Traction sheave elevator
The object of the invention is a method for modernizing an elevator, and a traction sheave elevator, which elevator comprises at least an elevator car and a traction sheave that moves the elevator car by means of elevator ropes, the rim of which traction sheave comprises one or more rope grooves. In connection with modernization a traction sheave is installed as the traction sheave of the elevator, the rope grooves of which traction sheave comprise a material, the frictive traction achieved by which is greater than the frictive traction between the parent material of the metallic traction sheave and the elevator ropes.
1. A traction sheave elevator, comprising:
an elevator car; and
a traction sheave that moves the elevator car via elevator ropes, the traction sheave includes one or more rope grooves corresponding to a number of elevator ropes, each rope groove includes at least two different materials in contact with the corresponding elevator rope, of which a first material is a hard and inflexible material, and a second material is a flexible material,
wherein the second material is fitted into the rope groove of the traction sheave and supports the elevator rope, whereby a radial force exerted on the second material by the elevator rope is smaller than a resulting radial force exerted on the elevator rope by the second material, and
wherein the second material is narrower in width than the rope groove, whereby air gaps between sidewalls of the second material and sidewalls of the rope groove are formed when the second material is fitted symmetrically in the rope groove, which air gaps accommodate an expansion of the second material when the elevator rope presses the second material towards a base of the rope groove.
2. The traction sheave elevator according to claim 1 , wherein each of the one or more rope grooves of the traction sheave includes an undercut, which contains the second material as an insert, and in that the rope groove, the undercut and a height of the insert are inter-dimensioned in relation to a diameter of the elevator rope such that the elevator rope compresses the insert in a direction of radius of the traction sheave a distance whereby a support surface of the rope groove bears the elevator rope along an entirety of contact in the one or more rope grooves, which entirety of contact defines an angle of traction of the elevator rope about the traction sheave.
3. The traction sheave elevator according to claim 2 , wherein the height of the insert is selected such that the insert is between approximately 15-40%, caused by the elevator rope.
4. The traction sheave elevator according to claim 3 , wherein the height of the insert is selected such that the insert is between approximately 18-25%, caused by the elevator rope.
5. The traction sheave elevator according to claim 4 , wherein the height of the insert is selected such that the insert is approximately 20%, caused by the elevator rope.
6. The traction sheave elevator according to claim 2 , wherein the height of the insert and the dimensioning of the undercut groove are selected such that the compression of the insert caused by the elevator rope is between approximately 1-2 mm.
7. The traction sheave elevator according to claim 2 , wherein on a surface of the insert or immediately below the surface is a plurality of consecutive relief cuts in a longitudinal direction of the insert, which are fitted to balance a deformation force produced in the insert by the elevator rope.
8. The traction sheave elevator according to claim 2 , wherein a stress of the elevator rope is reduced by reducing a width of the undercut groove.
9. The traction sheave elevator according to claim 2 , wherein a stress of the elevator rope is reduced by reducing an angle of contact between the elevator ropes and the traction sheave.
10. The traction sheave elevator according to claim 2 , wherein the insert is fixed immovably into the undercut of each of the one or more rope grooves.
11. The traction sheave elevator according to claim 1 , wherein the second material is a microcellular polyurethane.
12. The traction sheave elevator according to claim 11 , wherein the microcellular polyurethane has a size of bubbles in a region of 0.05-0.5 mm and a density of between approximately 300-600 kg/m 3 .
13. The traction sheave elevator according to claim 1 , wherein the second material is configured to provide an increase in friction traction when the second material is deformed in a direction of shear.
14. The traction sheave elevator according to claim 1 , wherein the first material is at least one of a metal and a hard plastic.
15. The traction sheave elevator according to claim 1 , wherein the second material is made from at least one of a rubber, a polyurethane, and a cellular rubber.