Crawler chassis and robot for cleaning high-altitude glass curtain wall

Abstract

The invention provides a crawler chassis and a robot for cleaning a high-altitude glass curtain wall, and belongs to the technical field of high-altitude operation equipment. Comprising a transmission support, a power device and a track assembly, the power device is arranged on the transmission support and comprises a driving motor, an air bin and an air pump, an air bag connected with the air pump is arranged in the air bin, and a negative pressure opening is formed in the bottom of the air bag. The track assembly comprises a track and a transmission wheel set connected with the transmission support, and the driving motor is in transmission connection with the transmission wheel set. The crawler belt is connected to the transmission wheel set in a wound mode, a plurality of suction cups are evenly arranged on the outer surface of the crawler belt at intervals in the length direction, and a plurality of air holes matched with the negative pressure opening and connected with the suction cups in a one-to-one correspondence mode are formed in the inner surface of the crawler belt. The air bin is arranged in an annular space formed by the crawler belt and makes contact with the section, located at the bottom, of the crawler belt. The adaptability and working safety of the robot body to the wall surface working environment during high-altitude glass curtain wall cleaning operation can be improved while the structural light weight is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of aerial work equipment, and in particular to a crawler chassis and a robot for cleaning aerial glass curtain walls. Background Art

[0002] As a new type of architectural decorative wall, glass curtain wall not only retains the original function of glass, but also has architectural aesthetic design, which has a beautifying effect on the building and brings people a beautiful and novel visual effect. However, due to the deposition of pollutants such as dust, haze, sandstorms and bird excrement in the air on the surface of the glass curtain wall, it greatly affects the beauty and light transmittance of the building. Therefore, it needs to be cleaned regularly.

[0003] In the related technologies, the commonly used high-altitude glass curtain wall operation methods are mostly manual operations, which use auxiliary equipment such as artificial hanging baskets and elevators to carry out manned construction through the side walls of high-rise buildings. This method is not only costly and inefficient, but also endangers the personal safety of operators. Furthermore, the use of related high-altitude glass curtain wall cleaning robots for cleaning operations has gradually become the mainstream.

[0004] The operation method in the related technology usually requires a high-power motor to drive the negative pressure adsorption component to provide negative pressure, so that the robot body can be adsorbed on the high-altitude glass curtain wall for cleaning. Although it can ensure stable adsorption during the cleaning process, the adsorption component used for adsorption on the wall has a single structure and can only ensure stable operation on a single wall. When encountering obstacles such as glass gaps and wall protrusions, there is a risk of falling off, and the work safety is poor. Summary of the invention

[0005] The embodiment of the present invention provides a crawler chassis and a robot for cleaning high-altitude glass curtain walls, which can achieve lightweight structure while improving the adaptability and working safety of the robot body to the wall working environment during high-altitude glass curtain wall cleaning operations. The technical solution is as follows:

[0006] In a first aspect, an embodiment of the present invention provides a crawler chassis for cleaning high-altitude glass curtain walls, comprising: a transmission bracket, a power device and a crawler assembly.

[0007] The power device is arranged on the transmission bracket, and includes a driving motor, an air chamber and an air pump. An air bag connected to the air pump is arranged in the air chamber, and a negative pressure port is arranged at the bottom of the air bag;

[0008] The track assembly includes a track and a transmission wheel group connected to the transmission bracket, the drive motor is transmission-connected to the transmission wheel group, the track is wound around the transmission wheel group, a plurality of suction cups are evenly spaced along the length direction on the outer surface of the track, a plurality of air holes matching the negative pressure port and connected one-to-one with the plurality of suction cups are provided on the inner surface of the track, the air chamber is arranged in the annular space formed by the track and in contact with the section of the track at the bottom.

[0009] Optionally, a sealing layer is provided on the inner surface of the crawler and is in contact with the bottom of the air bin through the sealing layer, and the air holes are provided on the sealing layer.

[0010] Optionally, a concave cavity is provided on the inner wall of the airbag, and the bottom of the concave cavity is connected to the negative pressure port.

