Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K19/00—Synchronous motors or generators
  • H02K19/02—Synchronous motors
  • H02K19/10—Synchronous motors for multi-phase current
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
  • B66B11/00—Main component parts of lifts in, or associated with, buildings or other structures
  • B66B11/04—Driving gear ; Details thereof, e.g. seals
  • B66B11/043—Driving gear ; Details thereof, e.g. seals actuated by rotating motor; Details, e.g. ventilation
  • B66B11/0438—Driving gear ; Details thereof, e.g. seals actuated by rotating motor; Details, e.g. ventilation with a gearless driving, e.g. integrated sheave, drum or winch in the stator or rotor of the cage motor
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K21/00—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets
  • H02K21/26—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with rotating armatures and stationary magnets
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
  • H02K7/10—Structural association with clutches, brakes, gears, pulleys or mechanical starters
  • H02K7/1004—Structural association with clutches, brakes, gears, pulleys or mechanical starters with pulleys
  • H02K7/1012—Machine arranged inside the pulley
  • H02K7/1016—Machine of the outer rotor type

Definitions

• Electric motor with a low number of revolutions , in particular to drive lifting devices .
• This invention refers to an electric motor with a low number of revolutions.
• this invention refers to an electric motor with a low number of revolutions which can be advantageously used for applications requiring torque.
• the electric motor according to the invention can be used to drive lifting devices, such as lifts.
• Electric motors used in applications with a heavy torque requirement for example electric motors for lifts, are generally positioned inside relatively small spaces, which is a source of problems as the motors are usually fairly large due to the presence, in addition to the motor itself, of a reduction unit and obviously the pulley around which the cables that raise and lower the lift cabin are wound.
• the reduction units used in these applications often have electromechnical characteristics that are fairly inconstant over time, leading to functioning irregularities that cause a considerable reduction in the performance of the motor. Description of the invention
• This invention proposes to provide a solution to the background art problems, thanks to a new design of motor which is small and is not equipped with a reduction unit.
• this invention proposes to provide an electric motor with a low number of revolutions (for example a motor with approximately 50 rpm corresponding to a lifting speed of around 1 m/sec) thanks to which the components necessary for the movement and the braking of the machine can be directly contained inside the drive pulley.
• the most typical configuration of the electric motor according to the invention consists of a rotor (with a high number of magnetic poles) powered by three- phase alternating voltage, and of a stator with the same number of magnetic poles as the rotor, created by a coil powered by direct voltage.
• the direct voltage consists of a single-phase rectified and thus pulsating alternating voltage.
• This direct voltage makes it possible to obtain excellent results in terms of motor performance.
• the reference number 10 indicates overall an electric motor with a low number of revolutions used to drive lifting devices according to the invention.
• the motor 10 is supported by a fixed metal shaft 11 by means of a pair of bearings 12, 12' (either roller or ball bearings) and is enclosed in the casing 13 of a pulley, the outer surface of which is equipped with a series of slots 14, 14" ... designed to accommodate cables (not shown in the figure) for driving a lifting device, for example a lift.
• the casing 13 is rigidly fixed by means of screws 15 to a pair of diamagnetic side plates 16, 16' which work in conjunction with the said roller bearings 12, 12".
• the actual electric motor is housed inside the space formed by the diamagnetic plates 16, 16' and the pulley casing 13.
• a rotor pack 17 integral with the inner surface of the pulley 13 is a rotor pack 17 fitted with a series of slots (not shown in the figure) designed to accommodate a three-phase winding powered by alternating voltage.
• This three-phase winding is connected to three respective conductor rings 18, 18', 18" inserted in appropriate slots cut in the side plate 16 '.
• a protective guard 19 consisting of two portions joined together and fixed to the shaft 11 supports three respective brushes 20, 20', 20" in contact with the said conductor rings 18, 18', 18".
• Respective magnets 21, 22 are positioned next to each other and fixed to the shaft 11. These magnets 21,
• stator 22 define a space which houses a stator-powered coil 24 powered by direct voltage in order to create the magnetic polarities of the stator.
• the motor 10 comprises an electromagnetic brake 25 consisting of a pair of metal discs, one of which is integral with the side plate 16 ' and the other with the magnet 22, and of disc-pushing springs contained in appropriate slots cut in the magnet 22.
• Such a motor is particularly suited for application as a machine without a reduction unit in the lifts sector, since the drive pulley can contain all the equipment necessary both to move and to brake the machine.
• the respective power supplies of the stator coil 24 (advantageously direct voltage obtained by rectifying single-phase alternating voltage) and of the rotor windings 17 (three-phase alternating voltage) are governed by means of an appropriate control device, until the required number of revolutions is reached, which depends on the number of poles of the motor and on the frequency of the three- phase power supply.
• control device that can be used for these applications is the variable frequency type, for example the ac-dc-ac or dc-ac type.
• the stator coil 24 is powered by direct voltage.
• the motor comprises a high number of magnetic poles, both stator and rotor having the same number, and in the stator the poles are the clawed type as in automobile alternators.
• the side plates 16, 16' are made from diamagnetic material .
• the stator 24 is constantly powered by direct voltage, while the rotor 17 has a variable frequency achieved by means of a frequency converter external to the rotor.
• the frequency of the three-phase voltage of the rotor 17 is adjusted by frequency converters (ac-dc-ac or dc-ac) which provide the frequencies, currents and thus the torques required.
• the invention is described above with reference to a preferred embodiment, in which the main shaft is fixed, the stator is integral with the shaft and the rotor turns around the shaft and the stator.
• Embodiments of this invention are nevertheless foreseen in which the conformation of the motor is inverted, and the main shaft rotates, while the motor casing integral with the three-phase windings is fixed.
• the main shaft is equipped with a pair of conductor rings connected to appropriate cables inserted in slots in the shaft and connected to windings of the coil and of the rotating magnets.
• a pair of brushes is then connected to the rings for transmission of the current, while the mechanical drive organs, in particular the lifting organs, are connected to the main shaft.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Civil Engineering (AREA)
• Mechanical Engineering (AREA)
• Structural Engineering (AREA)
• Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
• Load-Engaging Elements For Cranes (AREA)
• Dynamo-Electric Clutches, Dynamo-Electric Brakes (AREA)
• Cage And Drive Apparatuses For Elevators (AREA)
• Synchronous Machinery (AREA)

