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(11) | EP 1 333 000 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A machine-roomless traction sheave elevator |
| (57) A machine-roomless traction sheave elevator comprising an elevator car (1), moving
along elevator guides (3); a counterweight (4) moving along counterweight guides (7);
a set of hoisting ropes (6) on which said elevator car (1) and counterweight (4) are
suspended in an elevator shaft (2); a drive unit assembly (8), disposed in said elevator
shaft, which actuates a traction sheave (10) acting onto said hoisting ropes (6).
The drive unit assembly (8) is mounted in said elevator shaft (2) with its axis parallel
to the plane of said elevator car guides (3), and comprises an electric motor (11)
on which said traction sheave (10) is mounted with its axis perpendicular to said
plane. The control board of the elevator system is placed at a side of the landing door, in an independent box (14), and at least a removable panel is foreseen in the ceiling or in the side walls of the car (1) to facilitate the maintenance of the drive unit assembly (8) from the inside of the car. |
[0001] The present invention relates to an electric elevator and more particularly to an elevator system that does not require a machine room, i.e. a so-called "machine-roomless" elevator system, and utilises a traction sheave for engaging the hoist ropes, directly driven by an electric motor in a so-called "gearless" traction unit.
[0002] The conventional hoisting ropes elevator systems substantially comprise an elevator car and a counterweight, each one suspended at one end of a rope assembly and driven, by adhesion, through a traction sheave rotated by a winch/electric motor. The elevator car and the counterweight move into an appropriate elevator hoistway or shaft and the machinery, consisting of sheave, winch/motor and braking devices, is located in a suitable room usually placed above the elevator shaft and large enough for allowing the maintenance of the equipment.
[0003] The presence of the machine room in a building has become increasingly problematic as it brings considerable costs and occupies space which could be utilised for other purposes.
[0004] On the other hand, to obtain a torque large enough for moving the elevator system, either the electric drive motor is generally pretty large, heavy and expensive or a reduction gear has to be employed.
[0005] Disregarding hydraulic elevator systems whose use is limited to elevators for a few floors, many efforts have been made to implement an elevator system actuated by a gearless driving unit which does not require a machine room and houses the machinery directly within the shaft.
[0006] More particularly hoisting ropes elevator systems have been suggested (operating by adhesion/friction) that do not require a machine room but house the machinery directly in the elevator shaft. More particularly, the machine unit and the sheave are either located in an upper extension of the elevator shaft (in this case without obtaining the required elimination of spaces of the machine room), or in the space between the wall of the elevator shaft and the elevator car itself. Nevertheless, this solution requires the use of substantially flat machine units and/or disk-shaped rotors and arranged parallely with the sheave plane. These machinery and components are therefore of a particular type.
[0007] Always in view of eliminating the machine room, it has been suggested to use a sheave of a reduced size associated with a motor which is not flat and is secured to the elevator car, but such an arrangement requires nevertheless the use of special flat ropes.
[0008] Another aspect to be considered in elevator systems without a machine room is to ensure safe operating conditions for the maintenance personnel.
[0009] Besides, in the known plants, a certain integration is provided for between the elevator car and the frame, which makes rather difficult the insulation of the former.
[0010] It is therefore an object of the present invention to overcome the above mentioned drawbacks and limitations of the prior art, and more particularly to provide a machine-roomless elevator system, which allows for an easy access to the motor unit and to the equipment, is of reduced size and easy to be assembled, while nevertheless using non-flat motors and conventional ropes.
[0011] The present invention achieves the above objects through an elevator system with a frictional traction (adhesion) arrangement which does not require a machine room and is equipped with a traction unit arranged in the elevator shaft of the elevator system, as claimed in claims 1 and 3. Further advantageous features are recited in the dependent claims.
