EP1428784A2

EP1428784A2 - Machineroomless elevator with belt and/or chain traction

Info

Publication number: EP1428784A2
Application number: EP20030078602
Authority: EP
Inventors: Aldo Loiodice; Gino Loiodice
Original assignee: Bravo Srl
Current assignee: Bravo Srl
Priority date: 2002-11-19
Filing date: 2003-11-12
Publication date: 2004-06-16

Abstract

A machine-room-less elevator is described, in which the motor, normal or at variable speed, is placed between the elevator car guide rails, which is provided by a single reduction transmission or in cascade with belts and/or chains to the traction sheave, and which can also has a generator function, to recover energy when the unbalance between elevator car and counterweight is such that torque is not required from the motor, but the motor must exert a braking couple. Reducing cascade speed, a faster motor can be used, of lesser torque and therefore smaller dimensions with equal load.

Description

The present invention is about an elevator without the machine room having considerable innovative characteristics.
In the present evolution of the elevator technique the research is directed to develop elevator systems, without the machine room, requiring the least possible space other than that defined by the elevator car and/or counterweight guides, as well as they need a minimum height of the excess stroke; at the same time, said elevator systems, although they should keep all the safety related to use and maintenance, should be economic in relation to installation, operating and maintenance costs, and even ride comfort, and they should be flexible during their use, and also suitable for existent buildings.
The main factors to respect to satisfy these requirements are to support the traction machinery on the elevator car and/or counterweight guides, and to use a fast and small motor, and therefore of reduced cost.
These problems are brilliantly solved by an elevator without the machine room according to the present invention, which characteristics are described in the annexed claims.
System objects, characteristics and advantages will be better highlighted in the following detailed description, with reference to the annexed drawings, wherein:
Figure 1 is a schematic view of a belt or chain transmission with single reduction, in an elevator system embodiment, placed at the last floor, with the traction system installed between the elevator car guide rails;
Figure 2 is a schematic view of a belt or chain transmission in cascade with the elevator system also placed at the last floor, with the traction system installed between the elevator car guide rails;
Figure 3 is an enlarged view of the traction system of Figure 1;
Figure 4 is an enlarged view of the traction system of Figure 2;
Figure 5 is a schematic view of the elevator system with an auxiliary motor; and
Figure 6 is a schematic view similar to Figure 1, in which the elevator system is however equipped with two motors.
Referring to the figures of the annexed drawings, the elevator system is shown in its direct drive version 1:1, but it can also be used in suspension in 2:1, 3:1 or 4:1 ratio.
In the shaft 10 the elevator car 12 travels across guide rails 14, while the counterweight 16 travels across counterweight rails 18. The elevator car 12 has its car door 20 obviously turned towards the floor's door 22, but it is possible to have up to three car doors.
The entire elevator system is self-bearing, since both the traction machinery and the control board 24 are supported and fixed to the elevator car guide rails 14 (but it is also possible to fix them to the counterweight rails 18) through beams 26 and 28. To the upper beam 26 the control board 24 is fixed and the motor 30 is suspended through tie-rods 32. The motor 30 can be of the permanent magnet type, brushless, or of the asynchronous type and even gearless. The control board 24, arranged in the elevator shaft, allows to reduce the number of devices placed into the required external control board, and therefore its overall dimensions.
By means of the supporting frame 34, on the lower beam 28 the traction machinery is mounted, comprising the traction sheave 36, the brake 38 and the driving sheave 40, which receives motion from the motor's 30 driven sheave 41 through a reduction unit, comprising a double intermediate sheave 42A, 42B (Fig. 2 and 4). With such cascade reduction it is possible to use smaller, lighter and faster electric motors, while the transmission is realized by belts, or chains, or mixed (not shown in Figures). However, in case of single reduction transmission, shown in Fig. 1 and 3, this reduction unit is not present.
The motor 30, if of permanent magnet type, has also the generator function, to recover energy when the unbalance between elevator car and counterweight is such that torque is not required from the motor, but the motor must exert a braking couple. The current is returned to the power supply, improving its with cos ϕ = 1. The recovered energy can also be stored in storage buffer battery floating with the power supply and with the motor's recovering circuit, so with low power employed and absolute safety in case of energy cut-off, very useful to return to the floor, especially for hospitals and other essential public and/or private services.
The emergency or rescue handling can be provided by an auxiliary motor or by a coaxial spare motor for the main one, suitable for moving the elevator car in emergency situations, in case of failure, breakdown or even in case of energy cut-off.
Essential feature is that the auxiliary or spare motor 30A, or the second motor 30B, are coaxial with the main motor, to be connected to the reduction unit and to the electromagnetic brake, without requesting further transmission elements.
The auxiliary motor shall be asynchronous, or brushless of permanent magnet type, or of other type, however suitable for moving the elevator system, fed by battery and/or inverter.
It is also possible to adopt two separate motors so that, in case of breakdown of one of the two motors, the spare one is able to move the elevator car in emergency anyhow.
With such an elevator system, placed in the shaft overhead room, between the area delimited by the elevator car's wall during its stroke, including the excess stroke, and the elevator compartment's wall over the counterweight projection, in respect of safety distance, several advantageous features are obtained.
When the elevator car is in its stroke's highest point, including the excess stroke, its top portion reaches at least the driving unit's lower edge level.
The driving unit is substantially placed inside the space extension overhead of the elevator shaft required for the counterweight, safety distance included, in direction of the counterweight thickness.
A control panel is combined with the driving unit, including motor and controls power supply equipments, which operate the traction sheave, being this control panel preferably integrated with the driving unit.
The driving unit, although keeping all the elevator system characteristics mentioned above, can exceed the counterweight thickness and can also be fixed to a shaft wall and/or ceiling.
The counterweight suspension can also be of different type from the elevator car's one.
Other important feature is the maintenance footboard 44, applied in off-position against the shaft wall 46, which, being pivoted at the lower end, is pulled down in horizontal position when it must be used, laying on last floor's walking surface 48 and allowing the operator to perform his job in comfort and safety.
It is therefore evident that the elevator according to present invention fully achieves the intended objects, but it should be also pointed out that numerous elements alterations, variations, replacements and/or additions could be introduced to the system without departing from its object and even without falling outside its scope of protection, as it is also defined in the appended claims.

