CN218614592U

CN218614592U - Bark peeler for bark perfume and medicinal material

Info

Publication number: CN218614592U
Application number: CN202222890662.3U
Authority: CN
Inventors: 李健
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-11-01
Filing date: 2022-11-01
Publication date: 2023-03-14
Anticipated expiration: 2032-11-01

Abstract

The utility model provides a bark planer for the surface layer of bark of tree-like spice and medicinal material, which is provided with a transmission mechanism, a bark planing mechanism, a waste collecting mechanism and a power driving mechanism on a frame; the conveying mechanism is provided with an upper conveying belt and two lower conveying belts which are positioned on the same plane below the upper conveying belt and arranged at intervals left and right, and a channel between the lower belt surface of the upper conveying belt and the upper belt surfaces of the two lower conveying belts is a conveying channel; the peeling mechanism is provided with a planer tool, an adjusting plate and an elastic rubber roller, the planer tool and the adjusting plate are erected at a position between the two lower conveying belts below the upper conveying belt, and the elastic rubber roller elastically pushes the middle part of the lower belt surface of the upper conveying belt from the upper side, so that the conveying channel forms a channel with wide left and right ends and narrow middle. The elastic rubber roller of the skin planer can be adaptively adjusted and tightly press peltry with different thicknesses or with concave-convex and adjusting holes, and the planing depth of the surface layer of the peltry can be controlled by changing the mounting height of the adjusting plate. Therefore, the peeling machine has high processing efficiency, good product quality and stable quality.

Description

Bark peeler for bark perfume and medicinal material

Technical Field

The utility model relates to a peeler specifically is a raw skin top layer peeler of bark class spices and medicinal material, belongs to medicinal material processing machinery technical field.

Background

When medicinal plants such as the pimenta, the phellodendron, the mangnolia officinalis and the like are prepared into spices and medicinal materials, the bark of the medicinal plants is processed, the black bark on the surface layer of the bark needs to be removed during processing, and the inner layer of the bark is reserved as a product. The traditional processing method is that the raw hide collected by farmers is cut into a proper length and then is buckled on a cylindrical rod which is obliquely erected, the surface black skin of the raw hide is scraped by manually scraping the skin with a skin scraping knife, and then the raw hide is placed in a shade for air drying. The operation of artifical skin scraping is because everybody scrapes the dynamics of skin inconsistent, scrapes the skin depth difference, can't guarantee product quality's stability, and machining efficiency is low moreover, increases manufacturing cost, reduces peasant household income.

Because the raw hide recovered by farmers is soft, the cross section of the raw hide is curved in an arc shape in a natural state, and can be flattened under certain pressure, although the raw hide has different thicknesses and node holes, and has straight bends and concave and convex parts in the length direction, the node can be basically kept straight and the thickness can be basically kept consistent under the specific length of cutting into 400mm nodes, and the common thickness among the nodes is 1.5mm-5mm. It is therefore provided with the basis of using specially designed processing equipment instead of manual peeling operations.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a raw skin top layer peeler of bark class spices and medicinal material to be used for planing off the raw skin surface black skin of bark class spices and medicinal material such as pimenta, phellodendron, magnolia bark, thereby obtain higher machining efficiency and better processingquality.

The utility model discloses the technical scheme who adopts as follows:

a peeler for the surface layer of bark-type perfume or medicine is composed of machine frame, conveying mechanism, peeling mechanism, garbage collecting mechanism and power driver.

The conveying mechanism is provided with three groups of horizontally arranged annular wide conveying belts on the upper part of the frame, namely an upper conveying belt and two lower conveying belts which are positioned on the same plane below the upper conveying belt and arranged at intervals left and right, a channel between the lower belt surface of the upper conveying belt and the upper belt surfaces of the two lower conveying belts is a conveying channel, the left end of the conveying channel is a feeding hole, and the right end of the conveying channel is a discharging hole; the three groups of conveyer belts are provided with a driving roller and a driven roller for supporting and driving, and the two lower conveyer belts are also provided with an elastic tensioning roller below the lower belt surfaces thereof for upwards jacking and tensioning.

