CN220906899U - Traction mechanism and elevator host - Google Patents

Abstract

The utility model discloses a traction mechanism and an elevator main machine, and belongs to the technical field of elevator power equipment, wherein the traction mechanism comprises a traction shaft and a traction wheel, and the traction wheel is sleeved outside the traction shaft; the traction sheave is provided with a limiting assembly and is clamped with the traction shaft through the limiting assembly; the limiting assembly comprises a fixing pin and an elastic piece, the outer wall of the traction shaft is provided with a containing groove, the first end of the elastic piece is arranged at the bottom of the containing groove, and the fixing pin is in butt joint with the second end of the elastic piece; the traction wheel is provided with a first limit groove, the first limit groove is communicated with the accommodating groove, and the fixing pin is clamped with the first limit groove; realize segmentation installation or segmentation processing, when using, place the elastic component in the holding tank earlier, place the fixed pin in the holding tank afterwards, extrude the fixed pin, and cup joint the driving sheave in the preset position of towing shaft, the driving sheave is rotatory, the fixed pin is because the elasticity effect of elastic component to by extrusion to first spacing inslot, realize the equipment of driving sheave and towing shaft, and simplify the assembly of traction mechanism.

Description

Traction mechanism and elevator host

Technical Field

The utility model belongs to the technical field of elevator power equipment, and particularly relates to a traction mechanism and an elevator host.

Background

As a vertical transport means, elevators are closely related to modern society life, and as socioeconomic development and urban development progress are accelerated, high-rise buildings are increasingly made, and the high-rise buildings become a city sign, and some of the high-rise buildings even become city landmarks. With the appearance of high-rise buildings and the development of social culture, the requirements on the elevators are more and more strong, and particularly the significance of the elevators is more important when the elevator enters the society of aging today. The elevators in the world are running every day and are responsible for the transportation of a large amount of people and logistics, and the role of the elevators in the building has become very important and is an integral part of modern society life.

The elevator host is the power equipment of the elevator and is responsible for conveying and transmitting power to enable the elevator to run. The elevator host has great influence on the elevator whole elevator cost, the elevator technical development, the elevator structural arrangement, the elevator engineering installation and maintenance and the like. A traction mechanism is usually arranged in the elevator main machine, and is a device for transmitting traction power of the elevator, and the traction mechanism transmits power by using friction force of a traction steel wire rope and a rope groove on a traction rim. However, the existing steel belt type traction sheave shaft generally adopts an integral structure, and the integral traction sheave shaft has the following disadvantages: the integral cutting amount is large, the surface of the traction sheave needs to be treated, the production efficiency is low, and the machining precision is low; moreover, the brake disc of the brake section is connected with the main shaft by adopting interference plus keys, and the assembly is difficult.

Disclosure of Invention

The utility model aims to provide a traction mechanism and an elevator host machine, which realize the purposes of reducing the waste of materials, improving the production efficiency and simplifying the assembly of the traction mechanism.

The technical scheme is as follows:

The traction mechanism comprises a traction shaft, a limiting assembly and a traction wheel, wherein the traction wheel is sleeved outside the traction shaft; the limiting component is arranged on the outer wall of the traction shaft and is positioned between the traction wheel and the traction shaft;

The limiting assembly comprises a fixing pin and an elastic piece, wherein the outer wall of the traction shaft is provided with a containing groove, the first end of the elastic piece is installed at the bottom of the containing groove, and the fixing pin is abutted with the second end of the elastic piece and is partially positioned in the containing groove; the traction sheave is provided with a first limiting groove, the first limiting groove is communicated with the accommodating groove, and the fixing pin is clamped with the first limiting groove.

In one embodiment, the traction sheave comprises a first wheel body and a second wheel body, the first wheel body and the second wheel body are of an integrated structure, the first wheel body and the second wheel body are of hollow structures, and the first wheel body is sleeved on the outer wall of the traction shaft; the first limit groove is located on the first wheel body.

In one embodiment, the outer diameter of the second wheel body is larger than the outer diameter of the first wheel body; the traction wheels are at least two, and rope grooves are formed between the side walls of two adjacent second wheel bodies and the outer wall of the first wheel body in the two adjacent traction wheels.

