Linear motor driven elevator

Abstract: A linear motor driven elevator realising a high speed and a large transportation capacity comprises an elevator shaft (11) divided into an ascending passage (2) and a descending passage (3) by means of a fixed portion in such a manner that both passages are positioned oppositely. A plurality of cages (10) are accommodated in the both passages, the cages being provided with permanent magnets which opposite to the linear motor primary coils, and locking means for selectively locking the cage are provided. Transfer sections (20,30) are provided above and below the fixed portion to transfer cages between the ascending and descending passageways.

Description: The present invention relates to a linear motor driven elevator. Linear motor driven elevators are known from GB-A-967985 and FR-A-2297451 which disclose that the same passageway is used for raising and lowering the cage. With modern propensity for high-rise buildings, high speed and high capacity elevators are required, and a variety of high speed elevators are known. However, these high speed elevators include conventional winch drum raising and lowering mechanisms. Being driven by such traditional raising and lowering mechanisms, the speed and transporting capacity of the elevators is restricted. It is thus an object of the present invention to provide a linear motor driven elevator realising a high speed and a large transportation capacity. According to the present invention there is provided a linear motor driven elevator comprising an elevator shaft divided by a fixed portion into opposed ascending and descending passageways, a plurality of elevator cages disposed in said passageways, one of said fixed portion or said elevator cages being provided with linear motor primary coils and the other being provided with opposed permanent magnets, an upper transfer section provided above said fixed portion to transfer elevator cages from said ascending passageway to said descending passageway, and a lower transfer section provided below said fixed portion to transfer elevator cages from said descending passageway to said ascending passageway. Preferably the fixed portion comprises a central core supported by a pair of vertical frame members, the primary coils being oppositely positioned on the periphery of the central core, and the cages being provided with the opposed permanent magnets. The frame members may have a generally H-shaped cross-section and the cages may be provided with bearing means engaging the frame members so that the frame members act as a track for the cages in the passageways. In a preferred embodiment the shaft is cylindrical and the transfer sections comprise means for rotating the cages through 180° about the axis of the shaft. Preferably locking means are provided for selectively locking the cages at desired locations in the shaft. Preferably, the above-mentioned rotating means comprise a turn table fixed at the lower transfer section, a turn table suspended at the upper transfer section, crown gears being provided on both of these tables, respectively, pinion gears engaging with said crown gears and turn table driving motors. Also, preferably, the locking means comprise recesses formed on the edge of the frame members and a stopping device being provided with a pin which protrudes into and engages with the recess. The pin protrudes when the cage is normally stopped, or in a state of emergency, such as breakage of a rope suspending a cage, failure of electricity supply, etc. In a state of emergency, the pin operates a rock action as a safety device. Also, the pin protrudes when cages in the upper and lower sections are turned respectively. In the linear motor driven elevator constructed in accordance with a preferred embodiment, a linear synchronous motor (LSM) comprises linear motor primary coils of the central core and permanent magnets of the cages. The cages ascend at a high speed through the ascending passage by means of said linear synchronous motor. When one of the cages reaches the upper transfer section, the cage is shifted into the descending passage by means of said upper rotating means. Then, said cage descends through the descending passage. Thereafter, the cage is shifted into the ascending passage by means of the lower rotating means. In such a way, a plurality of cages ascend and descend successively in a cycle through the ascending passage and descending passage, respectively. An embodiment of the invention is explained below by way of example and with reference to the drawings, in which:- Fig. 1 is a schematic perspective view of an embodiment of the present invention; Fig. 2 is a perspective view showing a fixed portion; Fig. 3 is a perspective view showing a lower transfer section; Fig. 4 is a perspective view showing an upper transfer section; and Figs. 5 and 6 are a perspective view showing the facing side and the back side of a cage, respectively. In Fig. 1, a cylindrical elevator shaft 1 comprises a fixed portion 10, a lower transfer section 20 and an upper transfer section 30. The lower transfer section 20 is provided at a position being lower than the fixed portion 10, while the upper transfer section 30 is provided at a position above the fixed portion 10. In the elevator shaft 1, an ascending passage 2 and descending passage 3 are sectionally formed by these transfer sections 20 and 30 and the fixed portion 10, in such a manner that said passages 2 and 3 are positioned on opposed sides of fixed portion 10. Also, in both said passages 2 and 3, a plurality of elevator cages 40 are accommodated. In Fig. 2, the fixed portion 10 comprises a center core 13a along with a pair of frames 11a,11a, which frames are made of H-profile steel, connected to core 13a by means of a plurality of pairs of arms 12a,12a. The center core 13a is provided on opposed sides with linear motor primary coils 14a,15a. Also, on the opposed sides of the frames 11a,11a, a plurality of recesses 16a are formed at a predetermined pitch. In Fig. 3, the lower transfer section comprises rotating means 20, the frames 11b,11b, which are similar to the frames 11a,11a in the fixed portion 10, stand on a turn table 21. A center core 13b stands along with said frames 11b,11b, by means of arms 12b,12b. In the center core 13b, linear motor primary coils 14b,15b are provided, and also, recesses 16b are formed on the frames 11b,11b. The turn table 21 is supported by a plurality of rollers 22 being mounted to a fixed member (not shown), dampers 27 are provided on the upper surfaces of the turn table 21, two of which dampers are provided in each passage 2,3, respectively, and a crown gear 23 is formed at the periphery of the turn table 21. A pinion gear 24 engaging with said crown gear 23 is fixedly mounted to the fixed member (not-shown), by a bracket 26. The bracket 26 is provided with a turn table driving motor 25 for rotating the pinion gear 24. A turning means of the lower rotating means 20 comprises these members 21-25. In Fig. 4, the upper transfer section comprises rotating means 30 comprising substantially the same members as the lower rotating means 20, so that the corresponding members are designated by adding the suffix c, respectively, in order to prevent repetitive explanations. Frames 11c,11c are mounted to the turn table 32, in suspension, by means of beams 31,31, so, that the turn table 32 is turned by a crown gear 33, a not-shown pinion and a turn table driving motor 34. A turning means of the upper rotating means 30 comprises these members 32-34. In Figs. 5 and 6 (these drawings show a face side and a back side of a cage 40, respectively), the cage 40 is formed into a shape of substantially semi-circular cross-section, in the face side of which a door 41 is mounted so as to be capable of opening and closing. In the back side of said cage 40, which has a cut-away arc, permanent magnets 42 are mounted so as to oppose the linear motor primary coils 14a-14c and 15a-15c. A linear synchronous motor, so-called LSM, comprises these linear motor primary coils 14a-14c, 15a-15c and permanent magnets 42. However, without being limited thereto, a linear induction motor, so-called LIM, etc. can also be used. Both upper and lower ends of the cage 40 are provided with upper guides 43a, upper guide rollers 44a and lower guides 43b, and lower guide rollers 44a, respectively, for being guided by the edges of the frames 11a-11c. Below the upper guide 43a is provided a stopping device 45 comprising a pin 45a which engages with a recess 16a-16c by protruding at the time of stopping. A locking means comprises said stopping device 45 and recesses 16a-16c of frames 11a-11c. Moreover, at the inside of one of the upper guides 43a, a current collector 46 is provided. By means of the present embodiment constructed as explained above, when the cage 40 ascends through the ascending passage 2 by means of the linear synchronous motor driving mechanism, the cage 40 is shifted to the side of the descending passage 3 by the turning of the upper transfer section 30, and then, descends through the descending passage 3. When the cage 40 should be stopped at a required position, the pin 45a of the stopping device 45 protrudes so as to consequently fix the cage 40 to the frame 11a-11c by engaging with the recess 16a-16c. Thereafter, the cage 40 is shifted to the side of the ascending passage 2 by the turning of the lower transfer section 20. In such a way, a plurality of cages 40 ascend and descend successively in a cycle through the ascending passage 2 and the descending passage 3. Also, by inserting cages in one shaft, the projection are of the elevator becomes relatively small, however, transporting capability will be improved. Also, a structural efficiency in a structure including an elevator according to the present invention will be improved.