Priority Applications (9)

Applications Claiming Priority (6)

Publications (1)

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ID=38324192

Family Applications (1)

Country Status (11)

Cited By (1)

Families Citing this family (4)

Citations (9)

Family Cites Families (6)

• 2007
  • 2007-03-19 JP JP2008557849A patent/JP2009528815A/ja active Pending
  • 2007-03-19 BR BRPI0711451-6A patent/BRPI0711451A2/pt not_active IP Right Cessation
  • 2007-03-19 DE DE602007008552T patent/DE602007008552D1/de active Active
  • 2007-03-19 SM SM200700062T patent/SMAP200700062A/it unknown
  • 2007-03-19 AT AT07734007T patent/ATE478462T1/de active
  • 2007-03-19 AU AU2007246782A patent/AU2007246782B2/en not_active Ceased
  • 2007-03-19 KR KR1020087012019A patent/KR101045583B1/ko not_active Expired - Fee Related
  • 2007-03-19 CA CA2629630A patent/CA2629630C/en not_active Expired - Fee Related
  • 2007-03-19 US US12/096,937 patent/US7851956B2/en not_active Expired - Fee Related
  • 2007-03-19 WO PCT/IB2007/000669 patent/WO2007129150A1/en not_active Ceased
  • 2007-03-19 EP EP07734007A patent/EP2013960B1/en active Active

Patent Citations (9)

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