In one embodiment, a second limiting groove is formed in the circumferential direction of the first wheel body, a limiting block is arranged in the circumferential direction of the second wheel body, and the second limiting groove and the limiting block are arranged relatively far away from each other; the limiting block of one traction sheave is clamped with the second limiting groove of the other traction sheave, and the depth direction of the second limiting groove is intersected with the depth direction of the accommodating groove.

In one embodiment, the number of the second limiting grooves is at least two, the two second limiting grooves are oppositely arranged in the circumferential direction of the first wheel body, and the number of the limiting blocks corresponds to the number of the second limiting grooves.

In one embodiment, a first limiting plate is sleeved on the outer wall of the traction shaft, a third limiting groove is formed in the circumferential direction of the first limiting plate, and a limiting block close to the end portion of the traction shaft is clamped with the third limiting groove.

In one embodiment, the traction mechanism further comprises a second limiting plate, the second limiting plate is sleeved on the traction shaft, and the two traction sheaves are located between the first limiting plate and the second limiting plate.

In one embodiment, the inner diameter of the first wheel body is smaller than the outer diameter of the traction shaft, and the inner wall of the first wheel body is in interference fit with the outer wall of the traction shaft.

The utility model also provides an elevator host machine, which comprises a first supporting seat, a second supporting seat, a connecting frame and the traction mechanism, wherein the first supporting seat and the second supporting seat are oppositely arranged, and the first supporting seat is connected with the second supporting seat through the connecting frame; the first end of the traction mechanism is mounted on the first supporting seat, and the second end of the traction mechanism is mounted on the second supporting seat.

In one embodiment, the first support seat has a first bearing seat and a first bearing, the first bearing being mounted within the first bearing seat; the second supporting seat is provided with a second bearing seat and a second bearing, and the second bearing is installed in the second bearing seat; the first bearing is sleeved at the first end of the traction mechanism, and the second bearing is sleeved at the second end of the traction mechanism.

The technical scheme provided by the utility model has the following advantages and effects:

1. The traction wheel is clamped with the traction shaft through a limiting assembly, segmented installation or segmented processing is achieved, the limiting assembly comprises a fixing pin and an elastic piece, the outer wall of the traction shaft is provided with a containing groove, the first end of the elastic piece is installed at the bottom of the containing groove, and the fixing pin is abutted with the second end of the elastic piece and is partially located in the containing groove; when the traction mechanism is used, firstly, the elastic piece is placed in the accommodating groove, then, the fixing pin is placed in the accommodating groove, the fixing pin is extruded, the traction wheel is sleeved at the preset position of the traction shaft, the traction wheel rotates on the traction shaft, and the fixing pin is extruded into the first limiting groove by the elastic piece due to the reset reaction force of the elastic piece, so that the traction wheel is limited to move on the traction shaft, the assembly of the traction wheel and the traction shaft is realized, and the assembly of the traction mechanism is simplified; in addition, the traction shaft and the traction wheel are assembled separately, so that the traction wheel is machined independently, hard chromium plating treatment is only needed on the traction wheel, the properties of chromium are utilized to improve the hardness, wear resistance, temperature resistance, corrosion resistance and the like of the traction wheel, the waste of chromium plating electrolyte is reduced, the whole volume of a machining structure is reduced, the phenomenon of uneven plating thickness is not easy to cause, and the influence on the size and service life of a workpiece is avoided; the overall outer diameter size of the traction shaft is consistent, and additional processing is not needed; the waste of materials is reduced, and the production efficiency is improved.

2. The first wheel body and the second wheel body are of an integrated structure, so that the overall structural strength of the traction wheel is improved; the first wheel body is mainly used for sleeving the traction shaft, and is used for bearing friction force generated when the steel rope rotates, and the first limit groove is formed in the first wheel body, so that the connection stability between the first wheel body and the traction shaft is improved; the second wheel body is used for limiting the movement of the steel rope on the elevator host machine.

3. The external diameter of the second wheel body is larger than that of the first wheel body, and the traction wheels are at least two, and rope grooves are formed between the second wheel bodies of two adjacent traction wheels and are used for accommodating steel ropes and limiting the axial movement of the steel ropes, so that the stability of the traction mechanism during operation is improved.

