FI92181B - Method for driving a lift and lift machinery - Google Patents

Abstract

Method and machinery for driving a lift. The lift machinery comprises a counterweight 4 connected to the lift cage 1 by a cable element 3. In the method the lift is set in motion and the kinetic energy of the system is adjusted by means of the potential energy of the counterweight, and by kinetic and potential energy of the lift counterweight released by the descent of the lift, and the energy consumed by losses is replaced by raising the counterweight with a separate auxiliary machine 8. In the machinery the counterweight comprises a breaker element 5, by means of which the cable element is led to a functional element 7 coupled to the lift machinery power element 6, for driving the power element by means of the potential and kinetic energy of the counterweight when the lift cage is set in motion, and for raising the counterweight by means of the kinetic and potential energy released by descent of the lift cage 1. Auxiliary machinery 8 has moreover been coupled to the functional element for raising the counterweight. <IMAGE>

Description

92181

METHOD OF USING THE LIFT AND LIFT MACHINERY

The invention relates to a method for operating an elevator as defined in the preamble of claim 1 and to an elevator machine as defined in the preamble of claim 2.

Today, the power that elevators take from the mains varies greatly. The maximum power requirement is at the lift of a full elevator car, which is the maximum power that determines the electrical equipment used and the dimensioning of the connection. When driving the elevator car down, the elevator car can be braked electrically so that electricity is fed back into the network. Often, however, the kinetic and potential energy of the elevator car is converted in its entirety into waste heat in suitable brake-15 devices.

The object of the invention is to eliminate the above-mentioned drawbacks. In particular, the object of the invention is to provide a new type of elevator machinery which reduces the energy consumption of the elevator and, above all, reduces the connection power of the elevator to the electrical network.

With regard to the features characteristic of the invention, reference is made to the claims.

In the method according to the invention for operating an elevator, the elevator machinery comprises a counterweight connected to the elevator car by a rope member. According to the invention, the elevator car is moved and the kinetic energy of the system is changed by means of the counterweight potential energy, and the counterweight is released by the motion and potential energy released when the elevator car is lowered. In addition, the energy consumed by the losses 30 is compensated by raising the counterweight by a separate auxiliary mechanism. Thus, in the method according to the invention, the energy required in all the operating spaces of the elevator car is taken from the counterweight by lowering the counterweight and the energy released in the different business spaces of the elevator car is recovered by counterbalancing it by raising it. In addition, only the losses incurred are compensated by external energy.

The elevator machine according to the invention for raising and lowering the elevator car 2 92181 comprises a counterweight connected to the elevator car by a rope member. According to the invention, the counterweight comprises a folding member through which the rope member is guided to an actuator connected to the power unit 5 of the elevator machine. In this way, the power unit can be operated when the elevator car is moved by means of a counterweight and the counterweight can be raised by the kinetic and potential energy released when the elevator car is lowered. In addition, according to the invention, an auxiliary machine is connected to the actuator, by means of which the counterweight can be raised if necessary.

Thus, according to the invention, the counterweight acts as an immediate source of energy for the elevator car, by means of which the elevator car is lifted both empty and loaded, and to which the kinetic and potential energy of the elevator car is restored when the elevator car is lowered. Since the lifting and lowering of the elevator car always involves energy losses that turn into heat and because the use of the elevator machine can be uneven, e.g.

• 25 However, the power requirement of the auxiliary machinery used is considerably lower than the instantaneous maximum power requirements of the corresponding elevator machinery, because the auxiliary machinery can be operated at a constant continuous power requirement, regardless of the current elevator load and operating mode. Thus ·, in an extreme situation, the auxiliary machinery can be used continuously and at other times suitably periodically.

The method according to the invention is equally applicable to both a traction sheave elevator and a roller elevator.

The preferred actuator to be used is a hydraulic cylinder which communicates with a hydraulic motor acting as a drive device for the traction wheel. Thus, when the counterweight descends 92181 3 downwards, it compresses the hydraulic cylinder hydraulic fluid into a hydraulic motor acting as a drive wheel drive device, which rotates the drive wheel and raises the elevator car. At the same time, the counterweight, via the traction member 5, pulls the elevator car upwards.

When operating in the opposite direction, i.e. recovering the kinetic and potential energy of the downwardly moving elevator car, the drive wheel power unit acts as a hydraulic pump which pumps hydraulic fluid to the hydraulic cylinder, 10 increasing the counterweight and increasing its potential energy.

In a preferred embodiment of the invention, the mass of the counterweight is twice that of the car in equilibrium, e.g. about half-loaded car.

15 In this case, the rope forces on the traction sheave are as traditional counterweight in traction sheave equipped with mass of the counterweight has e.g. equal to the mass of the empty cage + side load.

