CN117166398A - Cleaning device with dust fall function for urban road - Google Patents

Abstract

The invention discloses an urban road cleaning device with dust reduction function, which relates to the technical field of gear machining. It includes a driving mechanism, a dust reduction mechanism and a vehicle frame. The dust reduction mechanism includes a third connecting seat and a positioning frame. The third The top end of the connecting seat is fixedly connected to the bottom surface of the vehicle frame. The inner wall of the third connecting seat is rotatably connected to a third rotating shaft. A transmission assembly is provided between the third rotating shaft and the positioning frame. In the present invention, the positioning wheel drives the tooth groove at the middle position to rotate, and the tooth groove drives the second gear above to rotate, so that the second gear drives the first gear located inside the positioning frame to rotate, and the first gear drives the connecting tube to rotate through the threaded outer wire. , the two water spray guns connected at the top of the communicating tube rotate, so that the water spray guns spray water evenly to various locations that need to be cleaned, which increases the area of water spraying and improves the dust reduction effect during cleaning.

Description

An urban road cleaning device with dust reduction function

Technical field

The invention relates to the technical field of gear machining, and in particular to an urban road cleaning device with dust reduction function.

Background technique

The road is mainly used to clean sediments on roads, squares, sewers, pipes, and clear mud ditches in dead corners. It can also be used to clean industrial drainage pipes, walls, etc. Its working principle is that the side brushes on both sides of the vehicle body sweep the garbage into the middle. Then the main brush in the middle cleans the garbage on the ground, and the suction of the fan sucks the garbage into the dustbin.

In the existing technology, for example, the Chinese patent number is: CN212248031U "A cleaning device for urban roads with dust reduction function", which includes a body, a motor and a mounting plate. A bucket is installed above the body, and the left side of the outer wall of the bucket A pressure plate is installed, and a slider is fixed at the bottom of the pressure plate. A threaded rod is installed on the left side of the outer wall of the pressure plate, and the outside of the threaded rod is connected to the limit plate. The motor is located inside the body, and a bearing is installed at the bottom of the motor. , the bottom of the bearing is connected to a rotating rod, and the bottom of the rotating rod is installed with a sleeve plate, and the inner side of the sleeve plate is connected with a brush.

However, in the prior art, when cleaning urban roads, due to the dust attached to the ground when the sweeping brush sweeps the ground, the sweeping brush will cause the dust to be raised into the air, resulting in an increase in suspended solids in the surrounding air, thereby making the cleaning difficult. causing pollution to the surrounding air.

Contents of the invention

The object of the present invention is to provide an urban road cleaning device with a dust reduction function to solve the above-mentioned problem in the background art that when cleaning urban roads, dust is attached to the ground when the cleaning brush is cleaning the ground, which will cause dust to rise. This leads to an increase in suspended solids in the surrounding air, causing pollution to the surrounding air when cleaning roads.

In order to achieve the above object, the present invention provides the following technical solution: an urban road cleaning device with a dust reduction function, including a driving mechanism, a dust reduction mechanism and a frame. The dust reduction mechanism includes a third connecting seat and a positioning frame. The top of the three connecting seats is fixedly connected to the bottom surface of the vehicle frame, the inner wall of the third connecting seat is rotatably connected to a third rotating shaft, and a transmission assembly is provided between the third rotating shaft and the positioning frame;

The transmission assembly includes a U-shaped frame, which is fixedly connected to the outer side wall of the positioning frame. Two positioning wheels are rotatably connected to the two inner walls of the U-shaped frame, and the two positioning wheels are fixedly connected to each other. The rotating wheels between the wheels are connected with tooth slots, and the outer side walls of the tooth slots are meshed with a second gear. The outer side walls of the second gear are rotationally connected to the outer side walls of the U-shaped frame. The top end of the second gear A first gear is rotatably connected, a communicating tube is provided on the outside of the first gear, a threaded outer wire is fixedly connected to the outer wall of the communicating tube, a water spray gun is fixedly connected to the top of the communicating tube, and the first The gear is threadedly connected to the threaded outer wire. The bottom end of the communication tube passes through the top wall of the positioning frame and is rotatably connected to a water inlet pipe. Both outer side walls of the first gear are connected to the positioning frame. The inner side walls of the water inlet pipe are rotationally connected, and the outer side walls of the water inlet pipes are fixedly connected with connecting posts.