4. The two adjacent traction sheaves are connected with the second limiting groove in a clamping mode through the limiting block, connection stability of the adjacent traction sheaves on the traction shaft is improved, each traction sheave is fixed with the traction shaft in a clamping mode through the fixing pin, the depth direction of the second limiting groove is intersected with the depth direction of the containing groove, the two adjacent traction sheaves are fixed relatively, rotation of the adjacent traction sheaves is limited in the axial direction of the traction shaft, axial movement and rotation of each traction sheave are limited in the radial direction of the traction shaft, connection strength of the traction sheaves and the traction shaft after assembly is further improved, and safety coefficient of a traction mechanism is improved.

5. The number of the second limiting grooves is at least two, the limiting blocks are corresponding to that of the second limiting grooves, the connection points between the two adjacent traction wheels are improved, the integrity and the connection strength of the two adjacent traction wheels after connection are improved, and the safety coefficient of the traction mechanism is further improved.

6. The outer wall cover at the traction shaft is established first limiting plate, and the circumference of first limiting plate upwards has the third spacing groove, is close to the stopper and the third spacing groove joint of traction shaft tip to make traction sheave pass through the stopper fixed with first limiting plate, first limiting plate restriction traction sheave is at the circumference removal of traction shaft, further improves the joint strength between traction sheave and the traction shaft.

7. The traction shaft is sleeved with the second limiting plate, the traction wheel is located between the first limiting plate and the second limiting plate, and the first limiting plate and the second limiting plate are used for further limiting axial movement of the traction wheel on the traction shaft, so that stability of the traction wheel and the traction shaft in operation is further improved.

8. The traction wheel is prevented from falling off from the traction shaft by adopting interference fit or transmitting large torque, the hole is enlarged and deformed by the elasticity of the material to be sleeved on the shaft by the interference fit, and the tightening force of the shaft is generated when the hole is restored, so that the traction wheel is connected with the traction shaft, and the connection strength between the traction wheel and the traction shaft is improved.

9. The traction mechanism is applied to the elevator main machine, so that the production efficiency is improved, and the assembly of the traction mechanism is simplified; the first supporting seat is used for supporting the first end of the traction mechanism, and the second supporting seat is used for supporting the second end of the traction mechanism, so that the stability of the traction mechanism in operation is improved.

10. The first bearing and the second bearing are sleeved outside the traction mechanism, so that friction resistance of the traction mechanism when the traction mechanism rotates on the first supporting seat and the second supporting seat is reduced.

Drawings

Fig. 1 is a structural sectional view of a traction mechanism in an embodiment of the present utility model.

Fig. 2 is a schematic structural view of a traction mechanism according to an embodiment of the present utility model.

Fig. 3 is an enlarged view of a portion of fig. 1 at a, in accordance with an embodiment of the present utility model.

Fig. 4 is an exploded view of the structure of an elevator host in yet another embodiment of the present utility model.

Fig. 5 is a schematic diagram of an elevator host according to still another embodiment of the present utility model.

Fig. 6 is a schematic diagram of an elevator host according to another embodiment of the present utility model.

Reference numerals illustrate:

100. A traction mechanism; 1. a traction shaft; 11. a receiving groove; 2. a first limiting plate; 21. a third limit groove; 3. traction sheave; 31. a first wheel body; 311. a first limit groove; 312. the second limit groove; 32. a second wheel body; 33. a limiting block; 4. a second limiting plate; 5. rope grooves; 6. a limit component; 61. a fixing pin; 62. an elastic member; 200. an elevator main machine; 7. a first support base; 71. a first bearing seat; 711. a first bearing; 8. a second support base; 81. a second bearing seat; 811. a second bearing; 9. and (5) connecting a frame.

Detailed Description

In order that the utility model may be readily understood, a more particular description of specific embodiments thereof will be rendered by reference to specific embodiments that are illustrated in the appended drawings.

The terms "first" and "second" … "as used herein, unless specifically indicated or otherwise defined, are merely used to distinguish between names and do not denote a particular quantity or order.

The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items, unless specifically stated or otherwise defined.

The term "fixed" or "connected" as used herein may be directly fixed or connected to an element, or indirectly fixed or connected to an element.

