Device for cleaning the surface of photovoltaic panels

Abstract

Device for cleaning the surface of photovoltaic panels, characterized in that it comprises the following: an adjustment unit (1) comprising a handle end (11), a connecting assembly (12) hinged to the front end of the handle end (11), two sets of slide rails (13) hinged to both ends of the connecting assembly (12), and an opening and closing assembly (14) connected to both sides of the handle end (11); a sweeping unit (2) located on both sides of the end section of the adjusting unit (1); wherein the sweeping unit (2) comprises an electric motor (21) slidably connected to the slide rail (13), a sweeping disc (22) fixedly connected to the base of the electric motor (21), a cable (23) connected to one side of the opening and closing assembly (14) and a load-bearing assembly (24) fixedly arranged on the outside of the electric motor (21).

Description

TECHNICAL AREA

[0001] The present invention relates to the cleaning technology for photovoltaic panels, in particular a device for cleaning the surface of photovoltaic panels. STATE OF THE ART

[0002] As a core component of solar power generation, the cleanliness of the surface of photovoltaic panels directly determines the efficiency of light energy conversion. However, photovoltaic panels are exposed to the outdoor environment for extended periods, making them susceptible to the accumulation of dust, sand particles, bird droppings, and industrial pollutants, which can reduce light reflection and impair light energy absorption efficiency. Studies show that a dust layer thickness of 0.1 mm on the surface of photovoltaic panels can decrease power generation efficiency by 5% to 10%; if the contaminants are not removed promptly, the efficiency loss can exceed 30%. To maintain power generation performance, photovoltaic panels must be thoroughly cleaned regularly.Existing cleaning technologies primarily use manual or semi-automatic devices, but semi-automatic devices can only be used in certain application scenarios, which is why manual cleaning is more commonly used.

[0003] Conventional cleaning devices with two brush discs use two brushless electric motors to drive the cleaning brush discs, thus increasing the output torque. The operator carries the battery pack and holds a retractable pole equipped with the electric motors and cleaning brush discs to perform the cleaning. However, the fixed distance between the brush discs cannot be adjusted for photovoltaic panels of varying sizes or installation angles. Photovoltaic panels have various installation configurations, including flat, inclined, and split arrangements. The distance between adjacent photovoltaic panels varies considerably depending on the installation method.In large photovoltaic power plants, the standard spacing between components is typically 500–800 mm, while the spacing for edge components or non-standard areas can be less than 300 mm. A device with two brush discs and a fixed spacing cannot be dynamically adjusted, leading to misalignment between the brush discs and the edges of the photovoltaic panels during cleaning of non-standard areas, resulting in blind spots (overlooked areas). Alternatively, in standard areas, an insufficient spacing between the brush discs leads to overlapping of adjacent brush discs (repeated brushing), causing surface friction damage. Furthermore, during water-assisted cleaning, variations in motor speed can result in inconsistent water spray patterns.High-speed rotating brush discs can fling water droplets into adjacent brush disc areas, leading to local water accumulation. CONTENT OF THE PRESENT INVENTION

[0004] The technical problem that the present invention is intended to solve is therefore that in existing cleaning devices with two brush discs for photovoltaic panels, the distance between the brush discs cannot be adjusted.

[0005] The above-mentioned technical problem is solved by the following technical solution: the present invention provides a device for cleaning the surface of photovoltaic panels, comprising: an adjustment unit comprising a handle end, a connecting assembly hinged to the front end of the handle end, two sets of slide rails hinged to both ends of the connecting assembly, and an opening and closing assembly connected to both sides of the handle end; a sweeping unit located on both sides of the end section of the adjusting unit; wherein the sweeping unit comprises an electric motor slidably connected to the slide rail, a spring washer fixedly connected to the base of the electric motor, a cable connected to one side of the opening and closing assembly, and a load-bearing assembly fixedly arranged on the outside of the electric motor. In a preferred embodiment of a device for cleaning the surface of photovoltaic panels according to the present invention, the handle end comprises a handle, a sleeve rod axially connected to one side of the handle, and an extendable long rod connected to one side of the sleeve rod; wherein the extendable long rod comprises an axle rod arranged at its end section.

