WO2024065342A1

WO2024065342A1 - Telescopic torsion joint structure and photovoltaic panel cleaning robot

Info

Publication number: WO2024065342A1
Application number: PCT/CN2022/122371
Authority: WO
Inventors: 张杏华; 李田蓥; 时永佳
Original assignee: 廊坊思拓新能源科技有限公司
Priority date: 2022-09-27
Filing date: 2022-09-29
Publication date: 2024-04-04
Also published as: CN115532755A

Abstract

Disclosed in the present invention are a telescopic torsion joint structure and a photovoltaic panel cleaning robot. The torsion joint structure comprises: an outer rod body, which has an axially extending first hole and a radially extending second hole; and an inner rod body, which has one end inserted into the first hole and forms a gap with a wall of the first hole, and a connecting pin, wherein the inner rod body is provided with a third hole corresponding to the second hole, the connecting pin passes through the second hole and the third hole, and one of the second hole and the third hole is a waist hole having a long side parallel to the axis of the rod body where the waist hole is located. In the robot, by means of the telescopic torsion joint structure, a wheel axle is connected to a transmission rod, and/or a brush core shaft is connected to a brush support shaft. Using the telescopic torsion joint structure enables the transmission rod and/or the brush to smoothly twist along with the cleaning robot, and compensates for the change in spacing at two ends of the cleaning robot twisting in opposite directions.

Description

A telescopic torsion joint structure and a photovoltaic panel cleaning robot

Technical Field

The invention relates to the field of photovoltaic panel cleaning robots, in particular to a telescopic torsion joint structure and a photovoltaic panel cleaning robot adopting the telescopic torsion joint structure.

Background technique

Due to the constraints of land and photovoltaic module prices, photovoltaic power stations have gradually begun to be built with flat single-axis tracking brackets. The length of a single-row flat single-axis can generally be built to be about 90 meters. In order to reduce the cleaning cost of photovoltaic modules, the power station will connect the flat single-axis tracking brackets into a long row of 1 to 2 kilometers through a bridge, so that a long row can be cleaned by only one cleaning robot.

Due to the errors in control accuracy and installation accuracy of the flat single axis, as well as the torsion angle error of the 90-meter-long torque tube, the final angle error of the ends between the two rows of flat single axes will reach a maximum of about 12°; such an angle error makes one end of the flat single axis bridge uphill and the other end downhill, as shown in Figure 1, the left end 401 of the bridge 400 in Figure 1 is downhill, and the right end 402 of the bridge 400 is uphill. The traditional frame structure cleaning robot cannot adapt to this bridge state, and the twistable photovoltaic panel cleaning robot can smoothly pass through this bridge state. However, when the twistable photovoltaic panel cleaning robot is twisted, the interval between the two axles connected by the transmission rod will also change, and the interval between the support shafts at both ends of the brush will also change, so it is necessary to design a corresponding structure to compensate for the interval change. Based on this, the inventor thought of using a torsion joint to compensate for the interval change, and then proposed the retractable torsion joint structure of the present application.

Summary of the invention

The object of the present invention is to provide a retractable torsion joint structure and a photovoltaic panel cleaning robot, so as to solve the above-mentioned defects of the photovoltaic panel cleaning robot at least to a certain extent.

To achieve the above object, the technical solution adopted by the present invention is as follows:

A telescopic torsion joint structure, comprising:

An outer rod body having a first hole extending axially and a second hole extending radially;

an inner rod body, one end of which is inserted into the first hole and a gap is formed between the inner rod body and the hole wall of the first hole so that the inner rod body can swing relative to the outer rod body, and the inner rod body is provided with a third hole corresponding to the second hole; and

A connecting pin, which is inserted into the second hole and the third hole;

One of the second hole and the third hole is a waist hole, and the long side of the waist hole is parallel to the axis of the rod body where the waist hole is located.

