Servovalve with torque motor

• US 7,234,482 B2
• Filed: 03/21/2005
• Issued: 06/26/2007
• Est. Priority Date: 03/22/2004
• Status: Active Grant

• Current Assignee: Jihostroj a.s. (Hendon as)
• Original Assignee: Jihostroj a.s. (Hendon as)
• Inventors: Rynes, Vladimi, Hrachovsk, Toma
• Primary Examiner(s): Krishnamurthy; Ramesh
• Application Number:
  US11/084,754
• Publication Number:
  US 20050205130A1
• Time in Patent Office: 827 Days
• Field of Search: 137 82- 86, 251/65, 251/129.18, 335/229, 335/230, 335/276, 335/238, 335/258
• US Class Current: 137/82
• CPC Class Codes: G05D 7/0635 by action on throttling means G05D7/0688, G05D7/0694 take precedence
• CPC Class Codes: Y10T 137/2278 Pressure modulating relays or followers

Abstract

The servovalve with torque motor consists of a cylindrical case (3) in which an armature (1) is arranged on one end of an arm (16) and a orifice (18) closing a nozzle (19) with working liquid (2) on the other side of the arm (16). The arm (16) is free to rotate round the pivot point of a flexible suspension (15) with a hole (21) of diameter corresponding to the maximum deflection of the arm (16). There are two magnetic pole shoes (5) and two electric pole shoes (4) located around the armature (1), equipped with sealing rings (6), and so the working liquid (2) filling the inside of the case (3) and surrounding the arm (16) and the armature (1) does not leak out of the inside space. Coils (7) are located outside the case (3). The pole shoes (4, 5) are equipped with threaded parts (12), fitting either into the outer ring (10) or the body (3). The magnetic pole shoes (5) are equipped with a non-magnetic protective housing (9). The servovalve solution minimizes flow of the working liquid (2) through the electromagnetic circuit area, separates this area from the working liquid (2) and facilitates adjustment of the torque motor characteristics. The servo valve is suitable for high pressures.

Claims

1. A servovalve with a torque motor consisting of a cylindrical case, in which an armature is arranged on one end of an arm and an orifice closing a nozzle on the other end of the arm, while the arm is free to rotate in a central part between the arm and the orifice around a pivot point of a flexible suspension, and there are two magnetic pole shoes opposite to each other and two electric pole shoes with coils, turned by 90°

from the magnetic pole shoes, both the magnetic pole shoes and the electric pole shoes are located in the cylindrical case around the armature, whereas distal ends of the magnetic pole shoes and the electric shoes that are farther from the armature are connected by an outer ring, wherein the arm including the armature is surrounded by working liquid, which fills inside space of the cylindrical case, the magnetic and electric pole shoes are equipped with sealing rings on their ends extending inside the cylindrical case, and the coils are located on a part of the electric pole shoes extending outside of the inside space of the cylindrical case that is filled with the working liquid.

2. The servovalve with a torque motor according to claim 1, wherein the flexible suspension is provided with a hole, through which the arm extends, and the hole has its diameter limiting the maximum deflection of the arm.

3. The servovalve with a torque motor according to claim 1, wherein the magnetic pole shoes and the electric pole shoes are fitted on ends farther from the armature with threaded parts with male thread fitting into inner thread in the outer ring fitted on the cylindrical case.

4. The servovalve with a torque motor according to claim 1, wherein the magnetic pole shoes are equipped with axial housing made of non-magnetic material.