[0006] In a preferred embodiment of a device for cleaning the surface of photovoltaic panels according to the present invention, the connecting assembly comprises several sets of plug-in tubes that are mounted on both ends of one side of the slide rail, and sleeves that are simultaneously hinged to the outside of the plug-in tubes; wherein the sleeve comprises a first sleeve piece mounted on the connecting tube and a second sleeve piece articulated to the axle rod. In a preferred embodiment of a device for cleaning the surface of photovoltaic panels according to the present invention, the load-bearing assembly comprises a load-bearing platform fixedly mounted on the outside of the electric motor, bolts screwed to both sides of the load-bearing platform, and a hinge element fixedly arranged at one end section of the load-bearing platform of the bolts; wherein the bolts comprise rollers arranged on both sides of them, and wherein the rollers are slidably clamped in the slide rails. In a preferred embodiment of a device for cleaning the surface of photovoltaic panels according to the present invention, the joint element comprises an angle steel arranged at an end section of the load-bearing platform, a drive shaft fixedly arranged at an end section of the angle steel and a wire clamp fixedly arranged at the bottom of the angle steel. In a preferred embodiment of a device for cleaning the surface of photovoltaic panels according to the present invention, the opening and closing assembly comprises two sets of pull arms, a sliding ring articulated to another end of the pull arm, a rotary disc articulated to both ends of the axle rod, and a transmission belt arranged on the rotary disc. In a preferred embodiment of a device for cleaning the surface of photovoltaic panels according to the present invention, the pull arm comprises a rotating ring articulated to the circumferential side of the drive shaft, a connecting end articulated to one end of the rotating ring and one side of the sliding ring, and a rod element screwed to the inside of the connecting end. In a preferred embodiment of a device for cleaning the surface of photovoltaic panels according to the present invention, the rotary disc comprises a synchronous disc for interlocking with the transmission belt and a cable disc projecting from the front end of the synchronous disc. In a preferred embodiment of a device for cleaning the surface of photovoltaic panels according to the present invention, the sliding ring comprises a sliding table slidably mounted on the outside of the extendable long rods, a rotary rod articulated to both sides of the sliding table, and fixed wheels projecting from the end face of the sliding table; the stationary wheels are firmly attached to the transmission belt. In a preferred embodiment of a device for cleaning the surface of photovoltaic panels according to the present invention, the end section of the transmission belt is provided with a winding wheel; a cable clamp sleeve is permanently attached to the connecting tube for clamping the cable.

[0007] The advantageous effects of the present invention are as follows: the device achieves a continuous, stepless adjustment of the sweeping distance through the linear guide structure of the slide rail and the roller, thus precisely eliminating the problem of cleaning dead zones caused by fixed distances in conventional devices, so that the sweeping unit can move synchronously to the center or to the outside, with the cleaning path always in contact with the edge of the photovoltaic panel, thereby completely eliminating water residues and cleaning blind spots caused by the impossibility of adjusting the distance in conventional devices.

[0008] Furthermore, the power transmission and cable winding and unwinding functions are integrated via a rotary disc: the transmission belt transfers power via the rotating synchronous disc to move the sliding ring for distance adjustment, while the cable pulley rotates coaxially with the synchronous disc to synchronously loosen or tighten the cable, ensuring that the cable remains under tension without any stress concentration points. This completely eliminates the risk of cable breakage caused by mechanical displacement in conventional devices. BRIEF DESCRIPTION OF THE DRAWING

[0009] To more clearly explain the technical solution in the exemplary embodiments of the present invention, the accompanying drawings of these embodiments are briefly presented below. It is evident that the following drawings relate only to some exemplary embodiments of the present invention and do not represent a limitation of the present invention. Fig. Figure 1 shows a schematic diagram of the overall structure of a device for cleaning the surface of photovoltaic panels according to the present invention; Fig. Figure 2 shows a schematic diagram of the structure of an adjustment unit of a device for cleaning the surface of photovoltaic panels according to the present invention; Fig. Figure 3 shows a schematic diagram of a sweeping structure of a device for cleaning the surface of photovoltaic panels according to the present invention; Fig. Figure 4 shows an enlarged view of the structure of a connecting assembly at location A according to Fig. 1 of the present invention; Fig. Figure 5 shows a partial schematic diagram of an extendable rod according to the present invention. DETAILED DESCRIPTION

[0010] In order to enable experts in this field to better understand the present invention, the present invention will be explained in more detail below with reference to a specific embodiment and the accompanying drawings.