As shown in fig. 1 to 4, a traction mechanism 100 comprises a traction shaft 1, a limiting assembly 6 and a traction sheave 3, wherein the traction sheave 3 is sleeved outside the traction shaft 1; the limiting component 6 is arranged on the outer wall of the traction shaft 1 and is positioned between the traction wheel 3 and the traction shaft 1; the limiting assembly 6 comprises a fixing pin 61 and an elastic piece 62, the outer wall of the traction shaft 1 is provided with a containing groove 11, a first end of the elastic piece 62 is arranged at the bottom of the containing groove 11, the fixing pin 61 is abutted with a second end of the elastic piece 62, and part of the fixing pin is positioned in the containing groove 11; the traction sheave 3 has a first limit groove 311, the first limit groove 311 communicates with the accommodation groove 11, and the fixing pin 61 is engaged with the first limit groove 311. The traction sheave 3 is clamped with the traction shaft 1 through a limiting assembly 6 to realize sectional installation or sectional processing, the limiting assembly 6 comprises a fixing pin 61 and an elastic piece 62, the outer wall of the traction shaft 1 is provided with a containing groove 11, a first end of the elastic piece 62 is installed at the bottom of the containing groove 11, the fixing pin 61 is abutted with a second end of the elastic piece 62, and part of the fixing pin is positioned in the containing groove 11; when the traction mechanism is used, the elastic piece 62 is firstly placed in the accommodating groove 11, then the fixing pin 61 is placed in the accommodating groove 11, the fixing pin 61 is extruded, the traction sheave 3 is sleeved at the preset position of the traction shaft 1, the traction sheave 3 rotates on the traction shaft 1, the fixing pin 61 is extruded into the first limiting groove 311 by the elastic piece due to the reset reaction force of the elastic piece 62, the movement of the traction sheave 3 on the traction shaft 1 is limited, the assembly of the traction sheave 3 and the traction shaft 1 is realized, and the assembly of the traction mechanism 100 is simplified.

In addition, the traction shaft 1 and the traction wheel 3 are assembled separately, so that the traction wheel 3 is processed independently, hard chromium plating treatment is only needed on the traction wheel 3, the properties of chromium are utilized to improve the hardness, wear resistance, temperature resistance, corrosion resistance and the like of the traction wheel 3, waste of chromium plating electrolyte is reduced, the whole volume of a processing structure is reduced, the phenomenon of uneven plating thickness is not easy to cause, and the influence on the size and service life of a workpiece is avoided; the overall external diameter size of the traction shaft 1 is consistent, and no additional processing treatment is needed; the waste of materials is reduced, and the production efficiency is improved.

As shown in fig. 2 and 3, the traction sheave 3 includes a first wheel body 31 and a second wheel body 32, the first wheel body 31 and the second wheel body 32 are in an integral structure, the first wheel body 31 and the second wheel body 32 are hollow structures, and the first wheel body 31 is sleeved on the outer wall of the traction shaft 1; the first limiting groove 311 is located on the first wheel 31. The first wheel body 31 and the second wheel body 32 are of an integrated structure, so that the overall structural strength of the traction sheave 3 is improved; the first wheel body 31 is mainly used for sleeving the traction shaft 1, the first wheel body 31 is used for bearing friction force generated when the steel rope rotates, and the first limiting groove 311 is formed in the first wheel body 31, so that the connection stability between the first wheel body 31 and the traction shaft 1 is improved; the second wheel 32 is used to limit the movement of the steel cord on the elevator main machine 200.

As shown in fig. 1 and 2, the outer diameter of the second wheel 32 is larger than the outer diameter of the first wheel 31; the traction sheave 3 has at least two, and in the adjacent two traction sheaves 3, a rope groove 5 is formed between the side wall of the two adjacent second sheave bodies 32 and the outer wall of the first sheave body 31. The outer diameter of the second wheel body 32 is larger than that of the first wheel body 31, and at least two traction sheaves 3 are arranged, and rope grooves 5 are formed between the second wheel bodies 32 of two adjacent traction sheaves 3, wherein the rope grooves 5 are used for accommodating steel ropes and limiting the axial movement of the steel ropes, so that the stability of the traction mechanism 100 during operation is improved.

