US 6,147,435 AGranted

Mechanism for driving a screw rod by supersonic vibration

AssigneeCentral Gikenkogyo Corporation

InventorKatsuyuki Fujimura

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Abstract

In order to provide a mechanism for driving a screw rod by supersonic vibrations, which may achieve space savings, prevent back-lash of a work rack, and effect smooth operation, a first screw rod rotation device is provided for rotation of a screw rod in a first direction, and a second screw rod rotation device is provided for rotation of the screw rod in a second direction. The first screw rod rotation device includes a first vibrator contacting a groove portion of the screw rod at a specific angle, a first spring urging the first vibrator toward the groove portion of a screw rod at a specific pressure and a first piezoelectric actuator for vibrating the first vibrator upon electrical activation. The second screw rod rotation device includes a second vibrator contacting a groove portion of the screw rod at a specific angle opposite that for rotation in the first direction, a second spring urging the second vibrator toward the groove portion of the screw rod at a specific pressure and a second piezoelectric actuator for vibrating the second vibrator upon electrical activation. The first and second screw rod rotation devices are directly mounted on the work rack which surrounds the screw rod and is slidable in the axial direction of the screw rod.

Claims8

Dependent claims

A mechanism for driving a screw rod by supersonic vibration, comprising:

a screw rod provided with a groove portion formed helically along an axial direction thereof;
a pair of stands rotatably holding opposite ends of said screw rod;
a work rack partially surrounding said screw rod and slidable in the axial direction of said screw rod;
at least one first screw rod rotation device secured on one side of said work rack and extending from said work rack to said screw rod, said at least one first screw rod rotation device comprising a first vibrator contacting with said groove portion of said screw rod at a first specific angle, a first spring urging said first vibrator toward said groove portion of said screw rod at a specific pressure and a first piezoelectric actuator for vibrating said first vibrator upon electrical activation to rotate said screw rod in a first rotational direction;
and
at least one second screw rod rotation device secured on another side of said work rack and extending from said work rack to said screw rod, said at least one second screw rod rotation device comprising a second vibrator contacting with said groove portion of said screw rod at a second specific angle opposite said first specific angle, a second spring urging said second vibrator toward said groove portion of said screw rod at a specific pressure and a second piezoelectric actuator for vibrating said second vibrator upon electrical activation to rotate said screw rod in a second direction.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/267,611Filed 15 Mar 1999
Priority: JP 10-14065522 May 1998
Granted: 14 Nov 2000
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

H02N 2/103
Producing rotary motion, e.g. rotary motors: by pressing one or more vibrators against the rotor
F16H 25/20
For conveying or interconverting oscillating or reciprocating motions: screw mechanisms
F16H 25/2409
Elements essential to such mechanisms, e.g. screws, nuts: one of the threads being replaced by elements specially formed for engaging the screw or…
H02N 2/126
Mechanical transmission means, e.g. for gearing: for conversion into linear motion