EP1042209B1

EP1042209B1 - Elevator system having drive motor located adjacent to hoistway door

Info

Publication number: EP1042209B1
Application number: EP99908296A
Authority: EP
Inventors: Armando Servia; Jose Sevilleja; Leandre Adifon; Richard J. Ericson; David Wayne Jones
Original assignee: Otis Elevator Co
Current assignee: Otis Elevator Co
Priority date: 1998-02-26
Filing date: 1999-02-19
Publication date: 2005-08-31
Anticipated expiration: 2019-02-19
Also published as: ES2244176T3; WO1999043596A2; PT1042209E; DE69926988D1; WO1999043596A3; DE69926988T2; EP1042209A2

Description

The present invention relates generally to an elevator system, and more particularly to an elevator system including a drive motor provided adjacent to a hoistway door.

BACKGROUND OF THE INVENTION

Considerable expense is involved in the construction of a machine room for an elevator. The expense includes the cost of constructing the machine room, the structure required to support the weight of the machine room and elevator equipment, and the cost of shading adjacent properties from sunlight (e.g., sunshine laws in Japan and elsewhere).
Elevator systems have been developed to avoid the expense of a machine room. These elevator systems are difficult to install and maintain because hoistway access can be difficult or dangerous especially to maintenance people while working in the hoistway on machinery that controls elevator motion.
It is an object of the present invention to provide an elevator system without a machine room which avoids the above-mentioned drawbacks associated with prior elevator systems.
An elevator system incorporating the features of the preamble of claim 1 is disclosed in EP-A- 0680921.

