JPH1130293A - Flywheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce moment of inertia at the time of starting and to increase moment of inertia at a steady driving mode. SOLUTION: Ribs 12 are arranged radially toward a centrifugal direction from a boss part 10 provided at a center of the flywheel 1. Movable weight 15 which is slidable in a rib longitudinal direction, and a spring 14 which pushs the movable weight 15 against the boss part 10 side are mounted to each of the rib 12. The weight 15 is displaced in a direction in which moment of inertia becomes large against the spring 14 by a centrifugal force acting on the weight 15 itself as a speed of a rotating machine increases.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flywheel used for a rotating machine such as an engine generator.
In particular, the present invention relates to a mechanism for changing the moment of inertia of a flywheel.

[0002]

2. Description of the Related Art An engine generator is often used as an emergency standby power supply, and requires a quick start. On the other hand, in an engine that drives a generator, rotational pulsation is inevitable, and the tendency is particularly strong for an engine with a small number of cylinders. In order to smooth this rotational pulsation, a flywheel having a large moment of inertia is attached to the rotating shaft of the engine.

In general, the flywheel of an engine generator has a constant shape, and its moment of inertia is always constant from start to steady operation. If the moment of inertia of the flywheel is constant as described above, increasing the moment of inertia to increase the smoothing effect of the pulsation increases the burden of starting and hinders the realization of rapid starting. If an attempt is made to reduce the moment of inertia of the flywheel in order to meet the demand for quick starting, the smoothing effect of pulsation during steady operation is reduced, and it has been difficult to satisfy both requirements.

As a flywheel of a conventional rotary machine, there has been proposed a technique of changing the moment of inertia of a flywheel for a motor or the like as disclosed in Japanese Patent Application Laid-Open No. 8-154357. In this conventional example, for example, a rotation center portion (boss portion) of a flywheel and an outer peripheral inertia portion (outer frame) are connected via an elastic arm (rib), and the arm flexes and rotates as the rotation speed increases. Distance from center to outer inertia (flywheel radius) r
As a result, at the time of starting, the inertia moment is large and the inertia moment is intended to decrease as the rotation speed increases (the control responsiveness is increased when the speed control width of the motor is large). Etc.) The moment of inertia I is expressed as the product of the square of the radius r of the flywheel and the mass M (I = MR ² ).

This flywheel technology is designed to minimize the moment of inertia required by the engine generator (ie, reduce the inertia moment of the flywheel as much as possible to reduce the load and start quickly when the generator is started, and to smooth the engine pulsation during steady operation. In order to enhance the effect, the inertia moment control is performed in reverse to the requirement of increasing the moment of inertia), and the requirements of the starting characteristics of the engine generator and the pulsation smoothing of the steady operation cannot be satisfied.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an unprecedented inertia capable of reducing the load at the start of a rotating machine such as an engine generator and improving the smoothing effect of the engine pulsation during a steady operation. The object is to realize a moment variable mechanism.

[0007]

Means for Solving the Problems The present invention basically comprises:
It is configured as follows.

That is, in a flywheel used for a rotating machine, ribs are radially arranged in a centrifugal direction from a boss provided at the center of the flywheel, and these ribs are slidable in the longitudinal direction of the rib. A movable weight and a biasing unit (for example, a spring) for pressing the movable weight against the boss portion are mounted.

According to the above configuration, the centrifugal force acting on the movable weight (secondary moment of rotation) is small in the low-speed state of the rotating machine at the time of starting, so that the movable weight is made to flywheel by the force of the urging means opposing the centrifugal force. Of the boss. Since the moment of inertia I of the movable weight is represented by the product of the square of the distance r from the center of rotation of the flywheel (the center of the boss) to the movable weight and the mass M of the movable weight (I = M · r ² ), Since the distance r at the time of starting is small, the moment of inertia is also small. Therefore, the load at the time of starting can be reduced, and the torque generated by the rotating machine (for example, the engine generator) can be used more for acceleration, and the steady-state rotation speed can be reached in a short time to meet the demand for quick starting.