Preferably, a universal joint is rotatably connected to the outer wall of the connecting column, and one end and the other end of the universal joint penetrate the inner wall of the positioning frame and are fixedly connected to the side wall of the first gear.

Preferably, a protective cover is connected to the top of the vehicle frame, a second cleaning mechanism is provided at the center of the top surface of the vehicle frame, and a first cleaning mechanism is provided at the center of the bottom surface of the vehicle frame.

Preferably, the driving mechanism includes two first connecting seats, the top ends of the first connecting seats are fixedly connected to the bottom surface of the frame, and a driving roller is rotatably connected between the two first connecting seats.

Preferably, both outer sides of the driving roller penetrate the outer side wall of the first connecting seat and are fixedly connected with driving wheels.

Preferably, the first cleaning mechanism includes two second connection seats, the top ends of the second connection seats are fixedly connected to the bottom surface of the vehicle frame, and a second rotation axis is rotatably connected between the two second connection seats. , the first cleaning tuft is fixedly connected to the center position of the outer wall of the second rotating shaft, the outer wall of the first cleaning mechanism is provided with a dust collection mechanism, the dust collection mechanism includes a limiting frame, and the limiting frame The bit frame is fixedly connected to the bottom surface of the vehicle frame.

Preferably, a dust collection box is fixedly connected to the inner wall of the limit frame, a connecting rod is fixedly connected to both outer walls of the limit frame, and a third connecting rod is rotatably connected to the inner wall of the two connecting rods. An axis of rotation.

Preferably, second sprockets are rotatably connected to the outer side walls of both ends of the first rotating shaft, a first chain is rotatably connected between the two second sprockets, and the two first chains are fixedly connected to each other. A transmission rod is connected.

Preferably, the second cleaning mechanism includes two fourth connection seats, the bottom ends of the fourth connection seats are fixedly connected to the top surface of the vehicle frame, and there is a rotation connection between the two fourth connection seats. The fourth rotating shaft has a second cleaning tuft rotatably connected to the outer wall of the fourth rotating shaft.

Preferably, the fourth sprocket is fixedly connected to the outer wall of the fourth rotating shaft, the third sprocket is fixedly connected to the outer wall of the second rotating shaft, and the first chain is fixedly connected to the outer wall of the driving roller. wheel, a second chain is drivingly connected between the first sprocket, the third sprocket and the fourth sprocket.

Compared with the prior art, the beneficial effects of the present invention are:

1. In the present invention, when the cleaning device moves, the positioning wheel drives the tooth groove at the middle position to rotate, and the tooth groove drives the second gear above to rotate, so that the second gear drives the first gear located inside the positioning frame to rotate, and the first gear The threaded outer wire drives the communicating tube to rotate, and the two water spray guns connected at the top of the communicating tube rotate, so that the water spray guns spray water evenly to various locations that need to be cleaned, achieving the effect of increasing the area of water spraying and improving the efficiency of cleaning. Dust reduction effect during cleaning.

2. In the present invention, a first cleaning mechanism is provided below the vehicle frame and a second cleaning mechanism is provided above the vehicle frame. The driving roller rotates to drive the first cleaning tufts and the second cleaning tufts to rotate simultaneously. The first cleaning mechanism The tufts transport large-volume garbage on the road to the top, and the second cleaning tufts transport the first cleaning tufts to the rear end of the frame for garbage collection, achieving the effect of collecting road garbage.

3. In the present invention, a dust collection mechanism is provided outside the first cleaning tuft, so that the first cleaning tuft drives the wet mud upward. Since the first cleaning tuft and the second cleaning tuft are soft materials, they cannot be clamped For large-scale garbage collection and recycling, the wet mud falls on the transmission rod, and the first rotating shaft drives the transmission rod to transport the wet mud inside the dust collection box, achieving the effect of separating and collecting the wet mud.