[0012] The arrangement disclosed by the present invention attains several advantages, and more precisely:
- a remarkable reduction of the height of the shaft extension that does not exceed the height of a standard floor and does not need any extension beyond the ceiling level of the topmost floor;
- it simplifies the assembly by shortening the assembling time thanks to the particular arrangement of the guide rails of the elevator car, of the counterweight and of the other associated devices;
- maintenance interventions can be carried out at the single floors, and the elevator shaft inspections as well as the maintenance interventions to the devices located in the shaft can be carried out from the inside of the elevator car rather than from the car roof, with a remarkable increase of the operator's safety;
- it allows for a wide adjusting of the elevator system thanks to the use of a permanent magnet brushless motor;
- it requires a remarkably low power, all conditions being equal, in respect of the traditional winch systems with reduction gear or the hydraulic plants;
- it has a reduced power consumption, traffic being equal, thanks to the reduction of the masses to be moved and the high efficiency of the type of employed motor;
- it allows for different arrangements of the plant components, i.e. various configurations of a same plant;
- in case of a power fault, the cab can be easily returned to the nearest floor with very few additional elements, thanks to the type of motor and drive chosen.
[0013] The present invention will now be disclosed with particular reference to the attached drawings, supplied by way of non limiting examples, in which:
Fig. 1 is a schematic perspective scrap view with parts removed for a clear illustration, which shows an elevator plant or system according to the invention;
Fig. 2 is a schematic perspective view illustrating in details the upper portion of the elevator system according to the invention;
Fig. 3 is an enlarged view which illustrates the motor group of the elevator system shown in Fig. 1;
Fig. 4 is a cross-sectional view from the top of the elevator system shown in Fig. 1;
Fig. 5 is an intermediate transverse cross-section view from the top of the elevator system shown in Fig. 1;
Fig. 6 is a perspective view from the outside of the elevator shown in Fig. 1, which shows a possible location of the control board of the elevator system;
Fig. 7 is a transverse cross-section view from the top of the system showing an alternative arrangement of the guide rails of the elevator system;
Fig. 8 is an intermediate transverse cross-section view from the top of the elevator system according to the present invention which illustrates an alternative arrangement of the guide rails of the elevator car;
Figs. 9A and 9B are two perspective views from the outside of the elevator car, which show two possible embodiments of an elevator car with removable panels in closed position;
Figs. 10A and 10B are two perspective views from the outside of the elevator car where the removable panels have been removed.
[0014] Throughout all the Figures, equal or substantially equivalent parts have been designated by the same references.
[0015] With reference to Figs. 1, 2, 4 and 5, an elevator system according to the present invention comprises an elevator car 1, moving in a hoistway or elevator shaft 2, along elevator guides 3 formed as rails. More particularly, the elevator car is carried by an independent supporting frame 5 which is projecting from the plane of the elevator guide rails and slidable along the same guides through suitable rolling or sliding shoes 15. The elevator car is a box-shaped component supported by or secured to a bearing structure comprising a car frame or car cage. This arrangement renders the car insulation easier, differently from what occurs in the known elevator systems where a certain integration between the elevator car and the bearing structure is provided, such as for instance a direct fastening of the shoes to the car and/or a fastening of the diverting/suspending sheaves to the bottom of the elevator car.
[0016] The elevator system further comprises a counterweight 4, movable along guide rails 7 and a set of hoisting ropes 6 made-up of two or more suspension and traction ropes which connect the counterweight with the supporting frame 5 of the elevator car. The counterweight 4 vertically moves between the corresponding guides through suitable rolling or sliding shoes 16.
[0017] A traction assembly or drive unit assembly 8, illustrated more in details in Fig. 3, comprises a traction sheave 10 which transmits by (frictional) adhesion the motion to the ropes 6. The diameter of the sheave 10 is such to allow nevertheless the use of conventional steel ropes and meeting the requirements of the rules in force.
[0018] Besides the sheave 10, the drive unit assembly 8 further comprises a motor 11, preferably a permanent magnet synchronous motor having a small overall diameter and a brake 13, preferably a disc brake or a shoe brake. On the motor there is further mounted an encoder (not illustrated in the Figures), either outside of or incorporated in the motor.