SUMMARY OF THE INVENTION

An elevator system in accordance with the invention includes a hoistway having a plurality of hoistway doors. An elevator car and at least one counterweight are provided in the hoistway. A drive motor is drivingly coupled to the elevator car and counterweight, and is located adjacent to and over the top of a hoistway door so as to eliminate the need to provide a machine room close to the hoistway. A control cabinet and a drive motor controller supported on the control cabinet may be provided, wherein the control cabinet is disposed at a side of a hoistway door and slidably movable from a first position within the hoistway to a second position in an adjacent elevator hallway for easy and safe access to the controller.
An advantage of the present invention is that the elevator system significantly reduces the space and construction costs associated with an elevator system having a machine room.
A second advantage of the present invention is simplified and safe access to the drive motor and associated equipment from an elevator hallway or landing.
A third advantage of the present invention is the provision of several alternative drive motor locations for safe and easy access.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic, side elevational view of an elevator system at a top portion of a hoistway having the drive motor accessibly located immediately above a hoistway door.
FIG. 2 is a broken away, perspective view of an elevator system employing flexible flat ropes in accordance with the present invention.
FIG. 3 is a schematic, top plan view of a drive motor/drive unit/control unit which may be provided above or below a hoistway door.
FIG. 4 is a partial, broken away, perspective view of an elevator system showing a slidable control panel for easy access.
FIG. 5 is a schematic, side elevational view of an elevator system in accordance with a further embodiment of the present invention.
FIG. 6 is a top, plan view of the elevator system of FIG. 8.
FIG. 7 is a sectional, side view of a traction sheave and a plurality of flat ropes each having a plurality of cords.
FIG. 8 is a sectional view of one of the flat ropes.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG.1 schematically illustrates a side elevational view of an elevator system 10 embodying the present invention which employs round ropes. FIG. 2 is a perspective view of an elevator system 50 which is similar to the elevator system 10 of FIG. 1 except that the elevator system 50 employs flat ropes. Because the elevator systems 10 and 50 are generally similar, both systems will be described together.
The employment of flat ropes or belts permits smaller drive motors and sheaves to drive and suspend elevator car and counterweight loads relative to drive motors and sheaves using conventional round ropes. The diameter of drive sheaves used in elevators with conventional round ropes is limited to 40 times the diameter of the ropes, or larger, due to fatigue of the ropes as they repeatedly conform to the diameter of the sheave and straighten out. Flat ropes or belts have an aspect ratio greater than one, where aspect ratio is defined as the ratio of rope or belt width w to thickness t (Aspect Ratio = w/t). Therefore, flat ropes or belts are inherently thin relative to conventional round ropes. Being thin, there is less bending stress in the fibers when the belt is wrapped around a given diameter sheave. This allows the use of smaller diameter traction sheaves. Torque is proportional to the diameter of the traction sheave. Therefore, the use of a smaller diameter traction sheave reduces motor torque. Motor size (rotor volume) is roughly proportional to torque; therefore, although the mechanical output power remains the same regardless of sheave size, flat ropes or belts allow the use of a smaller drive motor operating at a higher speed relative to systems using conventional round ropes. Consequently, smaller conventional and flat drive motors may be accommodated in the hoistway which significantly reduces the size and construction cost of the hoistway.
In summary, reducing the machine size (i.e., drive motor and sheaves) has a number of advantages. First, a small machine utilizes less material, and will be less costly to produce relative to a larger machine. Second, the light weight of a small machine reduces the time for handling the machine and the need for equipment to lift the machine into place so as to significantly reduce installation cost. Third, low torque and high speed allow the elimination of gears, which are costly. Further, gears can cause vibrations and noise, and require maintenance of lubrication. However, geared machines may also be employed if desired.
Flat ropes or belts also distribute the elevator and counterweight loads over a greater surface area on the sheaves relative to round ropes for reduced specific pressure on the ropes, thus increasing its operating life. Furthermore, the flat ropes or belts may be made from a high traction material such as urethane or rubber jacket with fiber or steel reinforcement.
The elevator systems 10, 50 include a hoistway 12 defined by the surrounding structure 14 (see FIG. 1) of a building. The hoistway 12 includes door openings at each level along the hoistway for accepting hoistway doors. As shown in FIGS. 1 and 2, for example, a hoistway door 16 is provided at an elevator hallway landing 18 at the topmost floor to be serviced by the elevator systems 10, 50. An elevator car 20 is provided in the hoistway 12 for upward and downward movement via elevator guide rails 21,21 (see FIG. 2) along the hoistway, and includes an elevator door 22 coupled to and for movement along the hoistway with the elevator. As shown in FIGS. 1 and 2, the elevator door 22 is opposed to and aligned with the hoistway door 16 for permitting passenger access to the elevator car 20 at the topmost landing 18.
The elevator systems 10, 50 include a drive motor 24 coupled to a sidewall 25 or an underside of a ceiling 27 (see FIG. 1) of the hoistway 12, and located adjacent to and above the hoistway door 16 for moving the elevator car 20 upwardly and downwardly along the hoistway 12. The drive motor may be geared or gearless in the traction system shown, or alternatively may be a drum motor in a drum drive implementation (not shown). A counterweight 26 movably coupled to counterweight guide rails 27, 27 (see FIG. 2) is provided to one side of the hoistway 12 unoccupied by the elevator 20 for balancing the elevator in its upward and downward movement. At least one elongated connector, such as a round rope 28 as shown in FIG.1 or at least one flat rope or belt 29 as shown in FIG. 2, rotatably engages a motor sheave 30 of the motor 24 for transmitting rotational movement of the motor sheave 30 to the elevator car 20 and the counterweight 22 in order to move the car and counterweight upwardly and downwardly along the hoistway 12. As shown in FIG. 2, the connector includes three flat ropes 29.
The connector is coupled at a first end to a bracket 32 (see FIG. 1) which is anchored to an upper sidewall or ceiling of the hoistway 12. The connector extends downwardly from its first end at the bracket 32, loops 180° about a counterweight sheave 34 coupled to a top of the counterweight 26, extends upwardly and then loops 90° about a first deflector or traction sheave 36 anchored to a sidewall, ceiling, guide rail or a structure of the hoistway directly above the counterweight, extends horizontally to the drive motor 24, loops 180° about the motor sheave 30, extends about a second deflector or traction sheave 38 anchored to a sidewall or ceiling of the hoistway, extends downwardly toward the elevator car 20, underslings or loops under a floor of the elevator car 20 via elevator sheaves 40, 40 (only one shown in FIGS. 1 and 2) provided underneath and at the sides of the elevator, and extends upwardly and is anchored at a second end to a sidewall or ceiling of the hoistway.
Because the drive motor 24 is provided above the hoistway door 16, the elevator systems 10, 50 avoid the additional expense and space associated with the construction of a conventional machine room for supporting and housing the drive motor 24 and associated control equipment such as a controller and a drive unit.