The peeling mechanism is provided with a planer tool, an adjusting plate and an elastic rubber roll, wherein the planer tool and the adjusting plate are erected at a position between two lower conveying belts below an upper conveying belt, the planer tool is fixedly installed on a rack through a tool apron, the cutting edge of the planer tool faces to the left, the top surface of the planer tool is flush with the upper belt surface of the lower conveying belt, the adjusting plate is arranged on the left side of the planer tool, the top surface of the adjusting plate is lower than the cutting edge of the planer tool, a certain cutting depth is formed, the adjusting plate is an adjusting plate with adjustable installation height, and the cutting depth is adjusted by changing the installation height of the adjusting plate; the elastic rubber roller is parallel to the driving roller of the upper conveying belt, the elastic rubber roller is erected in the position, corresponding to the position right above the cutting edge of the planer tool, in the ring sleeve of the upper conveying belt, and the lower roller surface of the elastic rubber roller elastically pushes the middle of the lower belt surface of the upper conveying belt from the upper side, so that the conveying channel is formed into a channel with wide left and right ends and narrow middle.

The waste collecting mechanism is provided with a funnel, the funnel is erected under the middle part of the rack corresponding to the peeling mechanism, and a section of waste discharging groove extending obliquely towards the lower side of the side is connected below the funnel.

The power driving mechanism is provided with a speed reducing motor at the lower part of the frame, the speed reducing motor drives the driving rollers of the two lower conveying belts, the driving rollers of the upper conveying belt and the elastic rubber roller to rotate simultaneously through the chain transmission assembly, so that the lower belt surface of the upper conveying belt and the upper belt surfaces of the two lower conveying belts move at the same speed from left to right in the same direction.

Furthermore, the elastic tensioning roller is provided with a roller main body, shaft heads at two ends of the roller main body are respectively and rotatably supported in two shaft sleeves with vertical supporting rods, the lower ends of the vertical supporting rods of the two shaft sleeves are slidably inserted in inserting holes at two ends of the same transverse plate, a pushing spring is movably sleeved between the shaft sleeve and the transverse plate outside the vertical supporting rods, the transverse plate is also respectively provided with an opening at the side of the two inserting holes, and the transverse plate is movably sleeved on a screw rod extending downwards from the rack through the opening and is fixed by a nut; the thrust of the pushing spring can be adjusted by adjusting the up-down position of the nut, so that the tension of the elastic tensioning roller is adjusted.

Furthermore, the upper conveying belt and the two lower conveying belts can adopt soft PVC plastic conveying belts so as to realize good friction conveying force.

Furthermore, the elastic rubber roller is provided with honeycomb-shaped column holes inside, so that elastic deformation can be formed conveniently and rapidly.

Furthermore, a bracket is arranged at the lower part of the adjusting plate, the bracket is slidably mounted in a corresponding vertical sliding groove on the rack through a sliding block which is extended outwards from the front side and the rear side of the bracket, a screw hole is formed in the sliding block, an adjusting screw rod which can rotate in situ is arranged below the vertical sliding groove of the rack, a rod body of the adjusting screw rod is in threaded connection with the screw hole of the sliding block, and a locking screw which can be used for jacking and locking the position of the bracket is further arranged beside the vertical sliding groove of the rack; after the locking screw is loosened, the position of the bracket in the vertical sliding groove can be adjusted by rotating the adjusting screw rod, and then the installation height of the adjusting plate can be adjusted.

Further, the chain transmission assembly comprises a lower chain ring, a middle chain ring, an upper chain ring, a first chain wheel connected with an output shaft of the speed reduction motor, a second chain wheel connected with a driving roller of the left lower conveying belt, a third chain wheel connected with a driving roller of the right lower conveying belt, a fourth chain wheel and a fifth chain wheel connected with a middle rotating shaft positioned right below the elastic rubber roller on the rack, a sixth chain wheel and a seventh chain wheel connected with the elastic rubber roller and an eighth chain wheel connected with the driving roller of the upper conveying belt, wherein the first chain wheel, the second chain wheel and the third chain wheel are encircled inside and respectively meshed by the lower chain ring, the lower chain ring is meshed with the lower chain ring from the outer side above the lower chain ring and downwards tensioned by the fourth chain wheel, the fifth chain wheel and the sixth chain wheel are encircled inside and respectively meshed by the middle chain ring, and the seventh chain wheel and the eighth chain wheel are encircled inside and respectively meshed by the upper chain ring.