[0011] Optionally, the concave cavity is circular, and the opening diameter of the concave cavity on the inner wall of the airbag is 2 cm larger than the diameter of the negative pressure port.

[0012] Optionally, the sealing layer is a strip-shaped thin steel sheet arranged along the length direction of the track.

[0013] Optionally, the surface of the sealing layer is coated with polytetrafluoroethylene adhesive.

[0014] Optionally, a plurality of circles of suction cups are provided on the outer surface of the track along the length direction, and the plurality of circles of suction cups are arranged at intervals along the width direction of the track, and the power device includes a plurality of air chambers matching the plurality of circles of suction cups.

[0015] Optionally, a vibration reduction assembly is also included, which includes a connecting plate and an elastic shock absorber. The connecting plate is connected to the transmission bracket and extends into the annular space formed by the track. The top of the air chamber is connected to the connecting plate through the elastic shock absorber.

[0016] Optionally, the suction cup is a rubber suction cup.

[0017] In the second aspect, an embodiment of the present invention provides a robot, comprising a plurality of crawler chassis for cleaning high-altitude glass curtain walls as described in the first aspect above, and also comprising a connecting arm and a cleaning module, the transmission brackets of two adjacent crawler chassis for cleaning high-altitude glass curtain walls are connected by the connecting arm, the middle part of the connecting arm has a rotating shaft structure, and the cleaning module is arranged on at least one of the transmission brackets.

[0018] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0019] The crawler chassis for cleaning high-altitude glass curtain walls provided in the embodiment of the present invention is used to carry the cleaning module to perform cleaning and maintenance work on the glass curtain walls. Compared with the prior art method that requires a high-power motor to drive the negative pressure component to provide negative pressure adsorption on the wall, the suction cup used for adsorption is integrated on the crawler used to drive the bearing body. The crawler-driven travel mode can cross obstacles such as glass gaps and wall protrusions, thereby improving the driving adaptability to the working surface. At the same time, an air chamber structure is provided, and the air bag structure connected to the air pump is used to cooperate with the suction cup on the moving crawler, and multiple suction cups are used to achieve multi-point stable adsorption of the wall. With this design, only the air pump needs to be controlled to achieve adsorption and desorption of the working surface, which simplifies its control, improves safety, and does not require the provision of a large negative pressure component. While achieving lightweight structure, the adaptability and work safety of the robot body to the wall working environment during high-altitude glass curtain wall cleaning operations can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 It is a schematic diagram of the three-dimensional structure of a crawler chassis for cleaning high-altitude glass curtain walls provided by an embodiment of the present invention;

[0022] Figure 2 It is a front view structural schematic diagram of a crawler chassis for cleaning high-altitude glass curtain walls provided by an embodiment of the present invention;

[0023] Figure 3 It is a schematic diagram of a top view of the structure of a crawler chassis for cleaning high-altitude glass curtain walls provided by an embodiment of the present invention;

[0024] Figure 4 is a schematic diagram of the inner structure of a crawler assembly provided in an embodiment of the invention;

[0025] Figure 5 yes Figure 4 A schematic diagram of the partial structure of the middle crawler assembly;

[0026] Figure 6 It is a structural cross-sectional view of the matching position of the air chamber and the crawler provided in an embodiment of the present invention;

[0027] Figure 7 is a control structure block diagram of a crawler chassis provided by an embodiment of the present invention;

[0028] Figure 8It is a schematic diagram of the structure of a robot provided by an embodiment of the present invention.