As best shown in FIG. 1, the drive motor 24 is substantially enclosed by a housing 42 which includes a movable front panel 44 facing and protruding externally of the hoistway 12 into an upper part of an adjacent elevator hallway 46 for easy and safe access by maintenance workers at the topmost landing 18 of the hallway 46. For example, the front panel may include a hinge 48 which permits the front panel 44 to pivot downwardly in the direction shown by the arrow A so that maintenance workers may access the drive motor 24 and any associated equipment from the hallway 46 over the landing 18.
The housings shown in FIGS. 1 and 2 substantially enclosing the drive motor 24 may also include associated control equipment for easy access from an elevator landing or hallway. As shown in FIG. 3, a housing 300 includes the drive motor 24, a drive unit 302 for supplying high voltage, high current equipment to the elevator car 20, and a drive motor controller 304 for performing operational control and motion control. Operational control includes, for example, storing the location of calls, resetting answered calls, initiating door operation, communicating with a passenger by signaling that a call has been received, providing elevator car position information, and providing a visual indication of an elevator car's direction of travel when the elevator car arrives at a landing. Motion control includes starting and stopping an elevator car by developing the dictation signal that regulates the acceleration, velocity and deceleration of the elevator car, as well as determining whether operation of the elevator car is safe.
FIG. 4 shows an elevator system 400 having alternative means for accessing control equipment. The elevator system 400 is similar to the elevator systems 10, 50 of FIGS. 1 and 2 except that the elevator system 400 includes a slidable control cabinet 402 located at an upper side of the hoistway 12 adjacent to a side of a topmost hoistway door 404. The control cabinet 402 supports a drive motor controller 406, and is slidably movable from a first position within the hoistway to a second position in an adjacent elevator hallway for easy and safe access to the controller by maintenance workers at a hallway landing 408.
FIGS. 6 and 7 illustrate an elevator system 600 in accordance with a further embodiment of the present invention. The elevator system 600 includes a hoistway 12 defined by the surrounding structure 14 of a building. An elevator car 20 is disposed in the hoistway 12 for upward and downward movement therealong. First and second support columns 602 extend along a vertical extent of the hoistway 12 associated with elevator car travel, and are respectively disposed adjacent to oppositely facing sidewalls 606, 608 of the elevator car 20 to support and guide the elevator car 20 for vertical movement therealong. Each of the first and second support columns 602, 604 defines a hollow interior or recess for accommodating an associated counterweight 610 (only one shown) for vertical movement along the associated support column.
A drive motor 612 and associated drive sheaves 614, 614 are disposed adjacent to and above an uppermost hoistway door 16 for moving the elevator car 20 vertically along the hoistway 12. First deflector sheaves 616, 616 and second deflector sheaves 618, 618 are disposed on each side of the elevator car 20 and at a top portion within the hoistway 12 for guiding flat rope or belts 620, 620 between the drive motor 612 and the elevator car 20 and the counterweights 610, 610.
A principal feature of the present invention is the flatness of the ropes used in the above described elevator system. The increase in aspect ratio results in a rope that has an engagement surface, defined by the width dimension "w", that is optimized to distribute the rope pressure. Therefore, the maximum rope pressure is minimized within the rope. In addition, by increasing the aspect ratio relative to a round rope, which has an aspect ratio equal to one, the thickness "t1" of the flat rope (see FIG. 8) may be reduced while maintaining a constant cross-sectional area of the portions of the rope supporting the tension load in the rope.
As shown in FIG. 7 and 8, the flat ropes 722 include a plurality of individual load carrying cords 726 encased within a common layer of coating 728. The coating layer 728 separates the individual cords 726 and defines an engagement surface 730 for engaging the traction sheave 724. The load carrying cords 726 may be formed from a high-strength, lightweight non-metallic material, such as aramid fibers, or may be formed from a metallic material, such as thin, high-carbon steel fibers. It is desirable to maintain the thickness "d" of the cords 726 as small as possible in order to maximize the flexibility and minimize the stress in the cords 726. In addition, for cords formed from steel fibers, the fiber diameters should be less than .25 millimeters in diameter and preferably in the range of about .10 millimeters to .20 millimeters in diameter. Steel fibers having such diameter improve the flexibility of the cords and the rope. By incorporating cords having the weight, strength, durability and, in particular, the flexibility characteristics of such materials into the flat ropes, the traction sheave diameter "D" may be reduced while maintaining the maximum rope pressure within acceptable limits.
The engagement surface 730 is in contact with a corresponding surface 750 of the traction sheave 724. The coating layer 728 is formed from a polyurethane material, preferably a thermoplastic urethane, that is extruded onto and through the plurality of cords 726 in such a manner that each of the individual cords 726 is restrained against longitudinal movement relative to the other cords 726. Other materials may also be used for the coating layer if they are sufficient to meet the required functions of the coating layer: traction, wear, transmission of traction loads to the cords and resistance to environmental factors. It should be understood that although other materials may be used for the coating layer, if they do hot meet or exceed the mechanical properties of a thermoplastic urethane, then the benefits resulting from the use of flat ropes may be reduced. With the thermoplastic urethane mechanical properties the traction sheave 724 diameter is reducible to 100 millimeters or less.
As a result of the configuration of the flat rope 722, the rope pressure may be distributed more uniformly throughout the rope 722. Because of the incorporation of a plurality of small cords 726 into the flat rope elastomer coating layer 728, the pressure on each cord 726 is significantly diminished over prior art ropes. Cord pressure is decreased at least as n^-½, with n being the number of parallel cords in the flat rope, for a given load and wire cross section. Therefore, the maximum rope pressure in the flat rope is significantly reduced as compared to a conventionally roped elevator having a similar load carrying capacity. Furthermore, the effective rope diameter 'd' (measured in the bending direction) is reduced for the equivalent load bearing capacity and smaller values for the sheave diameter 'D' may be attained without a reduction in the D/d ratio. In addition, minimizing the diameter D of the sheave permits the use of less costly, more compact, high speed motors as the drive machine.
A traction sheave 724 having a traction surface 750 configured to receive the flat rope 722 is also shown in FIG. 10. The engagement surface 750 is complementarily shaped to provide traction and to guide the engagement between the flat ropes 722 and the sheave 724. The traction sheave 724 includes a pair of rims 744 disposed on opposite sides of the sheave 724 and one or more dividers 745 disposed between adjacent flat ropes. The traction sheave 724 also includes liners 742 received within the spaces between the rims 744 and dividers 745. The liners 742 define the engagement surface 750 such that there are lateral gaps 754 between the sides of the flat ropes 722 and the liners 742. The pair of rims 744 and dividers, in conjunction with the liners, perform the function of guiding the flat ropes 722 to prevent gross alignment problems in the event of slack rope conditions, etc. Although shown as including liners, it should be noted that a traction sheave without liners may be used.