The utility model discloses dig skin machine simple structure, low in manufacturing cost is honest and clean. When in use, the conveying channel consisting of the upper conveying belt and the lower conveying belt flattens and unfolds the arched and bent peltry into a plane shape during conveying, and then the planer tool planes the black skin on the surface of the peltry while conveying the peltry rightwards; the elastic rubber roller can realize large-amplitude elastic deformation, can adaptively adjust and compress the rawhide with different thicknesses or with concave-convex and hole-adjusting, can conveniently adjust the depth of the plane cutter by changing the mounting height of the adjusting plate, and further control the planing depth of the surface layer of the rawhide, thereby ensuring that the shaving depth is uniform, stabilizing the product quality, controlling the survival rate of the remaining inner layer of the rawhide and maximizing the benefit of the product. Therefore, when the peeling machine is used for peeling off the surface layer of the bark spice and the raw hide of medicinal materials such as cinnamon, phellodendron, mangnolia officinalis and the like, the processing efficiency is high, the product looks good, the quality is stable, the processing scale can be effectively enlarged, and the income of farmers is increased.

Drawings

Fig. 1 is a schematic view of the three-dimensional structure of the peeling machine of the present invention.

Fig. 2 is a front view of fig. 1.

Fig. 3 is a left side view of fig. 1.

Fig. 4 is a schematic perspective view of the structure of fig. 1 rotated to a back side facing forward.

Fig. 5 is an internal cross-sectional view of the upper portion of fig. 2.

Fig. 6 is a partially enlarged view of a portion of the peeling mechanism in fig. 5.

In the figure: 1-frame, 1.1-screw, 1.2-vertical chute, 2-upper conveyor belt, 3-lower conveyor belt, 4-conveying channel, 5-driving roller, 6-driven roller, 7-elastic tensioning roller, 8-shaft sleeve, 8.1-vertical strut, 9-transverse plate, 10-pushing spring, 11-nut, 12-planer tool, 13-adjusting plate, 14-elastic rubber roller, 15-bracket, 15.1-slide block, 16-adjusting screw rod, 17-locking screw, 18-funnel, 18.1-waste discharge groove, 19-reduction motor, 20-lower chain ring, 21-middle chain ring, 22-upper chain ring, 23-first chain wheel, 24-second chain wheel, 25-third chain wheel, 26-middle rotating shaft, 27-fourth chain wheel, 28-fifth chain wheel, 29-sixth chain wheel, 30-seventh chain wheel, 31-eighth chain wheel.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings. In the description of the present invention, the directional terms of "upper", "lower", "left" and "right" are defined based on the directions or positional relationships shown in fig. 1 in the specification, and are only for convenience of description of the present invention, and do not refer to the specific directions that a device or element must have, and should not be considered as limitations of the present invention.

As shown in figures 1-6, the utility model discloses a peeling machine is equipped with frame 1, and frame 1 is put on the shelf and is equipped with transport mechanism, peeling mechanism, garbage collection mechanism and power drive mechanism.

The conveying mechanism is provided with three groups of horizontally arranged annular wide conveying belts on the upper part of a frame 1, namely an upper conveying belt 2 and two lower conveying belts 3 which are positioned on the same plane below the upper conveying belt 2 and are arranged at intervals left and right, a channel between the lower belt surface of the upper conveying belt 2 and the upper belt surfaces of the two lower conveying belts 3 is a conveying channel 4, the left end of the conveying channel 4 is a feeding hole, and the right end of the conveying channel 4 is a discharging hole; the three groups of conveyer belts are provided with a driving roller 5 and a driven roller 6 for supporting and driving, and the two lower conveyer belts 3 are also provided with an elastic tensioning roller 7 below the lower belt surfaces thereof for upward jacking and tensioning.

The elastic tensioning roller 7 is provided with a roller main body, shaft heads at two ends of the roller main body are respectively and rotatably supported in two shaft sleeves 8 with vertical supporting rods 8.1, the lower ends of the vertical supporting rods 8.1 of the two shaft sleeves 8 are slidably inserted into insertion holes at two ends of a same transverse plate 9, a pushing spring 10 is movably sleeved outside the vertical supporting rods 8.1 between the shaft sleeves 8 and the transverse plate 9, openings are also respectively formed at the sides of the two insertion holes of the transverse plate 9, and the transverse plate 9 is movably sleeved on a screw rod 1.1 extending downwards from the rack 1 through the openings and is provided with a nut 11 for fixing; the pushing force of the pushing spring 10 can be adjusted by adjusting the up-down position of the nut 11, so as to adjust the tension of the elastic tensioning roller 7.