Claims

A machine-room-less elevator, in which machine components are mounted inside the elevator shaft in the area included in the shaft overhead room, between the area delimited by the elevator car's wall during its stroke, including the excess stroke, and the elevator compartment's wall over the counterweight projection, in respect of safety distance, on beams fixed to the guide and/or counterweight rails, wherein the motion transmission from the motor to the traction sheave is provided through a single reduction or in cascade, consisting in an intermediate double sheave between the driven sheave outgoing from the motor and the driving sheave of the traction sheave, the motion being transmitted by belts and/or chains.
The elevator according to claim 1, wherein the motor works also as a generator for recovering energy, directly supplied to the power supply or stored in storage buffer batteries, to be reused in the same system.
The elevator according to claim 1, wherein the motor is of permanent magnet type, brushless, or of the asynchronous type.
The elevator according to claim 1, wherein a control board is also mounted on the beams fixed to the guide rails, allowing therefore a reduction of the required external control board.
The elevator according to one or more of the preceding claims, wherein it comprises a maintenance footboard applied against a shaft wall, which can be pulled down in horizontal position when used.
The elevator according to one or more of the preceding claims, wherein when the elevator car is in its stroke's highest point, including the excess stroke, its top portion reaches at least the driving unit's lower edge level.
The elevator according to one or more of the preceding claims, wherein the driving unit is substantially placed inside the overhead extension of the elevator shaft required for the counterweight, safety distance included, in direction of the counterweight thickness.
The elevator according to claim 7, wherein a control panel is combined with the driving unit, including motor and controls power supply equipments, which operate the traction sheave, being this control panel preferably integrated with the driving unit.
The elevator according to one or more of the preceding claims, wherein the driving unit is gearless.
The elevator according to one or more of the preceding claims, wherein the driving unit exceed the counterweight thickness, keeping system characteristics.
The elevator according to one or more of the preceding claims, wherein the driving unit can also be fixed to a shaft wall and/or ceiling.
The elevator according to one or more of the preceding claims, wherein the counterweight suspension can also be of different type from the elevator car's one.
The elevator according to one or more of the preceding claims, wherein an emergency handling comprising a second motor coaxial with the first motor or the main one is provided, adapted to move the elevator system in case of breakdown or stop of the first motor or the main one, or even in case of energy cut-off.
The elevator according to claim 13, wherein said second motor is an auxiliary asynchronous, or brushless of permanent magnet type, or of other type motor, fed by battery and/or inverter.
The elevator according to claim 13, wherein in case of breakdown of one of the two motors, the spare one is able to move the elevator car in emergency anyhow.
The elevator according to claim 13, wherein the two coaxial motors have subdivided power but altogether the same as the one required for the system, and both work at the same time but, in case of breakdown of one of the two motors, the other is able to perform emergency operations anyhow.
The elevator according to claims 13 - 16, wherein the two motors control the reduction unit and the electromagnetic brake through a single transmission element.