lower box body, the upper box body and the lower box body are fixedly connected by screws, and the lower support ear is fixed on the lower box body.

[0007] Furthermore, the present invention provides a multi-motor redundant synchronous drive electric cylinder, wherein the reducer is a planetary reducer and the servo motor has two built-in brakes.

[0008] Furthermore, the present invention provides a multi-motor redundant synchronous drive electric cylinder, wherein the reducer is fixed to the upper box body by screws, and the servo motor is fixed to the reducer by screws.

[0009] Furthermore, the present invention provides a multi-motor redundant synchronously driven electric cylinder, wherein the first-stage cylinder barrel is fixed to the upper box body by screws, and the upper support ear is fixed to the upper end of the fourth-stage cylinder barrel by threads.

[0010] Furthermore, the present invention provides a multi-motor redundant synchronously driven electric cylinder, wherein a first sealing ring extruded on the outer wall of the secondary cylinder is clamped on the inner wall of the upper end of the primary cylinder through a first sealing groove.

[0011] Furthermore, the present invention provides a multi-motor redundant synchronous drive electric cylinder, wherein a second sealing ring extruded on the outer wall of the tertiary cylinder is clamped on the inner wall of the upper end of the secondary cylinder through a second sealing groove.

[0012] Furthermore, the present invention provides a multi-motor redundant synchronous drive electric cylinder, wherein a third sealing ring extruded on the outer wall of the fourth-stage cylinder is clamped on the inner wall of the upper end of the third-stage cylinder through a third sealing groove.

[0013] Furthermore, the present invention provides a multi-motor redundant synchronous drive electric cylinder, wherein the driving gear, the reducer and the servo motor are provided with four respectively.

[0014] Compared with the prior art, the multi-motor redundant synchronous drive electric cylinder of the present invention has the following advantages: the present invention sets a transmission box, a ball screw subassembly, a cylinder assembly and multiple motor drive assemblies, fixes a lower support ear on the lower side of the transmission box, and installs a driven gear and multiple driving gears in the transmission box through a ball bearing, wherein the multiple driving gears are respectively meshed with the driven gears and evenly distributed along the circumferential direction, so that the lower end of the ball screw subassembly is coaxially fixedly connected with the driven gear, the lower end of the cylinder assembly is fixed on the upper side of the transmission box and cooperates with the ball screw subassembly to perform telescopic movements, and fixes an upper support ear on the upper end of the cylinder assembly, so that the multiple motor drive assemblies are arranged one by one with the driving gears, so that the motor drive assembly is arranged with a reducer fixed on the transmission box and a servo motor fixed on the reducer, wherein the output end of the reducer is coaxially fixedly connected with the driving gear, and the input end of the reducer is connected to the output shaft of the servo motor. Thus, a multi-motor redundant synchronously driven electric cylinder with compact structure, small size, safety, reliability and strong practicality is formed. In practical applications, multiple servo motors are respectively driven to rotate the corresponding driving gears, so that multiple driving gears jointly drive the driven gears to rotate, and the driven gear drives the ball screw subassembly to rotate to drive the cylinder assembly to telescope. Compared with the existing electric cylinder driven by a single motor, the present invention allows multiple servo motors to jointly drive the electric cylinder, which can greatly reduce the power of a single servo motor on the one hand, and by evenly distributing multiple servo motors along the circumference, effectively reduce the overall size and occupied space; on the other hand, multiple servo motors achieve the purpose of redundant synchronous driving. When a servo motor fails, other servo motors can still drive the electric cylinder to telescope, thereby improving work efficiency and safety and reliability.

[0015] The following is a detailed description of a multi-motor redundant synchronous drive electric cylinder of the present invention in conjunction with the specific implementation modes shown in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a front view structural schematic diagram of a multi-motor redundant synchronous drive electric cylinder of the present invention;

[0017] Figure 2 It is a schematic diagram of a top view of the structure of a multi-motor redundant synchronously driven electric cylinder according to the present invention;

[0018] Figure 3It is a schematic cross-sectional structure diagram of a multi-motor redundant synchronously driven electric cylinder of the present invention;

[0019] Figure 4 for Figure 3 A partial enlarged view of position A in the middle;

[0020] Figure 5 It is a schematic diagram of the matching relationship between the driven gear and multiple driving gears in the present invention. DETAILED DESCRIPTION

[0021] First of all, it should be explained that the directional words such as up, down, left, right, front and back described in the present invention are only described according to the drawings for the convenience of understanding, and are not intended to limit the technical solution and the scope of protection of the present invention.

