Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF THE INVENTION
The present invention reiates -to a drive apparatus for
a traction elevator lifting a cage up and down with cables.
An apparatus having reduction gears driven by a mo-tor
and a trac-tion sheave connec-ted 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 engayement be-tween the teeth
of the reduction gears travels through the cables to the
cage, whereby passengexs in the cage feel uncomfortable.
An elevator system employing reduction gears with
parallel axis helical gears and a variable-voltage-variable-
frequency controlled (W VFC) AC motor has also been introduced.
Such an elevator system has the advantages of saving energy
because of less power loss wi-th 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
engagedj and W VFC drives xipple the AC motor by the current
distortion which an inverter generates during modula-tion.
These vibrations are transmitted via the traction cables to
the passenger cage.
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ln Japanese laid-open pa-tent application No. 90381/
1982 published on June 5, 1982, an elevator apparatus has a
motor resiliently supported in a motor housing wh;ch pre-
vents vibra-tion -from the motor from travelling -to o-ther parts
oF the system, e.g. reduction gears and support members.
In this apparatus, however, the vibra-tions from the reduc-
tion gears are directly transmitted -to the traction sheave
and travel through the cables -to the cage, which results in
deteriorated ride conditions. Fur-thermore, 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.
The apparatus according to this invention over-
comes the above-mentioned disadvan-tages, and comprises drive
means having a motor and reduction gears vibroisolatedly
rnounted on support means, a traction sheave vibroisolatedly
mounted on the support means, and an elas-tic coupling bet-
ween a shaft o-F 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 mount-
ings, and are thus isolated from the sheave.
Thus, according to -the present invention there is
provided a drive apparatus for an elevator including an
electric drive motor, reduction gears driven by the motor,
and a traction sheave driven by the reduction gears, said
apparatus being installed in a machine room proximate a
hoistway of an elevator cage, and comprising: a) support
means disposed in the machine room; b) drive means including
the motor and the reduction gears; c) a plurali-ty of spaced
first resilient means disposed between said drive means and
said support means for absorbing vibrations generated by
the mesh of the reduction gears and pulsa-ting rotations of
the motor; d) -trac-tion sheave means wound with cables
connected to the cage; e) a plurality oF spaced second
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resilient means d-isposed be-tween said -traction sheave rneans
and said support means for absorbing vibrations generated
by or transmit-ted to the traction sheave means; and (f) elastic
torque transmission means including a res-ilient coupling
member disposed between said drive means and said trac-tion
sheave means -For minimizing vibration transmissions thereto
From the drive means, whereby the ride com-Fort level in -the
elevator cage is improved. Suitably the sheave means includes
a bed member moun-ted on said second resilient means, said
bed member mounting a -traction sheave. Desirably the support
means includes a first pair of spaced parallel beams and a
first support mernber comprising a second pair o-f spaced
parallel beams disposed on and perpendicular to said -First
pair oF beams and wherein said first resilient vibration
absorbing means are disposed on said second pair o-F beams,
said drive means being attached to said First resilient
vibration absorbing means. Preferably said suppor-t means
further includes a second support rnember comprising a third
pair of spaced parallel beams disposed on and perpendicular
to said First pair of beams, said second resilient vibra-
tion absorbing means being disposed on said third pair of
beams and wherein said traction sheave means includes a bed
member disposed on said second resilient vibration absorbing
means, a traction sheave being supported on said bed member.
The present inven-tion will be further illustrated
by way of the accompanying drawings, in which:-
Fig. 1 is a vertical sectional view of an elevator
drive apparatus according to the invention;
Fig. 2 is a plan view partly in sec-tion of a reduc-
tion gear mechanism for the drive appara-tus;
Fig. 3 is a vertical sectional view taken on line
III-III of Fig. l;
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Fig. 4 ls an enlarged sectional view of an elas-tic
coupling oF the invention; and
Fig. 5 is a plan view of an alternate elastic
coupling.
In Figs. 1-4 re-ference 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 appara-tus comprising reduction
gears, an elec-tric 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 F-iy. 2, an input shaft 7b and
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an output shaft 7c, 8 an AC mo-tor 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 moun-ted on -the second
support member via vibration isolating pads 12, 13 is a
traction sheave mounted on a shaft 13a whose ends are rotatably
journaled in bearing stands 14 on the bed member 11, and lS
is an elastic coupling connecting the shafts 13a and 7c. As
shown in Fig. 4/ the coupling has flanges 15a individually
attached to the shaf-ts 13a and 7c and a circular or toroidal
rubber member 15b connecting the flanges together in a compact
manner. Reference numeral 16 designates a deflection sheave
rotatably supported on the bottom surface of the bed member
11, 17 designa~es 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, 18a is a cage sling connected to the cables, 18b is
a passenger enclosure of the cage supported on the sling via
resilient rubbers 18c, 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
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12, the support member 10 heing 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 elas-tic coupling 15, any vlbra-
tions generated by the mesh of the reduction gears and by
the pulsating rotation of the motor 8 under WVFC are absorbed
by the coupling 15, which greatly reduces the vibration level
of the trac-tion 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 11. The vibration of
the traction sheave 13 is -thus substantlally reduced, and
attendantly the transmission of vibrations from the drive
apparatus to the cage 18 via the ropes 17 is greatly attenuated,
improving the comfort level in the cage.
In the above embodiment the elastic coupling 15 includes
a toroidal member 15b. As an alternative, an elastic belt 15c
as shown in ~ig. 4 may be employed as -the force transmission
member. The belt is reeved over two pulleys attached to the
shafts 13a and 7c, and operates in the same manner as described
above.
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In -the embodimen-t shown in Figs. 1-3, since both the
traction sheave 13 and the deflection sheave 16 are rotatably
supported on the same bed member 11, the horizontal force
between the sheaves 13 and 16 is never applied to the rubbers
12, whereby the structure for lsolating vibration is simple
and can be inexpensively manufacturecl. Furthermore, since
the drive apparatus 5 and the sheave 13 are vibration isolated
from the building, vibration and noise are not genera-ted 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 members 3.
Since the deflection sheave 16 is suppor-ted on the bed
member 11 via the isolating rubbers 12, the vibrations from
the reduction gears and the drive mo-tor are isolated from the
deflecti.on sheave, which further reduces any vibrations trans-
mitted to the cage 18 -thxough the deflection sheave and the
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cables 17. The isolating rubbers 12 suppress vibrations to
both the -traction sheave 13 and the deflection sheave 16,
whereby the cleflection sheave does not require an independen-t
rubber mounting and the quantity of par-ts can be reduced.
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