JPS6246028Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an improvement of a rotary exciter.

Rotating machinery connected by shafts constitutes a vibration system and has a unique frequency of vibration. On the other hand, since it is very difficult to completely align the center of gravity of the rotating shaft with the axial center, forced torsional vibration is often caused by applying periodically varying torque to a part of the vibration system. Therefore, depending on the usage conditions, the period of natural torsional vibration and the period of forced torsional vibration in the vibration system may match, and in this case, resonance may occur and a situation that cannot withstand use may occur. .

In a rotating machine, an inertial mass (a rotor with a large moment of inertia: usually called a flywheel) is added to reduce rotational fluctuations in the rotating shaft system, but when used with varying rotational speed,
The torsional natural frequency composed of the rotating shaft, the additional mass, the rotating electric machine, etc. tends to resonate with the forced frequency. For example, in a rotating machine, rotational fluctuations are generally larger at lower rotational speeds, so an inertial mass is added to keep the rotation constant, and at high speeds there is less fluctuation, so removing the inertial mass changes the natural torsional vibration and causes forced torsional vibration. It is necessary to suppress resonance by avoiding coincidence with Furthermore, since rotating something with a large inertial mass at high speed always puts a burden on bearing load capacity, it is advantageous to separate the inertial mass in a high-speed range. This is also necessary in order to increase the stability of rotary shafts with eccentric masses connected to rotating electrical machines, such as exciters. In other words, the vibration exciter generally has an excitation frequency of 1 to 30 Hz, that is, a forced torsional vibration frequency, and when connected to a rotating electric machine, its natural torsional vibration is as low as a few Hz for the first order and 30 Hz for the second order. Often close to. For this reason, rotational fluctuations may increase. Therefore,
When the speed is low, an inertial mass is added to lower the natural torsional frequency to, for example, 1Hz or less, and when it approaches 30Hz, the inertial mass is separated and the natural torsional frequency is reduced to, for example, 30Hz.
It is necessary to eliminate the natural torsional frequency within the usage range, that is, the forced torsional frequency range, at 30 Hz or higher. In this way, in a high-speed rotation range, it is desirable to remove the inertial mass to avoid coincidence between the natural torsional frequency and the forced torsional frequency, thereby preventing resonance and reducing the load on the bearing.

An object of the present invention is to provide a rotary vibration exciter that can automatically change the added mass according to the rotational speed of the rotating shaft system.

The structure of the present invention to achieve such an object includes an inertial mass rotatably supported on the same axis as the rotating shaft to which the eccentric weight is attached, and an inertial mass attached to one end of the rotating shaft and facing the inertial mass. a connecting member that is pivotally supported by the disk and swings in the radial direction of the disk due to centrifugal force; and a connecting member that is pressed in a centripetal direction to integrally connect the inertial mass and the disk. It is characterized by comprising a connecting spring and a brake that stops the inertial mass separated from the disk.

The configuration of the present invention will be explained in detail below based on a specific example shown in the drawings.

The rotating shaft 2 is rotatably supported by the frame 1 via bearings 4 and 5. An eccentric weight 3 is attached to the rotating shaft 2, and a flanged disk 6 is fixed to the shaft end. On the other hand, the inertial mass 7 is rotatably attached to a fixed shaft 14 fixed to the frame 1 via bearings 8 and 9. Alternatively, the fixed shaft 14 may be supported by the rotating shaft 2 without separately installing the fixed shaft 14. The inertial mass 7 and the disk 6 are integrally connected via a connecting member 10, usually by friction. In other words, the connecting member 10 is swingably attached to the disk by the pin 12, while the connecting member 10 is attached to the disk by the pin 12, while
It is pressed in the centripetal direction, that is, toward the inertial mass 7, by a spring 11 interposed between the flange and the flange. Therefore, when the rotating shaft 2 is not rotating and until it reaches a predetermined rotation range, the inertial mass 7
is attached to the rotating shaft 2 via a connecting member 10, but when the rotation speed exceeds a predetermined number, the connecting member 10 expands in the centrifugal direction while compressing the spring 11 due to centrifugal force, so that the two are separated. The inertial mass 7 is
Once separated from the rotating shaft 2, the electromagnetic brake 13 stops the rotation. The brake operation is performed after the operator confirms that the inertial mass 7 and the rotating shaft 2 have been separated. Alternatively, the brake 13 may be actuated by detecting the movement of the connecting member 10 using an electric contact (not shown) or the like.

In the case of this embodiment, an annular flange is formed on the disk 6 to serve as a spring receiver, but only the spring receiver portion may be formed protruding from the disk 6. Further, by adjusting the strength of the spring 11, the rotational speed for separating the inertial mass can be freely set.

As described above, the present invention connects the rotating shaft and the inertial mass using a connecting member that expands in the centrifugal direction against the spring force acting in the centripetal direction due to the centrifugal force accompanying the rotation of the rotating shaft. When the rotation is exceeded, the inertial mass is automatically separated from the rotating shaft.
Furthermore, the inertial mass separation rotation speed can be freely set by adjusting the spring force.

[Brief explanation of the drawing]

FIG. 1 is a central vertical sectional view of the rotary vibration exciter of the present invention, and FIG. 2 is a sectional view taken along the line A--A in FIG. In the drawings, 1 is a frame, 2 is a rotating shaft, 3 is an eccentric weight, 6 is a disc, 7 is an inertial mass, 10 is a connecting member, 11 is a spring, and 14 is a fixed shaft.

Claims (1)

[Scope of utility model registration request] an inertial mass that is rotatably supported on the same axis as the rotating shaft to which the eccentric weight is attached; a disc that is attached to one end of the rotating shaft and faces the inertial mass; a connecting member that swings in the radial direction of the disk due to centrifugal force; a spring that presses the connecting member in a centripetal direction to integrally connect the inertial mass and the disk; and a spring that is separated from the disk. A rotary vibration exciter comprising a brake for stopping the inertial mass.