[0022] like Figures 1 to 5 The specific implementation of a multi-motor redundant synchronous drive electric cylinder of the present invention is shown, comprising a transmission box 1, a ball screw subassembly 2, a cylinder assembly 3 and four motor drive assemblies. A lower support ear 4 is fixed on the lower side of the transmission box 1 for easy installation and connection, and a driven gear 12 and four driving gears 13 are installed in the transmission box 1 through a ball bearing 11, so that the four driving gears 13 are respectively meshed with the driven gear 12 and evenly distributed along the circumference. The lower end of the ball screw subassembly 2 is coaxially fixedly connected to the driven gear 12. The lower end of the cylinder assembly 3 is fixed on the upper side of the transmission box 1 and cooperates with the ball screw subassembly 2 to perform telescopic action, and an upper support ear 5 is fixed on the upper end of the cylinder assembly 3 for easy installation and connection. The four motor drive assemblies are arranged one by one with the driving gear 13, wherein the motor drive assembly includes a reducer 6 fixed on the transmission box 1 and a servo motor 7 fixed on the reducer 6, the output end of the reducer 6 is coaxially fixedly connected to the driving gear 13, and the input end of the reducer 6 is connected to the output shaft of the servo motor 7.

[0023] The above configuration constitutes a multi-motor redundant synchronously driven electric cylinder with compact structure, small size, safety, reliability and strong practicality. In practical applications, multiple servo motors 7 are respectively driven to rotate the corresponding driving gears 13 through the reducer 6, so that the multiple driving gears 13 jointly drive the driven gear 12 to rotate, and the driven gear 12 drives the ball screw subassembly 2 to rotate to drive the cylinder assembly 3 to telescope. Compared with the existing electric cylinder driven by a single motor, the present invention allows multiple servo motors 7 to jointly drive the electric cylinder, on the one hand, it can greatly reduce the power of a single servo motor 7, and by allowing multiple servo motors 7 to be evenly distributed along the circumference, it effectively reduces the overall size and occupied space; on the other hand, multiple servo motors 7 achieve the purpose of redundant synchronous driving. When a servo motor 7 fails, other servo motors 7 can still drive the electric cylinder to telescope, thereby improving work efficiency and safety and reliability. It should be noted that the motor drive assembly (the combination of the reducer 6 and the servo motor 7) and the driving gear 13 are not limited to four, and three or more can also be set, which can also achieve the technical purpose of the present invention. In order to achieve the purpose of redundant synchronous drive, it is assumed during design that one servo motor 7 fails, and the torque, power and other parameters of the remaining servo motor 7 meet the requirements of the electric cylinder load.

[0024] As a specific embodiment, the present invention makes the ball screw subassembly 2 and the cylinder assembly 3 respectively adopt the following structures: the ball screw subassembly 2 includes a primary screw 21, a secondary screw 22 and a tertiary screw 23 which are sequentially sleeved from the inside to the outside, wherein the lower end of the primary screw 21 is clamped in a through hole arranged along the axis of the driven gear 12 and a flat key is provided between the two, a push-pull bearing 8 is clamped between the primary screw 21 and the transmission box 1, a transmission torque rod 24 is provided in a guide hole arranged along the axis of the primary screw 21, a guide member 241 in the tertiary screw 23 is fixed to the upper end of the transmission torque rod 24, and a lower end of the secondary screw 22 is fixed to the guide hole of the secondary screw 22. A primary ball 25 is provided between the end and the primary screw 21, and a secondary ball 26 is provided between the lower end of the tertiary screw 23 and the secondary screw 22; the cylinder assembly 3 is sleeved on the outside of the ball screw sub-assembly 2, and the cylinder assembly 3 includes a primary cylinder 31, a secondary cylinder 32, a tertiary cylinder 33 and a fourth cylinder 34 which are sleeved from the outside to the inside, wherein the lower end of the primary cylinder 31 is fixed to the transmission box 1, the lower end of the secondary cylinder 32 is fixedly connected to the lower end of the secondary screw 22 through an adapter 221, a tertiary ball 27 is provided between the lower end of the fourth cylinder 34 and the tertiary screw 23, and the upper support ear 5 is fixed to the upper end of the fourth cylinder 34. In order to achieve mutual coordination and effective transmission, the present invention provides axial guide mechanisms between the transmission torque rod 24 and the primary screw 21, between the guide member 241 and the tertiary screw 23, between the secondary cylinder 32 and the primary cylinder 31, between the tertiary cylinder 33 and the secondary cylinder 32, and between the fourth cylinder 34 and the third cylinder 33.

