CN204664330U - A kind of electromechanical actuator leading screw supporting structure and comprise its electromechanical actuator - Google Patents

Abstract

The utility model provides a supporting structure of a lead screw of an electromechanical actuator and an electromechanical actuator containing it, including a lead screw, a nut, a support of the lead screw, an actuating rod, two support rings and a sliding bearing. Two angular contact bearings installed back to back at one end of the lead screw are the first support. The support ring is a torus with a cutout of a certain width in the circumferential direction, and another cutout is provided at the cutout in the tangential direction of the circumference. The support ring is installed in the groove in the circumferential direction of the outer diameter of the nut, or in the groove in the circumferential direction of the outer diameter of the actuator fixedly connected with the nut. The width and inner diameter of the support ring match the groove, leaving a gap for thermal expansion. The two support rings have a certain span and are made of composite materials, which are the second supports. The sliding bearing is supported on the other end of the actuating rod, which is the third support. The two support rings support the nuts through the span to reduce friction and withstand radial forces. Three radial supports make the supporting structure of the lead screw high in strength and easy to disassemble, avoiding the vibration of the lead screw and improving the accuracy of the system.

Description

An electromechanical actuator lead screw support structure and an electromechanical actuator including it

technical field

The utility model relates to a supporting structure of a leading screw, in particular to a supporting structure of a leading screw of an electromechanical actuator.

Background technique

The electromechanical servo system and the flexible nozzle constitute the thrust vector control system of the engine. The two electromechanical actuators are installed at 90 degrees. Through the expansion and contraction of the electromechanical actuators, the nozzle can swing on the whole axis to realize the pitch and yaw of the flight. navigation control.

The screw nut part, ball screw or planetary roller screw assembly in the electromechanical actuator, known as the linear displacement conversion device, can convert the rotational motion of the motor into linear reciprocating motion. The electromechanical actuator used in the thrust vector control system of the aero-engine has high power and long stroke. At the same time, it is affected by the radial component force generated by the friction force of the upper and lower lug hinges of the electromechanical actuator. The supporting structure of the screw is very important, which can Avoid the vibration of the screw, reduce the bending moment on the screw, and improve the control accuracy and stability of the system.

In the prior art, the screw support structure in the electromechanical actuator has two structural types: one end of the screw is equipped with two back-to-back angular contact bearings, the actuating rod and the nut are fixedly connected together, and the actuating rod A sliding bearing is installed on one side extending out of the actuator housing, and the sliding bearing is installed on the outer diameter of the actuator rod and in the center hole of the front end cover. This way of supporting at both ends, due to the high power and long stroke of the electromechanical actuator, the transmission accuracy and stability of the lead screw are not very good.

In the prior art, the second type of screw support structure in the electromechanical actuator is to install a support ring in the groove of the outer diameter of the actuator rod on the basis of retaining the first two supports. Please refer to FIG. 4 , which is a schematic structural diagram of a support ring in the prior art. The support ring is a torus, and has a cutout 16 with a certain width in the circumferential direction, and the edges and corners of the support ring are not blunt. When the support ring of this structure expands with friction and heat, the cutout will become smaller and sharper, causing scratches between the support ring and the cylinder housing.

Contents of the invention

Based on the deficiencies in the prior art, the purpose of this utility model is to provide a support structure for electromechanical actuators, which is applied to electromechanical actuators with large load, short-time work and narrow installation space. The screw support structure has high strength, is easy to disassemble, and can withstand a certain radial force, which greatly improves the transmission accuracy and stability of the screw.