In the above-mentioned telescopic torsion joint structure, by plugging and fitting the inner and outer rod bodies and forming a gap between the plug-fitting parts, the inner and outer rod bodies can swing at a certain angle with the center of the connecting pin as the center of the circle, so that the rotational motion can be transmitted at a variable angle; one of the second hole and the third hole is designed as a waist hole, so that the inner and outer rod bodies can contract when subjected to pressure from the connected parts, and can stretch when subjected to tension from the connected parts, so that the rotational motion can be transmitted at a variable angle while compensating for the change in the interval between the two connected parts.

The length of the waist hole is preferably configured to be 3 to 5 mm larger than the diameter of the connecting pin, and the size of the gap is preferably configured to allow the maximum swing angle of the inner rod body relative to the outer rod body to reach 10° to 12°.

A photovoltaic panel cleaning robot comprises a wheel axle and a transmission rod connecting two wheel axles, wherein the above-mentioned telescopic torsion joint structure is connected between the transmission rod and the wheel axle.

In the above-mentioned photovoltaic panel cleaning robot, the above-mentioned retractable torsion joint structure is added between the wheel axle and the transmission rod connecting the two wheel axles. When one end of the cleaning robot turns left around the rotating shaft and the other end turns right around the rotating shaft, without destroying the original rigid connection, the walking device and the transmission rod form a certain angle and do not affect the transmission of power. This structure can make the transmission rod smoothly follow the twisting of the cleaning robot and compensate for the change in the interval between the wheel axles caused by the twisting of the two ends of the cleaning robot in opposite directions.

In some embodiments, the end of the inner rod body is opposite to the end of the transmission rod and is fixedly connected with a clamp, the outer rod body is a tube structure, the axle is inserted into the tube structure and is fixedly connected to the tube structure.

In some embodiments, the end of the tube structure connected to the axle is provided with a long groove along the axial direction of the tube structure and is provided with a first connecting bolt, which passes through the tube structure and the axle in a direction perpendicular to the long groove to fix the tube structure to the axle.

In some embodiments, the transmission rod is a metal tube, and the joint surface between the metal tube and the clamp, and the joint surface between the inner rod body and the clamp are provided with an embossed structure. The clamp is equipped with a second and a third connecting bolt, the second connecting bolt passes through the clamp and the metal tube, and the third connecting bolt passes through the clamp and the inner rod body.

A photovoltaic panel cleaning robot comprises a brush core shaft and a brush support shaft, wherein the above-mentioned telescopic torsion joint structure is connected between the brush core shaft and the brush support shaft.

In the above-mentioned photovoltaic panel cleaning robot, the above-mentioned retractable torsion joint structure is added between the brush core shaft and the brush support shaft. When one end of the cleaning robot turns left around the rotating shaft and the other end turns right around the rotating shaft, without destroying the original rigid connection, the walking device forms a certain angle with the brush core shaft and does not affect the transmission of power. This structure can make the brush smoothly follow the twisting of the cleaning robot and compensate for the change in the interval between the brush support shafts caused by the twisting of the two ends of the cleaning robot in opposite directions.

In some embodiments, the brush core shaft is a metal tube, the outer rod body is embedded in the end of the metal tube and is fixedly connected to the metal tube, and the inner rod body is fixedly connected to the brush support shaft.

In some embodiments, the outer end of the inner rod body is provided with an axial hole and a keyway, the axial hole cooperates with the brush support shaft, and the keyway cooperates with the key on the brush support shaft to fix the inner rod body and the brush support shaft.

In some embodiments, the first hole of the outer rod body is a horn hole.

Compared with the prior art, the present invention has at least the following beneficial effects:

In the telescopic torsion joint structure of the present invention, the inner and outer rod bodies are plugged together and a gap is formed between the plugged-in parts, so that the inner and outer rod bodies can swing at a certain angle with the center of the connecting pin as the center of the circle, so that the rotational motion can be transmitted at a variable angle; one of the second hole and the third hole is designed as a waist hole, so that the inner and outer rod bodies can shrink when subjected to the pressure of the connected parts, and can stretch when subjected to the tension of the connected parts, so that the rotational motion can be transmitted at a variable angle while compensating for the change in the interval between the two connected parts. The telescopic torsion joint structure is simple in structure and easy to use.