Claims: A linear motor driven elevator comprising an elevator shaft divided by a fixed portion into opposed ascending and descending passageways, a plurality of elevator cages disposed in said passageways, one of said fixed portion or said elevator cages being provided with linear motor primary coils and the other being provided with opposed permanent magnets, an upper transfer section provided above said fixed portion to transfer elevator cages from said ascending passageway to said descending passageway, and a lower transfer section provided below said fixed portion to transfer elevator cages from said descending passageway to said ascending passageway. An elevator as claimed in claim 1 wherein said fixed portion comprises a central core supported by a pair of vertical frame members, said primary coils being oppositely positioned on the periphery of said central core, and said cages being provided with said opposed permanent magnets. An elevator as claimed in claim 2 wherein said vertical frame members have a generally H-shaped cross-section and said elevator cages are provided with bearing means adapted to engage said frame members whereby said frame members guide said cages in said ascending and descending passageways. An elevator as claimed in claim 1, 2 or 3 wherein said shaft is cylindrical and said upper and lower transfer sections comprise means for rotating an elevator cage through 180° about the central axis of said elevator shaft. An elevator as claimed in any preceding claim wherein locking means are provided for selectively locking an elevator cage at a desired location(s) in said shaft.

Inventors: MATSUI NOBUYUKI, SHIMAZU TADAHIRO, UCHIDA KAZUYOSHI, MATSUI, NOBUYUKI, SHIMAZU, TADAHIRO, UCHIDA, KAZUYOSHI
Applicants: KAJIMA CORP, KAJIMA CORPORATION
Application year: 1991
Main classification: B66B11
IPC codes: B66B11, B66B9, B66B7, H02K41