US 6,084,326 AGranted

Actuator

AssigneeSMC Corporation

InventorsShigekazu Nagai, Hiroyuki Shiomi

Life of this patent

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Abstract

A ball screw of an actuator is inserted through a displacement member. Driving-side axial magnetic patterns and driving-side circumferential magnetic patterns are formed on an outer circumference of the displacement member. The ball screw and the displacement member are surrounded by a tube. A slider is provided at the outside of the tube. Driven-side axial magnetic patterns opposing to the driving-side axial magnetic patterns and driven-side circumferential magnetic patterns opposing to the driving-side circumferential magnetic patterns are formed on the slider. Mutual magnetic attraction between the driving-side patterns and the driven-side patterns prevents the displacement member from rotation, and it causes the slider to make displacement in the axial direction together with the displacement member. Since the ball screw of the actuator is surrounded by the tube, the actuator can be prevented from scattering of lubricating oil, dust or the like.

Claims22

Dependent claims

An actuator for converting rotary motion generated by a rotary driving source into rectilinear motion to displace a slider in accordance with an action of said rectilinear motion, said actuator comprising:

a feed screw for being rotated by said rotary driving source;
a displacement member engaged with said feed screw, for converting said rotary motion of said feed screw into said rectilinear motion;
and
a slider arranged in the vicinity of an outer circumference of said displacement member in a non-contact state, said slider being linearly displaceable while being interlocked with said rectilinear motion of said displacement members
a plurality of magnetic poles, which are opposed to one another and which have different polarities in an axial direction of said feed screw formed on an outer circumference of said displacement member and on an inner circumference of said slider;
and
a magnetic coupling for preventing rotation of said displacement member about an axis of said feed screw upon rotation of said feed screw.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/241,285Filed 1 Feb 1999
Priority: JP 10-0236774 Feb 1998
Granted: 4 Jul 2000
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

H02K 49/102
Of the permanent-magnet type: magnetic gearings, i.e. assembly of gears, linear or rotary, by which motion is magnetically transferred without…
F16H 25/2418
Elements essential to such mechanisms, e.g. screws, nuts: screw seals, wipers, scrapers or the like
H02K 7/06
Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical…:…
H02K 49/10
Dynamo-electric clutches; Dynamo-electric brakes: of the permanent-magnet type