CN115493826A - Linear motion actuator service life testing device and testing method - Google Patents

Abstract

The invention belongs to the technical field of actuator performance detection, and particularly relates to a device and a method for testing the service life of a linear motion actuator. The service life testing equipment for the linear motion actuator comprises a first fixed frame, a rotating frame and a bearing device, wherein the first fixed frame is fixedly installed, the rotating frame is rotatably connected to the first fixed frame, and the bearing device is used for fixing the actuator to be tested. The rotating frame is provided with a friction disc rotating along with the rotating frame; and the first fixing frame is provided with a friction device which can controllably apply friction action to the friction disc. And in the process that the actuator to be tested applies force to the rotating frame, the friction device applies friction action to the friction disc according to the force application rule. The service life testing equipment and the service life testing method for the linear motion actuator can accurately simulate the stress change process of the actuator in operation, and particularly can accurately simulate the working condition of the linear motion actuator for opening a refrigerator door, so that the service life can be more accurately evaluated.

Description

Linear motion actuator service life testing device and testing method

Technical Field

The invention belongs to the technical field of performance detection of actuators, and particularly relates to a device and a method for testing the service life of a linear motion actuator.

Background

Along with the development of economy and the progress of society, the living standard of people is greatly improved. The household electrical appliances are essential electrical appliances in the life of people, and the life style of people is also continuously influenced. The intellectualization has become a mainstream trend in the household appliance industry, and the intellectualization makes household appliances have more choices in the aspects of daily use, overall household design and the like.

In household electrical appliances such as dish washing machines, wine cabinets, kitchen cabinets, refrigerators and the like, the use of an actuator for automatically controlling each movable part is the basis for realizing the intellectualization of the household electrical appliances. Taking the automatic door opening and closing of a refrigerator as an example, the mainstream scheme at present is to combine a linear motion actuator and a rotary actuator for intervention in different door opening and closing stages to realize the complete automation of the whole door opening and closing process, for example, the scheme adopted by the zhahigli electrical appliance corporation in the patent CN 114857828A. Further, patent CN106761149A and patent CN212752039U of yukshel plastic products (tai bin) limited have proposed a linear actuator and a rotary actuator, respectively, which are suitable for home electric appliances such as refrigerators. In recent years, after many units of research and attempts in the industry, it is widely recognized that a refrigerator is difficult to perform all door opening and closing actions by a single rotary actuator due to the need to overcome atmospheric pressure difference at the moment of opening the door and the strong resistance caused by a door seal. Therefore, the solution of driving the refrigerator door switch by the linear actuator in combination with the rotary actuator remains the mainstream solution at present and for a long time in the future.

In the scheme, the linear motion actuator is mainly used for providing high thrust to push the refrigerator door body open at the moment of opening the door. The refrigerator door opening moment needs to overcome atmospheric pressure difference and strong resistance caused by door sealing, and after the refrigerator door rotates for a small angle, the rotation resistance is obviously weakened. However, the existing devices for testing the service life of the linear motion actuator mainly operate the actuator under the constant load condition to evaluate the service life, and have a large difference from the actual working condition, so that the reliability of the service life obtained by evaluation is low. In order to ensure stable operation of the linear actuator within the design life, a solution that greatly increases the design margin is often adopted in practice, but this also results in increased cost and excessive redundancy of performance.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a device and a method for testing the service life of a linear motion actuator.

According to the invention, the whole-process tracking analysis is carried out on the process that the linear motion actuator actually drives the refrigerator door body to open, and the stress of the linear motion actuator in the process of pushing the refrigerator door body to open is greatly changed and irregular.

Based on this, the invention provides a life test device for a linear motion actuator, which comprises a test device body. The device comprises a first fixed frame, a rotating frame and a bearing device, wherein the first fixed frame is fixedly arranged, the rotating frame is rotatably connected to the first fixed frame, and the bearing device is used for fixing an actuator to be tested.

The rotating frame is provided with a friction disc rotating along with the rotating frame; and the first fixing frame is provided with a friction device which can controllably apply friction action to the friction disc.

