Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K41/00—Propulsion systems in which a rigid body is moved along a path due to dynamo-electric interaction between the body and a magnetic field travelling along the path
  • H02K41/02—Linear motors; Sectional motors
  • H02K41/03—Synchronous motors; Motors moving step by step; Reluctance motors
  • H02K41/031—Synchronous motors; Motors moving step by step; Reluctance motors of the permanent magnet type

Definitions

• the invention relates to a synchronous electric motor, suitable in particular for driving machine tools, or automatic machines.
• linear motors exhibit considerable advantages, with respect to traditional powering methods, essentially thanks to the absence of transmission organs of any kind which, as is well known, reduce the overall performance of the machine.
• Electric motors also guarantee that the moving block is driven at the speed and acceleration times required, as motion transmission is in no way affected by friction or adherence coefficient variables necessary for traditional mechanical transmissions, which use kinematic chains.
• the main aim of the present invention is to provide a linear motor, applied in particular to a drive for machine tools, or automatic machines, which has a simplified structure in relation to prior art motors and which offers an improvement in both dynamic performance and actuation.
• a further aim of the present invention is to provide a linear electric motor for actuating machine tools which is economically advantageous and reliable.
• a synchronous linear electric motor in which the coil block is compelled to slide with respect to the stator comprising the magnets, on a single mechanical guide.
• the guide is constrained to the shell of the motor, on a side opposite the side where the magnets are located.
• the support shell of the motor has a U-shaped transversal section, though it can be closed on all four side.
• the lie plane of the coil block can, in both cases, be arranged either vertically or horizontally.
• figure 1 is a partially-sectioned perspective view of the linear electric motor of the invention
• figure 2 is a view in horizontal longitudinal section of the motor of figure 1
• figure 3 is a perspective view relating to a traditional solution, of a linear motor applied to actuation of machine tools
• figure 4 is a detailed view of a linear motor according to the present invention.
• 10 denotes in its entirety a linear electric motor in a configuration which is suitable for application to machine tool drive.
• the motor is comprised within a U-shaped support structure 11, to a lateral wall 12 to which magnets 13 of the motor are fixed, while a mechanical guide 16 is fixed by screws 15 to an opposite wall 14.
• two slides 17, 18 are constrained to and mobile on the mechanical guide 16.
• the coil block 20 of the motor is anchored to a plate 19, which plate 19 is solidly constrained to the two slides 17, 18.
• the coil block 20 comprises a known lamination pack 21 made of a ferrous-magnetic material, shaped so as to form a series of cores 22 about which single coils 23 are wound (illustrated in figure 4).
• the motor of the invention can operate either vertically or horizontally.
• the perfect perpendicularity of the longitudinal halfway-line of the coil block 20 to the lie plane of the fixed magnets is guaranteed by the elevated force of attraction exerted by the magnets 13 on the coil block 20, thanks to the very strong magnetic field generated by the magnets themselves (in the cores 22 of the coil block 20).
• the coil block 20 is subject to a traction force, which is developed parallel to the axes of the cores 22 and is generated by the above-described constraining force of reaction of the guide 16.
• This traction is of sufficient entity to overcome (in the case a horizontal positioning illustrated in figure 1) the weight force tending to rotate the core block 20 downwards, about the axis of rotation constituted by the guide 16.
• the horizontal positioning in figure 1, or vertical positioning in figure 4 can therefore be adopted with no reservations about the operation of the motor. It can be chosen freely according to the architecture of the machine tool it is to be applied on and/or the workpiece-jig thereon.
• the U-shape adopted in the present embodiment for the support structure 11 affords a good level of protection, both of the motor (from the outside environment) and of the machine operator.
• Complete protection can be provided by using a support structure of the completely closed kind, on all four sides. This protects the motor from outside impurities, i.e. mechanically, and also limits the action of the magnetic field created by the fixed magnets with regard to the surrounding environment, when the material of the support structure 11 is made of a ferrous-magnetic material.
• the solution shown in figure 1 can be adapted for supporting and moving sheet steel, or a sheet of other material, in a horizontal direction, with application of special vertical attachments or similar to the plate 19. Frontal attachments could also be applied, for example a single or multiple shaft. Both the above solutions and the possible solution employing a closed structure on all four sides can also be used in a vertical position, with the tool or workpiece in a vertical plane.
• the moving coil block 20 exhibits decidedly less inertia in comparison to the moving block of figure 3; at the same time the energy needed to actuate the displacement is reduced, considering the smaller overall contact surface between the fixed and the moving part. Also, the total cost of actuation is reduced, as the invention is notably uncomplicated.
• the sliding between the guide 16 and the slides 17, 18, is achieved through ballbearing skates or similar low-friction elements.
• the means of attachment of the tools or workpieces to the plate 19 can obviously vary according to the applications.
• the shape of the guide 16 and the slides attached thereto can also be varied. If the length of the coil block 20 is limited, one slide 17 or 18 alone could be used on the guide 16; this would give the advantage of eliminating any possible misalignment of the slides 17 or 18, and consequent risks of sticking during motion.

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Electromagnetism (AREA)
• Power Engineering (AREA)
• Linear Motors (AREA)
• Machine Tool Units (AREA)
• Reciprocating, Oscillating Or Vibrating Motors (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=11453982

Family Applications (1)

Country Status (4)

Families Citing this family (1)

Citations (2)

Family Cites Families (1)

• 2000
  • 2000-11-02 IT IT2000RE000107A patent/IT1319440B1/it active
• 2001
  • 2001-10-24 AU AU2002215199A patent/AU2002215199A1/en not_active Abandoned
  • 2001-10-24 WO PCT/IT2001/000541 patent/WO2002037652A1/en active Application Filing
  • 2001-10-24 EP EP01983782A patent/EP1332544A1/de not_active Withdrawn

Patent Citations (2)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events