[0011] The terms used in the present invention are general terms that are currently widely used in this field, taking into account the functions of the present invention. However, these terms may vary depending on intent, precedents, or new technologies in this field, as interpreted by those skilled in the art. Furthermore, certain terms may be selected by the applicant, in which case their precise meaning will be explained in the detailed description of the present invention. Therefore, the terms used in the description should not be understood as mere designations, but rather as being based on the meaning of the terms and the overall description of the invention.

[0012] See Fig. 1, Fig. 2, Fig. 3, Fig. 4 to Fig. 5, the present embodiment provides a device for cleaning the surface of photovoltaic panels, comprising: an adjustment unit 1 comprising a handle end 11, a connecting assembly 12 hinged to the front end of the handle end 11, two sets of slide rails 13 hinged to both ends of the connecting assembly 12, and an opening and closing assembly 14 connected to both sides of the handle end 11; a sweeping unit 2 located on both sides of the end section of the adjusting unit 1; wherein the sweeping unit 2 comprises an electric motor 21 slidably connected to the slide rail 13, a sweeping disc 22 fixedly connected to the base of the electric motor 21, a cable 23 connected to one side of the opening and closing assembly 14, and a load-bearing assembly 24 fixedly arranged on the outside of the electric motor 21. In an embodiment provided by the present application, the handle end 11 comprises a handle 111, a sleeve rod 112 axially connected to one side of the handle 111, and an extendable long rod 113 connected to one side of the sleeve rod 112; wherein the extendable long rod 113 comprises an axle rod 1131 arranged at its end section.

[0013] In the present embodiment, the adjusting unit 1 can adjust the distance between the sweeping units 2. The handle end 11 serves as the operator's grip. The operator holds the handle 111 and the sleeve rod 112 and uses the telescopic adjustment function of the extendable long rod 113 to lay the sweeping unit 2 flat on the surface of the photovoltaic panel. An axle rod 1131 is welded to the end section of the extendable long rod 113 in a direction perpendicular to the axial direction of the extendable long rod 113. The axle rod 1131 is pivotally connected to the connecting assembly 12, allowing rotation about the axle rod 1131 as an axis to adjust the angle between the sweeping unit 2 and the extendable long rod 113. The connecting assembly 12 is connected to both sides of the slide rail 13 via a sleeve.The slide rail 13 has two sides, each arranged on either side of the extendable long rod 113. The slide rail 13 is a U-shaped annular rail that allows both ends of the slide rail 13 to be easily connected to the inside of the connecting assembly 12 via a sleeve, thereby docking the two sets of slide rails 13. Preferably, the sweeping unit 2 is slidably clamped to each set of slide rails 13, so that the sweeping unit 2 can move on the slide rail 13, thereby allowing the distance between the sweeping units 2 to be adjusted.

[0014] Furthermore, the load-bearing assembly 24 located on each side is suspended from the base of the slide rail 13. The load-bearing assembly 24 is clamped around the circumference of the electric motor 21 via its own structure, while the other side of the load-bearing assembly 24 is suspended from the base of the slide rail 13. The load-bearing assembly 24 is simultaneously connected to the opening and closing assembly 14. The opening and closing assembly 14 consists of two sets, each mounted on either side of the extendable long rod 113, thus enabling independent control of the sliding movement of the sweeping unit 2 on one side.

