DESCRIPTION
ELEVATOR DEVICE
TECHNICAL FIELD [0001]
The present invention relates to an elevator device including a car that ascends and descends in a hoistway.
BACKGROUND ART [0002]
In the related art, in an elevator device in which a car and a counterweight are connected to each other by a main rope, the main rope is wound around a drive sheave via a direction-changing sheave and sheaves of a car and a counterweight, and the car and the counterweight are hoisted up and down by the drive sheave is driven, it is commonly that the diameters of the drive sheave and the sheaves are set equal to or over than 40 times the main rope diameter to alleviate damage to the main rope due to friction drive and reduce the flexion resistance. However, recently, main ropes using synthetic resin with improved flexion performance such as aramid or Kevlar, main ropes made from a combination of a steel wire and urethane resin or the like for extended life, and the like have been devised, and main ropes are now being manufactured which achieve extended main rope life and improved flexion performance even through the diameters of the drive sheave and sheaves are set equal to or less than 30 times the main rope diameter.
However, main ropes manufactured with an aim to achieve extended life often lack flexibility, whereas main ropes manufactured with an aim to achieve flexibility often decrease in life, and there is a need for compensating for these drawbacks. [0004]
As a solution to this problem, there has been proposed a design in which a drive force is obtained by increasing the winding angle of the main rope on the drive sheave to reduce the diameter of the drive sheave, and since a large deflector sheave is not preferable, the deflector sheave is reduced to a size equivalent to that of the drive sheave (refer to, for example, Patent Document 1). Patent Document 1: JP-U NO. S58-117476
DISCLOSURE OF THE INVENTION
PROBLEM TO BE SOLVED BY THE INVENTION
[0005]
In the proposed related art mentioned above, only the drive sheave is reduced in size, and no consideration is given to improving the performance of the elevator as a whole.
[0006]
An object of the present invention is to provide an elevator device which can minimize a decrease in the life of the main rope even when the drive sheave is reduced in diameter.
MEANS FOR SOLVING THE PROBLEM [0007]

To attain the above-mentioned object, in an elevator device which uses a hoist having a drive sheave with a diameter equal to or less than 29 times a main rope diameter, and has sheaves provided to at least a car and a counterweight, diameters of the sheaves provided to the car and the counterweight are set larger than the diameter of the drive sheave. [0008]
With the above-mentioned configuration, the bending stress on the main rope and the flexion resistance of the main rope can be reduced, so a life-extending effect for the main rope and an energy saving effect can be expected. Also, since a reduction in the size of the hoist can be achieved by the reduction in the diameter of the drive sheave, it is possible to make effective use of space, and even an improvement in installation tolerance and maintainability of the hoist can be expected.
EFFECT OF THE INVENTION [0009]
According to the present invention, since the diameters of the car and counterweight sheaves are set larger than the diameter of the drive sheave, the bending stress on the main rope and the flexion resistance of the main rope can be reduced and, as a result, a life-extending effect for the main rope and an energy saving effect can be expected. Also, since a reduction in the size of the hoist can be achieved by the reduction in the diameter of the drive sheave, it is possible to make effective use of space, and even an improvement in installation tolerance and maintainability of the hoist can be expected.