As shown in fig. 2 and 4, the first wheel 31 has a second limit groove 312 in the circumferential direction, the second wheel 32 has a limit block 33 in the circumferential direction, and the second limit groove 312 is disposed relatively far from the limit block 33; the limiting block 33 of one traction sheave 3 is clamped with the second limiting groove 312 of the other traction sheave 3, and the depth direction of the second limiting groove 312 is intersected with the depth direction of the accommodating groove 11. The connection stability of the adjacent traction sheaves 3 on the traction shaft 1 is improved through the clamping connection between the limiting blocks 33 and the second limiting grooves 312 between the two adjacent traction sheaves 3, each traction sheave 3 is respectively fixed through the fixing pin 61 and the traction shaft 1 in a clamping connection mode, the depth direction of the second limiting grooves 312 is intersected with the depth direction of the containing groove 11, the two adjacent traction sheaves 3 are relatively fixed, the rotation of the adjacent traction sheaves 3 is limited in the axial direction of the traction shaft 1, the axial movement and the rotation of each traction sheave 3 are limited in the radial direction of the traction shaft 1, the connection strength of the traction sheaves 3 and the traction shaft 1 after being assembled is further improved, and the safety coefficient of the traction mechanism 100 is improved.

In addition, at least two second limiting grooves 312 are provided, the two second limiting grooves 312 are oppositely arranged in the circumferential direction of the first wheel body 31 and are positioned at the end part of the first wheel body 31, and the number of limiting blocks 33 corresponds to that of the second limiting grooves 312. The number of the second limiting grooves 312 is at least two, the limiting blocks 33 correspond to the number of the second limiting grooves 312, the connection point between the two adjacent traction sheaves 3 is improved, the integrity and the connection strength of the two adjacent traction sheaves 3 after connection are improved, and the safety factor of the traction mechanism 100 is further improved.

As shown in fig. 2 and 4, the outer wall of the traction shaft 1 is sleeved with a first limiting plate 2, a third limiting groove 21 is formed in the circumferential direction of the first limiting plate 2, and a limiting block 33 close to the end part of the traction shaft 1 is clamped with the third limiting groove 21. Thereby make traction sheave 3 pass through stopper 33 and fixed with first limiting plate 2, first limiting plate 2 restriction traction sheave 3 on traction shaft 1 circumference removes, further improves the joint strength between traction sheave 3 and traction shaft 1.

As shown in fig. 1 and 2, the traction mechanism 100 further has a second limiting plate 4, the second limiting plate 4 is sleeved on the traction shaft 1, and the two traction sheaves 3 are located between the first limiting plate 2 and the second limiting plate 4. The traction shaft 1 is sleeved with the second limiting plate 4, the traction wheel 3 is located between the first limiting plate 2 and the second limiting plate 4, and the first limiting plate 2 and the second limiting plate 4 are used for further limiting the axial movement of the traction wheel 3 on the traction shaft 1 and further improving the stability of the traction wheel 3 and the traction shaft 1 during operation.

In addition, the inner diameter of the first wheel body 31 is smaller than the outer diameter of the traction shaft 1, and the inner wall of the first wheel body 31 is in interference fit with the outer wall of the traction shaft 1. The interference fit is adopted to prevent the traction sheave 3 from being connected with the traction shaft 1 and falling off or transmitting large torque, the interference fit uses the elasticity of materials to expand and deform the hole to be sleeved on the shaft, and when the first wheel body 31 is restored, the tightening force on the traction shaft 1 is generated, so that the traction sheave 3 is connected with the traction shaft 1, and the connection strength between the traction sheave 3 and the traction shaft 1 is improved.

As shown in fig. 4 to 6, the present utility model further provides an elevator host 200, which includes a first supporting seat 7, a second supporting seat 8, a connecting frame 9, and a traction mechanism 100 as described above, wherein the first supporting seat 7 is disposed opposite to the second supporting seat 8, and the first supporting seat 7 is connected to the second supporting seat 8 through the connecting frame 9; the first end of the traction mechanism 100 is mounted on the first support base 7, and the second end of the traction mechanism 100 is mounted on the second support base 8. The traction mechanism 100 is applied to the elevator main machine 200, so that the production efficiency is improved, and the assembly of the traction mechanism 100 is simplified; the first supporting seat 7 is used for supporting the first end of the traction mechanism 100, and the second supporting seat 8 is used for supporting the second end of the traction mechanism 100, so that the stability of the traction mechanism 100 in operation is improved.

