JPS60252818A - Steam regulating valve - Google Patents

Abstract

PURPOSE:To enable wear powder to be discharged to the outside of a slide part and to prevent a steam regulating valve from being rendered ineffective, by a method wherein a spiral groove is provided in the inner surface of a bush. CONSTITUTION:The interior of a servo motor for a steam regulating valve is constituted such that, with a servo piston 3 moved upward, a coil spring 9 is compressed, and a rotation force is produced by dint of the spiral shape of the soil spring. This causes a rotation force to be transferred to a restoring arm 6 and exerted on an arm guide 5. The press force further produces a reaction force, and the servo piston 3 presses a bush 7. In which case, wear powder is produced at the slide part of the bush 7, but the spiral groove formed in the slide part of the bush 10(7) causes the wear powder to be discharged outside the slide part.

Description

Detailed Description of the Invention [Field of Application of the Invention] The present invention provides a bushing having a spiral groove for discharging wear particles generated by sliding between a servo piston and a bushing to the outside of the sliding part. This invention relates to a steam control valve equipped with a steam control valve.

[Background of the invention]

In the conventional steam control valve servo motor, as shown in FIG. 4, when the servo piston 3 moves upward (as shown in FIG. 4), the coil spring 9 (FIG. 2) is compressed, and the spiral shape of the coil spring 9 is compressed. Rotational force is generated from. This rotational force presses the arm guide 5 against the restoring arm 6 attached to the servo piston 3 shown in FIGS. 2 and 3.

This force applied to the arm guide 5 becomes a reaction force, and force is applied to the bush 7. Therefore, a large amount of surface pressure is generated between the servo piston 3 and the bush 7, and abrasion occurs between the servo piston 3 and the bush 7 due to sliding, and wear powder is generated. Furthermore, this abrasion powder induces galling between the sliding parts, causing the servo piston 3 to stop working, making it impossible to open and close the steam control valve, and making it impossible to control the steam turbine. There was a risk of it happening. That is, the inside of the conventional steam control valve servo motor is as shown in Fig. 2. When the servo piston 3 moves upward, the coil spring 9 is compressed, and the spiral shape of the coil spring is Rotational force is generated. Therefore, as shown in FIGS. 2 and 3, the rotational force is transmitted to the restoring arm 6 and is applied to the arm guide 5. The force of this pressing is further increased by the reaction force 1,
The servo piston 3 will press against the bush 7. For this reason, the frictional force is enormous, abrasion powder is generated on the sliding parts, which further accelerates wear and induces galling, and there is a risk that the servo piston 3 will stop midway, and even steam There was a risk that the control valve would not close.

[Purpose of the invention]

An object of the present invention is to provide a steam control valve servo motor that solves the problem of the steam control valve being unable to open and close due to abrasion powder generated by sliding due to the opening and closing operations of the servo piston remaining on the sliding part. There is something to do.

[Summary of the Invention] The key point of the present invention is that a spiral groove is provided in the bushing to discharge wear powder to the outside of the sliding part, thereby preventing the wear powder from remaining in the sliding part.

[Embodiments of the invention]

By using the bushing 10 with a spiral groove shown in FIG. 1 of the present invention, wear particles generated on the sliding part are collected in the spiral groove 11, and further, the leakage pressure of the control oil causes the sliding part to be removed. It is discharged outside. This way, the abrasion particles generated on the sliding parts will no longer promote wear, so the steam control valve servo motor can always ensure smooth operation.
Normal motion transmission can be obtained, and the effect is great.

〔Effect of the invention〕

According to the present invention, the abrasion powder generated on the sliding part during the opening/closing operation of the servo piston does not remain on the sliding part, and the particles are removed.
1 steam control valve surfo motor can always ensure smooth operation.

[Brief explanation of the drawing]

FIG. 1 is a detailed view of the bushing of the present invention, FIGS. 2 and 3 are detailed views of the steam control valve servomorph, and FIG. 4 is a detailed view of the spring housing and bushing portion. lO...Spiral grooved bushing, 11...Spiral groove. Agent Patent Attorney Akio Takahashi Figure 1 (+2) /n (υ) Figure 2 Day 3

Claims (1)

[Claims] 1. A steam control valve used in a steam turbine includes a servo motor for opening and closing the steam control valve, a servo casing for holding oil pressure, a servo piston installed inside the servo casing, and a coil spring. a spring housing that vertically guides the servo piston to move it up and down, a restoring arm for stopping the servo piston at a certain level, an arm guide for guiding the restoring arm, and a valve. A steam control valve comprising a bushing having a spiral groove that adjusts the gap between the servo piston and the spring housing and discharges generated abrasion powder to the outside of the sliding part during opening and closing operations.