[0029] In the figure: 1-transmission bracket; 2-power device; 3-track assembly; 4-vibration reduction assembly; 5-connecting arm; 6-cleaning module; 21-driving motor; 22-air chamber; 23-air pump; 31-track; 32-transmission wheel group; 33-suction cup; 34-air hole; 35-sealing layer; 41-connecting plate; 42-elastic shock absorber; 51-rotating shaft structure; 231-air bag; 232-negative pressure port; 233-concave cavity; 321-driving wheel; 322-driven wheel; 323-composite load-bearing wheel. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0031] Figure 1 It is a schematic diagram of the three-dimensional structure of a crawler chassis for cleaning high-altitude glass curtain walls provided by an embodiment of the present invention; Figure 2 It is a front view structural schematic diagram of a crawler chassis for cleaning high-altitude glass curtain walls provided by an embodiment of the present invention; Figure 3 It is a schematic diagram of a top view of the structure of a crawler chassis for cleaning high-altitude glass curtain walls provided by an embodiment of the present invention; Figure 4 is a schematic diagram of the inner structure of a crawler assembly provided in an embodiment of the invention; Figure 5 yes Figure 4 A schematic diagram of the partial structure of the middle crawler assembly; Figure 6 It is a structural cross-sectional view of the matching position of the air chamber and the crawler provided in an embodiment of the present invention; Figure 7 : is a control structure block diagram of the crawler chassis provided by an embodiment of the present invention. Figures 1 to 7 As shown, an embodiment of the present invention provides a crawler chassis for cleaning high-altitude glass curtain walls, including a transmission bracket 1, a power device 2 and a crawler assembly 3.

[0032] The power device 2 is arranged on the transmission bracket 1, including a driving motor 21, an air chamber 22 and an air pump 23. An air bag 231 connected to the air pump 23 is arranged in the air chamber 22, and a negative pressure port 232 is arranged at the bottom of the air bag 231.

[0033] The crawler assembly 3 includes a crawler 31 and a transmission wheel group 32 connected to the transmission bracket 1. The driving motor 21 is in transmission connection with the transmission wheel group 32, and the crawler 31 is wound around the transmission wheel group 32. A plurality of suction cups 33 are evenly spaced along the length direction on the outer surface of the crawler 31. A plurality of air holes 34 matching the negative pressure port 232 and connected to the plurality of suction cups 33 are provided on the inner surface of the crawler 31. The air chamber 22 is arranged in the annular space formed by the crawler 31 and contacts the section of the crawler 31 at the bottom.

[0034] In an embodiment of the present invention, the crawler chassis is used to support the cleaning assembly to form a cleaning robot to perform high-altitude glass curtain wall cleaning operations. Among them, the transmission bracket 1 is centered, and a crawler assembly 3 is arranged on each side. In each crawler assembly 3, its transmission wheel group 32 includes a driving wheel 321, a driven wheel 322 and a plurality of composite load-bearing wheels 323, wherein the driving wheel 321 and the driven wheel 322 are arranged at intervals in the horizontal direction, wherein the driving wheel 321 is connected to the output shaft of the driving motor 21, and the plurality of composite load-bearing wheels 323 are sequentially arranged between the driving wheel 321 and the driven wheel 322 in the horizontal direction, and the relative height is lower than the driving wheel 321 and the driven wheel 322, and the driving wheels on both sides can be coaxially connected through a support shaft. After the crawler 31 is wound around the driving wheel set 32, the sections at the top of the driving wheel 321 and the driven wheel 322, and the sections at the bottom of the multiple composite load-bearing wheels 323 are relatively parallel, and the entire crawler chassis relies on the crawler 31 sections at the bottom of the multiple composite load-bearing wheels 323 to contact the glass curtain wall for travel. The crawler 31 sections at the front and rear sides of the travel direction, that is, between the driving wheel 321 and the closest composite load-bearing wheel 323, and between the driven wheel 322 and the closest composite load-bearing wheel 323, are tilted and turned with the crawler 31 sections at the bottom of the multiple composite load-bearing wheels 323, so that when encountering obstacles such as wall protrusions, transition and climbing can be performed, thereby increasing the contact area and travel stability. Correspondingly, an air chamber 22 connected to the transmission bracket 1 is arranged in the annular space formed by the crawler 31, and an air bag 231 connected to the air pump 23 is arranged inside the air chamber 22. When the robot using the crawler chassis performs a traveling operation on the glass curtain wall, the air bag 231 is pumped to a negative pressure through the air pump 23. When the crawler 31 rotates around the transmission wheel group 32 under the drive of the driving wheel 321, its inner surface also moves relative to the bottom of the air chamber 22. When the air hole 34 on the inner surface of the crawler 31 moves to the negative pressure port 232 at the bottom of the air bag 231, it is connected with the air bag 231 to generate a negative pressure environment inside the suction cup 33, so that the crawler 31 section at the bottom of the multiple composite load-bearing wheels 323 generates suction, so that the crawler chassis can be stably adsorbed on the glass curtain wall while moving on the glass curtain wall. After the suction cup 33 leaving the bottom of the air chamber 22 is separated from the negative pressure supply of the negative pressure port 232 of the air bag 231, the air hole 34 is connected to the atmosphere to achieve automatic desorption.