The photovoltaic panel cleaning robot of the present invention is provided with a retractable torsion joint structure between the transmission rod and the wheel axle, so that the transmission rod can smoothly follow the torsion of the cleaning robot and compensate for the change in the interval between the wheel axles caused by the torsion of the two ends of the cleaning robot in opposite directions.

The photovoltaic panel cleaning robot of the present invention adds the above-mentioned retractable torsion joint structure between the brush core shaft and the brush support shaft, so that the brush can smoothly follow the twisting of the cleaning robot and compensate for the change in the interval between the brush support shafts caused by the twisting of the two ends of the cleaning robot in opposite directions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a flat single-axis bridge with one end being uphill and the other end being downhill;

FIG2 is a perspective view of a first embodiment of a telescopic torsion joint structure;

FIG3 is an end view of a first embodiment of a telescopic torsion joint structure;

Fig. 4 is a cross-sectional view taken along line A-A of Fig. 3;

Fig. 5 is a cross-sectional view taken along line B-B of Fig. 3;

FIG6 is a perspective view of a second embodiment of a telescopic torsion joint structure;

FIG7 is an end view of a second embodiment of a telescopic torsion joint structure;

Fig. 8 is a cross-sectional view taken along line C-C of Fig. 7;

Fig. 9 is a cross-sectional view taken along line D-D of Fig. 7;

FIG10 is a front view of an embodiment of a photovoltaic panel cleaning robot;

FIG11 is a top view of an embodiment of a photovoltaic panel cleaning robot;

FIG12 is a side view of an embodiment of a photovoltaic panel cleaning robot;

FIG13 is a schematic diagram of the connection between the telescopic torsion joint structure, the transmission rod and the wheel axle;

FIG14 is a top view of FIG13;

Fig. 15 is a cross-sectional view taken along line E-E of Fig. 14;

FIG16 is a schematic diagram of the connection between the telescopic torsion joint structure and the brush mandrel;

FIG17 is a cross-sectional view taken along line F-F in FIG16 .

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

First embodiment:

Please refer to FIG. 2 to FIG. 5 , the telescopic torsion joint structure 100 of the present embodiment includes: an outer rod body 101, an inner rod body 102 and a connecting pin 103. The outer rod body 101 has an axially extending first hole 107, the first hole 107 is a hole of equal diameter, one end of the inner rod body 102 is inserted into the first hole 107, and a gap is formed between the outer wall of the inner rod body 102 and the hole wall of the first hole 107. The outer rod body 101 also has a radially extending second hole 106, the inner rod body 102 has a third hole 108 corresponding to the second hole 106, the connecting pin 103 is penetrated through the second hole 106 and the third hole 108, and cooperates with the second hole 106 and the third hole 108 to connect the inner rod body 102 and the outer rod body 101 as a whole, wherein the second hole 106 on the outer rod body 101 is a waist hole, the long side of the waist hole is parallel to the axis of the outer rod body 101, so that the outer rod body 101 and the inner rod body 102 have a certain telescopic amount.

Specifically in this embodiment, screw holes are provided at both ends of the connecting pin 103, screws are installed in the screw holes, and a gasket 104 is arranged between the screw and the connecting pin 103. The gasket 104 cooperates with the hole edge of the second hole 106 to limit the connecting pin 103 and prevent the connecting pin 103 from falling off. As an alternative, the connecting pin 103 can also be a bolt.

The outer rod body 101, the inner rod body 102 and the connecting pin 103 are all moving parts. In order to reduce friction loss, they are preferably made of wear-resistant materials, such as steel, alloy and the like.

In the above-mentioned telescopic torsion joint structure 100, by plugging and fitting the inner and outer rod bodies and forming a gap between the plug-fitting parts, the inner rod body 102 and the outer rod body 101 can swing at a certain angle with the center of the connecting pin 103 as the center of the circle, so that the rotational motion can be transmitted at a variable angle; the second hole 106 is designed as a waist hole, so that the inner and outer rod bodies can shrink when subjected to pressure from the connected parts, and can stretch when subjected to tension from the connected parts, so that the rotational motion can be transmitted at a variable angle while compensating for the change in the interval between the two connected parts.