And in the process that the actuator to be tested applies force to the rotating frame, the friction device applies friction action to the friction disc according to the force application rule.

Furthermore, in the life test equipment for the linear motion actuator, the friction device comprises a sliding block connected to the first fixing frame in a sliding manner, a friction block connected with the sliding block in a sliding fit manner, an elastic part connected between the sliding block and the friction block, a driving rod connected with the sliding block in a threaded fit manner, and a power unit driving the driving rod to rotate.

The friction blocks may compress the friction discs; the sliding direction of the sliding block, the sliding direction of the friction block and the axial direction of the driving rod are all in the same direction.

Further, in the above device for testing the service life of the linear motion actuator, the end of the friction block has an arc-shaped recess, and the arc-shaped recess faces the circumferential surface of the friction disc.

Furthermore, in the device for testing the service life of the linear motion actuator, the elastic part is a spiral spring; one end of the elastic piece is fixedly connected with the friction block, and the other end of the elastic piece is fixedly connected with the sliding block.

Furthermore, the life test equipment for the linear motion actuator also comprises a second fixed frame fixedly installed; a plurality of electromagnetic generating pieces are arranged on one side of the second fixed frame close to the rotating frame; the rotating frame is provided with a plurality of magnetic suction pieces which are opposite to the electromagnetic generating pieces.

Furthermore, in the device for testing the service life of the linear motion actuator, the magnetically attractable piece is a strip-shaped iron sheet; the upper part, the middle part and the lower part of the rotating frame are transversely fixed with magnetically attractable parts, and one side of the rotating frame, which is far away from the friction disc, is fixed with a vertical magnetically attractable part; the electromagnetic generating piece is an electromagnet distributed along the magnetic piece.

Furthermore, in the device for testing the service life of the linear motion actuator, the bearing device is a rigid support which is fixedly installed; the actuator to be measured is fixed on the rigid support.

Further, in the life test equipment for the linear motion actuator, the bearing device comprises a vertical support fixedly installed, a pair of vertical screws rotatably installed on the vertical support, a screw motor driving the vertical screws to rotate, a lifting platform spirally matched with the screws, an adjusting motor fixed on the lifting platform, a worm installed on an output shaft of the adjusting motor, a rotating platform rotatably connected with the lifting platform, and a worm gear coaxially connected with the rotating platform; the worm wheel is meshed with the worm.

The test method is further provided for testing the service life of the linear motion actuator, and the service life test equipment for the linear motion actuator is adopted.

The test method comprises the following steps:

the method comprises the following steps: detecting the stress of the actuator to be tested in an actual application scene, recording to obtain a change curve of the actual stress along with time, and recording as a first stress curve;

step two: fixing the actuator to be tested on the bearing device, and enabling the acting part of the actuator to be tested to act on the rotating frame;

step three: supplying power to the electromagnetic generating element to make the electromagnetic generating element and the magnetic attracting element attract each other;

step four: starting the actuator to be tested to apply acting force on the rotating frame, recording the change curve of the actual stress along with the time, and recording the change curve as a second stress curve;

and 5: making a difference between the first stress curve and the second stress curve, and recording an obtained curve as a third stress curve;

step 6: multiplying the third stress curve by a correction factor K to obtain a curve which is recorded as a fourth stress curve; assuming that the extrusion acting force applied by the friction device to the friction disc is F1, and correspondingly, the extrusion force between the rotating frame and the acting part of the actuator to be tested is F2; then correction factor K = F1/F2;

and 7: controlling the friction device to apply extrusion force to the friction disc according to the change rule of the fourth stress curve, and supplying power to the electromagnetic generating element according to the power supply size consistent with that in the third step; and operating the actuator to be tested for multiple times under the condition, and evaluating the service life of the actuator to be tested.

Further, in the first step and the fourth step, the change curve of the actual stress along with the time is obtained by arranging a pressure sensor at the end part of the acting part of the actuator to be measured for recording.