Description of drawings

Figure 1 is a schematic three-dimensional structural diagram of an urban road cleaning device with dust reduction function according to the present invention;

Figure 2 is a schematic structural diagram of the top of the frame of an urban road cleaning device with dust reduction function according to the present invention;

Figure 3 is a schematic structural diagram of the bottom end of the frame of an urban road cleaning device with dust reduction function according to the present invention;

Figure 4 is a schematic diagram 2 of the structure of the bottom end of the frame of an urban road cleaning device with dust reduction function according to the present invention;

Figure 5 is a schematic structural diagram of the dust reduction mechanism of an urban road cleaning device with dust reduction function according to the present invention;

Figure 6 is a schematic structural diagram of the transmission assembly of an urban road cleaning device with dust reduction function according to the present invention;

Figure 7 is a schematic side structural view of the transmission assembly of an urban road cleaning device with dust reduction function according to the present invention;

Figure 8 is an enlarged rendering of the partial structure at point A in Figure 5.

In the picture:

1. Driving mechanism; 11. Driving wheel; 12. Driving roller; 13. First connecting seat; 14. First sprocket; 2. Protective cover;

3. Dust collection mechanism; 31. First chain; 32. Second sprocket; 33. Transmission rod; 34. Dust collection box; 35. Connecting rod; 36. Limiting frame; 37. First rotating shaft;

4. The first cleaning mechanism; 41. The second connecting seat; 42. The second rotating shaft; 43. The first cleaning tuft; 44. The third sprocket;

5. Dust reduction mechanism; 51. Third connecting seat; 52. Third rotating shaft; 53. Positioning wheel; 54. Water spray gun;

55. Transmission component; 551. U-shaped frame; 552. Connecting column; 553. First gear; 554. Threaded outer wire; 555. Second gear; 556. Cog; 557. Universal joint; 558. Connecting tube; 559. Water inlet pipe;

56. Positioning frame; 6. Frame;

7. The second cleaning mechanism; 71. The fourth connecting seat; 72. The fourth rotating shaft; 73. The second cleaning tuft; 74. The fourth sprocket; 8. The second chain.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described implementation regulations are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

Referring to Figures 1-8, an urban road cleaning device with dust reduction function includes a driving mechanism 1, a dust reduction mechanism 5 and a frame 6. The dust reduction mechanism 5 includes a third connection seat 51 and a positioning frame 56. The third connection The top of the seat 51 is fixedly connected to the bottom surface of the frame 6. The inner wall of the third connecting seat 51 is rotatably connected to a third rotating shaft 52. A transmission assembly 55 is provided between the third rotating shaft 52 and the positioning frame 56. When in use, The cleaning device is driven on the urban road. A driving motor is provided inside the driving mechanism 1, so that the rear drive of the frame 6 moves forward. At the same time, the positioning wheel 53 at the front end of the dust reduction mechanism 5 rolls between the road surface and the road surface. The dust reduction mechanism 5 sprinkles water on the dust in advance during road cleaning, thereby avoiding the problem of road dust rising when the cleaning device is cleaning;

The transmission assembly 55 includes a U-shaped frame 551. The U-shaped frame 551 is fixedly connected to the outer side walls of the positioning frame 56. The two inner walls of the U-shaped frame 551 are rotatably connected with two positioning wheels 53. Between the two positioning wheels 53 The rotating wheel is connected with a tooth slot 556. The outer wall of the tooth slot 556 is meshed with a second gear 555. The outer wall of the second gear 555 is rotationally connected to the outer wall of the U-shaped frame 551. The top of the second gear 555 is rotationally connected with the first gear. Gear 553, a communicating tube 558 is provided on the outside of the first gear 553, the outer wall of the communicating tube 558 is fixedly connected with a threaded external wire 554, the top of the communicating tube 558 is fixedly connected with a water spray gun 54, the first gear 553 and the threaded external wire 554 are threadedly connected. The bottom end of the communicating tube 558 passes through the top wall of the positioning frame 56 and is rotatably connected to the water inlet pipe 559. Both outer side walls of the first gear 553 are rotatably connected to the inner side wall of the positioning frame 56. The water inlet pipe 559 The outer side walls of the frame 6 are all fixedly connected with connecting posts 552. When in use, a water tank is placed on the top front end of the frame 6, and a garbage cleaning device is placed on the rear end. The water in the water tank is supplied to the rear end of the water inlet pipe 559, so that the water inlet pipe 559 will Water is supplied to the communicating tube 558, and a sealing ring is provided between the communicating tube 558 and the water inlet pipe 559 to reduce leakage problems when the water inlet pipe 559 transports water. When the positioning wheel 53 rolls on the ground, the positioning wheel 53 drives the positioning wheel 53 to the middle position. The tooth slot 556 rotates, causing the tooth slot 556 to drive the second gear 555 above to rotate, causing the second gear 555 to drive the first gear 553 located inside the positioning frame 56 to rotate, so that the first gear 553 drives the connecting barrel through the threaded outer wire 554 558 rotates, thereby causing the two water spray guns 54 connected at the top of the communicating tube 558 to rotate, so that the water spray guns 54 evenly sprinkle water to various locations that need to be cleaned, thereby increasing the locations for sprinkling water and improving the efficiency of dust reduction during cleaning. Effect.