As shown in fig. 4 to 6, the first support 7 has a first bearing housing 71 and a first bearing 711, the first bearing 711 being mounted in the first bearing housing 71; the second support seat 8 has a second bearing seat 81 and a second bearing 811, the second bearing 811 being mounted in the second bearing seat 81; the first bearing 711 is coupled to the first end of the traction mechanism 100, and the second bearing 811 is coupled to the second end of the traction mechanism 100. The first bearing 711 and the second bearing 811 are sleeved outside the traction mechanism 100, so that the friction resistance of the traction mechanism 100 when rotating on the first supporting seat 7 and the second supporting seat 8 is reduced, and the rotation precision is ensured. The bearing acts to fix and reduce the coefficient of friction of the load during mechanical transmission. Both the rotating "shaft" and the rotation support portion are rubbed, and the bearings can prevent such force from damaging, keeping the rotation smooth.

The above examples are also not an exhaustive list based on the utility model, and there may be a number of other embodiments not listed. Any substitutions and modifications made without departing from the spirit of the utility model are within the scope of the utility model.

Claims (10)

1. The traction mechanism is characterized by comprising a traction shaft, a limiting assembly and a traction wheel, wherein the traction wheel is sleeved outside the traction shaft; the limiting component is arranged on the outer wall of the traction shaft and is positioned between the traction wheel and the traction shaft;

The limiting assembly comprises a fixing pin and an elastic piece, wherein the outer wall of the traction shaft is provided with a containing groove, the first end of the elastic piece is installed at the bottom of the containing groove, and the fixing pin is abutted with the second end of the elastic piece and is partially positioned in the containing groove; the traction sheave is provided with a first limiting groove, the first limiting groove is communicated with the accommodating groove, and the fixing pin is clamped with the first limiting groove.

2. The traction mechanism of claim 1, wherein the traction sheave comprises a first wheel body and a second wheel body, the first wheel body and the second wheel body are of an integrated structure, the first wheel body and the second wheel body are of hollow structures, and the first wheel body is sleeved on the outer wall of the traction shaft; the first limit groove is located on the first wheel body.

3. The traction mechanism of claim 2, wherein an outer diameter of the second wheel is greater than an outer diameter of the first wheel; the traction wheels are at least two, and rope grooves are formed between the side walls of two adjacent second wheel bodies and the outer wall of the first wheel body in the two adjacent traction wheels.

4. The traction mechanism according to claim 3, wherein a second limit groove is formed in the circumferential direction of the first wheel body, a limit block is formed in the circumferential direction of the second wheel body, and the second limit groove is arranged relatively far away from the limit block; the limiting block of one traction sheave is clamped with the second limiting groove of the other traction sheave, and the depth direction of the second limiting groove is intersected with the depth direction of the accommodating groove.

5. The traction mechanism according to claim 4, wherein at least two second limit grooves are provided, the two second limit grooves are oppositely arranged in the circumferential direction of the first wheel body, and the number of the limit blocks corresponds to the number of the second limit grooves.

6. The traction mechanism according to claim 4 or 5, wherein a first limiting plate is sleeved on the outer wall of the traction shaft, a third limiting groove is formed in the circumferential direction of the first limiting plate, and a limiting block close to the end portion of the traction shaft is clamped with the third limiting groove.

7. The hoisting mechanism of claim 6 further comprising a second stop plate, wherein the second stop plate is coupled to the hoisting shaft and wherein the two traction sheaves are positioned between the first stop plate and the second stop plate.

8. The traction mechanism of any one of claims 3-5, wherein an inner diameter of the first wheel body is smaller than an outer diameter of the traction shaft, and an inner wall of the first wheel body is in interference fit with an outer wall of the traction shaft.

9. An elevator main machine, characterized by comprising a first supporting seat, a second supporting seat, a connecting frame and the traction mechanism according to any one of claims 1 to 8, wherein the first supporting seat is arranged opposite to the second supporting seat, and the first supporting seat is connected with the second supporting seat through the connecting frame; the first end of the traction mechanism is mounted on the first supporting seat, and the second end of the traction mechanism is mounted on the second supporting seat.

10. The elevator mainframe of claim 9, wherein the first support has a first bearing housing and a first bearing, the first bearing being mounted within the first bearing housing; the second supporting seat is provided with a second bearing seat and a second bearing, and the second bearing is installed in the second bearing seat; the first bearing is sleeved at the first end of the traction mechanism, and the second bearing is sleeved at the second end of the traction mechanism.