DEVICE FOR DRIVING A DOOR OF AN ELEVATOR

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to, and hereby incorporates by reference in its entirety, Korean Priority Application No. 10-2007-0087441, which was filed on August 30, 2007.

BACKGROUND

Fig. 1 is a front elevation view illustrating a conventional elevator car, and

Fig. 2 is a side view showing the car door apparatus in Fig. 1, with car body 1 being shown in cross-section. As illustrated, elevator car entrance 2 is provided at the front face of car body 1. Door frame 3 extends along the width of entrance 2, and is fixed to car body 1 above entrance 2. Door motor 4 having motor pulley 5 is mounted on door frame 3.

Reduction pulley 6 having a larger diameter than motor pulley 5 has belt 7 wound between motor pulley 5 and reduction pulley 6. Drive pulley 8 has a smaller diameter than and is coaxial with reduction pulley 6, can be rotated integrally with the reduction pulley 6. Following pulley 9 is provided at the door frame 3, with second belt 10 wound between drive pulley 8 and following pulley 9.

Door rail 11 extends along the width direction of entrance 2 and is attached to door frame 3. Two car doors 12 are suspended from door rail 11 through door hangers 13. Each door hanger 13 has two rollers 14 which are rotated along door rail 11. Car doors 12 are connected to second belt 10 through door hanger 13 and belt holders 15 and 16. A plurality of door shoes 17 are attached adjacent the lower edge of each of doors 12. Door shoes 17 are inserted into a groove (not shown) of sill 18 disposed at the lower portion of entrance 2. Further, car body 1 is provided with upper panel 19 and ceiling panel 20.

During operation, motor pulley 5 is rotated by door motor 4, and the rotation is transmitted to reduction pulley 6 through reduction belt 7. Drive pulley 8 is rotated with reduction pulley 6, and thus second belt 10 is circulated and following pulley 9 is rotated.

Since door hangers 13 are connected to belt 10, door hangers 13 and doors 12 are reciprocated along door rail 11 by the circulation of second belt 10 to open or close entrance 2. Doors 12 are suspended from door rail 11 and the bottom portions of doors 12 are guided by the sill groove of sill 18 during the opening and the closing of doors 12.

Figs. 1 and 2 show a prior art device for driving a door of an elevator car, wherein door motor 4 is located above car body 1 and ceiling plate 20 of car body 1 is placed just below door motor 4. When designing the elevator car with higher ceiling plate

20, which is equipped with such a door driving device, ceiling plate 20 cannot help but interfere with door motor 4. Accordingly, the door driving device must be redesigned in order to avoid such interference. Further, large noise may occur in such a door driving device due to reduction pulley 6 and reduction belt 7 during the movement of doors 12. Figs. 3 and 4 show another prior art device for driving doors 2 of elevator car

1, wherein door motor 22 is disposed under horizontal portion 21b of a door frame 21 inside plane A extending parallel to vertical end face 18b of a sill, thereby eliminating interference between door motor 22 and ceiling plate 20. In this embodiment, bolts 23 hold door motor 22 in place on horizontal portion 21b of door frame 21, while vertical portion 21a extends down to attach to rail 11. Driving pulley 24 is attached to drive motor 22, and connected to following pulley 25 via belt 26. Rail 11 extends along the width of car 1, with door hangers 13 and corresponding rollers 14 being supported thereon. Doors 12 are connected to belt 26 through door hangers 13 and belt holders 15 and 16. Door shoes 17 are attached adjacent lower edge of doors 12, and are inserted into groove 18a of sill 18. The door operates as described before, with the exception being that drive motor is connected directly to driving pulley 24 without a reduction mechanism.

However, since a driving shaft of door motor 22 is not directly supported by door frame 21, vibrations caused by the rotation of the driving shaft can be applied to door frame 21 during operation of door motor 22. Further, since the distal end of the driving shaft, to which driving pulley 24 is coupled, serves as a free end, the load applied to driving pulley 24 through belt 26 during movement of doors 12 cannot be smoothly supported, thereby causing vibrations and noise.

Accordingly, a driving motor, which is configured to cause less vibration and noise, is necessary for driving a door of an elevator. Further, a device for driving a door of an elevator that does not interfere with a ceiling plate of an elevator and is compactly configured is needed.

In light of the foregoing, the present invention aims to resolve one or more of the aforementioned issues that afflict elevator systems.