Has the beneficial effects that: compared with the prior art, the service life testing equipment and the service life testing method for the linear motion actuator can accurately simulate the stress change process of the actuator in operation, and particularly can accurately simulate the working condition of the linear motion actuator for opening the refrigerator door, so that the service life can be more accurately evaluated.

Drawings

Fig. 1 is a schematic structural view of a life test apparatus for a linear actuator according to embodiment 1.

Fig. 2 is a schematic structural view of the friction device.

Fig. 3 is a partially enlarged view of fig. 2.

Fig. 4 is a schematic structural view of the second fixing frame.

Fig. 5 is a schematic structural view of the rotating frame.

Fig. 6 is a schematic structural view of a life test apparatus for a linear actuator according to embodiment 2.

Fig. 7 is a schematic structural diagram of a carrier device according to embodiment 2.

Fig. 8 and 9 are partial structural schematic views of the carrying device of embodiment 2.

Fig. 10 is a schematic view of a first force curve.

FIG. 11 is a diagram illustrating a second force curve.

Fig. 12 is a schematic view of a third force curve.

Fig. 13 is a diagram illustrating a fourth force curve.

In the figure, a first fixed frame 1, a rotating frame 2, a bearing device 3, a friction disc 21, a friction device 11, a sliding block 111, a friction block 112, an elastic piece 113, a driving rod 114, a power unit 115, an arc-shaped recess 1121, a second fixed frame 4, an electromagnetic generating piece 41, a magnetic attracting piece 22, a vertical support 31, a vertical lead screw 32, a lead screw motor 33, a lifting platform 34, an adjusting motor 35, a worm 36, a rotating platform 37 and a worm wheel 38.

Detailed Description

The invention is further illustrated by the following examples, which are intended to illustrate the technical solutions of the invention more clearly and are not to be construed as a limitation.

Unless defined otherwise, technical or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The use of "first," "second," and the like, herein does not denote any order, quantity, or importance, but rather the terms "first," "second," and the like are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

Example 1

A life test device for a linear motion actuator comprises a first fixed frame 1, a rotating frame 2 and a bearing device 3, wherein the first fixed frame 1 is fixedly installed, the rotating frame 2 is rotatably connected to the first fixed frame 1, and the bearing device is used for fixing the actuator to be tested. As shown in fig. 1, a first fixing frame 1 is a substantially vertical bracket fixed on the ground or a bottom plate, and the first fixing frame 1 has a plurality of platforms for mounting other components; the rotating frame 2 is in a door plate shape, one side of the rotating frame 2 is hinged to the first fixing frame 1, and the hinged parts are connected through bearings, so that the rotating frame 2 is guaranteed to rotate smoothly; the carrying device 3 is also fixed on the ground or the bottom plate, the carrying device 3 of the embodiment is a rigid support, and the actuator to be measured can be directly fixed on the rigid support.

As shown in fig. 2, a friction disc 21 is further installed at the rotation connection part of the rotating frame 2, and the friction disc 21 rotates together with the rotating frame 2; the first fixing frame 1 is provided with a friction device 11 which can controllably apply friction action to the friction disc 21; in the process that the actuator to be tested applies force to the rotating frame 2, the friction device 11 can apply friction to the friction disc 21 according to the force application rule so as to simulate the actual operation condition, and therefore the service life of the actuator to be tested can be more accurately evaluated.

As shown in fig. 2, the friction device 11 includes a sliding block 111 slidably connected to the first fixing frame 1, a friction block 112 slidably coupled to the sliding block 111, an elastic member 113 connected between the sliding block 111 and the friction block 112, a driving rod 114 threadedly coupled to the sliding block 111, and a power unit 115 for driving the driving rod 114 to rotate. The bottom of the sliding block 111 is provided with a sliding rail which is in sliding connection with a sliding groove formed in the upper surface of the first fixing frame 1, and the bottom of the friction block 112 is also provided with a sliding rail which is in sliding connection with a sliding groove formed in the upper surface of the first fixing frame 1; a pair of guide rods also extend out of the side surface of the friction block 112 and penetrate into the sliding block 111, and spiral springs are sleeved on the guide rods to serve as elastic pieces 113; preferably, one end of the elastic member 113 is fixedly connected to the friction block 112, and the other end of the elastic member 113 is fixedly connected to the slider 111. The sliding direction of the slider 111, the sliding direction of the friction block 112, and the axial direction of the drive lever 114 are all in the same direction.