[0035] The crawler chassis for cleaning the high-altitude glass curtain wall provided in the embodiment of the present invention is used to carry the cleaning module to perform cleaning and maintenance work on the glass curtain wall. Compared with the method in the prior art that requires a high-power motor to drive the negative pressure component to provide negative pressure adsorption on the wall, the suction cup 33 used for adsorption is integrated on the crawler 31 used to drive the bearing body. The crawler-driven traveling mode can cross obstacles such as glass gaps and wall protrusions, thereby improving the driving adaptability to the working surface. At the same time, an air chamber 22 structure is provided, and the air bag 231 structure internally connected to the air pump 23 is used to cooperate with the suction cup 33 on the traveling crawler 31, and multiple suction cups 33 are used to achieve multi-point stable adsorption of the wall. With this design, only the air pump 23 needs to be controlled to achieve adsorption and desorption of the working surface, which simplifies its control, improves safety, and does not require the setting of a large negative pressure component. While achieving lightweight structure, the adaptability and work safety of the robot body to the wall working environment during the high-altitude glass curtain wall cleaning operation can be improved.

[0036] Optionally, a sealing layer 35 is provided on the inner surface of the crawler 31 and the crawler 31 contacts the bottom of the air chamber 22 through the sealing layer 35, and the air hole 34 is provided on the sealing layer 35. Exemplarily, in the embodiment of the present invention, the inner surface of the crawler 31 can be provided with a strip-shaped thin steel sheet extending in the length direction as the sealing layer 35 to contact the bottom opening of the air chamber 22 and the bottom surface of the internal air bag 231, the sealing layer 35 and the crawler 31 rotate synchronously, the top of the suction cup 33 is connected to the air hole 34 opened on the thin steel sheet, and the thin steel sheet with a flat surface is provided so that the inner surface of the crawler 31 can be closely fitted with the bottom surface of the air bag 231 during the rotation process. Furthermore, a layer of polytetrafluoroethylene adhesive can be coated on the surface of the thin steel sheet to bond the thin steel sheet to the bottom surface of the air bag 231, so as to achieve the effect of sealing and fitting between the thin steel sheet and the air bag 231, and can slide relative to each other. The sealing of the contact part is ensured, and the negative pressure stability of the working surface adsorbed by the suction cup 33 is improved.

[0037] Optionally, a concave cavity 233 is provided on the inner wall of the airbag 231, and the bottom of the concave cavity 233 is connected to the negative pressure port 232. Exemplarily, in the embodiment of the present invention, a circular arc-shaped concave cavity 233 structure is provided at the negative pressure port 232 for cooperating with the suction cup 33 at the lower part of the airbag 231, and the opening diameter of the concave cavity 233 on the inner wall of the airbag 231 is 2 cm larger than the diameter of the negative pressure port 232. When the air pump is used to suck the airbag 231 to form a negative pressure environment, a vacuum area will be generated in the bottom concave cavity 233 to form a vacuum groove. When the air hole 34 above the suction cup 33 is connected to the negative pressure port 232, the negative pressure at the terminal connection position is increased, the negative pressure adsorption force of the suction cup 33 is increased, and the working stability of the crawler chassis is further improved.