As shown in Figures 3, 7 and 8, a universal joint 557 is rotatably connected to the outer wall of the connecting column 552. One end and the other end of the universal joint 557 penetrates the inner wall of the positioning frame 56 and is connected to the side wall of the first gear 553. Fixed connection. A protective cover 2 is connected to the top of the vehicle frame 6 . A second cleaning mechanism 7 is provided at the center of the top surface of the vehicle frame 6 . A first cleaning mechanism 4 is provided at the center of the bottom surface of the vehicle frame 6 . The driving mechanism 1 includes two first connecting seats 13. The top ends of the first connecting seats 13 are fixedly connected to the bottom surface of the frame 6. A driving roller 12 is rotatably connected between the two first connecting seats 13. Both outer sides of the driving roller 12 penetrate the outer side wall of the first connecting seat 13 and are fixedly connected with the driving wheel 11. When in use, a driving motor is provided at the rear end of the frame 6 at the position of the driving mechanism 1, so that the driving motor drives The driving roller 12 rotates, causing the driving roller 12 to drive the first connecting seat 13 to rotate, thereby driving the two driving wheels 11 to rotate, providing driving force for the vehicle frame 6 to travel on the road. A first cleaning mechanism 4 is provided below the vehicle frame 6 , a second cleaning mechanism 7 is provided above the vehicle frame 6 , so that the vehicle frame 6 and the second cleaning mechanism 7 rotate to clean and store garbage on the top surface of the vehicle frame 6 .

As shown in Figures 2, 3 and 4, the first cleaning mechanism 4 includes two second connection seats 41. The top ends of the second connection seats 41 are fixedly connected to the bottom surface of the vehicle frame 6. The two second connection seats 41 A second rotating shaft 42 is rotatably connected in between. A first cleaning tuft 43 is fixedly connected to the center of the outer wall of the second rotating shaft 42. A dust collection mechanism 3 is provided on the outer wall of the first cleaning mechanism 4. The dust collection mechanism 3 It includes a limiting frame 36 which is fixedly connected to the bottom surface of the vehicle frame 6 . A dust collection box 34 is fixedly connected to the inner wall of the limiting frame 36, a connecting rod 35 is fixedly connected to both outer walls of the limiting frame 36, and a first rotation shaft 37 is rotatably connected between the inner walls of the two connecting rods 35. . A second sprocket 32 is rotatably connected to the outer side walls of both ends of the first rotating shaft 37 , a first chain 31 is rotatably connected between the two second sprockets 32 , and a transmission rod is fixedly connected between the two first chains 31 33. When in use, the second rotating shaft 42 is rotated, so that the second rotating shaft 42 drives the first cleaning tufts 43 to rotate, so that the first cleaning tufts 43 transport large-volume garbage on the road to the upper part, so that the garbage on the road surface is The garbage is cleaned. Since the first cleaning tufts 43 and the second cleaning tufts 73 are made of soft materials, after the dust is sprinkled with water, the wet mud cannot be collected by the clamping of the second cleaning tufts 73 and the first cleaning tufts 43. The top surface of the vehicle frame 6 allows the first rotating shaft 37 to drive the transmission rod 33 to transport the wet mud inside the dust collection box 34, thereby achieving the effect of separate collection of large garbage and wet mud.