The peeling mechanism is provided with a planer tool 12, an adjusting plate 13 and an elastic rubber roller 14, wherein the planer tool 12 and the adjusting plate 13 are erected at a position between two lower conveying belts 3 below an upper conveying belt 2, the planer tool 12 is fixedly installed on a rack 1 through a tool apron, the cutting edge of the planer tool 12 faces to the left, the top surface of the planer tool 12 is flush with the upper belt surface of the lower conveying belt 3, the adjusting plate 13 is arranged on the left side of the planer tool 12, the top surface of the adjusting plate 13 is lower than the cutting edge of the planer tool 12, a certain cutting depth is formed, the adjusting plate 13 is an adjusting plate with adjustable installation height, and the cutting depth is adjusted by changing the installation height of the adjusting plate 13; the elastic rubber roller 14 is an elastic rubber roller with honeycomb-shaped column holes arranged inside, the elastic rubber roller 14 is parallel to the driving roller 5 of the upper conveying belt 2, the elastic rubber roller 14 is erected in a ring sleeve of the upper conveying belt 2 and corresponds to a position right above a cutting edge of the planer tool 12, and a lower roller surface of the elastic rubber roller 14 elastically pushes against the middle of a lower belt surface of the upper conveying belt 2 from the upper side, so that the conveying channel 4 is formed into a channel with wide left and right ends and narrow middle.

A bracket 15 is arranged at the lower part of the adjusting plate 13, the bracket 15 is slidably mounted in a corresponding vertical chute 1.2 on the frame 1 through a slide block 15.1 with outward branches at the front and rear sides, a screw hole is arranged on the slide block 15.1, an adjusting screw rod 16 capable of rotating in situ is arranged below the vertical chute 1.2 of the frame 1, a rod body of the adjusting screw rod 16 is in threaded connection with the screw hole of the slide block 15.1, and a locking screw 17 capable of jacking and locking the position of the bracket 15 is further arranged at the side of the vertical chute 1.2 of the frame 1; after the locking screw 17 is loosened, the position of the bracket 15 in the vertical chute 1.2 can be adjusted by rotating the adjusting screw rod 16, and further, the installation height of the adjusting plate 13 can be adjusted.

The waste collecting mechanism is provided with a funnel 18, the funnel 18 is erected under the middle part of the frame 1 corresponding to the peeling mechanism, and a waste discharge groove 18.1 which obliquely extends to the lower side is connected below the funnel 18.

The power driving mechanism is provided with a speed reducing motor 19 at the lower part of the frame 1, the speed reducing motor 19 drives the driving rollers 5 of the two lower conveying belts 3, the driving rollers 5 of the upper conveying belt 2 and the elastic rubber roller 14 to rotate simultaneously through the chain transmission assembly, so that the lower belt surface of the upper conveying belt 2 and the upper belt surfaces of the two lower conveying belts 3 move at the same speed in the same direction from left to right.

The chain transmission assembly comprises a lower chain ring 20, a middle chain ring 21, an upper chain ring 22, a first chain wheel 23 connected with an output shaft of a speed reducing motor 19, a second chain wheel 24 connected with a driving roller 5 of a left lower conveying belt 3, a third chain wheel 25 connected with the driving roller 5 of a right lower conveying belt 3, a fourth chain wheel 27 and a fifth chain wheel 28 connected with a middle rotating shaft 26 positioned right below an elastic rubber roller 14 on a machine frame 1, a sixth chain wheel 29 and a seventh chain wheel 30 connected with the elastic rubber roller 14, and an eighth chain wheel 31 connected with the driving roller 5 of an upper conveying belt 2, wherein the lower chain ring 20 surrounds the first chain wheel 23, the second chain wheel 24 and the third chain wheel 25 and respectively forms meshing, the fourth chain wheel 27 meshes with the lower chain ring 20 from the upper outer side above the lower chain ring 20 and tensions the lower chain ring 20 downwards, the fifth chain wheel 28 and the sixth chain wheel 29 are surrounded and respectively form meshing by the middle chain ring 21, and the seventh chain wheel 30 and the eighth chain wheel 31 are surrounded and respectively form meshing.