SUMMARY

An embodiment of the present invention is directed to a device for driving a door of an elevator, which device includes a door header, a door, and a driving motor. The

door header, which is mounted on a frame defining a doorway, includes a vertical portion substantially parallel to a plane of the doorway. The door is movably supported on the frame. The driving motor, which is disposed on the vertical portion of the door header, includes a housing fixed with respect to the vertical portion, a rotating shaft having an axis that is oriented substantially perpendicularly to the vertical portion, a driving pulley, and a driving portion. The rotating shaft is rotatably supported by the vertical portion at one end thereof and is rotatably supported by the housing at the other end thereof. The driving pulley is coupled to the rotating shaft. The driving portion drives the rotating shaft.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the present invention will become apparent from the following description, appended claims, and the accompanying exemplary embodiments shown in the drawings, which are hereafter briefly described.

FIG. 1 is a front elevation view of a sliding elevator door known in the prior art.

FIG. 2 is a side elevation view of a portion of the door shown in FIG. 1. FIG. 3 is a front elevation view of a different embodiment of a sliding elevator door known in the prior art.

FIG. 4 is a side elevation view of a portion of the door shown in FIG. 3. FIG. 5 is a front elevation view of a portion of an embodiment of an elevator car according to the present invention.

FIG. 6 is a cross-sectional view of a portion of the door shown in FIG. 5. FIG. 7 is a perspective view of an embodiment of a motor for driving an elevator door according to the present invention. FIG. 8 is a cross-sectional view of the motor illustrated in FIG. 7.

DETAILED DESCRIPTION

Efforts have been made throughout the drawings to use the same or similar reference numerals for the same or like components.

FIG. 5 is a front elevation view of a portion of an embodiment of an elevator car. FIG. 6 is a cross-sectional view of a portion of the car shown in FIG. 5. Illustrated in FIGS. 5 and 6 are elevator door driving device 100, elevator car 110, frame 112, doorway 114, ceiling plate 116, doors 121 and 122, door hangers 123 and 124 having upper portions 123a and 124a and belt holders 123b and 124b, upper roller 125b, lower roller 126b, door header 130 with vertical portion 130a, horizontal portion 130b, and bent section 130c, rail 132, driving motor 140, driven pulley 152, and belt 154 having lower portion 154a and upper portion 154b.

As shown in FIGS. 5 and 6, elevator door driving device 100 is configured to be disposed at elevator car 110 to drive doors 121 and 122. Elevator door driving device 100 has door header 130 mounted above doorway 114 of elevator car 110; door rail 132 provided on door header 130 for supporting upper sides of doors 121 and 122; driving motor 140 disposed on door header 130 above door rail 132 and having driving pulley (not shown) therein; driven (or following or idler) pulley 152 rotatably provided on door header 130 as being apart from driving pulley; and drive belt 154 wound around driving pulley and driven pulley 152 along a lengthwise direction of door header 130. Drive belt 154 is a continuous piece of material, such as a rubber strap or rope.

Doors 121 and 122 each contain door hanger 123 and 124, respectively, which attach doors 121 and 122 to drive belt 154. Upper portion 123a of door hanger 123 contains belt holder 123b for attaching to lower portion 154a of drive belt 154, and upper portion 124a of door hanger 124 contains belt holder 124b for attaching to upper portion 154b of drive belt 154. Belt holders 123b and 124b are pulleys, sheaves, or similar wheels with a slot or similar surface for receiving drive belt 154, and may be constructed from metal, polymers, or similarly rigid materials. Door hanger 124 also has upper roller 125b and lower roller 126b that engage rail 132 to provide smooth motion for the operation of door 122. Rollers 125b and 126b are wheels or similarly round structures with a surface for engaging rail 132, and may be constructed from metal, polymers, resilient material, or any combination thereof. In the embodiment illustrated, upper roller 125b is a pulley or sheave with outer lips that extend past the engagement surface of rail 132, while lower roller 126b is a wheel having a rim covered by a resilient material to engage rail 132 to dampen

vibrations and other resultant forces during operation of door 122. Door hanger 123 contains similar corresponding structures.

Elevator car 110 includes frame 112 defining doorway 114. A portion of ceiling plate 116 is attached to an upper side of frame 112. Door header 130 includes vertical portion 130a substantially parallel to doorway 114, and horizontal portion 130b extending from an upper end of vertical portion 130a. Horizontal portion 130b may be omitted. Driving motor 140 is mounted on vertical portion 130a of door header 130 above door rail 132. Door header may contain bent section 130c that secures and spaces the position of door rail 132 with respect to driving motor 140. FIG. 7 is a perspective view of an embodiment of a motor for driving an elevator door, and FIG. 8 is a cross-sectional view of the motor illustrated in FIG. 7. Illustrated in FIGS. 7 and 8 are vertical portion 130a, driving motor 140, cover 141, fastener 141a, stator portion 142 with core 142a and coil 142b, rotor portion 143 with disk portion 143a, rim portion 143b, and magnet 143c, rotating shaft 144, driving pulley 145, bearings 146a and 146b, first housing 147 with rotor cover 147a, inner connection 147b, and outer connection 147c, second housing 148 with inner portion 148a, fasteners 148b, cover plate 149, and transducer 156 with rotor 156a.