[0015] Preferably, the length adjustment of the extendable long rod 113 is achieved by a multi-stage sleeve structure, wherein an anti-loosening retaining spring is provided between the outer sleeve and the inner extendable rod. When the operator turns the handle 111, the sleeve rod 112 drives the extendable long rod 113 to extend and retract it via a gear drive mechanism; the axle rod 1131 is a spherical bearing and is articulated to the connecting assembly 12, allowing the sweeping unit 2 to be tilted by 15°–30° in the vertical plane to adapt to different heights or positions.

[0016] Furthermore, a spring-loaded disc 22 is rigidly connected to the output shaft at the base of the electric motor 21, with the electric motor 21 driving the spring-loaded disc 22 to rotate in order to perform rotary cleaning of the photovoltaic panel surface. Preferably, the electric motor 21 is a brushless electric motor, and the cleaning disc 22 comprises flexible bristles arranged on the underside of the disc, flexible scrapers embedded between the flexible bristles, and a superhydrophobic coating embedded at the end section of the scrapers. The flexible bristles are made of polyurethane material with a longitudinal hardness of Shore A 50-60 and a transverse elastic deformation of 15% to 20%; the flexible scrapers are made of silicone material with a wave-shaped protrusion structure on the surface for removing sticky contaminants.The superhydrophobic coating 223 is formed by spraying nano-fluorocarbon resin with a contact angle greater than 150°, thereby reducing water spot residue to below 85%.

[0017] See Fig. 1, Fig. 2 to Fig. 3, in an optional embodiment, the connecting assembly 12 comprises several sets of plug-in tubes 121 which are mounted on both ends of one side of the slide rail 13, and sleeves 122 which are simultaneously hinged to the outside of the plug-in tubes 121; wherein the sleeve 122 comprises a first sleeve piece 1221 mounted on the connecting tube 121 and a second sleeve piece 1222 articulated to the axle rod 1131. In an embodiment provided by the present application, the load-bearing assembly 24 comprises a load-bearing platform 241 fixedly mounted on the outside of the electric motor 21, bolts 242 screwed to both sides of the load-bearing platform 241, and a hinge element 243 fixedly arranged on an end section of the load-bearing platform 241 of the bolts 242; wherein the bolts 242 comprise rollers 2421 arranged on both sides of them, and wherein the rollers 2421 are slidably clamped in the slide rails 13.

[0018] In the present embodiment, the connecting tube 121 of the connecting assembly 12 is a connecting rod that can connect the slide rails 13 on both sides, while the sleeve 122 pivotally connects the two sets of docked connecting tubes 121, located at the base, to the axle rod 1131 of the extendable long rod 113. The sleeve 122 has an integrated three-tube structure, with each tube's inner wall equipped with an elastic sealing ring. The two sets of first sleeve sections 1221 are each mounted on the outside of the connecting tube 121, while the second sleeve section 1222 forms a pivot structure with the axle rod 1131 of the extendable long rod 113.The two sets of first sleeve pieces 1221 and the second sleeve piece 1222 are firmly connected to each other to form a stable triangular relationship, so that only the axle rod 1131 can rotate relative to the second sleeve piece 1222, which facilitates stepless adjustment of the angle of the extendable long rod 113.

[0019] Preferably, the electric motor 21 is supported by a semi-enclosed load-bearing metal frame platform 241, which is clamped to the casing of the electric motor, wherein the bolts 242 penetrate the two sides of the bottom of the frame of the load-bearing platform 241, and wherein the rollers 2421 welded to the end section of the bolts 242 contact the inner slide rail of the slide rails 13, so that the rollers 2421 are slidably embedded in the slide rails 13 on both sides of the electric motor 21, thereby achieving a suspended sliding connection.Furthermore, a joint element 243 is firmly connected to the upper end surface of one of the sides of the load-bearing platform 241 facing the extendable long rod 113, and is articulated to the opening and closing assembly 14, so that the opening and closing assembly 14 can pull the joint element 243 when moving along the axial direction of the extendable long rod 113, causing the electric motor 21 to move linearly on the slide rail 13.