The elevator machine according to the invention has significant advantages over the prior art. It substantially reduces energy consumption because the potential and kinetic energy released by the elevator car is stored in a counterweight, eliminating the need for expensive and uneconomical feedback to the power grid, which can also cause disturbances in the power grid. In addition, the energy is stored in the form in which it is used by the hydraulic motor, so the overall efficiency is good. Likewise, the invention significantly reduces the connection power because so little energy is taken from the network that no feedback is required. In addition, energy is taken from the grid at constant power, regardless of the current load and operating mode of the elevator car. It is also an advantage that no separate devices are required for the emergency operation and emergency driving of the elevator car, but for example, driving to the floor 35 during a power failure takes place by means of counterbalance energy.

In the following, the invention will be described in detail with reference to the accompanying drawing, which schematically shows an elevator machine according to the invention.

An elevator machine according to the invention 5 shown in the drawing comprises an elevator car 1 suspended via a rope member 3 on a traction sheave 2 and via a traction sheave on a counterweight 4 and via a counterweight folding wheel 5 on a hydraulic cylinder 7 to which one end of the rope member is attached. An adjustable hydraulic motor 6 acting as a power device is connected to the traction wheel 10, which has a hydraulic connection 10 to the hydraulic cylinder 7. The hydraulic connection 10 can be closed, if necessary, by a shut-off valve 9. In addition, the elevator

The elevator machinery shown in the drawing is used as follows. The loaded elevator car is driven up by the potential energy of the counterweight 4 so that a pressurized hydraulic fluid flow is taken from the hydraulic cylinder 20 7 attached to the rope member 3 to the hydraulic motor 6. Thus the potential energy of the counterweight 4 is When moving an empty or underloaded body 25, depending on the ratio of body to counterweight masses, the hydraulic motor 6 either acts as a pump that pumps hydraulic fluid to the hydraulic cylinder 7 and raises the counterweight or acts as a hydraulic motor receiving the required hydraulic pressure 30 from the hydraulic cylinder 7.

Due to the natural losses of the elevator machinery, such as friction and leaks, as well as congestion, the potential energy of the counterweight is depleted, i.e. it reaches its lower position during a few full car starts-up, so a 35 . this

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5 The 92181 machinery is not required to have the characteristics of the actual driving machinery of the lift, since its operation does not depend on the current operating space of the lift, but mainly on the energy needs of subsequent runs.

5 During congestion, the auxiliary machinery 8 can run 100% of the switching capacity, so that the connection power to the mains can be dimensioned very small compared to conventional elevators. Otherwise, the auxiliary machinery can be switched on if necessary, i.e. according to the current position 10 of the counterweight and the future or expected traffic need.

It is essential in the elevator machine according to the invention shown in the drawing that the elevator car is lifted practically only by means of the potential energy of the counterweight, and the kinetic and potential energy released during lowering and braking of the elevator car or counterweight is recovered.

The invention has been described in detail above by means of a drawing, however, various embodiments of the invention 20 are possible within the scope of the inventive idea defined by the claims.

Claims (8)

A method of driving an elevator when a lifting machine belongs to a lifting basket (1) with a counterbalance (4) connected to a lifting member (3), it can be characterized that - the lifting basket is set in motion and the system's movement energy is reduced. gi is changed using the potential energy of the counterweight (4), - with the movement-and-potential energy released at the lift-off of the lift basket, the counterweight is lifted and - the loss of eating energy is replaced by raising the counterweight with a separate auxiliary machine (8). Elevator machinery for the lifting and lowering of a lift basket (1), to which the lifting machine belongs to a counterbalance (4) connected to a lift basket (4), characterized in that the lifting means (4) includes a switching member (5). , by means of which the rope means (3) is guided into a functional means (7) in contact with the lifting device's power device (6) for driving the power device with the potential and motion energy of the counterweight as the lift basket is set in motion and for lifting the counterweight with upon movement of the lift basket (1), the released energy and potential energy are released and that auxiliary machinery (8) for lifting the counterweight (4) is joined to the functional member (7). Elevator machinery according to Claim 2, characterized in that the operating means (7) is a hydraulic cylinder, which in connection with a hydraulic motor (6) acting as a drive wheel (2), operates. Elevator machinery according to claim 3, characterized in that in the resting position the hydraulic motor (6) is separated from the pressure space of the hydraulic cylinder (7) by a shut-off valve (9). Elevator machinery according to any one of claims 2-4, characterized in that the switching means (5) is constituted by a switching disk, through which the rope means (3) 1 9 92181 can move freely. Elevator machinery according to any of claims 2-5, characterized in that the mass of the counterweight (4) is substantially twice as large as the mass of the elevator basket (1) loaded half. Elevator machinery according to any of claims 2-6, characterized in that the elevator machinery is connected to a drive disk elevator. Elevator machinery according to any of claims 10 to 6, characterized in that the elevator machinery is connected to a roller lift.