As shown in Figures 3 and 4, the second cleaning mechanism 7 includes two fourth connection seats 71. The bottom end of the fourth connection seats 71 is fixedly connected to the top surface of the vehicle frame 6. There is a gap between the two fourth connection seats 71. A fourth rotating shaft 72 is rotatably connected, and a second cleaning tuft 73 is rotatably connected to the outer wall of the fourth rotating shaft 72 . The fourth sprocket 74 is fixedly connected to the outer wall of the fourth rotating shaft 72 , the third sprocket 44 is fixedly connected to the outer wall of the second rotating shaft 42 , the first sprocket 14 is fixedly connected to the outer wall of the driving roller 12 , and the third sprocket 44 is fixedly connected to the outer wall of the second rotating shaft 42 . A second chain 8 is drivingly connected between the first sprocket 14, the third sprocket 44 and the fourth sprocket 74. When in use, the driving motor drives the driving roller 12 to rotate, so that the driving roller 12 drives the first sprocket 14 on the outer wall. rotation, since the outer wall of the first sprocket 14 is connected to the second chain 8, the second chain 8 drives the third sprocket 44 and the fourth sprocket 74 to rotate at the same time, so that the first cleaning tufts 43 and the second cleaning tufts The tufts 73 rotate simultaneously, the first cleaning tuft 43 transports the garbage at the position of the vehicle frame 6, and the second cleaning tuft 73 transports the first cleaning tuft 43 to the rear end of the vehicle frame 6 for garbage collection.

The usage method and working principle of this device: the cleaning device drives on the urban road, causing the drive roller 12 to drive the first sprocket 14 on the outer wall to rotate. Since the outer wall of the first sprocket 14 is connected to the second chain 8, the second chain 8 is connected to the outer wall of the first sprocket 14. The chain 8 drives the third sprocket 44 and the fourth sprocket 74 to rotate at the same time, thereby causing the first cleaning tufts 43 and the second cleaning tufts 73 to rotate at the same time. The first cleaning tufts 43 transport large-volume garbage on the road to Above, the second cleaning tufts 73 clean and store garbage on the top surface of the vehicle frame 6;

The first cleaning tuft 43 will raise dust when cleaning the ground. When the positioning wheel 53 rolls on the ground, the positioning wheel 53 drives the tooth groove 556 at the middle position to rotate, so that the tooth groove 556 drives the second gear 555 above to rotate, causing the third gear 555 to rotate. The second gear 555 drives the first gear 553 located inside the positioning frame 56 to rotate, so that the first gear 553 drives the communicating tube 558 to rotate through the threaded outer wire 554, thereby causing the two water spray guns 54 connected at the top of the communicating tube 558 to rotate, and the vehicle frame 6. The top water tank transports water to the outlet of the water spray gun 54 through the water inlet pipe 559, so that the water spray gun 54 can evenly spray water to various locations that need to be cleaned;

Since the first cleaning tufts 43 and the second cleaning tufts 73 are made of soft materials, after the dust is sprinkled with water, the wet mud cannot be collected on the top of the vehicle frame 6 by the clamping of the second cleaning tufts 73 and the first cleaning tufts 43 . On the other hand, the first cleaning tuft 43 rotates to drive the wet mud on the ground to the transmission rod 33, so that the first rotating shaft 37 drives the transmission rod 33 to transport the wet mud inside the dust collection box 34, realizing the collection of large garbage and wet mud. Separate collection effects.

Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims (10)