[0020] Preferably, the load-bearing assembly 24 rolls over the rollers 2421 along the inside of the slide rail 13, the rollers are made of high molecular weight polyformaldehyde material and have a graphite lubricating layer on their surface to reduce the coefficient of friction;

[0021] Preferably, the motion control of the sweeping unit 2 is achieved by two methods: firstly, the clamping assembly 14 is connected to the joint element 243 via a high-strength steel cable, a ratchet locking mechanism being arranged at the end section of the steel cable, and the operator adjusts the tension of the steel cable by turning the handle, thereby causing the rollers 2421 to move precisely along the guide rail 13 and thus achieving linear scanning of the sweeping disc 22 across the surface of the photovoltaic panel; secondly, the clamping assembly 14 has a screw-like split connection structure with a trapezoidal threaded adjustment knob at the end of the connecting rod, and by changing the length of the connecting rod the roller 2421 can be positioned and fixed, making this design particularly suitable for scenarios where precise cleaning of stubborn dirt is required;The two control methods utilize the bearings of the joint element 243 to convert the direction of movement and thus ensure the movement precision and stability of the sweeping unit 2 under complex operating conditions.

[0022] See Fig. 1, Fig. 2, Fig. 3, Fig. 4 to Fig. 5, in an optional embodiment, the joint element 243 comprises an angle steel 2431 arranged at an end section of the load-bearing platform 241, a drive shaft 2432 fixedly arranged at an end section of the angle steel 2431 and a wire clamp 2433 fixedly arranged at the bottom of the angle steel 2431.

[0023] In an embodiment provided by the present application, the opening and closing assembly 14 comprises two sets of pull arms 141, a sliding ring 142 articulated to another end of the pull arm 141, a turntable 143 articulated to both ends of the axle rod 1131 and a transmission belt 144 arranged on the turntable 143.

[0024] In an embodiment provided by the present application, the drawbar 141 comprises a rotating ring 1411 articulated to the circumferential side of the cardan shaft 2432, a connecting end 1412 articulated to one end of the rotating ring 1411 and to one side of the sliding ring 142, and a rod element 1413 screwed to the inside of the connecting end 1412.

[0025] In an embodiment provided by the present application, the sliding ring 142 comprises a sliding table 1421 slidably mounted on the outside of the extendable long rods 113, a rotary rod 1422 articulated to both sides of the sliding table 1421 and fixed wheels 1423 projecting from the end face of the sliding table 1421; wherein the stationary wheels 1423 are firmly mounted on the transmission belt 144.

[0026] In the present embodiment, the joint element 243 has a three-way limiting structure, wherein the angle steel 2431 is welded to the end section of the load-bearing platform 241 via an L-shaped bending operation with a bending angle of 90° and forms a rigid support frame; the drive shaft 2432 is embedded in the shaft bore at the end section of the angle steel 2431, with a ball bearing located on the inner wall of the shaft bore to enable low-friction rotation; the wire clamp 2433 is attached to the bottom of the angle steel 2431 via a threaded connection element, its clamping part having a V-shaped groove that can be clamped with the cable 23 on the underside of the slide rail 13 to prevent an interruption of the power supply at the connection end of the cable 23 due to tensile forces during the movement of the electric motor 21.

[0027] Preferably, the opening and closing assembly 14 forms a connection system with the rotary disc 143 and the transmission belt 144, wherein the rotary disc 143 is pluggably hinged to both ends of the axle rod 1131 and its outer edge is provided with a toothed projection structure. The transmission belt 144 is designed as a synchronous belt, the teeth of which engage in the toothed projections on the rotary disc 143 to transmit power. When the operator pulls the transmission belt 144, the rotary disc 143 rotates, thereby reversing the direction of the transmission belt 144. The transmission belt 144 then drives the sliding ring 142 to move along the axial direction of the extendable long rod 113, and the displacement of the sliding ring 142 drives the pull arm 141 to complete the opening and closing movement.The fitting structure between the rotary disk 143 and the transmission belt 144 adopts a double-sided symmetrical arrangement to ensure a balanced distribution of force on both sides of the opening and closing assembly 14 while simultaneously driving the two sets of electric motors 21 for displacement.