The working process of the peeling machine is as follows:

(1) After the speed reducing motor 19 is started to drive the whole machine to work, the surface layer of the peltry cut into specific length faces downwards and is fed from the feeding hole at the left end of the conveying channel 4 in the length direction, and the peltry needs to be horizontally placed in a single piece and cannot be stacked when being fed. It should be noted that the machine is suitable for surface shaving of soft and plastic hides and is not suitable for hard and non-plastic dry hides.

(2) The pelts are conveyed from left to right under the clamping conveying of the upper conveying belt 2 and the left lower conveying belt 3, and the pelts can be flattened and unfolded gradually to form a plane shape by arc-shaped bending when conveyed to the middle of the conveying passage from the feeding hole due to the wide left end and the narrow middle of the conveying passage 4.

(3) The flat raw hide is pressed downwards by an elastic rubber roller 14 in the middle of the conveying channel 4 through the lower belt surface of the upper conveying belt 2 to ensure that the surface layer of the flat raw hide is attached to the adjusting plate 13 and the planer tool 12, and the planer tool 12 scrapes off the black skin on the surface of the raw hide while the raw hide is conveyed rightwards; because the elastic rubber roller 14 can realize large elastic deformation, the leather skins with different thicknesses or with concave-convex and adjusting holes can be adaptively adjusted and pressed; the depth of cut of the plane cutter 12 can be adjusted by changing the mounting height of the adjusting plate 13, so as to control the planing depth of the surface layer of the rawhide; the black skin scraped off by the planing tool 12 falls down into the lower hopper 18 and is discharged through the waste discharge chute 18.1.

(4) The raw hide scraping the black skin is conveyed by the clamping of the upper conveying belt 2 and the right lower conveying belt 3 and is discharged from the discharge hole at the right end of the conveying channel 4, and the raw hide is narrow in the middle of the conveying channel 4 and wide at the right end, so that the raw hide can recover certain arc-shaped bending when conveyed to the discharge hole from the middle of the conveying channel 4.

The drawings described above are merely exemplary embodiments of the present invention and are not intended to limit the present invention, and any modifications, equivalent alterations, improvements and the like which are made within the spirit and principles of the present invention should be included in the scope of the present invention.

Claims

1. A hide surface layer peeling machine for bark spices and medicinal materials is characterized in that: the peeling machine is provided with a rack (1), and a conveying mechanism, a peeling mechanism, a waste collecting mechanism and a power driving mechanism are erected on the rack (1);

the conveying mechanism is provided with three groups of annular wide conveying belts which are horizontally arranged on the upper part of the rack, namely an upper conveying belt (2) and two lower conveying belts (3) which are positioned on the same plane below the upper conveying belt (2) and are arranged at intervals left and right, a channel between the lower belt surface of the upper conveying belt (2) and the upper belt surfaces of the two lower conveying belts (3) is a conveying channel (4), the left end of the conveying channel (4) is a feeding hole, and the right end of the conveying channel is a discharging hole; the three groups of conveyer belts are provided with a driving roller (5) and a driven roller (6) for supporting and driving, and the two lower conveyer belts (3) are also provided with an elastic tensioning roller (7) below the lower belt surfaces thereof for upward jacking and tensioning;

the peeling mechanism is provided with a planer tool (12), an adjusting plate (13) and an elastic rubber roller (14), wherein the planer tool (12) and the adjusting plate (13) are erected between two lower conveying belts (3) below an upper conveying belt (2), the planer tool (12) is fixedly mounted on a rack (1) through a tool apron, a cutting edge of the planer tool (12) faces to the left, the top surface of the planer tool (12) is flush with an upper belt surface of the lower conveying belt (3), the adjusting plate (13) is arranged on the left side of the planer tool (12), the top surface of the adjusting plate (13) is lower than the cutting edge of the planer tool (12), so that a cutting depth is formed, the adjusting plate (13) is an adjusting plate with adjustable mounting height, and the cutting depth is adjusted by changing the mounting height of the adjusting plate (13); the elastic rubber roller (14) is parallel to the driving roller (5) of the upper conveying belt (2), the elastic rubber roller (14) is erected in a ring sleeve of the upper conveying belt (2) at a position right above a cutting edge of the planer tool (12), and the lower roller surface of the elastic rubber roller (14) elastically pushes the middle part of the lower belt surface of the upper conveying belt (2) from the upper side, so that the conveying channel (4) forms a channel with wide left and right ends and narrow middle;

