ELEVATOR APPARATUS

Abstract

 In an elevator apparatus, a car and a counterweight are suspended by means of suspension ropes in a hoistway. A drive rope is wound around a drive sheave of a drive device. The drive rope is connected to the counterweight. Further, a tensile force is applied to the drive rope by a tensile force generating device. A driving force of the drive device is transmitted to the counterweight through the drive rope so that the counterweight is raised/lowered, thereby raising/lowering the car.

Description

Technical Field

[0001] The present invention relates to an elevator apparatus having a structure in which a car and a counterweight are raised/lowered within a hoistway.

Background Art

[0002] In a conventional elevator apparatus, a car and a counterweight are suspended within a hoistway by means of a rope. The counterweight is mounted with an armature of a linear motor. A secondary conductor of the linear motor is disposed within the hoistway along a direction in which the counterweight is raised/lowered. The car and the counterweight are raised/lowered within the hoistway due to a driving force of the linear motor (e.g., see Patent Document 1).

[0003] Patent Document 1: JP 2003-40555 A

Disclosure of the Invention

Problems to be solved by the Invention

[0004]  In the conventional elevator apparatus constructed as described above, however, the linear motor is employed as a drive source, so the cost of the elevator apparatus is considerably high. Further, the secondary conductor is installed substantially along an entire length of the hoistway, so it is difficult to perform maintenance.

[0005] The present invention has been made to solve the above-mentionedproblems, and it is therefore an obj ect of the present invention to obtain an elevator apparatus which makes it possible to suppress an increase in cost, to perform maintenance with ease, and to alleviate vibrations of a drive device transmitted to a car.

Means for solving the Problems

[0006] An elevator apparatus according to the present invention includes: a car and a counterweight which are raised/lowered within a hoistway; a suspension rope for suspending the car and the counterweight within the hoistway; a drive device having a drive device body and a drive sheave rotated by the drive device body; a drive rope wound around the drive sheave and connected to the counterweight; and a tensile force generating device for adjusting a tensile force of the drive rope, in which the drive rope serves to transmit a driving force of the drive device to the counterweight so that the counterweight is raised/lowered, whereby the car is raised/lowered.

Brief Description of the Drawings

[0007] 

[Fig. 1] Fig. 1 is a perspective view showing an elevator apparatus according to Embodiment 1 of the present invention.

[Fig. 2] Fig. 2 is a lateral view showing the elevator apparatus of Fig. 1.

[Fig. 3] Fig. 3 is a plan view showing the elevator apparatus of Fig. 1.

[Fig. 4] Fig. 4 is a cross-sectional view of a tensile force generating device of Fig. 1.

[Fig. 5] Fig. 5 is a front view showing a relationship between a counterweight and a drive device of an elevator apparatus according to Embodiment 2 of the present invention.

[Fig. 6] Fig. 6 is a general schematic diagram showing an elevator apparatus according to Embodiment 3 of the present invention.

[Fig. 7] Fig. 7 is a general schematic diagram showing an elevator apparatus according to Embodiment 4 of the present invention.

[Fig. 8] Fig. 8 is a schematic diagram showing a tensile force generating device of an elevator apparatus according to Embodiment 5 of the present invention.

[Fig. 9] Fig. 9 is a schematic diagram showing a tensile force generating device of an elevator apparatus according to Embodiment 6 of the present invention.

[Fig. 10] Fig. 10 is a schematic diagram showing a tensile force generating device of an elevator apparatus according to Embodiment 7 of the present invention.

[Fig. 11] Fig. 11 is a schematic diagram showing a tensile force generating device of an elevator apparatus according to Embodiment 8 of the present invention.

Best Modes for carrying out the Invention

[0008] Preferred embodiments of the present invention will be described hereinafter with reference to the drawings.

Embodiment 1

[0009] Fig. 1 is a perspective view showing an elevator apparatus according to Embodiment 1 of the present invention. Fig. 2 is a lateral view showing the elevator apparatus of Fig. 1. Fig. 3 is a plan view showing the elevator apparatus of Fig. 1.

[0010] In the figures, a pair of car guide rails 2a and 2b and a pair of counterweight guide rails 3a and 3b are installed within a hoistway 1. Fig. 1 shows only lower portions of the guide rails 2a, 2b, 3a, and 3b. Fig. 2 does not show the guide rails 2a, 2b, 3a, and 3b.

[0011] A car 4 is raised/lowered within the hoistway 1 while being guided by the car guide rails 2a and 2b. A counterweight 5 is raised/lowered within the hoistway 1 while being guided by the counterweight guide rails 3a and 3b. A front surface of the car 4 is provided with a pair of car doors 6a and 6b for opening/closing a car doorway. The counterweight 5 is disposed behind the car 4 so as to be opposed to a back surface of the car 4 when being located at the same height as the car 4.