In the telescopic torsion joint structure 100, the length of the waist hole corresponds to the maximum telescopic amount between the inner and outer rod bodies, and the gap between the inner and outer rod bodies corresponds to the maximum swing angle between the inner and outer rod bodies. In some embodiments, the length of the waist hole of the telescopic torsion joint structure 100 is designed to be 3 to 5 mm larger than the diameter of the connecting pin 103, that is, the relative telescopic amount between the inner and outer rod bodies is 3 to 5 mm, and the size of the gap between the inner and outer rod bodies is configured so that the maximum swing angle of the inner rod body relative to the outer rod body can reach 10° to 12°.

Second embodiment:

Please refer to FIG. 6 to FIG. 9 , the telescopic torsion joint structure 200 of the present embodiment includes: an outer rod body 201, an inner rod body 202 and a connecting pin 203. The outer rod body 201 has an axially extending first hole 207, one end of the inner rod body 202 is inserted into the first hole 207, and a gap is formed between the outer wall of the inner rod body 202 and the hole wall of the first hole 207. The outer rod body 201 also has a radially extending second hole 206, and the inner rod body 202 has a third hole 208 corresponding to the second hole 206. The connecting pin 203 is penetrated through the second hole 206 and the third hole 208, and cooperates with the second hole 206 and the third hole 208 to connect the inner rod body 202 and the outer rod body 201 as a whole, wherein the third hole 208 on the inner rod body 202 is a waist hole, and the long side of the waist hole is parallel to the axis of the inner rod body 202, so that the outer rod body 201 and the inner rod body 202 have a certain telescopic amount. The first hole 207 of the outer rod body 201 is designed as a trumpet hole, which is larger at both ends and smaller in the middle. The hole diameter is the smallest at the position corresponding to the connection pin 203 .

The connecting pin 203 in this embodiment is interference fit with the second hole 206 on the outer rod body 201. As an alternative, the connecting pin can also be a bolt, which passes through the second hole 206 and the third hole 208, is connected with a nut, and is fixed to the outer rod body. The connecting pin 203 can also be the connecting pin in the first embodiment.

The outer rod body 201, the inner rod body 202 and the connecting pin 205 are preferably made of wear-resistant materials, such as steel, alloy and the like.

In the above-mentioned telescopic torsion joint structure 200, by plugging and fitting the inner and outer rod bodies and forming a gap between the plug-fitting parts, the inner rod body 202 and the outer rod body 201 can swing at a certain angle with the center of the connecting pin 203 as the center of the circle, so that the rotational motion can be transmitted at a variable angle; the third hole 208 is designed as a waist hole, so that the inner and outer rod bodies can contract when subjected to pressure from the connected parts, and can stretch when subjected to tension from the connected parts, so that the rotational motion can be transmitted at a variable angle while compensating for the change in the interval between the two connected parts.

In the telescopic torsion joint structure 200, the length of the waist hole corresponds to the maximum telescopic amount between the inner and outer rod bodies, and the structure of the horn hole corresponds to the maximum swing angle between the inner and outer rod bodies. In some embodiments, the length of the waist hole of the telescopic torsion joint structure 200 is designed to be 3 to 5 mm larger than the diameter of the connecting pin 203, that is, the relative telescopic amount between the inner and outer rod bodies is 3 to 5 mm.

Third embodiment:

Figures 10 to 12 show a photovoltaic panel cleaning robot, wherein Figure 10 is a front view, Figure 11 is a top view, and Figure 12 is a side view. The photovoltaic panel cleaning robot is in a twisted state.

Referring to Figure 10, the photovoltaic panel cleaning robot has two

edge walking devices

301, 304 and an intermediate walking device 303. All walking devices are installed on the rotating shaft 302 and can be twisted around the rotating shaft 302. Each walking device is equipped with a walking wheel 305 through a wheel axle. The two

edge walking devices

301, 304 and the intermediate walking device 303 include front wheels and rear wheels, and the corresponding walking wheels 305 are connected through a transmission rod 307.