[0028] Furthermore, the pull arm 141 forms a pivoting pair with the drive shaft 2432 via the rotary ring 1411, the inner wall of the rotary ring 1411 being provided with a ball bearing to allow pivoting at multiple angles; the connecting end 1412 adopts a pivoting ear plate structure, with one end being hinged to the rotary ring 1411 and the other end being connected via a pin bolt to the rotary rod 1422 of the sliding ring 142, thus forming a four-bar linkage mechanism; the rod element 1413 is screwed to the inside of the connecting end 1412; by adjusting the insertion depth of the rod element 1413, the effective length of the pull arm 141 can be changed, thereby allowing the stroke range of the opening and closing assembly 14 to be adapted to the cleaning requirements for photovoltaic panels of different thicknesses.

[0029] Furthermore, the sliding ring 142 forms, as in Fig. Figure 5 shows a sliding pair with the extendable long rod 113 via the sliding table 1421. The outer wall of the sliding table 1421 is provided with an annular guide groove which interacts with the axial keyway of the extendable long rod 113 to limit circumferential rotation; the rotary rod 1422 is articulated to the ear plate structures on both sides of the sliding table 1421, and the opening and closing drive of the pull arm 141 is achieved by pivoting the rotary rod 1422; the stationary wheel 1423 is attached to the end face of the sliding table 1421 via a keyway, and its wheel groove shape matches the tooth profile of the transmission belt 144, and the transmission belt 144 is wound around the stationary wheel 1423 for one turn to create a tight connection;When the transmission belt 144 is pulled, the turntable 143 rotates to reverse the transmission belt 144, thereby driving the stationary wheel 1423 by the transmission belt 144 to move along the axial direction of the extendable long rod 113; then the pulling arm 141 is driven by the pivoting of the rotary rod 1422 to complete the opening and closing movement; finally, the opening and closing movement is converted into a linear displacement of the sweeping unit 2.

[0030] See Fig. 2, Fig. 4 and Fig. 5, in an optional embodiment, the rotary disk 143 comprises a synchronous disk 1431 for interlocking with the transmission belt 144 and a cable pulley 1432 projecting from the front end of the synchronous disk 1431.

[0031] In an embodiment provided by the present application, the end section of the transmission belt 144 is provided with a winding wheel 31; wherein a cable clamping sleeve 32 for clamping the cable 23 is fixedly arranged on the plug tube 121.

[0032] In the present embodiment, the rotary disk 143 has a two-layer structure, one side being the synchronous disk 1431 for interlocking with the transmission belt 144 and the other side being the cable disk 1432 for winding and arranging the cable 23 of the electric motor 21.The cable pulley 1432 is rigidly connected to the synchronous pulley 1431 via a shaft, so that the cable pulley 1432 rotates when the synchronous pulley 1431 rotates, thereby cooperating with the rotation of the synchronous pulley 1431 to drive the transmission belt 144, which drives the sliding ring 142 to move and drives the pull arm 141 to pull the electric motors 21 on both sides to move linearly along the slide rail 13, while at the same time the cable 23 on one side of the electric motor 21 is tensioned or released, thus achieving synchronous order of the cable 23 and avoiding power failures caused by the pulling of the connecting end of the cable 23 due to spacing adjustments.

[0033] Preferably, the winding wheel 31 at the end section of the transmission belt 144 serves as a power source for the transmission belt 144. The rotation of the winding wheel 31 drives the transmission belt 144 to move along the axial direction of the extendable long rod 113.

[0034] Preferably, the cable clamp sleeve 32 on the connecting tube 121 has a one-piece arc-shaped structure with a cable clamp on its underside. The cable clamp allows a sliding connection of the cable 23 without hindering the forward or backward rotation of the cable disc 1432 for releasing or tightening the cable 23. This prevents the cable 23 from becoming entangled on the surface of the photovoltaic panel and ensures a dynamic balance of the tension force of the cable 23.

[0035] Finally, it should be noted that the methods and devices described in detail above are only exemplary embodiments of the implementation and that those skilled in the art may modify these exemplary embodiments in various ways, as long as they do not deviate from the scope of the present invention.