FIGS. 7 and 8 show driving motor 140, which has first and second housings 147 and 148 fixed with respect to vertical portion 130a; rotating shaft 144 oriented perpendicularly to vertical portion 130a and being rotatably supported at both its ends; driving pulley 145 coupled to rotating shaft 144; and a driving portion formed of stator 142 and rotor portion 143 for driving rotating shaft 144. Cover 141 is provided between vertical portion 130a and first housing 147, and is secured to vertical portion 130a via fasteners such as 141a. First housing 147 contains rotor cover 147a, inner connection 147b and outer connection 147c. Second housing 148 is attached to inner connection 147b and outer connection 147c through fasteners 148b, which may be machine screws, bolts, or similar structures. Second housing 148 may contain cover plate 149 that is generally parallel to cover 141. Cover plate 149, first and second housings 147, 148, and cover 141 may be constructed from sheet metal, cast alloys or metals, or polymers. Also attached to shaft 144 is transducer 156, which may be either an encoder or resolver, secured by inner portion 148a of second housing 148. In the embodiment illustrated, transducer 156 is a resolver with rotor 156a surrounded by stator windings.

The driving portion has stator portion 142 radially disposed about rotating

shaft 144 and rotor portion 143 relatively rotated with respect to stator portion 142 by a magnetic force. Stator portion 142 includes a plurality of cores 142a and coils 142b wound around respective cores 142a. Rotor portion 143 includes: disk portion 143a with a central hole; rim portion 143b extending from an edge of disk portion 143 a; and a plurality of magnets 143 c attached on an inner periphery of rim portion 143b. First housing 147 is fixed to vertical portion 130a via the cover 141 while surrounding stator portion 142 and rotor portion 143. Second housing 148 is fixed to first housing 147 with driving pulley 145 interposed therebetween. Driving motor 140 further has first bearing 146a fixed to cover 141, and second bearing 146b disposed at second housing 148. One end portion and the other end portion of rotating shaft 144 are fitted to first bearing 146a and second bearing 146b, respectively.

Since driving motor 140 is disposed on vertical portion 130a of door header 130, door header 130 becomes small in terms of height and an unnecessary space to be induced by driving motor 140 can be eliminated. Thus, elevator door driving device 100 can be easily applied without any redesign thereof even when designing an elevator car with higher ceiling plate 116.

Further, since the one end of rotating shaft 144 is fitted to first bearing 146a, which is supported with respect to vertical portion 130a via cover 141, vertical portion 130a can directly support rotating shaft 144. Therefore, driving motor 140 can be more stably operated while making less vibration. Further, since rotating shaft 144 is rotatably supported via first and second bearings 146a, 146b at both its ends, the load applied to driving pulley 145 during operation of elevator door driving device 100 can be more stably supported. Thus, vibration and noise occurring during movement of doors 121 and 122 can be remarkably reduced, thereby providing a faster driving of doors 121 and 122. In addition, there is provided an integrated constitution, wherein rotor portion 143 and driving pulley 145 are coupled to rotating shaft 144 in a lengthwise direction thereof. Thus, the power output of driving motor 140 can be transmitted to driving pulley 145 without any loss and driving motor 140 can be configured more compactly. The orientation of rotor 143 having disk 143a located outside of bearing 146a instead of adjacent vertical portion 130a provides the advantage of further stability of motor 140. In contrast, prior art motors place the disk portion on the end of shaft 144, next to vertical portion 130a and inside of bearing 146; such a prior art arrangement produces more imbalance in the rotor due to the cantilevered positioning, as well as provides less

protection for the motor from outside vibrations on header 130. Further, the current arrangement with cover plate 141 and first housing 147 provide better protection from foreign particles, such as dust or water, during assembly and operation of the motor compared to prior art designs. The aforementioned discussion is intended to be merely illustrative of the present invention and should not be construed as limiting the appended claims to any particular embodiment or group of embodiments. Thus, while the present invention has been described in particular detail with reference to specific exemplary embodiments thereof, it should also be appreciated that numerous modifications and changes may be made thereto without departing from the broader and intended scope of the invention as set forth in the claims that follow.

The specification and drawings are accordingly to be regarded in an illustrative manner and are not intended to limit the scope of the appended claims. In light of the foregoing disclosure of the present invention, one versed in the art would appreciate that there may be other embodiments and modifications within the scope of the present invention. Accordingly, all modifications attainable by one versed in the art from the present disclosure within the scope of the present invention are to be included as further embodiments of the present invention. The scope of the present invention is to be defined as set forth in the following claims.