SYMMETRICALLY ARRANGED ELEVATOR DRIVE APPARATUS

MECANISME MOTEUR A CONFIGURATION PARALLELE POUR ASCENSEUR

English Abstract

ABSTRACT OF THE DISCLOSURE

A drive apparatus for an elevator has a base member 5
centrally mounted in a machine room 2 and a driving sheave 7
centrally mounted on the base member. The ends of the
rotational shaft 11a of the driving sheave are supported
by a reduction gear mechanism 11 and a bearing holder 10
mounted to the base member on opposite sides of the driving
sheave. An electric motor 12 for driving the gear mechanism
is mounted at one end of the base member, opposite a deflector
sheave 8 mounted at the other end. This symmetrical arrange-
ment reduces the size of the apparatus and vibrations.

Claims

The embodiments of the invention in which an
exclusive property or privilege is claimed are defined as
follows:

1. A drive apparatus for an elevator, comprising:
(a) a base member mounted in a machine room,
(b) a driving sheave mounted centrally lengthwise
on said base member and in a central area of the room a
rotational shaft for said driving sheave being arranged
transversely across said base member,
(c) a bearing holder mounted on said base member
to one side of said driving sheave for supporting one end
of said rotational shaft,
(d) a reduction gear mechanism mounted on said
base member on another, opposite side of said driving
sheave for supporting the other end of said rotational
shaft,
(e) drive means for driving said sheave mounted
on said base member on the side opposite an output side of
said driving sheave, and
(f) a deflector sleeve mounted on said base
member for deflecting a cable reeved around said driving
sheave.

2. A drive apparatus as in claim 1, wherein said
drive means is an electric motor.

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3. A drive apparatus as in claim 1, wherein said
drive means and deflector sheave are mounted on opposite
sides of said driving sheave.

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Description

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SYMMETRICALLY ARRANGED ELEVATOR DRIVE APP~RATUS


BACKGROUND OF THE INVENTION

Field of the Invention

This invention relates to a drive apparatus for an
elevator, adapted to be installed in a machine room above an
elevator shaft or hoistway.

Description of the Prior Art

Conventional electric elevators are provided with an
electric drive appara~us located above the hoistway for raising
and lowering the car suspended by a main cable. The car is
essentially disposed in the cross-sectional center of the
hois~way, and the center portion of the car is suspended by
the main cable reeved on a driving sheave of the apparatus~
Otle drawback of a drive apparatus of this type is that the
driving sheave is not centrally mounted and the machine room
1$ space thus projects outwardly from the upper portion of the
ho:i~tway, which is unAesirable from a space saving standpoint
in buildings.
Another drawback of a drive apparatus of this type is
that the machine room space ïs increased because of the ineffi-
cient arrangement of the apparatus components~ Furthermore, if



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space design limitations for ~he elevator cannot be overcome~
then a given elevator drive apparatus may be limited to
installation only in small buildings.


SUMMARY OF THE INVENTIO~

It is an object of this invention to produce a drive
apparatus for an elevator which is designed to eliminate the
above~mentioned defects of conventional devices by providing
; a drive apparatus that efficiently utilizes ~he space in the
machine room. To accomplish this object a bearing holder for
journaling the rotating shaft of the driving sheave is disposed
on one side of the sheave, and a reduction gear mechanism is
disposed on the other side of the sheave. An electric motor
for driving the input shaft of the gear mechanism is disposed
at one end of a base member centrally mounting the sheave and
other components, opposite a deflector sheave from which a
counterweight is suspended. This symmetrical arrangement not
only minimi7,es the si7.e and space requirements of the apparatus,
but also reduces operational noise and vibrations.

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BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a side sectional view of an elevator
employing a drive apparatus according to the present invention,
Fig. 2 shows a sectional view of the drive apparatus
from the right side of Fig. 1,
Fig. 3 shows a plan view of the drive apparatus of
Fig. l, and
Fig. 4 shows a sectional view of a reductlon gear mechanism
according to the present invention.

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DETAILF,D DESCRIPTION OF THE PREFERRE-D EMBODIMENT

Figs. 1 to 3 show a hoistway 1 for an elevator car formed
ln a building. A machine room 2 is provided above the hoistway,
and communicates therewith through holes 2b in the floor 2a of
the machine room. A traction drive base bed 3 i~ mounted to
the floor 2a, and a machine bed 4 is supported on the base bed
at both of its ends. A base member 5 is mounted in the center
of the machine room 2 on the machine bed 4 by damping members 6
made of vibration absorbing material. A driving sheave 7 is
centrally mounted lengthwise CFig. 1) above the base member 5
on a transverse output shaft lla as descr-ibed below. A
deflector sheave 8 arranged behind and below the driving sheave
is journaled to a support member 9 suspended from the base
member. A bearing holder 10 i5 mounted on the base member 5
.,

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alongside the driving sheave 7. A reduction gear mechanism 11
is installed on the base member S, and is driven by an input
shaft llb arranged at one end of the base member.
As shown in Fig. 4, the reduction gear mechanism includes
an output shaft lla, a casing llc, and first, second, third,
fourth, fifth and sixth gear wheels lld through lli all of
the parallel tooth type. One end llk of ~he output shaft lla
is rotatably supported by bearings llj, while its other end llQ
is rotatably supported by the bearing holder 10.
An electric drive motor 12 mounted on the base member S
is connected to the inpu~ shaft llb of the reduction gear
mechanism by a coupling 18. A concrete cinder floor 13 covers
the main floor 2a. A main cable 14 is reeved around the driving
sheave 7 and deflector sheave 8, and passes through the hol2s 2b
to the hoistway 1 from the machine room 2. An elevator car 15
ls connec~ed to one end of the main cable, and includes a
frame lSa in which a cab 15b is supported by vibration absorbing
rubber members 15c. A counter weight 16 is connected to the
other end of the cable. A brake unit 17 is provided on the input
shaft llb.
With the bearing holder 10, the reduction gear mechsnism 11
nrld the elec~ric drive tnotor 12 arranged around the driving
shea~e 7 as described above, the overall drive apparatus is
substantially symmetrical on both the right and left sides of
the centered driving sheave 7, whereby the apparatus can be
installed in a narrow machine room 2 formed to correspond with
the upper space of the hois~way 1. Thus, the elevator of this

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invention can be set up inside a small space in buildings.
Further9 with one end of the shaft lla of the driving
sheave supported by the bearing holder 10 independent of the
gear mechanism 11, the load on the gear mechanism and atten-
dantly its si~e is considerahly reduced. Since the drive
motor 12 is independently mounted on the base member 5, it
can comprise any appropriate mass produced type of motor
whereby the cost of the drive apparatus is further reduced.
With both ends of the driving sheave shaft being independently
supported and journaled the operational flexing of the shaft
is decreased and the mesh~between the gears of the reduc~ion
mechanism is improved, whereby the level of vibration and noise
occurring in the gear mechanism is reduced. The propagation of
any vibration to the hoistway 1 or to the building is minimized
by the base member 5 being supported by damping members 6.
Further, the propagation of vibration to the cab 15b is pre-
vented by the cab being supported by the vibration absorbing
rubber Members 15c on the car frame 15a, whereby the environment
created in and around tbe elevator is quiet and pleasing to
~he passengers.




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