[0012] A first car return pulley 7a, a second car return pulley 7b, a third car return pulley 7c, and a fourth car return pulley 7d are provided in an upper portion within the hoistway 1. The car return pulleys 7a to 7d are disposed such that their rotary shafts extend horizontally and parallel to a width direction of the car 4. The car return pulleys 7a to 7d are disposed outside a region of the car 4 so as to be opposed to lateral surfaces of the car 4 on a vertical projection plane. In other words, the car 4 does not interfere with the car return pulleys 7a to 7d even after having moved to an uppermost portion within the hoistway 1.

[0013] A first suspension rope 8 is wound around the first car return pulley 7a and the second car return pulley 7b. The first suspension rope 8 has a first end 8a connected to one end of an upper portion (upper beam) of the car 4 in the width direction thereof, and a second end 8b connected to one end of an upper portion of the counterweight 5 in a width direction thereof. A second suspension rope 9 is wound around the third car return pulley 7c and the fourth car return pulley 7d. The second suspension rope 9 has a third end 9a connected to the other end of the upper portion (upper beam) of the car 4 in the width direction thereof, and a fourth end 9b connected to the other end of the upper portion of the counterweight 5 in the width direction thereof.

[0014] The car 4 and the counterweight 5 are suspended within the hoistway 1 by a 1:1 roping method by means of the first suspension rope 8 and the second suspension rope 9. A pair of car shock absorbers 10a and 10b and a pair of counterweight shock absorbers 11a and 11b are installed in a lower portion (bottom portion) of the hoistway 1.

[0015] A drive device 12 for generating a driving force for raising/lowering the car 4 and the counterweight 5 is installed in the lower portion of the hoistway 1. The drive device 12 has a drive device body 13 including a motor and a brake, and a drive sheave 14 rotated by the drive device body 13. The drive device 12 is disposed such that a rotary shaft of the drive sheave 14 extends horizontally and parallel to a depth direction of the car 4. The drive device 12 is disposed directly under the counterweight 5 so as to be superposed on the counterweight 5 on the vertical projection plane. In addition, a low-profile hoisting machine having a structure in which an axial outside dimension of the drive sheave 14 is shorter than a radial outside dimension thereof is employed as the drive device 12.

[0016] A drive rope return pulley 15 is disposed in the upper portion within the hoistway 1. The drive rope return pulley 15 is disposed such that a rotary shaft thereof extends parallel to the drive sheave 14. The drive rope return pulley 15 is disposed directly above the counterweight 5 so as to be superposed on the counterweight 5 on the vertical projection plane. Furthermore, the drive rope return pulley 15 and the drive device 12 are disposed outside the region of the car 4 so as not to be superposed on the car 4 on the vertical projection plane.

[0017] A plurality of drive ropes 16 (only one of them is shown in Figs. 2 and 3) are looped between the drive sheave 14 and the drive rope return pulley 15. The drive ropes 16 on one side of the drive sheave 14 are connected to the counterweight 5, and transmit a driving force of the drive device 12 to the counterweight 5. The counterweight 5 is provided with a notch portion 5a for preventing interference with a portion of the drive ropes 16 on the other side of the drive sheave 14.

[0018] The counterweight 5 is mounted with a tensile force generating device 17 for applying a tensile force to each of the drive ropes 16. The tensile force generating device 17 applies the tensile force to each of the drive ropes 16, so a frictional force (traction force) between the drive sheave 14 and each of the drive ropes 16 is ensured.

[0019] Fig. 4 is a cross-sectional view of the tensile force generating device 17 of Fig. 1. The tensile force generating device 17 is fitted to a rope end connecting portion 5b of the counterweight 5. Each of the drive ropes 16 is connected at one end thereof to the rope end connecting portion 5b. The tensile force generating device 17 has an extensible multiple tube portion (extension portion) 18, a plurality of coil springs 19a to 19c as elastic members disposed in the multiple tube portion 18, and a rope end connecting rod 20 inserted in a center of the multiple tube portion 18.

[0020] The multiple tube portion 18 has a triple tube structure including a first cylinder portion 18a, a second cylinder portion 18b, and a third cylinder portion 18c, which are different in diameter from one another. A lower end of the first cylinder portion 18a is fixed to the rope end connecting portion 5b. Each of the drive ropes 16 is connected at the other end thereof to the rope end connecting rod 20.