BEST MODE FOR CARRYING OUT THE INVENTION [0010]
An embodiment of the present invention will be described below with reference to the drawings. [0011]
Fig. 1 is a perspective view showing an embodiment of an elevator device according to the present invention, Fig. 2 is a plan view of Fig. 1 as seen from above, Fig. 3 is a perspective view showing another embodiment of an elevator device according to the present invention, Fig. 4 is a plan view of Fig. 3 as seen from above, Fig. 5 is a perspective view showing still another embodiment of an elevator device according to the present invention, and Fig. 6 is a plan view of Fig. 5 as seen from above. [0012]
In Fig. 1, a car-side main rope stop 3 is installed above the lateral side of a car 1, a main rope 5 extends downward from the car-side main rope stop 3, and after being passed over from a car sheave 7a to another car sheave 7b, reaches a drive sheave 9 installed above the car 1. The main rope 5 is wound around the drive sheave 9 at about 180 degrees and extends downward again, and reaches a counterweight-side main rope stop 14 located above via a counterweight sheave 12a attached to a counterweight 2. [0013]
The general layout according to the present invention will be described with reference to Fig. 2. Fig. 2 illustrates a case where an elongated hoist 10 is arranged above the car 1, and a direction-changing sheave for connecting the car 1 and the counterweight 2 to each other is not used. The counterweight 2 is
installed to the side of the car 1. In this regard, when, for example, the main rope 5 having a resin coating applied over a steel wire is used, the friction coefficient between the drive sheave 9 and the main rope 5 is improved as compared with a case where a main rope made of only a steel wire without a resin coating is used, thereby making it possible to reduce the diameter of the drive sheave 9 and, as a result, reduce the size of the hoist 10. However, since the local stress on the main rope 5 increases as the diameter of the drive sheave 9 is reduced, measures must be taken to extend the life of the resin-coated main rope 5 described above, such as increasing the hardness of the resin. Using the main rope 5 with the hardness of the resin thus increased allows a reduction in the size of the drive sheave 9. At the same time, since the required drive torque or brake torque becomes smaller, it is also possible to achieve a reduction in equipment size, and as the space around the hoist 10 becomes larger as the hoist 10 is reduced in size, enhanced maintainability is achieved. [0014]
On the other hand, if the car sheaves 7a, 7b and the counterweight sheave 12a are also reduced in size, the flexion resistance of the main rope 5 becomes greater when the main rope 5 is wound onto the sheaves 7a, 7b and the counter sheave 12a. It leads to an increase in the travel loss of the elevator. Also, if the car sheaves 7a, 7b and the counterweight sheave 12a are reduced in diameter, the local stress on the main rope 5 increases. It leads to a decrease in the life of the main rope 5. Accordingly, to keep the flexion resistance and the life of the
main rope within a permissible range by enlarging the car sheaves 7a, 7b and/or the counterweight sheave 12a as reguired relative to the drive sheave 9, the efficiency of installation of the hoist 10 in a space can be enhanced without largely changing the general configuration of the elevator.
[0015]
At this time, although this object can be accomplished by making the diameters of the sheaves larger than the diameter of the drive sheave 9, if possible, by setting the diameters of the sheaves to be 1.5 times the diameter of the drive sheave 9, an improvement in the life of the main rope 5 can be achieved in a more stable manner.
[0016]
Also, while the diameter of the drive sheave 9 is set equal to or less than 29 times that of the main rope 5, it is optimally set equal to or less than 16 to 29 times. This is because if the diameter is less than 16 times, the local stress increases, so a life cannot be expected.
[0017]
Further, if a resin-coated wire rope, Kevlar, or aramid resin is used for the main rope 5, the flexibility can be increased, and it becomes extremely easy to make the diameter of the drive sheave 9 be equal to or less than 29 times that of the main rope 5.
[0018]
Next, another embodiment will be described with reference to Figs. 3,4. In Fig. 3, a car-side main rope stop 3 is installed above the lateral side of a car 1, a main rope 5
extends downward from the car-side main rope stop 3, is passed over from a car sheave 7a to another car sheave 7b, and then extends downward again via car-side direction-changing sheaves 8a, 8b installed above the car 1 before reaching a drive sheave 9. The main rope 5 is wound around the drive sheave 9 at about 180 degrees and extends toward counterweight sheaves 12a, 12b installed on a counterweight 2 located below from a counterweight-side direction-changing sheave 11 located above, before finally reaching a counterweight-side main rope stop 14 located above. [0019]
In Fig. 4, the differences from Fig. 2 reside in that the car-side direction-changing sheaves 8a, 8b are arranged between the car 1 and the drive sheave 9 and a thin hoist 10A is installed in a lower part of the hoistway, and that the counterweight-side direction-changing sheave 11 is arranged between the drive sheave 9 and the counterweight 2, and the two sheaves 12a, 12b are provided as counterweight sheaves, so the counterweight 2 is installed in rear of the car 1. [0020]
Although this configuration increases the tolerance for the placement of the counterweight 2, and makes it possible to improve the efficiency of installation in the hoistway, the number of sheaves increases as compared with the embodiment described above with reference to Figs. 1, 2, so the problems regarding the flexion resistance and the life of the main rope become conspicuous. Accordingly, in the embodiment illustrated in Figs. 3, 4, by making the diameters of all of the sheaves 7a, 7b,
12a, 12b of at least the car 1 and the counterweight 2, and of all or the majority of the other direction-changing sheaves 8a, 8b, 11 larger than the diameter of the drive sheave, the same effect as that of the embodiment illustrated in Figs. 1, 2 can be expected.