Further, as the rotating machine moves toward the steady operation speed (as the rotation speed increases), the centrifugal force acting on the movable weight itself increases, and the movable weight gradually displaces in the outer circumferential direction of the flywheel, and the inertial moment element Becomes large, and the distance r becomes maximum at the steady operation speed. As a result, the moment of inertia can be maximized at a steady operation speed, whereby pulsating rotation of the rotating machine can be suppressed, and stable rotation can be ensured.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram illustrating an engine generator as a rotating machine to which the present invention is applied. FIGS. 2 and 3 are flywheels according to a first embodiment of the present invention applied to the engine generator. FIG. 4 is a front view showing a use state of the wheel.

As shown in FIG. 1, the engine generator includes an engine unit 2 and a generator unit 3. The engine unit 2 and the generator unit 3 are directly connected by a coupling 4,
The flywheel 1 is mounted on the shaft 5.

FIG. 2 shows the state of the flywheel 1 when the engine is started. The flywheel 1 has a boss 1 fitted and fixed at its center to a shaft 5 of an engine generator.
0 are formed, and a plurality of (here, eight as an example) ribs 12 are radially extended from the boss portion 10, and the boss portion 10 and an outer frame portion (outer ring) of the flywheel 1 are extended through these ribs 12. 11) are connected. The outer frame portion 11 becomes a part of the weight (fixed weight portion) so as to form a concentric circle with the boss portion 10 outside the boss portion 10.

A movable weight 15 is mounted on each rib 12 so as to be slidable on the rib 12, and a coil spring 14 is interposed between the movable weight 15 and the outer frame portion 11. The movable weight 15 is always moved to the center of the flywheel (the boss 1) by the spring pressure of the coil spring 14.
It is pressed (biased) in the 0) direction. Reference numeral 13 denotes a spring receiver provided inside the outer frame portion 11.

The movable weights 15 are set to have substantially the same shape and the same weight, are symmetrically arranged around the axis 5, and all the springs 14 are of the same strength so that they can be balanced. It is. Further, in this example, the movable weight 15 is formed in a tapered shape, so that even if the movable weight 15 is concentrated at a position near the boss portion 10 as shown in FIG.
Care has been taken to ensure that The number of the ribs 12 is not limited to the above-mentioned number, and may be appropriately set (for example, four or six), and the interval between the adjacent movable weights 15 may have a sufficient margin. If it can be kept, the movable weight 15 may have a straight cylindrical shape.

As shown in FIG. 2, when the engine is started, the centrifugal force acting on the movable weight 15 when the generator is at a low speed is small. In this case, the movable weight 15 is It is located closest to 10.

The moment of inertia I of the movable weight 15 is
As described above, the relationship between the distance r from the center of rotation of the flywheel (the center of the boss 10) to the movable weight 15 and the mass M of the movable weight 15 is represented by I = M · r ² . Since the moment of inertia (secondary moment of rotation) is small, more torque generated by the engine can be used for acceleration, and a steady rotational speed is reached in a short time.

As the rotational speed of the engine 2 (generator 3) increases, the centrifugal force acting on the movable weight 15 increases, and the weight 15 gradually displaces in the outer circumferential direction while compressing the spring 14.

When the rotation speed of the engine reaches a steady speed, as shown in FIG.
Is displaced to a position where maximum compression is performed, and is held at this position.
The moment of inertia of the flywheel 1 is maximized, and the effect of smoothing the rotational pulsation of the engine 2 is increased.

When the operation of the engine 2 is stopped, the weight 15 is returned to the center by the spring 14 and returns to the state shown in FIG. 1 to prepare for the next start.

