Rope traction elevator

An elevator drive for a rope traction elevator, which is intended for installation in an elevator hoistway, includes of a gear with a traction sheave, a motor in an upright position on top of the gear, a brake and suspension elements which are slung over the traction sheave and provide vertical motion for an elevator car with a counterweight. The motor and the gear are inclined at an angle to the vertical. With this slightly tilted arrangement no part of the motor extends beyond the horizontal boundary of the gear. Furthermore, the brake is a part of the gear and non-detachably fastened to it, which makes it possible to mount the motor on the gear, and to dismount it therefrom, without difficulty.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 The present invention relates to a rope traction elevator with an elevator
 drive, and comprises a gear with a traction sheave, a motor, a brake, and
 suspension elements which pass over the traction sheave to provide
 vertical motion to an elevator car, preferably with a counterweight. The
 motor of the elevator drive is in an upright position.
 2. Discussion of the Prior Art
 An elevator drive of the type mentioned is known from German reference DE
 37 37 773 C2. The purpose of this construction is to make it easy to
 assemble the gear, and to permit rapid mounting and dismounting of the
 motor, while keeping the bearings aligned during the process. The motor,
 which is in an upright position on top of the gear, has a drum brake at
 its upper end.
 With today's high level of thermal load on motor windings, the occurrence
 of a fault in the windings due to an overload appears to be more probable
 than a mechanical defect in the gear. If a defective motor has to be
 replaced, the brake on top of the motor also has to be removed together
 with the defective motor. A prerequisite for this operation is that the
 car and counterweight must first be secured against unbraked movement, for
 example by applying clamps to the ropes and/or supporting the
 counterweight in the hoistway. This procedure is time-consuming and
 carries the risk of accidents.
 The German utility model 1 918 376 discloses an elevator drive consisting
 of a worm gear and a motor which is also in an upright position, but in
 which the motor is an external rotor motor and whose cylindrical external
 surface simultaneously serves as a brake drum. With this drive the brake
 also has to be removed when the motor is replaced, which gives rise to the
 same disadvantageous effect as already described above. Furthermore, the
 large gyrating mass resulting from the external rotor principle can have a
 negative effect on the acceleration and deceleration of the elevator car.
 In both of the drives mentioned, the small size of the motors in relation
 to the size of the gear leads to the conclusion that these drives are
 designed only for relatively low power output. If a motor for the medium
 power range is used which has a higher power output and is therefore
 larger, the horizontal dimensions of the motor may be greater than those
 of the gear base, which has negative consequences for the range of
 possible layouts.
 SUMMARY OF THE INVENTION
 The object of the present invention is therefore to create an elevator
 drive whose motor and gear cases have narrow dimensions, i.e. in at least
 one horizontal dimension they are narrow enough for the drive to be
 located in the side of the hoistway in such a manner as to save space, but
 at the same time using a normal shape of motor. Moreover, it must be
 possible to replace the motor rapidly and easily without the disadvantages
 mentioned above.
 Pursuant to this object, and others which will become apparent hereafter,
 one aspect of the present invention resides in the elevator drive,
 including the upright motor attached to it, being slightly tilted so that
 a vertical projection of the motor from above lies within the horizontal
 boundary of the gear. Another object is to achieve this without complex
 structural modifications.
 The inclination of the axis of the motor and gear is achieved by the
 mounting feet of the gear being in an inclined plane relative to the base
 of the gear.
 The mechanical brake is positioned between the motor and the gear and does
 not have to be removed if the motor is replaced. As a result, movement of
 the drive and traction sheave after the motor has been removed is
 prevented by the closed brake, and no additional measures are needed to
 hold the elevator in position.
 The mechanical brake is constructed as an integral part of the gear and is
 contained in a part of the gear case. The part of the gear case containing
 the brake is constructed as a flange collar, which faces upwards and has a
 flange plate to receive the motor, and which together with the lower part
 of the gear is constructed as a single-piece casting.
 The vertical cross-section of the gear case, which optimally is oval in
 shape for high strength and rigidity, whose curves are constructed from
 several different radii, and whose height is greater than its width, makes
 it possible for the gear case to have thin walls and compact dimensions in
 the horizontal direction.
 By positioning a flywheel above the motor it is possible to use a flywheel
 which projects beyond the cross-section of the motor case without
 exceeding the dimensions available for installation.
 The various features of novelty which characterize the invention are
 pointed out with particularity in the claims annexed to and forming a part
 of the disclosure. For a better understanding of the invention, its
 operating advantages, and specific objects attained by its use, reference
 should be had to the drawing and descriptive matted in which there are
 illustrated and described preferred embodiments of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
 FIG. 1 shows an example of the elevator drive according to the invention
 installed in a hoistway. The elevator drive consists of a gear 2 with a
 flange collar 8, which faces upwards and has in its side openings
 containing the mechanical brake, and a motor 1 mounted above the brake and
 having a flywheel 9. The mechanical brake consists of a brake drum 5, a
 brake magnet 3, and brake shoes 4. Through openings in the sides of the
 flange collar 8, the brake shoes 4 act from outside on the brake drum 5.