During cleaning, the walking wheel 305 walks on the frame at the edge of the photovoltaic panel, driving the brush to pass through the photovoltaic panel to clean the photovoltaic panel. After the photovoltaic panels on a row of flat single shafts are cleaned, they walk through the bridge between two rows of flat single shafts to the photovoltaic panels on the next row of flat single shafts to continue cleaning.

11 , a telescopic torsion joint structure 100 is connected at the end of the transmission rod 307, that is, between the transmission rod 307 and the axle. The telescopic torsion joint structure 100 is the same as the telescopic torsion joint structure 100 in the first embodiment, and will not be described in detail.

In the above-mentioned photovoltaic panel cleaning robot, a retractable torsion joint structure 100 is added between the wheel axle and the transmission rod 307 connecting the two wheel axles. When one end of the cleaning robot turns left around the rotating shaft 302 and the other end turns right around the rotating shaft 302, without destroying the original rigid connection, the

walking device

301, 304 forms a certain angle with the transmission rod 307 and does not affect the transmission of power. This structure enables the transmission rod 307 to smoothly follow the twisting of the cleaning robot and compensate for the change in the spacing between the wheel axles caused by the twisting of the two ends of the cleaning robot in opposite directions.

13 to 15 show a specific connection structure between the telescopic torsion joint structure 100 and the axle 312 and the transmission rod 307 .

Referring to Figures 13 to 15, in this embodiment, the inner rod body 102 of the telescopic torsion joint structure 100 is connected to the transmission rod 307, and the outer rod body 101 of the telescopic torsion joint structure 100 is connected to the axle 312. Among them, the end of the inner rod body 102 is opposite to the end of the transmission rod 307, and is fixedly connected with a clamp 309. The outer rod body 101 is a tube structure, and the axle 312 is inserted into the tube structure and fixedly connected with the tube structure. Here, the characteristics of the axle 312 being a solid structure and the characteristics of the outer rod body 101 itself having an axially extending first hole 107 are utilized, and the outer rod body 101 is designed as a tube structure as a whole, so that the structure of the telescopic torsion joint structure 100 is simple, and it can be directly plugged and connected with the axle 312 without the need to use a clamp.

Furthermore, a long slot 313 is provided at the end of the tube structure connected to the axle 312 along the axial direction of the tube structure, and a first connecting bolt 311 is provided. The first connecting bolt 311 penetrates the tube structure and the axle 312 in a direction perpendicular to the long slot 313 to fixedly connect the tube structure to the axle 312. In this way, the tube structure can be squeezed by the first connecting bolt 311 to deform the tube structure and hold the axle 312 tightly. The axle 312 is completely fixed to the outer tube body 101 by utilizing the holding force of the tube structure on the axle 312 and the connecting effect of the first connecting bolt 311 on the tube structure and the axle 312.

Furthermore, the transmission rod 307 is made of a metal tube, and the metal tube is preferably an aluminum tube to reduce the weight of the robot. An embossing structure is provided on the outer surface of the metal tube, and an embossing structure is also provided on the inner surface of the clamp 309. The embossing structure increases the friction between the clamp 309 and the transmission rod 307. The clamp 309 is provided with a second connecting bolt 308 and a third connecting bolt 310. The second connecting bolt 308 penetrates the clamp 309 and the metal tube, and the third connecting bolt 310 penetrates the clamp 309 and the inner rod body 102. In the above structure, on the one hand, the clamping force is improved by the embossing structure, and on the other hand, the connecting bolts are increased. The combination of the two aspects completely fixes the inner rod body 102 and the transmission rod 307.

