GB2125362A - Elevator drive apparatus with vibration isolation means - Google Patents

Abstract

An elevator drive apparatus comprising a motor and reduction gear unit 5 resiliently mounted on a first support member 4 via vibration isolators 6, and a traction sheave 13 rotatably mounted on a second support member 10 via a bed member 11 and vibration isolators 12. An output shaft 7c of the reduction gear unit is connected to the sheave by an elastic coupling 15. The vibration isolators and the elastic coupling isolate vibrations generated by the engagement between the teeth of the reduction gears and by the pulsating rotation of the drive motor and reducing such vibrations from the sheave, which improves the ride comfort in the elevator cage on hoist cable 17. <IMAGE>

Description

SPECIFICATION Elevator drive apparatus with vibration isolation means The present invention relates to a drive apparatus for a traction elevator lifting a cage up and down with cables.

An apparatus having reduction gears driven by a motor and a traction sheave connected to a rotatable output shaft of the reduction gears is known for driving elevators. The apparatus drives a cage and a counter weight with cables wound over the traction sheave. In such an apparatus the vibrations generated by the engagement between the teeth of the reduction gears travels through the cables to the cage, whereby passengers in the cage feel uncomfortable.

An elevator system employing reduction gears with parallel axis helical gears and a variable voltage-variable-frequency controlled (VVVFC) AC motor has also been introduced. Such an elevator system has the advantages of saving energy because of less power loss with the parallel axis reduction gears, and because the AC motor is smaller than a DC motor, strong and reliable since there are no brushes, and less costly and easy to maintain. The parallel axis gears, however, generate a greater vibration when the teeth are engaged, and VVVFC drives ripple the AC motor by the current distortion which an inverter generates during modulation. These vibrations are transmitted via the traction cables to the passenger cage.

In Japanese laid-open patent application No.

90381/1982 published on June 5, 1982, an elevator apparatus has a motor resiliently supported in a motor housing which prevents vibration from the motor from travelling to other parts of the system, e.g. reduction gears and support members. In this apparatus, however, the vibrations from the reduction gears are directly transmitted to the traction sheave and travel through the cables to the cage, which results in deteriorated ride conditions. Furthermore, since vibration generated by the brake is also transmitted to the sheave, it is not sufficient in suppressing vibration to only consider countermeasures for the motor.

Summary of the Invention The apparatus according to this invention overcomes the above-mentioned disadvantages, and comprises drive means having a motor and reduction gears vibroisolatedly mounted on support means, a traction sheave vibroisolatedly mounted on the support means, and an elastic coupling between a shaft of the sheave and an output shaft of the drive means, whereby vibrations from the drive means are absorbed by the elastic coupling and vibrationally cushioned mountings, and are thus isolated from the sheave.

Brief Description of the Drawings Fig. 1 is a vertical sectional view of an elevator drive apparatus according to the invention; Fig. 2 is a plan view partly in section of a reduction gear mechanism for the drive apparatus; Fig. 3 is a vertical sectional view taken on line Ill-Ill of Fig. 1; Fig. 4 is an enlarged sectional view of an elastic coupling of the invention; and Fig. 5 is a plan view of an alternate elastic coupling.

Detailed Description of the Preferred Embodiments In Figs. 1-4 reference numeral 1 designates an elevator shaft or hoistway, 2 a machine room disposed above the hoistway, 2a a floor of the machine room, 3 a pair of base members vertically upstanding from the floor, 4 a first support member comprising two beams extending across the base members 3, 5 a drive apparatus comprising reduction gears, an electric motor and a brake described more fully below and mounted on the first support member 4 via rubber vibration isolating pads 6, 7 a reduction gear box having helical gears 7a as shown in Fig. 2, an input shaft 7b and an output shaft 7c, 8 an AC motor connected to the input shaft 7b, and 9 a magnetic brake attached to the motor for braking the drive apparatus when necessary.A second support member 10 comprises two parallel beams extending across the base members 3 separate from the first support member 4, reference numeral 11 designates a bed member mounted on the second support member via vibration isolating pads 12, 13 is a traction sheave mounted on a shaft 1 3a whose ends are rotatably journaled in bearing stands 14 on the bed member 11, and 1 5 is an elastic coupling connecting the shafts 1 3a and 7c. As shown in Fig. 4, the coupling has flanges 1 5a individually attached to the shafts 1 3a and 7c and a circular or toroidal rubber member 1 sub connecting the flanges together in a compact manner.Reference numeral 1 6 designates a deflection sheave rotatably supported on the bottom surface of the bed member 11, 17 designates a plurality of hoist cables reeved over the traction and deflection sheaves and extending down into the hoistway, 18 is an elevator cage hung at one end of the cables, 1 8a is a cage sling connected to the cables, 1 8b is a passaenger enclosure of the cage supported on the sling via resilient rubbers 1 8c, and 19 is a counter weight hung at the other end of the cables.