1. An urban road cleaning device with dust reduction function, including a driving mechanism (1), a dust reduction mechanism (5) and a frame (6), characterized in that: the dust reduction mechanism (5) includes a third connecting seat ( 51) and the positioning frame (56), the top of the third connecting seat (51) is fixedly connected to the bottom surface of the frame (6), and the inner wall of the third connecting seat (51) is rotationally connected with a third Rotating shaft (52), a transmission assembly (55) is provided between the third rotating shaft (52) and the positioning frame (56); The transmission assembly (55) includes a U-shaped frame (551). The U-shaped frame (551) is fixedly connected to the outer side wall of the positioning frame (56). The two inner sides of the U-shaped frame (551) Two positioning wheels (53) are rotatably connected to the walls, and a tooth slot (556) is connected to the rotating wheel between the two positioning wheels (53). A second gear (556) is engaged with the outer wall of the tooth slot (556). 555), the outer side wall of the second gear (555) is rotationally connected to the outer side wall of the U-shaped frame (551), and the top end of the second gear (555) is rotationally connected with the first gear (553), so A communicating tube (558) is provided on the outside of the first gear (553), the outer wall of the communicating tube (558) is fixedly connected with a threaded outer wire (554), and the top of the communicating tube (558) is fixedly connected with a nozzle. Water gun (54), the first gear (553) and the threaded outer wire (554) are threadedly connected, and the bottom end of the communicating tube (558) penetrates the top wall of the positioning frame (56) and A water inlet pipe (559) is rotatably connected. Both outer side walls of the first gear (553) are rotatably connected to the inner side walls of the positioning frame (56). Both outer side walls of the water inlet pipe (559) are fixedly connected. There are connecting posts (552). 2. An urban road cleaning device with dust reduction function according to claim 1, characterized in that: a universal joint (557) is rotatably connected to the outer wall of the connecting column (552), and the universal joint One end and the other end of (557) pass through the inner wall of the positioning frame (56) and are fixedly connected to the side wall of the first gear (553). 3. An urban road cleaning device with dust reduction function according to claim 1, characterized in that: a protective cover (2) is connected to the top of the frame (6), and a protective cover (2) is connected to the top of the frame (6). A second cleaning mechanism (7) is provided at the center of the top surface, and a first cleaning mechanism (4) is provided at the center of the bottom surface of the frame (6). 4. An urban road cleaning device with dust reduction function according to claim 3, characterized in that: the driving mechanism (1) includes two first connection seats (13), and the first connection seats (13) The top end of 13) is fixedly connected to the bottom surface of the frame (6), and a driving roller (12) is rotatably connected between the two first connecting seats (13). 5. An urban road cleaning device with dust reduction function according to claim 4, characterized in that both outer sides of the driving roller (12) penetrate the outer side wall of the first connecting seat (13). And is fixedly connected with the driving wheel (11). 6. An urban road cleaning device with dust reduction function according to claim 4, characterized in that: the first cleaning mechanism (4) includes two second connection seats (41), and the second connection seats The top of the seat (41) is fixedly connected to the bottom surface of the frame (6), and a second rotation shaft (42) is rotatably connected between the two second connection seats (41). The second rotation shaft (42) A first cleaning tuft (43) is fixedly connected to the center of the outer side wall of the first cleaning mechanism (4). A dust collection mechanism (3) is provided on the outer side wall of the first cleaning mechanism (4). The dust collection mechanism (3) includes a limiter. Frame (36), the limiting frame (36) is fixedly connected to the bottom surface of the frame (6). 7. An urban road cleaning device with dust reduction function according to claim 6, characterized in that: a dust collection box (34) is fixedly connected to the inner wall of the limit frame (36), and the limit frame (36) is fixedly connected with a dust collection box (34). Both outer side walls of the frame (36) are fixedly connected with connecting rods (35), and a first rotation axis (37) is rotatably connected between the inner side walls of the two connecting rods (35). 8. An urban road cleaning device with dust reduction function according to claim 7, characterized in that: the outer side walls of both ends of the first rotating shaft (37) are rotatably connected with second sprockets (32) , a first chain (31) is rotatably connected between the two second sprockets (32), and a transmission rod (33) is fixedly connected between the two first chains (31). 9. An urban road cleaning device with dust reduction function according to claim 6, characterized in that: the second cleaning mechanism (7) includes two fourth connection seats (71), and the fourth connection seat The bottom end of the seat (71) is fixedly connected to the top surface of the frame (6), and a fourth rotation axis (72) is rotatably connected between the two fourth connection seats (71). A second cleaning tuft (73) is rotatably connected to the outer wall of the shaft (72). 10. An urban road cleaning device with dust reduction function according to claim 9, characterized in that: a fourth sprocket (74) is fixedly connected to the outer wall of the fourth rotating shaft (72), and the The third sprocket (44) is fixedly connected to the outer wall of the second rotating shaft (42), and the first sprocket (14) is fixedly connected to the outer wall of the driving roller (12). The first sprocket (14) ), a second chain (8) is drivingly connected between the third sprocket (44) and the fourth sprocket (74).