 The flange collar 8 is closed on its upper side with a flange plate 38
 onto which the motor 1 is fastened with screws. The gear 2 is detachably
 fastened by means of mounting feet 10 at the sides to horizontal supports
 11, 12 for the gear. A traction sheave 6 with a cover 7 is located to the
 side of the gear 2. Suspension elements 18 are slung over the traction
 sheave 6 and support a car, not shown and a counterweight. The gear
 supports 11, 12 are positioned on a horizontal transverse beam 13 which is
 itself connected via elastic supporting pads 14 and a bracket 15 to the
 car guide rails 17 and the counterweight guide rails 16. The parts 11-14
 thereby form a supporting framework for the elevator drive machine. It can
 also be seen from FIG. 1 that the motor 1 is not exactly vertical, but at
 a slight inclination to the vertical and tilting towards the back.
 Further details of the elevator drive are explained below with reference to
 FIG. 2. The active parts of the gear, a worm 20 and a worm wheel 27 which
 is enmeshed with the worm 20, are installed in an enclosed, oil tight and
 approximately rectangular hollow space in the lower part of the gear case
 28. The worm 20 is part of a motor/worm shaft 19 which is held radially at
 its lower end in a fixed bearing 30 and axially in the gear case 28, and
 is guided by a movable bearing 29 at the point where the shaft 19 emerges
 from this part of the gear case 28. The worm wheel 27 is connected to a
 traction sheave shaft 35 in such a way that they cannot rotate relative to
 each other. This part of the gear case 28 is closed at the right-hand side
 with a gear cover 31, has an oil drainage screw 32 at its lowest point,
 and is filled with gear oil 34 up to the level 33. Together with the
 upward facing flange collar 8 and flange plate 38, this part of the gear
 case 28 is constructed as a single-piece cast case.
 On a flat part of the right-hand side of the gear case 28, and adjacent to
 the flange collar 8, the brake magnet 3 is mounted. A manual brake release
 lever for opening the brake by hand is shown in the drawing as number 37.
 The brake drum 5, which is located above the movable bearing 29 and inside
 the flange collar 8, is non-detachably fastened to the motor/worm shaft
 19. A motor case 24 of the motor 1 is detachably fastened to the flange
 plate 38, preferably by means of screws. The motor case 24 surrounds a
 laminated stator core 23 with a stator winding 22 whose winding ends
 project at the lower end into the flange collar 8. A rotor 21 with a
 laminated core and a short-circuited winding of a type typical for
 alternating current motors is located on the motor/worm shaft 19 adjacent
 to the stator laminations 23.
 A fan wheel 25 and the flywheel 9 are attached to the motor/worm shaft 19
 close to its upper end in such a way that they cannot turn relative to it
 and are axially secured with a screw 40. Number 36 shows a bevel gear ring
 which is screwed onto the flywheel 9. The air ventilation opening on the
 circumference of the fan wheel 25 is covered with a ventilation grille 26.
 The angle .beta. is the angle of inclination of the motor axis 100
 relative to a vertical axis 101. The angle of inclination .beta. can be
 any number of angular degrees that allows the advantages previously
 mentioned to be obtained. In the example shown, the angle .beta. is
 approximately 10.degree.. The plane of the bottom of the gear case, shown
 as number 39, is inclined by the same angle .beta. to the horizontal
 plane.
 In FIG. 3 the front elevation shows additional parts of a manually operated
 evacuation device consisting of a manual operation shaft 44, a pivoting
 clutch mechanism 43, a bevel gear pinion 42, and the bevel gear ring 36
 mentioned above. The oval-like shape of the gear with the gear cover 31 is
 also visible.
 FIG. 4 clearly shows the advantage of the axis of the motor 1 being
 inclined at an angle .beta. to the vertical. Because the motor 1 does not
 project anywhere along its length beyond the base of the gear case, this
 elevator drive can be placed correspondingly close to a hoistway wall 41,
 as the extent perpendicular to the plane of the guide rails, and therefore
 the horizontal dimension of the drive between the hoistway wall and the
 path of the car, is correspondingly narrow. Furthermore, an elevator car
 having suspension ropes fastened to its lower part can travel along the
 car guide rails 17 upwards and to the right of the elevator drive as
 depicted in FIG. 4 and past the motor 1 of the elevator drive.
 FIG. 5 shows a cross-section of the gear case 28 on the plane cutting the
 gear case 28 marked in FIG. 2. FIG. 5 shows an ideal contour for the case
 wall in relation to strength and torsional rigidity for this gear 2. The
 height h of the external case contour is greater than the width b. In the
 example shown, the contour of the gear case, which was calculated using
 the method of finite elements, has four different radii R1-R4 along its
 perimeter, although the number of radii which flow into each other can be
 greater or less than four. This results in the wall of the gear case
 having a cross-section with a shape similar to an oval. The case wall can
 also be kept relatively thin, which also has a positive effect on the
 external dimensions and the weight of the gear 2.
 The detailed manner of constructing the elevator drive is not limited to
 the example shown. The mechanical brake, for example, can also be
 implemented as a disk brake with the corresponding mounting parts.
 The size and shape of the motor 1 can deviate from the embodiment shown.
 The invention is not limited by the embodiments described above which are
 presented as examples only but can be modified in various ways within the
 scope of protection defined by the appended patent claims.