In the above structure, by reason of the traction sheave 13 being rotatably supported on the bed member 11 attached to the second support member 10 via the vibration isolating pads 12, the support member 10 being separate from the first support member 4 mounting the drive apparatus 5, and the traction sheave being connected to the output shaft 7c of the drive apparatus via the elastic coupling 15, any vibrations generated by the mesh of the reduction gears and by the pulsating rotation of the motor 8 under VVVFC are absorbed by the coupling 15, which greatly reduces the vibration level of the traction sheave 13.

Considering vertical vibrations generated by the reduction gears and the drive motor, because of the isolating rubbers 6 and 12 these vibrations are prevented from travelling to the sheave 13 through the path including the drive apparatus 5, the first support member 4, the base member 3, the second support member 10, and the bed member 1 The vibration of the traction sheave 13 is thus substantially reduced, and attendantly the transmission of vibrations from the drive apparatus to the cage 1 8 via the ropes 17 is greatly attenuated, improving the comfort level in the cage.

In the above embodiment the elastic coupling 15 inciudes a toroidal member 1 sub. As an alternative, an elastic belt 1 sic as shown in Fig. 4 may be employed as the force transmission member The belt is reeved over two pulleys attached to the shafts 1 3a and 7c, and operates in the same manner as described above.

in the embodiment shown in Figs. 1-3, since both the traction sheave 13 and the deflection sheave 1 6 are rotatably supported on the same bed member 1 the horizontal force between the sheaves 13 and 1 6 is never applied to the rubbers 12, whereby the structure for isolating vibration is simple and can be inexpensiveiy manufactured.

Furthermore, since the drive apparatus 5 and the sheave 1 3 are vibration isolated from the building, vibration and noise are not generated in the rooms of the building and do not degrade the working environment.

With isolating rubbers 6 disposed between the first support member 4 and the drive apparatus 5, the amplitude of any vibrations generated is minimized. That is, if the rubbers were disposed between the first support member 4 and the base member 3, the first support member would also vibrate relative to the base member and reinforce the vibrations of the drive apparatus. The same analysis applies to isolating rubbers 12 by reason of their being mounted between the second support member 10 and bed member 11 instead of between the second support member and base member 3.

Since the deflection sheave 1 6 is supported on the bed member 11 via the isolating rubbers 12, the vibrations from the reduction gears and the drive motor are isolated from the deflection sheave, which further reduces any vibrations transmitted to the cage 1 8 through the deflection sheave and the cables 1 7. The isolating rubbers 12 suppress vibrations to both the traction sheave 1 3 and the deflection sheave 16, whereby the def!ection sheave does not require an independent rubber mounting and the quantity of parts can be reduced.

Claims (13)

1. Drive apparatus for an elevator including an electric drive motor, reduction gearing driven by the motor, and a traction sheave driven by the reduction gears, said apparatus being installed in a machine room proximate an elevator shaft and comprising: a) support means disposed in the machine room; b) drive means including the said motor and reduction gearing mounted via first vibration isolating means on said support means; c) the said traction sheave, wound with hoisting cables connected to the cage, mounted via second vibration isolating means on said support means; and d) elastic torque transmission means including a resilient coupling member disposed between said drive means and said traction sheave.

2. Drive apparatus as claimed in claim 1, wherein said reduction gearing is helical gearing.

3. Drive apparatus as claimed in claim 1 or 2, wherein the motor is a variable-voltage, variablefrequency controlled AC motor.

4. Drive apparatus as claimed in claim 1, 2 or 3 including a bed member vibroisolatedly mounted on said support means, said bed member mounting said traction sheave.

5. Drive apparatus as claimed in claim 4, including a deflection sheave wound with the cables, said deflection sheave together with said traction sheave being mounted on said bed member.

6. Drive apparatus as claimed in any preceding claim, wherein said drive means is mounted on said support means via a first support member disposed on said support means and wherein said first vibration isolating means is disposed on said first support member, said drive means being attached to said first vibration isolating means.

7. Drive apparatus as claimed in any preceding claim, wherein said traction sheave is mounted on said support means via a second support member disposed on said support means, said second vibration isolating means being disposed on said second support member, and a bed member disposed on said second vibration absorbing means, said traction sheave being supported on said bed member.

8. Drive apparatus as claimed in any preceding claim, wherein said drive means includes brake means.

9. Drive apparatus as claimed in any preceding, wherein said elastic transmission means comprises a circu!ar resilient connector having side surfaces individually connected to a rotative shaft of said traction sheave and an output shaft of said drive means.

10. Drive apparatus as claimed in claim 9, wherein said circular resilient connector is hollow and has holes communicating with the hollow at central portions of each side surface, said connector being coupled to said shafts via respective flanges individually fixed to the shafts and to peripheral portions of the holes.

11. Drive apparatus as claimed in claim 10, wherein said connector is a hollow toroidal ring having a peripheral wall shaped into a half circle in radial section, and is bidirectionally deformable along the axes of the shafts and the side surfaces of the connector.

12. Drive apparatus for elevator as claimed in claim 10, wherein the diameter of said circular connector is greater than that of the flanges.

13. Drive apparatus for an elevator, substantially as herein described with reference to the accompanying drawings.