the waste collecting mechanism is provided with a funnel (18), the funnel (18) is erected right below the middle part of the frame (1) corresponding to the peeling mechanism, and a waste discharging groove (18.1) which obliquely extends towards the lateral lower part is connected below the funnel (18);

the power driving mechanism is characterized in that a speed reducing motor (19) is arranged on the lower portion of the rack (1), the speed reducing motor (19) drives the driving rollers (5) of the two lower conveying belts (3), the driving rollers (5) of the upper conveying belt (2) and the elastic rubber roller (14) to rotate simultaneously through the chain transmission assembly, and the lower belt surface of the upper conveying belt (2) and the upper belt surface of the two lower conveying belts (3) move in the same direction and at the same speed from left to right.

2. The surface layer peeler for rawhide for bark-based spices and medicinal materials as claimed in claim 1, wherein: elasticity tensioning roller (7) are equipped with roller main body, the spindle nose at roller main body both ends rotationally supports respectively in two axle sleeves (8) of taking vertical branch (8.1), slide grafting in the jack at same diaphragm (9) both ends vertical branch (8.1) lower extreme of two axle sleeves (8), vertical branch (8.1) outside activity has cup jointed between axle sleeve (8) and diaphragm (9) and has pushed away spring (10), diaphragm (9) still are equipped with the trompil respectively at the side of two jacks, diaphragm (9) cup joint through its trompil activity and are fixed on screw rod (1.1) that downwardly extending in frame (1) and are equipped with nut (11).

3. The surface layer peeler for rawhide for bark-based spices and medicinal materials as claimed in claim 1, wherein: the upper conveying belt (2) and the two lower conveying belts (3) are soft PVC plastic conveying belts.

4. The surface layer peeler for raw hide of bark type spice and medicinal material according to claim 1, wherein: the elastic rubber roller (14) is an elastic rubber roller with honeycomb-shaped column holes arranged inside.

5. The surface layer peeler for rawhide for bark-based spices and medicinal materials as claimed in claim 1, wherein: adjusting plate (13) lower part is equipped with bracket (15), slider (15.1) slidable mounting that bracket (15) both sides are paid outward through its front and back is in vertical spout (1.2) that correspond on frame (1), be equipped with the screw on slider (15.1), but frame (1) below vertical spout (1.2) is equipped with normal position pivoted accommodate the lead screw (16), the body of rod of accommodate the lead screw (16) forms threaded connection with the screw of slider (15.1), frame (1) still is equipped with locking screw (17) that can carry out the roof pressure locking to the position of bracket (15) at the side of vertical spout (1.2).

6. The surface layer peeler for rawhide for bark-based spices and medicinal materials as claimed in claim 1, wherein: the chain transmission assembly comprises a lower chain ring (20), a middle chain ring (21), an upper chain ring (22), a first chain wheel (23) connected with an output shaft of a speed reducing motor (19), a second chain wheel (24) connected with a driving roller (5) of a left lower conveying belt (3), a third chain wheel (25) connected with the driving roller (5) of a right lower conveying belt (3), a fourth chain wheel (27) and a fifth chain wheel (28) connected with a middle rotating shaft (26) which is positioned right below an elastic rubber roller (14) on a rack (1), a sixth chain wheel (29) and a seventh chain wheel (30) connected with the elastic rubber roller (14), and an eighth chain wheel (31) connected with the driving roller (5) of an upper conveying belt (2), wherein the first chain wheel (23), the second chain wheel (24) and the third chain wheel (25) are encircled and engaged respectively by the lower chain ring (20), the fourth chain wheel (27) is meshed with the lower chain ring (20) from the outer side above the lower chain ring (20) and winds the lower chain ring (20) downwards, the middle chain ring (24) and the third chain wheel (25) and meshes with the middle chain wheel (29) and the fifth chain wheel (30) and the fifth chain wheel (22) and meshes and the eighth chain wheel (31) respectively, and the fifth chain ring) and the fifth chain ring (22) and the sixth chain wheel (31) are meshed.