EP0534348A2

EP0534348A2 - Winch for elevators with improved support

Info

Publication number: EP0534348A2
Application number: EP92116120A
Authority: EP
Inventors: Alberto Sassi
Original assignee: ALBERTO SASSI SpA
Current assignee: ALBERTO SASSI SpA
Priority date: 1991-09-24
Filing date: 1992-09-21
Publication date: 1993-03-31
Also published as: IT1253037B; ITBO910341A1; EP0534348A3; ITBO910341A0

Abstract

Winch for elevators with improved support, consisting of the fact that the slow shaft (5) of the winch (1) has a first load support (6) and a second load support (7), between which the pulley for the traction cables is keyed, the slow shaft (5) having one end (5a) which extends to the side of the support for the cantilever mounting of the reduction gearwheel (4), and of the fact that a reduction casing (13) is rigidly associated with the first support (6); the gearwheel (4) is arranged inside the reduction casing (13), and power supports for the fast shaft (3) and means for fixing the drive unit are mounted inside the reduction casing (13).

Description

The present invention relates to a winch for elevators with improved support.
Winches for elevators are known which comprise a slow shaft, on which a pulley for the car lifting cables is keyed, and a fast shaft, which is actuated directly by an electric motor: the fast shaft and the slow shaft are supported so as to be able to rotate by means of bearings, bushings or the like in a reduction casing, and motion is often transmitted between the shafts by means of a worm-screw/helical gearwheel coupling, but can also be transmitted in another manner; the winch is installed by fixing the reduction casing on a base, sometimes arranging a further support at the end of the slow shaft which is provided with the pulley: when fixing is performed without this further support, the shaft is stressed considerably (the traction pulley in fact operates in a cantilever condition, and the same is true of the bearing close to the pulley); instead, when the end support is present, the shaft is supported in three points and is thus statically indeterminable: the loading supports, between which the pulley is mounted, support the load of the cables, car etc. (a load in the range of tons), and the shaft tends to be subject to deflection, transmitting abnormal stresses to the other support of the reduction casing.
Owing to all this, the slow shaft and the related supports at the reduction casing must be oversized in order to bear these very high loads even if the part of slow shaft which supports the reduction gearwheel is stressed by low power loads (in the range of a few tens, or at the most hundreds, of kilograms).
The above causes the slow shaft and the supports of the reduction casing to be stressed improperly, to be subject to excessive friction and wear and to have to be oversized in order to withstand the internal stresses induced by the statically indeterminable condition.
The technical aim of the present invention is to obviate said problems, i.e. to provide a winch for elevators with improved support wherein the slow shaft, its supports and the reduction casing are stressed correctly in order to minimize wear and friction and to allow to assume more appropriate dimensions and costs.
Within the scope of this technical aim, an object of the present invention is to provide a winch for elevators with improved support which facilitates the operations for assembly and access for maintenance or repairs.
Another object of the present invention is to achieve said aim with a simple structure which is relatively easy to execute in practice, is safe in use and effective in operation as well as relatively modest in cost.
This aim and these objects are all achieved by the present winch for elevators with improved support, characterized in that the slow shaft of the winch has a first load support and a second load support, between which the pulley for the traction cables is keyed, said slow shaft having one end which extends to the side of said support for the cantilever mounting of the reduction gearwheel, and in that a reduction casing is rigidly associated with said first support, said gearwheel being arranged inside said reduction casing, power supports for the fast shaft and means for fixing the drive unit being mounted inside said reduction casing.
Further peculiarities will become apparent and evident from the detailed description of a preferred but not exclusive embodiment of a winch for elevators with improved support according to the invention, illustrated only by way of non-limitative example in the accompanying drawings, wherein:

figure 1 is a front view of the winch for elevators with improved support according to the invention;
figure 2 is a side view of said winch.

With particular reference to the above figures, the reference numeral 1 generally designates the winch for elevators with improved support according to the invention.
The figures illustrate a winch of the type having a worm screw type 2 keyed or defined on the fast shaft 3 and a gearwheel 4 with helical teeth keyed on the slow shaft 5; in any case, reduction might also be obtained with another type of coupling.
The slow shaft 5, which is horizontal, has a first support 6 and a second support 7 defined, in the particular case, with bearings 9a and 9b which are mounted so as to be mutually aligned on strong supports 11 and 12: a pulley 10 is keyed between the supports 6 and 7, and the traction cables of the car are wound on said pulley, which is thus loaded in the direction of the arrow A (the term "bearings" defines rolling bearings of any type, bushes, bushings or the like).
An end 5a of the shaft 5 extends to the side of the first support for the cantilever keying of the reduction gearwheel (which in the particular case is the helical gearwheel 4).
The support 11 is monolithic with a reduction casing 13 inside which the gearwheel 4 is arranged; the reduction casing has an opening which is provided with a front cover 14 which can be fixed with perimetric bolts schematically indicated by 15; advantageously, the shaft 5 has a flange 16 which is rigidly associated therewith and on which a gasket 17 with a deformable lip forms a seal.
The power supports 18 and 19 of the shaft 2 are arranged above the casing 13, at right angles to the vertical plane of arrangement of the axis of the shaft 5.
The supports 18 and 19 comprise bearings 20a, 20b and 20c, of which the bearing 20c also has a thrust-bearing function, a gasket 21 with a deformable lip, a ring 22 which is screwed on the threaded end of the shaft, and a closing cover 23 which can be fixed with screws schematically indicated by 24.
Abutments 25 are provided to the side of the support 18 on the outside of the box 13, and have threaded holes 26 which constitute fixing means for a motor M which is schematically shown in broken lines; the motor fixing means may also be constituted by a strong bracket system 27, shown in broken lines, which is fixed to a lateral panel 28 of the casing 13 by means of bolts, schematically indicated by 29, onto which pedestal motors can be mounted.
It is stressed that the two loading supports 6 and 7, which are executed with appropriate dimensions, discharge downward onto respective profiled elements 30 and 31 which can in turn be fixed to the floor slab: the stresses due to the load of the car on the pulley 10, which is in a position comprised between the supports 6 and 7, do not affect at all the coupling for the transmission of power between the slow shaft and the fast shaft and between the fast shaft and the reduction casing.
It is stressed that access through the opening of the door 14 for maintenance is extremely easy, and so is the assembly of the unit.
It has thus been seen that the invention achieves the intended aim and objects.
The invention thus conceived is susceptible to numerous modifications and variations, all of which are within the scope of the inventive concept.
All the details may furthermore be replaced with other technically equivalent elements.
In practice, the materials employed, as well as the shapes and dimensions, may be any according to the requirements without thereby abandoning the scope of the protection of the following claims.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.

Claims

Winch for elevators with improved support, characterized in that the slow shaft of the winch has a first load support and a second load support, between which the pulley for the traction cables is keyed, said slow shaft having one end which extends to the side of said support for the cantilever mounting of the reduction gearwheel, and in that a reduction casing is rigidly associated with said first support, said gearwheel being arranged inside said reduction casing, power supports for the fast shaft and means for fixing the drive unit being mounted inside said reduction casing.
Winch according to claim 1, characterized in that said fast shaft and said slow shaft are arranged on mutually orthogonal vertical planes and are mutually connected by a worm screw/helical gearwheel coupling.
Winch according to claim 1, characterized in that said means for fixing the drive unit are constituted by threaded holes to which the motor is fixed directly or to which a bracket system for supporting the motor is fixed.