[0021] The coil spring 19a is disposed between the first cylinder portion 18a and the second cylinder portion 18b. The coil spring 19b is disposed between the second cylinder portion 18b and the third cylinder portion 18c. The coil spring 19c is disposed between the third cylinder portion 18c and the rope end connecting rod 20. That is, the coil springs 19a to 19c are arranged in a multistage manner. Spring forces of the coil springs 19a to 19c act in such a direction as to reduce an overall length of the multiple tube portion 18 and pull the drive ropes 16.

[0022] In the elevator apparatus constructed as described above, a driving force of the drive device 12 is transmitted to the counterweight 5 via the drive ropes 16, so the car 4 and the counterweight 5 are thereby raised/lowered. Accordingly, it is possible to significantly alleviate vibrations of the drive device 12 transmitted to the car 4 to relax a countermeasure against vibrations of the car 4, and to enhance ride comfort. Further, an increase in cost can be suppressed and maintenance can be facilitated as compared to a case in which the counterweight 5 is mounted with a linear motor.

[0023]  The tensile force generating device 17 having the coil springs 19a to 19c for applying a tensile force to each of the drive ropes 16 through an elastic force thereof is employed. Therefore, maintenance can be simplified, and the tensile force can be generated with a simple structure.
In addition, the coil springs 19a to 19c are arranged in the multistage manner, so a change in tensile force for a change in length can be reduced. To be more specific, a change in tensile force involved in a change in length can be confined within 5% of an overall stroke length.

[0024] Still further, the counterweight 5 is mounted with the tensile force generating device 17, so the counterweight 5 can be lightened by a weight of the tensile force generating device 17.
The car return pulleys 7a to 7d are disposed outside the region of the car 4 on the vertical projection plane. Therefore, an overhead dimension can be reduced, and a vertical dimension of the entire hoistway 1 can be reduced.
In addition, the drive device 12 is disposed so as to be superposed on the counterweight 5 on the vertical projection plane, so the planar dimension of the hoistway 1 can be reduced.

[0025] Yet further, the car 4 is suspended at both the ends thereof in the width direction thereof by means of the two suspension ropes 8 and 9. Therefore, the car 4 can be suspended in a well-balanced manner and raised/lowered stably.
The drive device 12 is installed in the lower portion within the hoistway 1, so maintenance and inspection of the drive device 12 can be carried out with ease.

Embodiment 2

[0026] Next, Fig. 5 is a front view showing a relationship between a counterweight and a drive device of an elevator apparatus according to Embodiment 2 of the present invention. A counterweight 21 has a first weight portion 22 and a second weight portion 23, which are respectively distributed on both sides in a width direction thereof, and a coupling portion 24 for coupling the first weight portion 22 and the second weight portion 23 to each other. The tensile force generating device 17 is attached to the coupling portion 24.

[0027] The first weight portion 22 and the second weight portion 23, which are arranged apart from each other in the width direction, are equal in weight to each other. The counterweight 21 is provided with a first recess portion 21a in which the drive device 12 is accommodated when the counterweight 21 is lowered to a lowest moving position (position where the counterweight 21 compresses the counterweight shock absorbers 11a and 11b of Fig. 1) within the hoistway 1. That is, the counterweight 21 does not interfere with the drive device 12 even after having been lowered to the lowest moving position.

[0028] The counterweight 21 is provided with a second recess portion 21b in which the drive rope return pulley 15 is accommodated when the counterweight 21 is raised to a highest moving position within the hoistway 1. That is, the counterweight 21 does not interfere with the drive rope return pulley 15 even after having been raised to the highest moving position. In other words, the counterweight 21 is divided into the first weight portion 22 and the second weight portion 23 in order to form the first recess portion 21a and the second recess portion 21b. Embodiment 2 is identical to Embodiment 1 in other constructional details.

[0029] By employing the counterweight 21 constructed as described above, the vertical dimension of the hoistway 1 can further be reduced.
The drive device 12 and the drive rope return pulley 15 are disposed so as to be superposed on the counterweight 21 on the vertical projection plane, so the planar dimension of the hoistway 1 can be reduced.

Embodiment 3

[0030] Next, Fig. 6 is a general schematic diagram showing an elevator apparatus according to Embodiment 3 of the present invention. In the figure, each of the drive ropes 16 is connected at both the ends thereof to a counterweight 31. The drive device 12 is supported by a base 33 via a tensile force generating device 32. The tensile force generating device 32 vertically displaces the entire drive device 12 including the drive sheave 14 to adjust a tensile force applied to each of the drive ropes 16. Embodiment 3 is identical to Embodiment 1 in other constructional details.

