Electrically operated valve actuator with electro-mechanical end stop detection device

Patent metadata

Field	Value
Publication number	US-9482359-B2
Application number	US-201013391138-A
Country	US
Kind code	B2
Filing date	Aug 18, 2010
Priority date	Aug 20, 2009
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

Abstract

An electrically operated valve actuator effective for shifting a valve ( 10 ) between open and closed positions is disclosed, the valve actuator comprising a movable member in the form of a valve stem ( 21 ) connected to a valve body ( 14 ), the movable member being driven by an electric motor ( 22 ) in linear motion between valve closing and valve opening positions, wherein electrical power to the motor is supplied via a current ( 25 ) control including a supplied current detection device. The movable member is designed for an idling length of travel (L) in the opening and closing directions during which the valve ( 10 ) is either fully open or fully closed, and the movable member is associated with buffer means ( 30 ) that during the idling length of travel gradually increases the torque and power required to move the movable member further in the open and closed positions of the valve ( 10 ), respectively.

First claim

The invention claimed is:

1. An electrically operated valve actuator effective for shifting a valve between open and closed positions, the valve actuator comprising:
a movable member comprising a valve stem connected to a valve body, a first end surface, a second end surface, and a side surface extending between the first end surface and the second end surface, the movable member being driven by an electric motor in a linear motion between valve closing and valve opening positions, wherein
electrical power to the motor is supplied via a current control comprising a supplied current detection device;
the movable member, at each end of travel, is designed for an idling length of travel in the opening and closing directions during which the valve is either fully open or fully closed;
the movable member is associated with a buffer positioned so that, during the idling length of travel, the torque and current required to move the movable member further in the open and closed positions of the valve, respectively, gradually increases, wherein the movable member is contained between a first wall and an opposite second wall in a valve or actuator housing, and the buffer is supported in each end of the valve or actuator housing between the first and second end surfaces and first and second walls in the valve or actuator housing, respectively; and
the current detection device monitors an increase in supplied current during the idling length and stops the motor within a time window of the idling length.

2. The actuator of claim 1 , wherein the buffer comprises an elastic element.

3. The actuator of claim 2 , wherein the buffer comprises at least one disc spring.

4. The actuator of claim 3 , wherein the buffer comprises a set of disc springs, at least one of which has a flexibility which is different from the flexibility of at least one additional disc spring in the set of disc springs.

5. The actuator of claim 1 , wherein the buffer comprises an elastic element.

6. The actuator of claim 5 , wherein the buffer comprises at least one disc spring.

7. The actuator of claim 6 , wherein the buffer comprises a set of disc springs, at least one of which has a flexibility which is different from the flexibility of at least one additional disc spring in the set of disc springs.

8. The actuator of claim 1 , further comprising a position sensor.

9. The actuator of claim 8 , wherein the position sensor is arranged in the actuator housing.

10. The actuator of claim 8 , wherein the position sensor is an electrical transformer for measuring linear displacement.

11. The actuator of claim 8 , wherein the position sensor is configured to detect the valve body and/or valve stem position.

12. An electrically operated valve actuator effective for shifting a valve between open and closed positions and having fail-safe electro-mechanical end stop detection, the valve actuator comprising:
a movable member comprising a valve stem connected to a valve body, the valve stem having a first end with a first end surface, and operably coupled to a valve body of a valve, a second end with a second end surface, and operably coupled to a rotary-to-linear converter operably coupled to an electric motor, and a side surface extending between the first end surface and the second end surface, the valve stem positioned to be driven by the electric motor in a linear motion to drive the valve body between valve closing and valve opening positions;
a current control comprising a supplied current detection device to supply electrical power to the motor;
a first end detection buffer device positioned to be engaged at a first end of travel of the valve body so that during the linear motion when the valve body approaches a valve opening position limit, torque and current required to move the valve body gradually increases; and
a second end detection buffer device positioned to be engaged at a second end of travel of the valve body so that during the linear motion when the valve body approaches a valve closing position limit, the torque and the current required to move the valve body gradually increases;
wherein the valve body is contained between a first wall and a second wall in a valve or actuator housing, and wherein the first end detection buffer device is supported on a first end of the valve body between the first end surface of the valve body and the first wall of the valve or actuator housing, and the second buffer device is supported on a second end of the valve body between the second end surface of the valve body and the second wall of the valve or actuator housing; and
wherein the current detection device monitors a increase in supplied current during the idling length and stops the motor within a time window of the idling length.

13. The actuator of claim 12 , wherein the valve stem is contained between opposite walls in a valve or actuator housing, and wherein the first end detection buffer device is supported on a first of the opposite walls and the second and detection buffer device is supported on a second of the opposite walls.

14. The actuator of claim 12 , wherein the first and second end detection buffer devices each comprise an elastic element connected to one or more of the following: an inner portion of the opposite walls of the housing, and one of the ends of the valve body.

15. The actuator of claim 14 , wherein each elastic element comprises at least one disc spring.

16. The actuator of claim 14 , wherein each elastic element comprises a set of disc springs, at least one of which has a flexibility which is different from the flexibility of at least one additional disc spring in the set of disc springs.

17. An electrically operated valve actuator effective for shifting a valve in a valve or actuator housing between open and closed positions and having fail-safe electro-mechanical end stop detection, the valve actuator comprising:
a movable member comprising a valve stem connected to a valve body, the valve stem having a first end with a first end surface, and operably coupled to a valve body of a valve, a second end with a second end surface, and operably coupled to a rotary-to-linear converter operably coupled to an electric motor, and a side surface extending between the first end surface and the second end surface, the valve stem positioned to be driven by the electric motor in a linear motion to drive the valve body between valve closing and valve opening positions;
a current control comprising a supplied current detection device to supply electrical power to the motor;
a first end detection buffer device positioned between the first end surface of the valve body and the valve or actuator housing to be engaged at a first end of travel of the valve body so that during the linear motion when the valve body approaches a valve opening position limit, torque and current required to move the valve body gradually increases, the first end detection buffer device comprising a set of disc springs, at least one of which has a flexibility which, is different from the flexibility of at least one additional disc spring in the set of disc springs; and
a second end detection buffer device located at an opposite side of the valve body from the first end detection buffer device, and positioned between the second end surface of the valve body and the valve or actuator housing, to be engaged at a second end of travel of the valve body so that during the linear motion when the valve body approaches a valve closing position limit, the torque and the current required to move the valve body gradually increases, the second end dete

Assignees

• Borchgrevink Christian
• Flidh Jon
• Guimaraes Paula
• Flidh Christopher
• Vetco Gray Scandinavia As

Inventors

• Borchgrevink Christian
• Flidh Jon

Classifications

• F16K31/045

  with torque limiters · CPC title

• F16K31/0689

  Braking of the valve element · CPC title

• F16K31/047

  characterised by mechanical means between the motor and the valve, e.g. lost motion means reducing backlash, clutches, brakes or return means (F16K31/043 takes precedence) · CPC title

• F16K31/04 Primary

  using a motor · CPC title

• H01H35/06

  Switches operated by change of speed (operated by change of fluid flow H01H35/24) · CPC title