The screw support structure of the electromechanical actuator provided by the utility model includes a screw, a nut, and a screw support. The screw support is two back-to-back angular contact bearings installed on one end of the screw, and also includes an actuating Rod, two support rings, sliding bearings, the support ring is a torus with a cutout of a certain width in the circumferential direction, and the cutout also has another cutout in the tangential direction of the circumference. The support ring is installed in the groove in the circumferential direction of the outer diameter of the actuating rod fixedly connected with the nut, and the width and inner diameter of the support ring match the groove, leaving a gap for thermal expansion. There is a certain span between the two supporting rings, and the outer diameter of the supporting ring is larger than that of the actuating rod; the sliding bearing is supported on the other end of the actuating rod. The screw support structure provided by the utility model, on the basis of the prior art, adds two support rings installed in the circumferential groove of the outer diameter of the actuating rod, and the two support rings are separated by a certain span, and the structure is simple , the support strength is high, and the span support also has the characteristics of being able to withstand radial forces. The support ring has a slit of a certain width in the circumferential direction to prevent the support ring from being stuck during thermal expansion; there is another slit in the tangential direction of the circumference of the slit to prevent the slit from becoming smaller and sharper when the support ring expands in the diameter direction , causing scratches with the cylinder. The outer diameter of the support ring is larger than the outer diameter of the actuating rod, so that the outer diameter of the axially moving actuating rod does not directly contact the inner cavity of the actuator housing, and the two supporting rings on the actuating rod and the actuator housing The holes in the body cooperate to realize the simultaneous support of the screw nut assembly and the actuating rod, which enables the screw and the nut to bear the radial load from the upper and lower lugs.

Optionally, the support ring can also be installed in a groove in the circumferential direction on the outer diameter of the nut. The width and inner diameter of the support ring match the groove, leaving a gap for thermal expansion. The outer diameter of the support ring is larger than that of the nut. outside diameter.

In a further technical solution, the two support rings are made of composite material, and the surface is coated with lubricating oil. The wear resistance of the support ring is improved and the friction force is reduced.

In a further technical solution, all edges of the support ring are processed with rounded corners to avoid scratching between the support ring and the cylinder housing.

In a further technical solution, the angular contact bearing is overloaded by 1 to 2 times. Due to the short-time working condition of the electromechanical actuator, the bearing can be overloaded, which reduces the volume of the screw support structure.

In a further technical solution, the screw support structure of the electromechanical actuator also includes a front end cover, and the sliding bearing is installed in the inner hole of the front end cover for axial positioning of the sliding bearing.

In a further technical solution, the screw support structure of the electromechanical actuator also includes the rear end cover, the rear end cover pressure plate, the bearing lock nut, the set screw, and the back-to-back angular contact bearings are installed in the inner hole of the rear end cover , The rear end cover pressure plate fixes the outer ring of the bearing, the bearing lock nut fixes the inner ring of the bearing, and the set screw is tightly fixed at the thread tail of the bearing lock nut, which will not reduce the thread strength of the lock nut.

The electromechanical actuator provided by the utility model has the screw support structure provided by the utility model in its linear displacement conversion device.

Description of drawings

Fig. 1 is the schematic diagram of the front view section structure of the screw support provided by the utility model;

Fig. 2 is a schematic diagram of the top view section structure of the screw support provided by the utility model;

Fig. 3 is the structural representation of the utility model support ring;

Fig. 4 is a structural schematic diagram of a support ring in the prior art.

In the figure, 1-screw, 2-nut, 3-screw support, 4-screw, 5-actuating cylinder housing, 6-actuating rod, 7-support ring, 8-sliding bearing, 9-front end cover , 10-rear end cover, 11-rear end cover pressure plate, 12-bearing lock nut, 13-cone end set screw and flat end set screw, 14-the notch of the utility model support ring in the circumferential direction, 15-this The notch of the utility model support ring in the circumferential tangential direction, 16-the notch of the support ring in the prior art in the circumferential direction.

Detailed ways

The utility model will be described in detail below in conjunction with the accompanying drawings. The description in this part is only exemplary and explanatory, and should not have any limiting effect on the protection scope of the utility model.