[0025] In this arrangement of the ball screw subassembly 2 and cylinder assembly 3, the transmission torque rod 24 and the third-stage screw 23 will rotate with the first-stage screw 21 on the one hand, and move axially on the other hand under the action of the guide mechanism, and cooperate with the second-stage screw 22 and the fourth-stage cylinder 34 to achieve the purpose of three-stage telescopic extension, increase the stroke of the electric cylinder, and improve practicality.

[0026] As a specific embodiment, the present invention provides the transmission box 1 with an upper box body 14 and a lower box body 15 that cooperate with each other, and the upper box body 14 and the lower box body 15 are fixedly connected by screws to improve the convenience of disassembly and assembly. Among them, the lower support ear 4 is fixed on the lower box body 15. As a specific embodiment, the present invention uses a planetary reducer for the reducer 6 to reduce the volume and weight; and the servo motor 7 has two built-in brakes 71 to achieve the purpose of redundant braking. When one of the brakes 71 fails, the other brake 71 can still meet the braking requirements of the electric cylinder, thereby improving safety and reliability. As a specific embodiment, the present invention fixes the reducer 6 to the upper box body 14 by screws, and fixes the servo motor 7 to the reducer 6 by screws to improve the convenience of disassembly and assembly. Similarly, the present invention fixes the first-stage cylinder 31 to the upper box body 14 by screws, and fixes the upper support ear 5 to the upper end of the fourth-stage cylinder 34 by threads to improve the convenience of disassembly and assembly. In practical applications, in order to improve the sealing and safety reliability of the electric cylinder, the present invention clamps a first sealing ring (not shown in the figure) extruded on the outer wall of the secondary cylinder 32 on the upper inner wall of the first cylinder 31 through a first sealing groove; a second sealing ring (not shown in the figure) extruded on the outer wall of the tertiary cylinder 33 is clamped on the upper inner wall of the secondary cylinder 32 through a second sealing groove; and a third sealing ring (not shown in the figure) extruded on the outer wall of the fourth cylinder 34 is clamped on the upper inner wall of the tertiary cylinder 33 through a third sealing groove.

[0027] Practical application shows that the multi-motor redundant synchronous drive electric cylinder provided by the present invention can produce the following beneficial effects: a) it can realize the miniaturization of the overall size of the electric cylinder, which can meet the use requirements of some installation spaces that are limited; b) multiple servo motors are used for mutual redundancy, which improves safety and reliability; c) each servo motor uses two brakes, which realizes the purpose of brake redundancy and improves the reliability of the locking of the electric cylinder.

[0028] The above embodiments are only descriptions of the preferred implementation modes of the present invention, and are not intended to limit the protection scope of the present invention. Without departing from the design concept of the present invention, various modifications made by those skilled in the art based on the technical solution of the present invention should fall within the protection scope determined by the claims of the present invention.

Claims

1. A multi-motor redundant synchronous drive electric cylinder, characterized in that: The invention comprises a transmission box (1), a ball screw subassembly (2), a cylinder assembly (3) and a plurality of motor drive assemblies. A lower lug (4) is fixed on the lower side of the transmission box (1). A driven gear (12) and a plurality of driving gears (13) are installed in the transmission box (1) via a ball bearing (11). The plurality of driving gears (13) are respectively meshed with the driven gear (12) and are evenly distributed along the circumferential direction. The lower end of the ball screw subassembly (2) is coaxially fixedly connected to the driven gear (12). The lower end of the cylinder assembly (3) is fixedly connected to the driven gear (12). The cylinder assembly (3) is fixed on the upper side of the transmission box (1) and cooperates with the ball screw subassembly (2) to perform telescopic action. An upper support ear (5) is fixed on the upper end of the cylinder assembly (3). The plurality of motor drive assemblies are arranged in a one-to-one correspondence with the driving gear (13). The motor drive assembly comprises a reducer (6) fixed on the transmission box (1) and a servo motor (7) fixed on the reducer (6). The output end of the reducer (6) is coaxially fixedly connected to the driving gear (13), and the input end of the reducer (6) is connected to the output shaft of the servo motor (7).