As shown in fig. 3, the friction block 112 has an end portion provided with an arc-shaped recess portion 1121, and the arc-shaped recess portion 1121 faces the circumferential side surface of the friction disk 21; the diameter of the arcuate recesses 1121 is preferably slightly larger than the diameter of the friction discs 21.

In the friction device 11, the power unit 115 preferably adopts a speed reduction motor, the power unit 115 rotates to drive the driving rod 114 to rotate, the driving rod 114 rotates to drive the slider 111 to slide, the slider 111 slides to drive the spiral spring serving as the elastic member 113 to compress or rebound, the elastic force of the elastic member 113 drives the friction block 112 to extrude the friction disc 21, so as to provide resistance for the rotation of the rotating frame 2, thereby simulating the actual operation condition of the actuator to be tested. The exact distance that the slider 111 slides can be obtained by multiplying the number of rotations of the power unit 115 by the pitch of the drive rod 114, the pressing force that the friction block 112 applies to the friction disc 21 can be exactly obtained by multiplying the distance that the slider 111 slides by the stiffness coefficient of the elastic member 113, and the friction force that the friction block 112 applies to the outer periphery of the friction disc 21 can be exactly obtained by multiplying the pressing force that the friction block 112 applies to the friction disc 21 by the friction coefficient. Therefore, with the above-described structure, the rotation angle of the power unit 115 can be adjusted and controlled, and the resistance received by the rotating frame 2 during rotation can be accurately adjusted.

As shown in fig. 1, the life test device for a linear motion actuator of the present embodiment further includes a second fixing frame 4 fixedly installed. As shown in fig. 4, the second fixing frame 4 has a plurality of electromagnetic generators 41 on a side thereof close to the rotating frame 2. As shown in FIG. 5, the rotating frame 2 has a plurality of magnetically attractable members 22 facing the electromagnetic generating member 41. Specifically, the magnetically attractable element 22 is an elongated iron sheet; the upper part, the middle part and the lower part of the rotating frame 2 are transversely fixed with magnetically attractable pieces 22, and one side of the rotating frame 2, which is far away from the friction disc 21, is fixed with a vertical magnetically attractable piece 22; the electromagnetic generating element 41 is an electromagnet distributed along the magnetically attractable element 22.

Example 2

Fig. 6 shows a life test device for a linear actuator provided in this embodiment, which is mainly different from embodiment 1 in the specific structure of the carrier 3 and the number and positions of the friction devices 11.

Fig. 6 shows a life test device for a linear motion actuator, which includes a first fixed frame 1 fixedly installed, a rotating frame 2 rotatably connected to the first fixed frame 1, and a bearing device 3 for fixing the actuator to be tested. The first fixing frame 1 is a vertical bracket which is fixed on the ground or a bottom plate, and the first fixing frame 1 is provided with a plurality of platforms for installing other components; the rotating frame 2 is in a door plate shape, one side of the rotating frame 2 is hinged to the first fixing frame 1, and the hinged parts are connected through bearings, so that the rotating frame 2 is guaranteed to rotate smoothly; bearing device 3 is also fixed on ground or bottom plate, and the bearing device 3 of this embodiment has lift and rotation regulation function, can simulate in order to satisfy diversified test requirement to the application scene of difference. For example, the application scenario shown in fig. 7 of patent CN106761149A is different from the application scenario shown in fig. 1 of patent CN114857828A, and the angle change and force change between the push rod as the acting component and the component pushed by the push rod are different with the movement of the linear motion actuator.

