Valve actuator differential worm planetary gear drive

• US 4,896,562 A
• Filed: 03/24/1988
• Issued: 01/30/1990
• Est. Priority Date: 03/24/1988
• Status: Expired due to Term

• Current Assignee: Flowserve Management Company (Flowserve Corporation)
• Original Assignee: Limitorque Corp. (Schneider Electric SE)
• Inventors: Hylton, Charles L., Pence, R. Gregory, Wilkinson, Ivan E.
• Primary Examiner(s): Herrmann, Allan D.
• Application Number:
  US07/173,195
• Time in Patent Office: 677 Days
• Field of Search: 74/626, 251/129.03
• US Class Current: 475/3
• CPC Class Codes: F16H 2025/2065 Manual back-up means for overriding motor control, e.g. hand operation in case of failure
• CPC Class Codes: F16H 2025/2084 Perpendicular arrangement of drive motor to screw axis
• CPC Class Codes: F16H 2025/2087 using planetary gears
• CPC Class Codes: F16H 2025/209 using worm gears
• CPC Class Codes: F16H 37/0826 with only one output shaft
• CPC Class Codes: F16K 31/05 specially adapted for operating hand-operated valves or for combined motor and hand operation
• CPC Class Codes: G05G 11/00 Manually-actuated control mechanisms provided with two or more controlling members co-operating with one single controlled member

Abstract

A valve actuator differential worm planetary gear drive provides forward or reverse motion to a valve stem, from an input from either a motor-driven worm or a handwheel driven worm, by using a plurality of planet gears to send motion to the sun gear. If the preference is to have the motor driven the valve primarily, the manual worm stays locked and the motor worm acts as a planetary arm. When it is desired to move the valve by hand, the motor gear is fixed and rotation of the handwheel worm gear transmits the power through the ring gear and the planet gears to the drive sleeve.

Claims

1. A valve actuator for controlling reciprocating motion of an elongated stem connected to the valve, comprising:

an elongated stem having helically-wound screw threads thereabout;

a tubular-shaped drive sleeve having an internal bore therethrough with helically-wound threads engaging the threads of said stem;

first and second, bi-directional, drive force input means to transmit an input force adjacent a said drive sleeve;

first and second worms operatively connected to said first and second input means to receive rotational forces therefrom and transmit rotational forces;

first and second axially spaced cylindrical gears, each have a bore therethrough, concentrically and rotationally mounted on said sleeve adjacent each said first and second worms and connected to receive a force transmitted from said first and second worms, respectively;

a tubular-shaped sun gear of a first pre-determined diameter concentrically rotating with said first cylindrical gear about said drive sleeve;

a tubular-shaped ring gear of a second, larger, predetermined diameter, adjacent said sun gear and concentrically rotating with said second cylindrical gear about said drive sleeve; and

a plurality of right cylindrically-shaped planet gears operationally connected between said sun gear and said ring gear, each said planet gear fixedly held by a carrier arm connected to said drive sleeve whereby a rotational force transmitted by said first input device is transmitted to said ring gear and through said planet gears and then to said drive sleeve which moves said stem, and a rotational force transmitted by said second input device is transmitted to said sun gear and through said planet gears and then to said drive sleeve which moves said stem,