[0031] As described above, the tensile force generating device 32, which may be provided on the drive device 12 instead of being mounted on the counterweight 31, can apply a tensile force to each of the drive ropes 16.

Embodiment 4

[0032] Next, Fig. 7 is a general schematic diagram showing an elevator apparatus according to Embodiment 4 of the present invention. In the figure, each of the drive ropes 16 is connected at both the ends thereof to the counterweight 31. A tensile force generating device 34, which is interposed between the drive rope return pulley 15 and a support portion thereof, vertically displaces the drive rope return pulley 15 to adjust a tensile force applied to each of the drive ropes 16. Embodiment 4 is identical to Embodiment 1 in other constructional details.

[0033]  As described above, the tensile force generating device 34, which may be provided on the drive rope return pulley 15 instead of being mounted on the counterweight 31, can apply a tensile force to each of the drive ropes 16.

Embodiment 5

[0034] Next, Fig. 8 is a schematic diagram showing a tensile force generating device of an elevator apparatus according to Embodiment 5 of the present invention. The tensile force generating device employed in this example has a spring 35 as an elastic member. The spring 35 applies an upward force to a center of the drive rope return pulley 15 through an elastic force (restoring force) of the spring 35, thereby applying a tensile force to each of the drive ropes 16.

[0035] By employing such the spring 35, the structure of the tensile force generating device can be simplified. As a result, the tensile force generating device can be made inexpensive.

Embodiment 6

[0036] Next, Fig. 9 is a schematic diagram showing a tensile force generating device of an elevator apparatus according to Embodiment 6 of the present invention. The tensile force generating device employed in this example has a rubber member 36 as an elastic member. The rubber member 36 applies an upward force to the center of the drive rope return pulley 15 by an elastic force (restoring force) of the rubber member 36, thereby applying a tensile force to each of the drive ropes 16.

[0037] By employing such the rubber member 36 as well, the structure of the tensile force generating device can be simplified. As a result, the tensile force generating device can be made inexpensive.

Embodiment 7

[0038] Next, Fig. 10 is a schematic diagram showing a tensile force generating device of an elevator apparatus according to Embodiment 7 of the present invention. The tensile force generating device employed in this example has an actuator 37. The actuator 37 applies an upward force to the center of the drive rope return pulley 15 by a driving force of the actuator 37, thereby applying a tensile force to each of the drive ropes 16. The actuator 37 can hold the tensile force applied to each of the drive ropes 16 constant over the entire stroke thereof. In addition, the actuator 37 can also change and adjust the tensile force applied to each of the drive ropes 16.

[0039] For example, a hydraulic cylinder, an air cylinder, or an electromagnetic actuator having an electromagnetic coil can be employed as the actuator 37.

[0040] By employing the actuator 37 constructed as described above, the tensile force applied to each of the drive ropes 16 can be held constant in accordance with extension or contraction of the drive ropes 16, so a stable traction force between the drive sheave 14 and each of the drive ropes 16 can be ensured. Further, the actuator 37 is controlled so as to absorb vibrations or torque ripples of the drive ropes 16, which makes it possible to enhance riding comfort.

Embodiment 8

[0041] Next, Fig. 11 is a schematic diagram showing a tensile force generating device of an elevator apparatus according to Embodiment 8 of the present invention. The tensile force generating device employed in this example has a spring 38 as an elastic member and an actuator 39. The spring 38 applies a tensile force to each of the drive ropes 16 by an elastic force (restoring force) of the spring 38. The actuator 39 applies a tensile force to each of the drive ropes 16 by a driving force of the actuator 39.

[0042] As described above, the tensile force generating device having a combination of the spring 38 and the actuator 39 can use the spring 38 to cope with a short-period change in the tensile force applied to each of the drive ropes 16, and can use the actuator 39 to cope with a secular change in the tensile force applied to each of the drive ropes 16. Accordingly, the tensile force applied to each of the drive ropes 16 can further be stabilized.

[0043] The tensile force generating devices illustrated in Embodiments 5 to 8 are each applicable to both a tensile force generating device mounted on a counterweight and a tensile force generating device mounted on a drive device.
The counterweight is disposed behind the car in the foregoing examples. However, the counterweight may be disposed beside the car so as to be opposed to a lateral surface of the car when being located at the same height as the car.

[0044] Further, the drive device is disposed such that the rotary shaft of the drive sheave extends parallel to the depth direction of the car in the foregoing examples. However, the drive device may be disposed such that the rotary shaft of the drive sheave extends obliquely with respect to the depth direction of the car or parallel to the width direction of the car.
Still further, the drive device is disposed such that the rotary shaft of the drive sheave extends horizontally in the foregoing examples. However, the drive device may be disposed such that the rotary shaft of the drive sheave extends vertically or substantially vertically.

