JPH0720061U - Structure of large capacity electric servo motor - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a structure of a large-capacity electric servomotor capable of increasing the capacity by strengthening the shock absorbing function. [Structure] The rotational force of the drive motor 1 is converted into a linear motion via a ball screw mechanism 3, and the ball screw mechanism 3
In a large-capacity electric servomotor in which a housing 10 for accommodating a housing is provided with a stopper 10 for restricting a moving end of a nut portion 3a which moves linearly, the stopper 10 is attached to the housing 4 by a shock absorbing bolt 11 in the linear movement direction. It is characterized by being tightened to.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a structure of a large-capacity electric servo motor (operating force of about 40 tons) used for operating guide vanes of hydroelectric power generation equipment.

[0002]

[Prior art]

 As an electric servomotor for operating a guide vane with an operating force of up to 20 tons, there is a structure as shown in FIG. In this, the rotational force of the drive motor 1 is reduced by the speed reducer 2, and the ball screw mechanism 3 converts the rotational force into a linear motion to open and close a guide vane (not shown).

By the way, when the control device fails, the electric servomotor is operated to the fully closed side in order to stop the water turbine. However, when a failure occurs, the nut portion 3a of the ball screw mechanism 3 collides with the stopper 5 attached to the housing 4 at a closing speed. A torque limiter 6 is interposed between the speed reducer 2 and the ball screw mechanism 3 for mitigating this collision.

The torque limiter 6 sandwiches the gear 6a from both sides with friction plates 6b, and transmits the force from the gear 6a to the shaft 6d integrated with the screw shaft portion 3b of the ball screw mechanism 3 by the pressing force of the spring 6c. When a rotational force greater than the pushing force of the spring 6c is applied, the rotational force is released by slipping between the gear 6a and the friction plate 6b.

[0005]

[Problems to be solved by the device]

 However, in the structure of the conventional electric servomotor described above, when the operating force is increased to about 40 tons, the collision force of the stopper 5 and the inertial force of the drive motor 1 increase accordingly. Although the inertial force is protected by the torque limiter, there is a risk that the stopper 5 and the like may be damaged due to a collision.

The present invention has been proposed to solve such a problem, and an object thereof is to provide a structure of a large-capacity electric servomotor capable of enhancing the shock absorbing function and increasing the capacity. .

[0007]

[Means for Solving the Problems]

 The structure of the large-capacity electric servomotor according to the present invention for solving the above-mentioned problems converts the rotational force of the drive motor into a linear motion, and the moving end of the linear motion part is mounted on the housing for accommodating the motion conversion mechanism. A large-capacity electric servomotor provided with a stopper for restricting is characterized in that the stopper is fastened to the housing in the direction of the linear movement with a shock absorbing bolt. Further, it is preferable to attach a torque limiter to the motion conversion mechanism.

[0008]

[Action]

 According to the above configuration, when the linear motion portion collides with the stopper, the shock is absorbed by the extension of the bolt. Further, when the torque limiter is provided, the inertial force of the drive motor is absorbed.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view of a large capacity electric servomotor according to a first embodiment of the present invention, and FIG. 2 is an operation state diagram thereof. In FIGS. 1 and 2, the same members as those in FIG. 4 are designated by the same reference numerals, and duplicated description will be omitted.

As shown in the figure, an outward flange portion 4a is integrally formed at the opening end of the cylindrical ball screw housing portion of the housing 4, and a flanged cylindrical stopper 10 is provided on the outward flange portion 4a. It is fastened and fixed with.

The bolt 11 is formed in a thin body, and when the nut portion 3 a of the ball screw mechanism 3 collides with the stopper 10, the bolt 11 extends by δ mm (within elastic deformation) as shown in FIG. It is designed to absorb shocks.

By the way, in hydraulic power plants, up to 20,000 kW, an oil servo has been implemented by using an electric servomotor. And, if the servo motor is doubled, it is possible up to 40,000 kW. However, in power plants larger than this, the operating force of the guide vanes is large and the closing speed is high, so the risk of failure is great and it is difficult to adopt.

However, by adopting the collision mitigation method of this embodiment, it is possible to increase the capacity of the electric servomotor. That is, when the nut portion 3a of the ball screw mechanism 3 collides with the stopper 10 at the time of failure of the control device, the impact is absorbed by the expansion of the bolt 11 described above, and the inertia force of the drive motor 1 is generated by the torque limiter 6. Since it is absorbed as before, the guide vanes can be closed while preventing damage to the servo motor.

FIG. 3 is a partially cutaway side view of a second embodiment of the large-capacity electric servomotor according to the present invention. Like the first embodiment, the same members as those in FIG. The explanation is omitted.

This is because the ring-shaped stopper 10 is fastened and fixed to the inward flange 4b integrally formed in the cylindrical ball screw housing of the housing 4 with the bolt 11, and the nut is actuated when the ball screw mechanism 3 operates on the contracted side. In this example, the portion 3a collides with the stopper 10. With this, the same effect as that of the first embodiment can be obtained.

[0016]

[Effect of device]

 As described above, according to the present invention, by adopting the shock absorbing bolt, the shock absorbing function is strengthened and the servo motor can have a large capacity.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment of a large capacity electric servomotor according to the present invention.

FIG. 2 is an operation state diagram of FIG.

FIG. 3 is a partially cutaway side view of a large capacity electric servomotor according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a conventional example.

[Explanation of symbols]

 1 Drive Motor 2 Reduction Gear 3 Ball Screw Mechanism 4 Housing 6 Torque Limiter 10 Stopper 11 Bolt

Claims (2)

[Scope of utility model registration request] 1. A large-capacity electric servomotor in which a rotational force of a drive motor is converted into a linear motion and a stopper for restricting a moving end of a linear motion portion is provided in a housing accommodating the motion conversion mechanism. Is a structure for a large-capacity electric servomotor, wherein the housing is fastened to the housing with a shock absorbing bolt in the linear movement direction. 2. The structure of the large capacity electric servomotor according to claim 1, wherein a torque limiter is attached to the motion conversion mechanism.