[0021]
Next, still another embodiment will be described with reference to Figs. 5, 6. In Fig. 5, a main rope 5 extends upward via a main rope return sheave 4 from a car-side main rope stop 3 installed on the floor portion of a car 1, is passed over from car upper direction-changing sheaves 6a, 6b to a car sheave 7a on the ceiling portion of the car 1, and extends from a car-side direction-changing sheave 8a installed above the car 1 to a drive sheave 9. After being wound around this drive sheave, the main rope 5 is passed over a counterweight sheave 12a provided to a countershaft 2 located below, and then extends toward a counterweight-side sheave 13 in an upper part of the hoistway again, before finally reaching a counterweight-side rope stop 14 of the counterweight 2.
[0022]
In Fig. 6, the major difference from Fig. 4 resides in that, while the roping indicating the way the main rope is wound is a 2:1 arrangement, the roping is set to a 3:1 arrangement, and an elongated hoist 10 is installed above the car 1. This configuration allows the drive torque or brake torque to be reduced even when the diameter of the drive sheave 9 is the same as that in Fig. 4, thereby making it possible to further reduce the size of the hoist. As described above, while there are
4 Main rope return sheave
5 Main rope
6a, 6b Car upper direction-changing sheave 7a, 7b Car sheave
numerous possible configurations of the elevator, in any case, the same effect as that of the above-described embodiments can be expected by making sheaves other than the drive sheave larger than the drive sheave in diameter in accordance with the above-described conditions.
BRIEF DESCRIPTION OF THE DRAWINGS [0023]
Fig. 1 is a perspective view showing an embodiment of an elevator device according to the present invention.
Fig. 2 is a plan view of Fig. 1 as seen from above.
Fig. 3 is a perspective view showing another embodiment of an elevator device according to the present invention.
Fig. 4 is a plan view of Fig. 3 as seen from above.
Fig. 5 is a perspective view showing still another embodiment of an elevator device according to the present invention.
Fig. 6 is a plan view of Fig. 5 as seen from above.
DESCRIPTION OF REFERENCE NUMERALS [0024]
1 Car
2 Counterweight
3 Car-side main rope stop
4 Main rope return sheave
5 Main rope
6a, 6b Car upper direction-changing sheave 7a, 7b Car sheave
8a, 8b Car-side direction-changing sheave
9 Drive sheave
10 Elongated hoist 10A Thin hoist
11 Counterweight-side direction-changing sheave 12a, 12b Counterweight sheave

13 Counterweight upper direction-changing sheave
14 Counterweight-side main rope stop 15a, 15b Car guide rail
16a, 16b Counterweight guide rail

CLAIMS
1. An elevator device which uses a hoist having a drive
sheave with a diameter equal to or less than 29 times a main rope
diameter, and has sheaves provided to at least a car and a
counterweight, wherein:
diameters of the sheaves provided to the car and the counterweight are set larger than the diameter of the drive sheave.
2. The elevator device according to Claim 1, wherein the diameters of the sheaves are set equal to or greater than 1.5 times the diameter of the drive sheave.
3. The elevator device according to Claim 1, wherein the hoist is arranged in a hoistway as a thin hoist.
4. The elevator device according to Claim 1, wherein the hoist is arranged in a hoistway as an elongated hoist.
5. The elevator device according to Claim 1, wherein a resin-coated wire rope, Kevlar, or aramid resin is used for the main rope.