[0045] The low-profile hoisting machine is employed as the drive device in the foregoing examples. However, it is also possible to employ a drive device designed such that an outside dimension thereof in an axial direction is larger than an outside dimension thereof in a direction perpendicular to the axial direction.
Further, the drive device is installed in the lower portion within the hoistway in the foregoing examples. However, the drive device may be installed in the upper portion within the hoistway or in a machine room to make it possible to relax a countermeasure against water immersion.

[0046] Still further, the tensile force generating device is provided on the counterweight, the drive device, or the drive rope return pulley in the foregoing examples. However, the present invention is not limited to those constructions. For instance, a tension pulley around which the drive ropes are looped may be provided in addition to the drive sheave and the drive rope return pulley so that a tensile force is applied to each of the drive ropes via the tension pulley.

[0047] The number of the drive ropes may be set arbitrarily according to need.
In addition, for example, a steel rope, a high-flexure rope or the like can be employed as each of the suspension ropes and the drive ropes . Mentionable as the high-f lexure rope is, for example, a resin-coated rope having an outer-layer coating body, which is made of a resin material with a high coefficient of friction, provided on an outer peripheral portion thereof. By employing the high-flexure rope, a large traction force can be ensured for a small looping angle. The high-flexure rope can serve to enhance flexibility in comparison with the mere steel rope, so the diameter of the drive sheave can be reduced.
Furthermore, a belt-shaped rope as well as a rope having a circular cross-section can be employed as each of the suspension ropes and the drive ropes.
Ropes of different kinds may be employed as the suspension ropes and the drive ropes, respectively.

Claims

1. An elevator apparatus, comprising:

a car and a counterweight which are raised/lowered within a hoistway;

a suspension rope for suspending the car and the counterweight within the hoistway;

a drive device having a drive device body and a drive sheave rotated by the drive device body;

a drive rope wound around the drive sheave and connected to the counterweight; and

a tensile force generating device for applying a tensile force to the drive rope, wherein

the drive rope serves to transmit a driving force of the drive device to the counterweight so that the counterweight is raised/lowered, whereby the car is raised/lowered.

2. An elevator apparatus according to Claim 1, wherein the tensile force generating device has an elastic member for applying a tensile force to the drive rope by an elastic force of the elastic member.

3. An elevator apparatus according to Claim 2, wherein the elastic member includes a plurality of springs that are arranged in a multistage manner.

4. An elevator apparatus according to Claim 1, wherein the tensile force generating device has an actuator for applying a tensile force to the drive rope by a driving force of the actuator.

5. An elevator apparatus according to Claim 1, wherein:

the tensile force generating device has an elastic member for applying a tensile force to the drive rope by an elastic force of the elastic member, and an actuator for applying a tensile force to the drive rope by a driving force of the actuator;

the elastic member is used to cope with a short-period change in the tensile force applied to the drive rope; and

the actuator is used to cope with a secular change in the tensile force applied to the drive rope.

6. An elevator apparatus according to Claim 1, wherein the tensile force generating device is mounted to the counterweight.

7. An elevator apparatus according to Claim 1, wherein the tensile force generating device displaces the drive sheave to adjust the tensile force applied to the drive rope.

8. An elevator apparatus according to Claim 1, wherein:

the drive rope is looped between the drive sheave and a drive rope return pulley; and

the tensile force generating device displaces the drive rope return pulley to adjust the tensile force applied to the drive rope.

9. An elevator apparatus according to Claim 1, wherein:

a plurality of car return pulleys, around which the suspension rope is looped, are disposed in an upper portion of the hoistway; and

the car return pulleys are disposed outside a region of the car on a vertical projection plane.

10. An elevator apparatus according to Claim 1, wherein the drive device is disposed so that the drive device is superposed on the counterweight on a vertical projection plane.

11. An elevator apparatus according to Claim 10, wherein:

the drive device is disposed in one of a lower portion and an upper portion within the hoistway; and

the counterweight is provided with a recess portion in which the drive device is accommodated after having moved to one of a lowest moving position and a highest moving position within the hoistway.

12. An elevator apparatus according to Claim 1, wherein:

a drive rope return pulley, around which the drive rope is looped, is disposed in one of a lower portion and an upper portion within the hoistway; and

the drive rope return pulley is disposed so that the drive rope return pulley is superposed on the counterweight on a vertical projection plane.

13. An elevator apparatus according to Claim 12, wherein the counterweight is provided with a recess portion in which the drive rope return pulley is accommodated after having moved to one of a lowest moving position and a highest moving position within the hoistway.

Drawing