[0019] The suspension of the counterweight 4 and of the elevator car 1 is of the tackle type and therefore the rope ends are anchored at two fixed points, one indicated by 17 and formed in a baseplate 21 on which the drive unit is mounted and the other one, shown at 18, formed on the shaft side wall which is opposite to the guides 3.
[0020] As shown in the illustrated embodiment, the car guides 3 are preferably located on the same side of the shaft 2, or in other words they lie in a plane that does not cross the elevator car 1, and this latter is cantilevered in respect the guides, an arrangement known as "rucksack" configuration.
[0021] Advantageously, also the guides 7 of the counterweight substantially lie in such a plane, as better shown in Fig. 5. In the embodiment illustrated, the guides 3, 7 are secured to the shaft wall through an adjustable bracket 23 of one type only. Thanks to this arrangement, the assembling of the guides is remarkably simplified and it is possible to assemble the guides sections directly at the factory, with an appreciable saving of time and equipment for the control.
[0022] According to the embodiment shown in Figs. 7 and 8, the plane of the elevator guides 3 and the plane of the counterweight guides 7 cross each other at 90°.
[0023] The suspension (diverting) sheaves of the elevator car can be mounted either at the bottom of the car, as the sheaves 19 in the Figures 2 and 4, or at the top thereof. Thanks to the type of suspension and arrangement adopted by the invention, the lifting force is applied through the centre of gravity of the elevator car and the counterweight, thus avoiding overturning torques and limiting the stresses acting onto the guides and the structures only to the dynamic loads deriving from the motion.
[0024] Advantageously, by using a supporting structure which is independent from the elevator car, the elevator car 1 can be completely insulated from the supporting frame 5 through appropriate pads or buffers for dampening vibrations which allow a better quality of the motion in respect of the quietness and the abatement of vibrations.
[0025] According to preferred embodiments shown in Figs. 9 and 10, the ceiling and/or the side wall of the elevator car is equipped with one or more easily removable panels allowing for an easy maintenance of the drive unit assembly 8 from the inside of the elevator car.
[0026] More precisely, Fig. 9A illustrates an elevator car 1 adapted to allow interventions on the drive unit assembly from the inside of the car. The elevator car is equipped with ceiling panels 25 which can be easily removed and which, in Figure 9A, are shown in their positions when the elevator is operating.
[0027] According to another embodiment, the elevator car can be equipped with removable side panels or wall panels, such as those indicated by 27 in Fig. 9B which panels too allow for an intervention on the drive unit assembly from the inside of the elevator car. The same Figure also shows a false ceiling 26 which covers the ceiling panels and can be displaced, for example rotated, when panels 25 are to be removed.
[0028] Figures 10A and 10B illustrate the elevator car 1 with the panels 25 and 27 removed, and the false ceiling 26 hinged at a side and lowered to allow the access to panels 25.
[0029] The structure illustrated in the discussed Figures can nevertheless be used in a conventional arrangement, i.e. one in which maintenance is carried out by an operator standing on the car ceiling, when there is room enough for, or rules prevent a maintenance from the inside of the elevator car, and in such case proper safety spaces will be provided for at the shaft top.
[0030] The drive unit assembly 8 is mounted with its axis parallel to the plane of the guide rails, so that the traction sheave 10 is disposed perpendicular to this plane. Besides, the size of the unit is pretty reduced in the direction perpendicular the plane of the guide rails thus allowing a reduction of the shaft dimensions.
[0031] The drive unit assembly 8, as illustrated in Fig. 3, is mounted on a baseplate 21 secured through rubber dampers 22 to a pair of side supports 23 that in turn can be fastened either to the shaft wall, or only to the guide rails 3,7, or to both the shaft wall and the guide rails. The baseplate 21 is secured either to the shaft wall, or to the guide rails 3, 7 only, or to both to the shaft wall and the guide rails. In the baseplate 21 one (17) of the fixed anchorages for the traction ropes 6 is implemented.