Claims

An elevator system (10; 50; 400; 600), comprising:

a hoistway (12) having a plurality of hoistway doors (16; 404);

an elevator car (20) and at least one counterweight (26; 610) located in the hoistway; and

a drive motor (24; 612) drivingly coupled to the elevator car and counterweight via elongated connectors (28; 29; 620),

characterized by the drive motor being located adjacent to and over the top of a hoistway door.
An elevator system as defined in claim 1, wherein the drive motor (24; 612) is located above the top of a topmost hoistway door (16; 404).
An elevator system as defined in claim 1 or 2, further including a housing (42) for substantially enclosing the drive motor (24; 612) relative to an adjacent hallway (46).
An elevator system as defined in claim 3, wherein the housing (42) includes a movable panel (44) protruding externally of the hoistway (12) into an adjacent elevator hallway (46).
An elevator system as defined in claim 4, wherein the movable panel (44) is located above a hoistway door (16; 404).
An elevator system as defined in any of claims 3 to 5, further including a drive unit (302) and a controller (304; 406), and wherein the drive motor (24; 612), drive unit and controller are substantially enclosed by the housing (42).
An elevator system as defined in any of claims 1 to 6, further including a control cabinet (402) and a drive motor controller (304; 406) supported thereon, the control cabinet being located at a side of a hoistway door (16; 404) and slidably movable from a first position within the hoistway (12) to a second position in an adjacent elevator hallway (46; 204) for easy and safe access to the controller.
An elevator system as defined in any preceding claim, wherein the elongated connector (28; 29; 620) is a flat rope.
An elevator system as defined in any preceding claim, further including at least two elevator sheaves (40) coupled to an underside of the elevator car (20), and wherein a portion of the elongated connector (28; 29; 620) underslings the elevator car to minimize overhead space between a top of the elevator car and a ceiling (27) of the hoistway (12).
An elevator system as defined in claim 9, wherein the drive motor (24; 612) includes a drive sheave (30; 614), and further includes a first deflector sheave (36; 616) and a second deflector sheave (38; 618) axially coupled to the first deflector sheave, the first and second deflector sheaves being disposed in the hoistway (12) and above the elevator car (20), the first deflector sheave having a diameter larger than that of the second deflector sheave, and the second deflector sheave having a diameter about the same as that of the drive sheave, an additional connector drivingly coupling the drive sheave to the first deflector sheave, and said elongated connector coupled to the second deflector sheave and to the elevator car, whereby the first and second deflector sheaves rotate at a smaller revolutions per minute relative to the drive sheave to produce a gearing effect to the drive motor.
An elevator system as defined in any preceding claim, wherein the drive motor (24; 612) is gearless.
An elevator system as defined in any preceding claim, further including first (602) and second support columns (604) each being generally hollow and extending vertically along a vertical portion of the hoistway (12) associated with elevator car travel, the first and second support columns being disposed adjacent opposite sidewalls (606; 608) of the elevator car (20) relative to each other, and wherein the at least one counterweight (26; 610) includes first and second counterweights respectively disposed within the first and second support columns.