In order to adapt to the cleaning of flat single-axis photovoltaic power stations, the maximum torsion angle of the photovoltaic panel cleaning machine is preferably designed to be 10° to 12°. If the torsion angle is designed to be too small, the walking wheel set may not be able to completely land on the track when passing through the bridge, and the robot is at risk of falling. If the torsion angle is designed to be too large, the transmission rod 307 connecting the wheel axle will interfere with the brush. In order to meet the above-mentioned maximum torsion angle, so that the transmission rod 307 can smoothly follow the torsion of the cleaning robot, and compensate for the change in the interval between the wheel axles caused by the torsion of the two ends of the cleaning robot in opposite directions, the length of the waist hole of the telescopic torsion joint structure 100 is designed to be 3 to 5 mm larger than the diameter of the connecting pin 103, that is, the relative telescopic amount of the inner rod body and the outer rod body is 3 to 5 mm, and the size of the gap between the inner and outer rod bodies is configured so that the maximum swing angle of the inner rod body relative to the outer rod body can reach 10° to 12°.

It should be noted that, although as described in the background technology, the maximum final angle error between the ends of the two rows of flat single shafts can reach about 12°, the maximum torsion angle of the photovoltaic panel cleaning machine can also be less than 12°, and the maximum swing angle of the inner rod body of the telescopic torsion joint structure 100 relative to the outer rod body can be less than 12°. Because on the one hand, the slope of the bridge between the two rows of flat single shafts is not only related to the final angle error between the ends of the two rows of flat single shafts, but also to the spacing between the two rows of flat single shafts. When the spacing is large, the slope will be gentle; on the other hand, when the photovoltaic panel cleaning robot is provided with one or more intermediate walking devices 303, the maximum swing angle of the inner rod body of a single telescopic torsion joint structure 100 relative to the outer rod body can be smaller.

The photovoltaic panel cleaning robot may also be without the intermediate walking device 303 , or may be designed with two or more intermediate walking devices 303 .

Fourth embodiment:

10 , the photovoltaic panel cleaning robot has two

edge walking devices

301 , 304 and a middle walking device 303 , and a brush 306 is arranged between the walking devices. When the robot is walking, the brush 306 rotates around the brush core shaft to clean the photovoltaic panel.

A telescopic torsion joint structure is connected between the brush core shaft and the brush support shaft on the walking device. The telescopic torsion joint structure is the same as the telescopic torsion joint structure 200 of the second embodiment, and will not be described in detail.

In the above-mentioned photovoltaic panel cleaning robot, a retractable torsion joint structure is added between the brush core shaft and the brush support shaft on the walking device. When one end of the cleaning robot turns left around the rotating shaft and the other end turns right around the rotating shaft, without destroying the original rigid connection, the walking device and the brush core shaft form a certain angle and do not affect the transmission of power. This structure can make the brush smoothly follow the twisting of the cleaning robot and compensate for the change in the interval between the brush support shafts caused by the twisting of the two ends of the cleaning robot in opposite directions.

FIG. 16 to FIG. 17 show a specific connection structure between the telescopic torsion joint structure 200 and the brush core shaft 314 .

Referring to Figures 16 and 17, in this embodiment, the outer rod 201 of the telescopic torsion joint structure 200 is connected to the brush mandrel 314, and the inner rod 202 of the telescopic torsion joint structure 200 is used to fix the brush support shaft. Among them, the brush mandrel 314 adopts a metal tube, and the outer rod 201 of the telescopic torsion joint structure 200 is embedded at the end of the metal tube and fixedly connected to the metal tube. The metal tube used as the brush mandrel is preferably an aluminum tube, so as to reduce the weight of the cleaning robot. It is preferred to set an embossing structure on the inner wall of the metal tube and the outer wall of the outer rod 201 to increase the friction of the joint and avoid relative rotation. In this embodiment, the characteristic of the brush mandrel 314 as a tube structure is utilized, and the outer rod 201 of the telescopic torsion joint structure 200 is embedded at the end of the brush mandrel 314 and fixedly connected to the brush mandrel 314. It does not need to add accessories such as a clamp to the brush mandrel 314, and the structure is simpler and more convenient to install.