Claims

[1] Device for cleaning the surface of photovoltaic panels, characterized by that it includes the following: an adjustment unit (1) comprising a handle end (11), a connecting assembly (12) hinged to the front end of the handle end (11), two sets of slide rails (13) hinged to both ends of the connecting assembly (12), and an opening and closing assembly (14) connected to both sides of the handle end (11); a sweeping unit (2) located on both sides of the end section of the adjusting unit (1); wherein the sweeping unit (2) comprises an electric motor (21) slidably connected to the slide rail (13), a sweeping disc (22) fixedly connected to the base of the electric motor (21), a cable (23) connected to one side of the opening and closing assembly (14) and a load-bearing assembly (24) fixedly arranged on the outside of the electric motor (21). [2] Device for cleaning the surface of photovoltaic panels according to claim 1, characterized by , that the handle end (11) comprises a handle (111), a sleeve rod (112) axially connected to one side of the handle (111) and an extendable long rod (113) connected to one side of the sleeve rod (112); wherein the extendable long rod (113) comprises an axle rod (1131) arranged at its end section. [3] Device for cleaning the surface of photovoltaic panels according to claim 2, characterized by , that the connecting assembly (12) comprises several sets of plug-in tubes (121) which are mounted on both ends of one side of the slide rail (13), and sleeves (122) which are simultaneously hinged to the outside of the plug-in tubes (121); wherein the sleeve (122) comprises a first sleeve piece (1221) mounted on the connecting tube (121) and a second sleeve piece (1222) articulated to the axle rod (1131). [4] Device for cleaning the surface of photovoltaic panels according to claim 3, characterized by , the load-bearing assembly (24) comprises a load-bearing platform (241) fixedly mounted on the outside of the electric motor (21), bolts (242) screwed to both sides of the load-bearing platform (241) and a joint element (243) fixedly arranged on an end section of the load-bearing platform (241) of the bolts (242); wherein the bolts (242) comprise rollers (2421) arranged on both sides of them, and wherein the rollers (2421) are slidably clamped in the slide rails (13). [5] Device for cleaning the surface of photovoltaic panels according to claim 4, characterized by, the joint element (243) comprises an angle steel (2431) arranged at an end section of the load-bearing platform (241), a cardan shaft (2432) fixedly arranged at an end section of the angle steel (2431) and a wire clamp (2433) fixedly arranged at the bottom of the angle steel (2431). [6] Device for cleaning the surface of photovoltaic panels according to claim 5, characterized by , that the opening and closing assembly (14) comprises two sets of pull arms (141), a sliding ring (142) articulated to another end of the pull arm (141), a turntable (143) articulated to both ends of the axle rod (1131) and a transmission belt (144) arranged on the turntable (143). [7] Device for cleaning the surface of photovoltaic panels according to claim 6, characterized by, that the drawbar (141) comprises a rotating ring (1411) articulated to the circumferential side of the cardan shaft (2432), a connecting end (1412) articulated to one end of the rotating ring (1411) and one side of the sliding ring (142), and a rod element (1413) screwed to the inside of the connecting end (1412). [8] Device for cleaning the surface of photovoltaic panels according to claim 7, characterized by , that the turntable (143) comprises a synchronous disc (1431) for interlocking with the transmission belt (144) and a cable pulley (1432) projecting from the front end of the synchronous disc (1431). [9] Device for cleaning the surface of photovoltaic panels according to claim 8, characterized by, that the sliding ring (142) comprises a sliding table (1421) slidably mounted on the outside of the extendable long rods (113), a rotary rod (1422) articulated to both sides of the sliding table (1412) and fixed wheels (1423) projecting from the end face of the sliding table (1421); wherein the fixed wheels (1423) are fixedly mounted on the transmission belt (144). [10] Device for cleaning the surface of photovoltaic panels according to claim 9, characterized by , that the end section of the transmission belt (144) is provided with a winding wheel (31); wherein a cable clamping sleeve (32) for clamping the cable (23) is fixedly arranged on the plug tube (121).

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