[0038] Optionally, multiple circles of suction cups 33 are arranged on the outer surface of the track 31 along the length direction, and the multiple circles of suction cups 33 are arranged at intervals along the width direction of the track 31, and the power device 2 includes multiple air chambers 22 matching the multiple circles of suction cups 33. Exemplarily, in order to ensure the contact area and improve the traction, the width of the track 31 is usually wide, and the adsorption capacity of only one circle of suction cups 33 is limited, and it is difficult to achieve a balanced fit between the track 31 and the wall due to the specifications of the suction cups 33. Therefore, in an embodiment of the present invention, two circles of suction cups 33 are arranged along the length direction of the track 31, and are symmetrically arranged along the center line in the length direction. Correspondingly, two air chambers 22 are correspondingly arranged on both sides of the multiple composite load-bearing wheels 323, and negative pressure suction is performed on the two circles of suction cups 33 that rotate to the bottom of the multiple composite load-bearing wheels 323. While improving the adsorption capacity and balance of the crawler chassis, according to the actual wall conditions, negative pressure adsorption can also be performed by only using a single-circle suction cup 33 through external communication control or the like. When crossing obstacles such as wall protrusions, the negative pressure adsorption of the suction cup 33 at the corresponding position can be temporarily canceled to ensure smooth passage, thereby further improving the adaptability of the crawler chassis to the working environment.

[0039] Optionally, a vibration reduction assembly 4 is also included, and the vibration reduction assembly 4 includes a connecting plate 41 and an elastic shock absorber 42. The connecting plate 41 is connected to the transmission bracket 1 and extends into the annular space formed by the crawler 31. The top of the air chamber 22 is connected to the connecting plate 41 through the elastic shock absorber 42. For example, in the embodiment of the present invention, for example, in the embodiment of the present invention, by setting the vibration reduction assembly 4, in the process of the bottom crawler 31 driving the entire crawler chassis to move, it is inevitable that the crawler 31 has longitudinal vibrations to transfer stress to the corresponding air chamber 22 due to uneven wall surfaces, or when crossing obstacles such as glass gaps and wall protrusions. At this time, by setting the connecting plate 41 integrally connected to the transmission bracket 1 and connecting to the air chamber 22 through the elastic shock absorber 42, this part of the longitudinal stress can be buffered and absorbed, further improving the adaptability to the working environment and service life of the crawler chassis.

[0040] Optionally, the suction cup 33 is a rubber suction cup. For example, in the embodiment of the present invention, the suction cup 33 is an octopus-like suction cup constructed on the surface of a silicone rubber soft lining material, which has a strong adsorption capacity, and its flexible material can prevent the track 31 from scratching and damaging the wall surface during the movement on the glass curtain wall surface, thereby improving practicality.

[0041] Figure 8 Schematic diagram of the structure of a robot provided by an embodiment of the present invention. Figure 8 As shown, the embodiment of the present invention also provides a robot, including multiple Figures 1 to 7The crawler chassis for cleaning high-altitude glass curtain walls shown is characterized in that it also includes a connecting arm 5 and a cleaning module 6. The transmission brackets 1 of the crawler chassis for cleaning two adjacent high-altitude glass curtain walls are connected by the connecting arm 5. The middle part of the connecting arm 5 has a rotating shaft structure 51, and the cleaning module 6 is arranged on at least one transmission bracket 1. Exemplarily, in an embodiment of the present invention, the robot includes two crawler chassis, and the transmission brackets 1 of the two are connected by the same two-stage connecting arm 5. By arranging the rotating shaft structure 51 in the middle part of the connecting arm 5, the relative angle adjustment of the two crawler chassis in the longitudinal direction can be achieved. At the same time, the two sides of the connecting arm 5 can be set as telescopic rod structures. While using the two crawler chassis for multi-point adsorption to ensure the travel stability and the load-bearing capacity of the cleaning module 6, the lifting and lowering operations are realized, thereby realizing the multi-angle steering of the device and the adaptation to the vertical wall. While achieving lightweight structure on the crawler chassis, the robot body's adaptability to the wall working environment and working safety during high-altitude glass curtain wall cleaning operations are improved, while ensuring high flexibility and multiple degrees of freedom of the device, thus achieving integrated operations of cleaning, inspection and maintenance of high-rise glass curtain walls.