As shown in fig. 7, 8 and 9, the carrying device 3 adopted in this embodiment includes a vertical bracket 31 fixedly installed, a pair of vertical screws 32 rotatably installed on the vertical bracket 31, a screw motor 33 driving the vertical screws 32 to rotate, an elevating platform 34 screw-engaged with the screws 32, an adjusting motor 35 fixed on the elevating platform 34, a worm 36 installed on an output shaft of the adjusting motor 35, a rotating platform 37 rotatably connected with the elevating platform 34, and a worm wheel 38 coaxially connected with the rotating platform 37; the worm gear 38 meshes with the worm 36. During testing, the actuator to be tested is fixed on the rotating platform 37, the actuator to be tested is rotated and locked at a proper angle by controlling the adjusting motor 35, and the actuator to be tested is lifted and locked at a proper height by controlling the screw motor 33.

As shown in fig. 2, a friction disc 21 is further installed at the rotating connection part of the rotating frame 2, and the friction disc 21 rotates along with the rotating frame 2; the first fixing frame 1 is provided with a friction device 11 which can controllably apply friction action to the friction disc 21; in the process that the actuator to be tested applies force to the rotating frame 2, the friction device 11 can apply friction to the friction disc 21 according to the required force application rule so as to simulate the actual operation condition.

As shown in fig. 2, the friction device 11 includes a sliding block 111 slidably connected to the first fixing frame 1, a friction block 112 slidably connected to the sliding block 111, an elastic member 113 connected between the sliding block 111 and the friction block 112, a driving rod 114 connected to the sliding block 111 in a threaded manner, and a power unit 115 for driving the driving rod 114 to rotate. The bottom of the sliding block 111 is provided with a sliding rail which is in sliding connection with a sliding groove formed in the upper surface of the first fixing frame 1, and the bottom of the friction block 112 is also provided with a sliding rail which is in sliding connection with a sliding groove formed in the upper surface of the first fixing frame 1; a pair of guide rods extend out of the side surface of the friction block 112 and penetrate into the sliding block 111, and spiral springs are sleeved on the guide rods to serve as elastic pieces 113; preferably, one end of the elastic member 113 is fixedly connected to the friction block 112, and the other end of the elastic member 113 is fixedly connected to the slider 111. The sliding direction of the slider 111, the sliding direction of the friction block 112, and the axial direction of the drive lever 114 are all in the same direction.

As shown in fig. 3, the friction block 112 has an end portion provided with an arc-shaped recess portion 1121, and the arc-shaped recess portion 1121 faces the circumferential side surface of the friction disk 21; the diameter of the arcuate recesses 1121 should preferably be slightly larger than the diameter of the friction plates 21.

In the friction device 11, the power unit 115 preferably adopts a speed reduction motor, the power unit 115 rotates to drive the driving rod 114 to rotate, the driving rod 114 rotates to drive the sliding block 111 to slide, the sliding block 111 slides to drive the spiral spring serving as the elastic member 113 to compress or rebound, the elastic force of the elastic member 113 drives the friction block 112 to extrude the friction disc 21, so as to cause resistance to the rotation of the rotating frame 2, thereby simulating the actual operation condition of the actuator to be tested.

As shown in fig. 7, the life test device for the linear motion actuator further includes a second fixing frame 4 fixedly installed. As shown in fig. 4, the second fixing frame 4 has a plurality of electromagnetic generators 41 on a side thereof close to the rotating frame 2. As shown in fig. 5, the rotating frame 2 has a plurality of magnetically attractable members 22 facing the electromagnetic generating member 41. Specifically, the magnetically attractable element 22 is an elongated iron sheet; the upper part, the middle part and the lower part of the rotating frame 2 are transversely fixed with magnetically attractable pieces 22, and one side of the rotating frame 2, which is far away from the friction disc 21, is fixed with a vertical magnetically attractable piece 22; the electromagnetic generating element 41 is an electromagnet distributed along the magnetically attractable element 22.

Example 3

A testing method is used for testing the service life of a linear motion actuator, and the service life testing equipment of the linear motion actuator described in embodiment 1 or embodiment 2 is used for detection.

The method comprises the following steps: the stress of the actuator to be tested in the actual application scene is detected, and the change curve of the actual stress along with the time is recorded and recorded as a first stress curve, as shown in fig. 10.