Please refer to Fig. 1 and Fig. 2, Fig. 1 is a schematic diagram of the front sectional structure of the screw support provided by the utility model, and Fig. 2 is a schematic diagram of the top sectional structure of the screw support provided by the utility model. The screw support structure of the electromechanical actuator provided by the utility model includes a screw 1, a nut 2, a screw support 3, a screw 4, an actuator housing 5, an actuator rod 6, a support ring 7, a sliding bearing 8, Front end cover 9, rear end cover 10, rear end cover pressing plate 11, bearing lock nut 12, taper end set screw and flat end set screw 13. The nut 2 is set around the lead screw 1, the lead screw support 3 is two angular contact bearings installed back to back, the inner ring of the bearing is installed on the shaft shoulder of the lead screw 1, axially positioned by the bearing lock nut 12, the bearing lock nut 12 It rotates synchronously with the lead screw and is easy to loosen. It is locked by the set screw with conical end and the set screw with flat end (13). This is because when the thread is loaded, the front thread bears most of the load, if the tapered end set screw and the flat end set screw (13) are close to the front portion of the bearing lock nut 12, the thread strength will be reduced. The bearing outer ring fits in the hole of the rear end cover 10, and the bearing outer ring is axially fixed by the rear end cover pressing plate 11, and the rear end cover 10 can independently bear the load, and is designed separately from the cylinder housing 5. The above constitutes the first support of the screw support structure. Due to the small installation space and the characteristics of the short-time work system, the angular contact bearing is overloaded by 1 to 2 times, which reduces the volume of the screw support structure to a certain extent. The two support rings 7 are installed on the parts for axial movement in the linear displacement device, which can be in the groove of the outer diameter of the actuating rod 6 or in the groove of the outer diameter of the nut 2 . In this embodiment, the supporting ring 7 is installed in a groove in the circumferential direction of the outer diameter of the actuating rod 6 . The actuating rod 6 is fixedly connected with the nut 2 through the screw 4 . The two supporting rings 7 have a certain span. The outer diameter of the support ring 7 is greater than the outer diameter of the actuator rod 6, the support ring 7 is in contact with the inner cavity of the actuator housing 5 during movement, and the outer diameter of the actuator rod 6 and the nut 2 is in contact with the actuator housing 5. The inner cavity of 5 does not touch, the stroke of the high-power electromechanical actuator is too long, and is affected by the radial component force generated by the friction force of the upper and lower lug hinges, the two support rings 7 with a certain span are very important to avoid wires The radial force component borne by the rod has an adverse effect on the transmission. The support formed by the two support rings 7 with a certain span and the actuator housing 5 is the second support of the screw support structure, which realizes the simultaneous support of the screw nut assembly and the actuator rod 6 . The sliding bearing 8 is installed on the outer diameter of the actuating rod 6 and in the center hole of the front end cover 9, and the notch of the front end cover 9 is matched with the inner cavity of the actuator housing 5, and seals the opening of the front end of the actuator housing 5. Blocking. The sliding bearing 8 inside the front end cover 9 constitutes the third support of the screw support structure, which is more important when the screw is deformed due to excessive radial force.

When the drive unit drives the lead screw 1 to rotate, the nut 2 moves axially on the lead screw 1, the actuating rod 6 and the nut 2 are fixedly connected by the screw 4, and the actuating rod 6 moves axially on the lead screw 1 synchronously . The outer diameters of the two supporting rings 7 with a certain span are larger than the outer diameter of the actuating rod 6. During the actual movement, the two supporting rings 7 and the inner cavity of the actuator housing form a moving pair, and the actuating rod 6 and the actuating rod The inner cavity of the cylinder shell is not in contact, which reduces the friction area, and the span support also has the characteristics of bearing radial force.

Please refer to FIG. 3 . FIG. 3 is a structural schematic diagram of the supporting ring of the present invention. The support ring 7 is a torus, and has a cutout 14 with a certain width in the circumferential direction, and a cutout 15 in the tangential direction of the circumference at the cutout 14 . The width and inner diameter of the support ring are matched with the groove on the outer diameter of the actuating rod 6 , and an appropriate gap is left to avoid stagnation during frictional thermal expansion. When the support ring expands in the diameter direction, the support ring will become peach-shaped, and the slit 14 will become smaller and sharper. At this time, the slit 15 becomes particularly important. The support ring 7 is made of composite material, which is more wear-resistant and impact-resistant. The outer surface of the support ring 7 is coated with lubricating oil, which reduces friction.