In the configuration shown in FIG. 3, during centrifugal operation, all the centrifugal force acting on the movable weight 15 is received by the spring 14, but when the spring 14 is likely to buckle,
A stopper 16 is provided on the rib 12 as shown in FIG.
When the movable weight 15 is displaced outward to the maximum position in the centrifugal direction, the movable weight 15 may be received by the stopper 16. In this example, a sleeve-shaped stopper is used as the stopper 16, and the sleeve 16 is fitted and fixed to one end of the rib 12 near the outer frame 11, and the outer diameter of the sleeve is made larger than the inner diameter of the movable weight 15. Thus, the movable weight 15 is received.

According to such a sleeve-shaped stopper 16, the mounting to the rib 12 is easy, and the rib 12
There is no need to process itself for forming the stopper, and there is an advantage that the force received in the thrust direction on the rib 12 is strong and the centrifugal force of the movable weight 15 can be sufficiently received with a simple structure. Note that the stopper 16 is not limited to the above-described shape, and may be configured by forming a step or a protrusion on the rib 12.

FIG. 4 shows a state in which the movable weight 15 is displaced to the maximum outer position in the centrifugal direction during a steady operation, according to the second embodiment. It is returned to the same position as in FIG.

FIG. 5 shows a flywheel according to a third embodiment of the present invention, and shows a state when the engine of the generator is started or stopped. The present embodiment is different from the first and second embodiments in the shape of the outer frame portion 11 ′. In this example, the outer frame portion 11 ′ is plural and arranged for each rib 12.
Further, the outer frame portions 11 'are arranged in a circular arc on the same circular locus.

[0026]

As described above, according to the present invention, it is possible to reduce the load at the time of starting a rotating machine such as an engine generator and to enhance the smoothing effect of the engine pulsation during a steady operation. To realize a moment variable mechanism.

[Brief description of the drawings]

FIG. 1 is a schematic diagram when a flywheel is attached to an engine generator to which the present invention is applied.

FIG. 2 is a flywheel according to a first embodiment of the present invention,
State explanatory drawing at the time of engine starting.

FIG. 3 is a flywheel according to the first embodiment of the present invention,
State explanatory drawing at the time of engine steady operation.

FIG. 4 is a flywheel according to a second embodiment of the present invention;
State explanatory drawing at the time of engine steady operation.

FIG. 5 is a flywheel according to the first embodiment of the present invention;
State explanatory drawing at the time of engine starting.

[Explanation of symbols]

1: Flywheel, 2: Engine part, 3: Generator part,
5 ... shaft, 10 ... boss, 11 ... outer frame part (outer ring part), 12 ...
Ribs, 14: springs (biasing means), 15: movable weights.

Claims (4)

[Claims] In a flywheel used for a rotating machine, ribs are radially arranged in a centrifugal direction from a boss provided at the center of the flywheel.
A flywheel comprising: a movable weight slidable in a longitudinal direction of a rib; and a biasing means for pressing the movable weight against the boss. 2. A flywheel used in a rotating machine, wherein a boss portion fitted and fixed to a shaft of the rotating machine, an outer frame disposed outside the boss portion and serving as a part of a weight, and the boss portion is provided. And a plurality of ribs for coupling the outer frame,
A movable weight mounted on the rib so as to be slidable in the longitudinal direction of the rib, and biasing means for pressing the movable weight against the boss portion, wherein the movable weight is attached to itself according to an increase in the speed of the rotating machine. A flywheel, wherein the flywheel is set so as to be displaced in a direction in which the moment of inertia increases against the urging means by an applied centrifugal force. 3. The outer frame has a ring shape or an arc shape in which a plurality of arcs are arranged on the same circular locus, and the urging means is a spring, and the spring is interposed between the outer frame and the movable weight. 3. The flywheel according to claim 2, wherein the flywheel is fitted to the rib in such a manner. 4. The rotating machine is an engine generator, such that the movable weight can be displaced to the outermost of a sliding range on the rib by centrifugal force acting on the movable weight when the generator rotates at a steady speed. The flywheel according to claim 1, wherein the strength of the spring is set.