[0042] Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the present invention belongs. The words "first", "second" and similar words used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "one" do not indicate a quantity limitation, but indicate the existence of at least one. Words such as "include" or "comprise" and similar words mean that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. Words such as "connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0043] The above descriptions are merely optional embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A crawler chassis for cleaning high-altitude glass curtain walls, characterized in that: include: Transmission bracket (1), power unit (2) and track assembly (3), The power device (2) is arranged on the transmission bracket (1), and comprises a driving motor (21), an air chamber (22) and an air pump (23); an air bag (231) connected to the air pump (23) is arranged in the air chamber (22); a negative pressure port (232) is arranged at the bottom of the air bag (231); The crawler assembly (3) comprises a crawler (31) and a transmission wheel group (32) connected to the transmission bracket (1); the drive motor (21) is transmission-connected to the transmission wheel group (32); the crawler (31) is wound around the transmission wheel group (32); a plurality of suction cups (33) are evenly spaced along the length direction on the outer surface of the crawler (31); a plurality of air holes (34) matching the negative pressure port (232) and connected one-to-one with the plurality of suction cups (33) are provided on the inner surface of the crawler (31); the air chamber (22) is arranged in the annular space formed by the crawler (31) and in contact with the section of the crawler (31) at the bottom.

2. The crawler chassis for cleaning high-altitude glass curtain walls according to claim 1 is characterized in that: A sealing layer (35) is provided on the inner surface of the crawler (31) and is in contact with the bottom of the air chamber (22) through the sealing layer (35), and the air hole (34) is provided on the sealing layer (35).

3. The crawler chassis for cleaning high-altitude glass curtain walls according to claim 2 is characterized in that: A concave cavity (233) is provided on the inner wall of the airbag (231), and the bottom of the concave cavity (233) is connected to the negative pressure port (232).

4. The crawler chassis for cleaning high-altitude glass curtain walls according to claim 3 is characterized in that: The concave cavity (233) is circular, and the opening diameter of the concave cavity (233) on the inner wall of the airbag (231) is 2 cm larger than the diameter of the negative pressure port (232).

5. The crawler chassis for cleaning high-altitude glass curtain walls according to claim 2 is characterized in that: The sealing layer (35) is a strip-shaped thin steel sheet arranged along the length direction of the crawler track (31).

6. The crawler chassis for cleaning high-altitude glass curtain walls according to claim 5 is characterized in that: The surface of the sealing layer (35) is coated with polytetrafluoroethylene adhesive.

7. The crawler chassis for cleaning high-altitude glass curtain walls according to any one of claims 1 to 6, characterized in that: A plurality of circles of suction cups (33) are arranged on the outer surface of the crawler (31) along the length direction, and the plurality of circles of suction cups (33) are arranged at intervals along the width direction of the crawler (31), and the power device (2) includes a plurality of air chambers (22) matched with the plurality of circles of suction cups (33).

8. The crawler chassis for cleaning high-altitude glass curtain walls according to claim 7 is characterized in that: The invention also comprises a vibration reduction assembly (4), wherein the vibration reduction assembly (4) comprises a connecting plate (41) and an elastic shock absorber (42), wherein the connecting plate (41) is connected to the transmission bracket (1) and extends into the annular space formed by the crawler track (31), and the top of the air chamber (22) is connected to the connecting plate (41) via the elastic shock absorber (42).

9. The crawler chassis for cleaning high-altitude glass curtain walls according to any one of claims 1 to 6, characterized in that: The suction cup (33) is a rubber suction cup.

10. A robot comprising a plurality of crawler chassis for cleaning high-altitude glass curtain walls as claimed in any one of claims 1 to 9, characterized in that: It also comprises a connecting arm (5) and a cleaning module (6); the transmission brackets (1) of two adjacent crawler chassis for cleaning the high-altitude glass curtain wall are connected via the connecting arm (5); the middle part of the connecting arm (5) has a rotating shaft structure (51); and the cleaning module (6) is arranged on at least one of the transmission brackets (1).

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