Furthermore, the metal tube used as the brush core shaft 314 is a double-layer tube, and a plug 315 is embedded in the end of the inner tube. The end of the outer rod body 201 of the telescopic torsion joint structure 200 abuts against the plug 315 to increase the contact area between the outer rod body 201 and the end of the brush core shaft 314.

Further referring to FIG. 7 and FIG. 9 , an axial hole 210 and a key slot 209 are provided at the outer end of the inner rod body 202 of the telescopic torsion joint structure 200. The connection between the inner rod body 202 of the telescopic torsion joint structure 200 and the brush support shaft is realized through the axial hole 210 and the key slot 209. Specifically, the axial hole 210 cooperates with the brush support shaft, and the key slot 209 cooperates with the key on the brush support shaft to fix the inner rod body 202 with the brush support shaft. With this structure, there is no need to use a clamp, the structure is simpler, and the installation is more convenient.

The present invention is described in detail above through specific embodiments, and these detailed descriptions are only limited to helping those skilled in the art understand the content of the present invention, and cannot be understood as limiting the scope of protection of the present invention. Various modifications, equivalent transformations, etc. made by those skilled in the art to the above scheme under the conception of the present invention should be included in the scope of protection of the present invention.

Claims

A telescopic torsion joint structure, characterized by comprising:

An outer rod body having a first hole extending axially and a second hole extending radially;

an inner rod body, one end of which is inserted into the first hole and a gap is formed between the inner rod body and the hole wall of the first hole so that the inner rod body can swing relative to the outer rod body, and the inner rod body is provided with a third hole corresponding to the second hole; and

A connecting pin, which is inserted into the second hole and the third hole;

One of the second hole and the third hole is a waist hole, and the long side of the waist hole is parallel to the axis of the rod body where the waist hole is located.
The telescopic torsion joint structure according to claim 1 is characterized in that the length of the waist hole is configured to be 3 to 5 mm larger than the diameter of the connecting pin, and the size of the gap is configured so that the maximum swing angle of the inner rod body relative to the outer rod body can reach 10° to 12°.
A photovoltaic panel cleaning robot comprises a wheel axle and a transmission rod connecting two wheel axles, wherein a telescopic torsion joint structure as claimed in claim 1 is connected between the transmission rod and the wheel axle.
The photovoltaic panel cleaning robot according to claim 3 is characterized in that the end of the inner rod body is opposite to the end of the transmission rod and is fixedly connected with a clamp, the outer rod body is a tube structure, the wheel axle is inserted into the tube structure and is fixedly connected to the tube structure.
The photovoltaic panel cleaning robot according to claim 4 is characterized in that the end of the tube structure connected to the wheel axle is provided with a long groove along the axial direction of the tube structure, and is provided with a first connecting bolt, and the first connecting bolt passes through the tube structure and the wheel axle in a direction perpendicular to the long groove to fix the tube structure to the wheel axle.
The photovoltaic panel cleaning robot according to claim 4 is characterized in that the transmission rod is a metal tube, and the joint surface between the metal tube and the clamp, and the joint surface between the inner rod body and the clamp are provided with an embossed structure, and the clamp is provided with a second and a third connecting bolt, the second connecting bolt passes through the clamp and the metal tube, and the third connecting bolt passes through the clamp and the inner rod body.
A photovoltaic panel cleaning robot comprises a brush core shaft and a brush support shaft, wherein the brush core shaft and the brush support shaft are connected with the retractable torsion joint structure as claimed in claim 1.
According to the photovoltaic panel cleaning robot according to claim 7, it is characterized in that the brush core shaft is a metal tube, the outer rod body is embedded in the end of the metal tube and is fixedly connected to the metal tube, and the inner rod body is fixedly connected to the brush support shaft.
The photovoltaic panel cleaning robot according to claim 8 is characterized in that an axial hole and a key slot are provided at the outer end of the inner rod body, the axial hole cooperates with the brush support shaft, and the key slot cooperates with the key on the brush support shaft to fix the inner rod body to the brush support shaft.
The photovoltaic panel cleaning robot according to claim 7 is characterized in that the first hole of the outer rod body is a trumpet hole.