[0032] Additionally a fastening clamp 24 for clamping the ropes is provided in the baseplate 21, which is very useful during the maintenance of the drive unit assembly.
[0033] The elevator system further comprises a controller or control panel which houses the control system of the elevator system, the drive unit assembly of the motor and several switches.
[0034] According to the present invention, such a control panel is usually located at the topmost floor, at a side of the landing door, in a suitable independent box 14 as illustrated in Figure 6. Alternatively it be located at any other floor, or inside the elevator shaft, and being or not extractable. According to a further embodiment, it can be formed by a plurality of sub-assemblies placed in the most appropriate positions.
[0035] The elevator system further comprises other components such as landing and car doors, a speed limiter, a take-up of the limiter, shock absorbers for the elevator car and the counterweight; control devices of the elevator car and floor, which are not illustrated in details since they can be of conventional design and are well known to the skilled of the art.
1. A traction sheave elevator system comprising:
an elevator car (1), moving along elevator guides (3);
a counterweight (4) moving along counterweight guides (7);
a set of hoisting ropes (6) on which said elevator car (1) and counterweight (4) are suspended in a hoistway or elevator shaft (2) of said elevator system;
a traction assembly or drive unit assembly (8), disposed in said elevator shaft, which actuates a traction sheave (10) acting onto said hoisting ropes (6);
characterised in that said drive unit assembly (8) is mounted in said elevator shaft (2) with its axis parallel to the plane of said elevator car guides (3), and comprises an electric motor (11) on which said traction sheave (10) is mounted with its axis perpendicular to said plane.2. An elevator as claimed in the claim 1, characterised in that said guides (7) of the counterweight (4) lie in the same plane of said guides (3)
of the elevator car (1), and in that said electric motor (11) has a small diameter.
3. A traction sheave elevator comprising:
an elevator car (1), moving along elevator guides (3);
a counterweight (4) moving along counterweight guides (7);
a set of hoisting ropes (6) on which said elevator car (1) and counterweight (4) are suspended in a hoistway or elevator shaft (2) of said elevator system;
a traction assembly or drive unit assembly (8), disposed in said elevator shaft, which actuates a traction sheave (10) acting onto said hoisting ropes (6);
characterised in that said elevator car (1) is equipped with at least one removable panel (25; 27) for allowing the access to said machine group (8) for intervention and maintenance operations by an operator operating inside said elevator car (1).4. An elevator as claimed in the preceding claims, characterised in that said electric motor (11) with reduced diameter is a permanent magnet brushless motor.
5. An elevator as claimed in the preceding claims, characterised in that all said guides (3, 7) are secured to the shaft wall through only one type of adjustable
bracket (23).
6. An elevator as claimed in the preceding claims, characterised in that said elevator car (1) is supported by a supporting frame (5) which is cantilever
from the plane of said guides and which slides along the elevator guides through rolling
or sliding shoes.
7. An elevator as claimed in the preceding claims, characterised in that it further provides a control panel located at a side of the landing door, in an
independent control box (14).
8. An elevator as claimed in claims 3 to 7, characterised in that said at least one removable panel (25; 27) is positioned on the ceiling (25) and/or
on the side wall (27) of said elevator car (1) for intervention and maintenance operations
through an operator who operates inside of said elevator car (1).
9. An elevator as claimed in the preceding claims, characterised in that said drive unit assembly (8) is mounted through rubber bumpers; that said baseplate
(21) is fastened either to the shaft wall, or only to the guides (3, 7), or both to
the shaft wall and to the guides, and incorporates a clamp for fastening said ropes.
10. An elevator as claimed in claim 9, characterised in that said suspension ropes (6) of the counterweight and car are of the tackle type, and
in that one (17) of said fixed anchorages of the traction ropes is implemented in said baseplate
(21), while the other anchorage (18) of said tackle is on the side of the elevator
shaft (2) which is opposite to said guides (3, 7).