Step two: and fixing the actuator to be tested on the bearing device 3, so that the acting part of the actuator to be tested acts on the rotating frame 2.

Step three: the electromagnetic generator 41 is powered to attract the magnetically attractable element 22.

Step four: and starting the actuator to be tested to apply acting force to the rotating frame 2, recording the change curve of the actual stress along with the time, and recording the change curve as a second stress curve as shown in fig. 11.

And 5: the difference is made between the first force curve and the second force curve, and the obtained curve is marked as a third force curve, as shown in fig. 12.

And 6: the third stress curve is multiplied by the correction factor K, and the obtained curve is recorded as a fourth stress curve, as shown in fig. 13. The actual meaning of the correction factor K is as follows: assuming that the extrusion acting force applied by the friction device 11 to the friction disc 21 is F1, correspondingly, the extrusion force between the rotating frame 2 and the working part of the actuator to be tested is F2; the correction factor K = F1/F2. The actual value of the correction factor K may be calculated according to the distance between the contact position of the rotating frame 2 and the actuator to be measured and the rotating shaft of the rotating frame 2, the radius of the friction disc 21, and the friction coefficient between the friction disc 21 and the friction block 112.

And 7: controlling the friction device 11 to apply a pressing force to the friction disc 21 according to a change rule of a fourth force-bearing curve, and supplying power to the electromagnetic generating element 41 according to the power supply size consistent with the third step; and running the actuator to be tested for many times under the condition to evaluate the service life of the actuator to be tested. When the friction device 11 is controlled, the forces of the four force curves can directly correspond to the rotation angle of the power unit 115 through conversion, so that accurate control is realized. The specific conversion method is as follows: the distance that the slider 111 slides can be obtained by multiplying the number of rotations of the power unit 115 by the pitch of the drive rod 114, and the pressing force that the friction block 112 applies to the friction disc 21 can be obtained by multiplying the distance that the slider 111 slides by the stiffness coefficient of the elastic member 113.

In the first step and the fourth step, the change curve of the actual stress along with the time is obtained by arranging a pressure sensor at the end part of the acting part of the actuator to be tested for recording.

The testing method of the embodiment is based on the stress data measured actually, and finds that the stress formed by overcoming the atmospheric pressure difference and the door seal resistance in the early stage of opening the door of the refrigerator is violently changed and irregular, and the stress in the later stage of opening the door of the refrigerator is smaller than that in the early stage, but is not obviously regular. In view of the above situation, the testing method of the embodiment includes that the electromagnetic generating element 41 and the magnetically attractable element 22 are arranged between the second fixing frame 4 and the rotating frame 2, so that the stress condition of the door in the early stage can be simulated to a great extent, the difference between the actual stress and the electromagnetic force is compensated through the friction device 11, and the compensation is accurately compensated according to the difference curve, so that the complex stress change process of the actual working condition can be objectively and accurately simulated.

The above embodiments are provided for illustrative purposes, so that those skilled in the art can understand the technical idea and features of the present invention and implement the invention, and the protection scope of the present invention is not limited thereby. All equivalent changes and modifications made according to the spirit of the present invention should be covered in the protection scope of the present invention.

Claims (10)

1. A life test device for a linear motion actuator is characterized in that: the device comprises a first fixed frame (1) which is fixedly installed, a rotating frame (2) which is rotatably connected to the first fixed frame (1) and a bearing device (3) which is used for fixing an actuator to be tested;

the rotating frame (2) is provided with a friction disc (21) rotating along with the rotating frame (2); a friction device (11) which can controllably apply friction action to the friction disc (21) is arranged on the first fixing frame (1);

and in the process that the actuator to be tested applies force to the rotating frame (2), the friction device (11) applies friction to the friction disc (21) according to the force application rule.

2. The linear motion actuator life test apparatus of claim 1, wherein: the friction device (11) comprises a sliding block (111) connected to the first fixing frame (1) in a sliding mode, a friction block (112) connected with the sliding block (111) in a sliding fit mode, an elastic piece (113) connected between the sliding block (111) and the friction block (112), a driving rod (114) connected with the sliding block (111) in a threaded fit mode, and a power unit (115) driving the driving rod (114) to rotate;

said friction block (112) being adapted to compress said friction disc (21); the sliding direction of the sliding block (111), the sliding direction of the friction block (112) and the axial direction of the driving rod (114) are all in the same direction.