The lead screw support structure of the electromechanical actuator provided by the utility model has three radial supports in total, wherein the support ring 7 with a certain span is arranged on the parts of the linear displacement conversion device for axial movement, and moves synchronously. Provide radial support for the lead screw 1, the structure is simple and ingenious, the support strength is high, the assembly is simple, and it can also withstand a certain radial force. The new structure of the support ring avoids the stagnation caused by the thermal expansion of the original structure. The noise caused by the vibration of the lead screw is avoided, the bending moment borne by the lead screw is reduced, the stability of the lead screw is improved, and the control accuracy of the system is improved.

The above is only a preferred embodiment of the present utility model, it should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, these improvements and modifications It should also be regarded as the protection scope of the present utility model.

Claims (9)

1. an electromechanical actuator leading screw supporting structure, comprise leading screw (1), nut (2), leading screw supports (3), it is two angular contact bearings installed back-to-back that described leading screw supports (3), be installed on one end of leading screw (1), it is characterized in that: also comprise operating bar (6), two support rings (7), sliding bearing (8), described support ring (7) is the cirque body having one fixed width otch (14) at circumferencial direction, and the tangential direction that otch (14) is in circumference also has otch (15); Support ring (7) is installed in the groove of circumferencial direction on operating bar (6) external diameter that is fixedly connected with nut (2), the width of described support ring (7) and internal diameter and groove match, and leave the gap of thermal expansion, have certain span between two support rings (7), the external diameter of described support ring (7) is greater than the external diameter of operating bar (6); Described sliding bearing (8) is bearing in the other end of operating bar (6).

2. electromechanical actuator leading screw supporting structure according to claim 1, it is characterized in that: described support ring (7) can also be installed in the groove of circumferencial direction on nut (2) external diameter, the width of described support ring (7) and internal diameter and groove match, and leaving the gap of thermal expansion, the external diameter of described support ring (7) is greater than the external diameter of nut (2).

3. electromechanical actuator leading screw supporting structure according to claim 1, it is characterized in that: the material of described support ring (7) is different from the material of operating bar (6) or nut (2), for composite material, surface is coated with lubricant oil.

4. electromechanical actuator leading screw supporting structure according to claim 2, it is characterized in that: the material of described support ring (7) is different from the material of operating bar (6) or nut (2), for composite material, surface is coated with lubricant oil.

5. the electromechanical actuator leading screw supporting structure according to any one of Claims 1 to 4, is characterized in that: all seamed edge of described support ring (7) is processed with chamfering.

6. the electromechanical actuator leading screw supporting structure according to any one of Claims 1 to 4, is characterized in that: angular contact bearing overload 1 ~ 2 times of use.

7. electromechanical actuator leading screw supporting structure according to claim 1 and 2, it is characterized in that: also comprise front cover (9), sliding bearing (8) is installed in the endoporus of front cover (9), for the axially locating of sliding bearing (8).

8. electromechanical actuator leading screw supporting structure according to claim 1 and 2, it is characterized in that: also comprise rear end cover (10), rear end cover pressing plate (11), bearing lock nuts (12), Cock screw (13), back-to-back angular contact bearing is arranged in rear end cover (10) endoporus, rear end cover pressing plate (11) rigid bearing outer ring, bearing lock nuts (12) rigid bearing inner ring, Cock screw (13) tightening is in the run-out(of thread) of bearing lock nuts (12).

9. an electromechanical actuator, is characterized in that, straight-line displacement conversion equipment have employed the electromechanical actuator leading screw supporting structure described in any one of claim 1 ~ 8.