2. The multi-motor redundant synchronous drive electric cylinder according to claim 1, characterized in that: The ball screw subassembly (2) comprises a primary screw (21), a secondary screw (22) and a tertiary screw (23) which are sequentially sleeved from the inside to the outside. The lower end of the primary screw (21) is clamped in a through hole arranged along the axis of the driven gear (12) and a flat key is arranged between the two. A push-pull bearing (8) is clamped between the primary screw (21) and the transmission box (1). A transmission torque rod (24) is arranged in a guide hole arranged along the axis of the primary screw (21). A guide member (241) in the tertiary screw (23) is fixed to the upper end of the transmission torque rod (24). A primary ball (25) is arranged between the lower end of the secondary screw (22) and the primary screw (21). A secondary ball (26) is arranged between the lower end of the tertiary screw (23) and the secondary screw (22). The cylinder assembly (3) is sleeved on the outer side of the ball screw subassembly (2). (3) comprises a primary cylinder (31), a secondary cylinder (32), a tertiary cylinder (33) and a quaternary cylinder (34) which are sequentially sleeved from the outside to the inside, wherein the lower end of the primary cylinder (31) is fixed to the transmission box (1), the lower end of the secondary cylinder (32) is fixedly connected to the lower end of the secondary lead screw (22) via an adapter (221), and a tertiary roller is provided between the lower end of the tertiary lead screw (23). The upper support ear (5) is fixed to the upper end of the fourth-stage cylinder (34), wherein an axial guide mechanism is provided between the transmission torque rod (24) and the first-stage screw (21), between the guide member (241) and the third-stage screw (23), between the second-stage cylinder (32) and the first-stage cylinder (31), between the third-stage cylinder (33) and the second-stage cylinder (32), and between the fourth-stage cylinder (34) and the third-stage cylinder (33).

3. The multi-motor redundant synchronous drive electric cylinder according to claim 2, characterized in that: The transmission box (1) comprises an upper box body (14) and a lower box body (15), wherein the upper box body (14) and the lower box body (15) are fixedly connected by screws, and the lower support ear (4) is fixed on the lower box body (15).

4. The multi-motor redundant synchronous drive electric cylinder according to claim 3 is characterized in that: The reducer (6) is a planetary reducer, and the servo motor (7) has two built-in brakes (71).

5. The multi-motor redundant synchronous drive electric cylinder according to claim 4, characterized in that: The reducer (6) is fixed to the upper box body (14) by means of screws, and the servo motor (7) is fixed to the reducer (6) by means of screws.

6. The multi-motor redundant synchronous drive electric cylinder according to claim 4, characterized in that: The first-stage cylinder (31) is fixed to the upper box body (14) by means of screws, and the upper support ear (5) is fixed to the upper end of the fourth-stage cylinder (34) by means of threads.

7. The multi-motor redundant synchronous drive electric cylinder according to claim 4, characterized in that: A first sealing ring pressed on the outer wall of the secondary cylinder (32) is clamped on the inner wall of the upper end of the primary cylinder (31) through a first sealing groove.

8. The multi-motor redundant synchronous drive electric cylinder according to claim 4, characterized in that: A second sealing ring pressed on the outer wall of the tertiary cylinder (33) is clamped on the inner wall of the upper end of the secondary cylinder (32) through a second sealing groove.

9. The multi-motor redundant synchronous drive electric cylinder according to claim 4, characterized in that: A third sealing ring pressed on the outer wall of the fourth-stage cylinder (34) is clamped on the inner wall of the upper end of the third-stage cylinder (33) through a third sealing groove.

10. The multi-motor redundant synchronous drive electric cylinder according to claim 4, characterized in that: The number of the driving gear (13), the speed reducer (6) and the servo motor (7) is four respectively.

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