3. The linear motion actuator life test apparatus of claim 2, wherein: the friction block (112) has an end portion provided with an arc-shaped recess portion (1121), and the arc-shaped recess portion (1121) faces the circumferential side surface of the friction disk (21).

4. The linear motion actuator life test apparatus of claim 3, wherein: the elastic piece (113) is a spiral spring; one end of the elastic piece (113) is fixedly connected with the friction block (112), and the other end of the elastic piece (113) is fixedly connected with the sliding block (111).

5. The linear motion actuator life test apparatus of any one of claims 1 to 4, wherein: the device also comprises a second fixed frame (4) which is fixedly arranged; a plurality of electromagnetic generating pieces (41) are arranged on one side, close to the rotating frame (2), of the second fixing frame (4); the rotating frame (2) is provided with a plurality of magnetic attracting pieces (22) which are opposite to the electromagnetic generating piece (41).

6. The linear motion actuator life test apparatus of claim 5, wherein: the magnetic piece (22) is a long iron sheet; the upper part, the middle part and the lower part of the rotating frame (2) are transversely fixed with magnetically attractable pieces (22), and one side of the rotating frame (2) far away from the friction disc (21) is fixed with a vertical magnetically attractable piece (22); the electromagnetic generating piece (41) is electromagnets distributed along the magnetic piece (22).

7. The linear motion actuator life test apparatus of any one of claims 1 to 4, wherein: the bearing device (3) is a rigid support which is fixedly arranged; the actuator to be tested is fixed on the rigid support.

8. The linear motion actuator life test apparatus of any one of claims 1 to 4, wherein: the bearing device (3) comprises a vertical support (31) fixedly installed, a pair of vertical lead screws (32) rotatably installed on the vertical support (31), a lead screw motor (33) driving the vertical lead screws (32) to rotate, a lifting platform (34) in spiral fit with the lead screws (32), an adjusting motor (35) fixed on the lifting platform (34), a worm (36) installed on an output shaft of the adjusting motor (35), a rotating platform (37) rotatably connected with the lifting platform (34), and a worm wheel (38) coaxially connected with the rotating platform (37); the worm wheel (38) is meshed with the worm (36).

9. A method of testing the life of a linear motion actuator, comprising: employing the linear motion actuator life test apparatus of claim 5;

the test method comprises the following steps:

the method comprises the following steps: detecting the stress of the actuator to be tested in an actual application scene, recording to obtain a change curve of the actual stress along with time, and recording as a first stress curve;

step two: fixing the actuator to be tested on the bearing device (3) to enable the acting component of the actuator to be tested to act on the rotating frame (2);

step three: supplying power to the electromagnetic generating element (41) to make it attract the magnetically attractable element (22);

step four: starting the actuator to be tested to apply acting force on the rotating frame (2), recording to obtain a change curve of actual stress along with time, and recording as a second stress curve;

and 5: making a difference between the first stress curve and the second stress curve, and marking the obtained curve as a third stress curve;

step 6: multiplying the third stress curve by a correction factor K to obtain a curve which is recorded as a fourth stress curve; assuming that the extrusion acting force applied by the friction device (11) to the friction disc (21) is F1, and correspondingly, the extrusion force between the rotating frame (2) and the working part of the actuator to be tested is F2; then the correction factor K = F1/F2;

and 7: controlling the friction device (11) to apply extrusion force to the friction disc (21) according to the change rule of a fourth stress curve, and supplying power to the electromagnetic generating element (41) according to the power supply size consistent with the third step; and running the actuator to be tested for many times under the condition to evaluate the service life of the actuator to be tested.

10. The test method of claim 9, wherein: in the first step and the fourth step, the change curve of the actual stress along with the time is obtained by arranging a pressure sensor at the end part of the acting part of the actuator to be tested for recording.

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