JP2005248937A - Rotor for prime mover - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor for a prime mover in which heat generated at a power source or a clutch drum is effectively radiated outward of an engine to achieve compactness, light weight, and low cost of a rotor and a rotor cover. <P>SOLUTION: As illustrated, a proper number of through holes 31 are disposed close to a rotation center of the rotor 11 for cooling air to pass from the opposite side of a fin, that is the clutch drum side in a bush cutter. High heat generated from the clutch drum is also effectively radiated outward through the fin with the cooling air in the prime mover. Since cooling air can be taken in from two directions, no serious failure due to heat occurs even when one air intake part is clogged with bush or the like as in conventional devices. By employing resin for a clutch cover, compactness, light weight, and low vibration can be achieved, thereby a work machine with less burden on an operator can be realized. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a shape of a rotor for a prime mover that effectively discharges heat generated by a power source and a clutch drum to the outside of the engine machine, thereby enabling reduction in size, weight, and cost of the rotor and rotor cover.

  In a conventional rotor for a prime mover, external air is taken into the rotor cover by a plurality of fins arranged on the outer periphery of the rotor as the prime mover is rotated, and is used for cooling the heat generated by the power source. The air intake was only on the fin side near the rotation center of the rotor.

  In air-cooled prime movers, it is essential to secure efficient cooling air. In a prime mover used for a portable work machine, miniaturization and weight reduction are important design issues. In order to reduce the weight of recent brush cutters, long-time heavy loads such as nylon rotors are increasing with a small power source.

  In the conventional method, it is difficult for high-temperature generated heat from the clutch drum to be discharged outside the machine. Further, in the brushing work using a nylon rotor, there is a defect that grass and dust are sucked into the cooling air intake part together with the air and become clogged.

  Countermeasures against heat generated from the clutch drum were made of heat-resistant metal, which increased the weight of the rotor cover. In addition, the increase in weight has the disadvantage of increasing the weight of the entire work machine.

Means to solve the problem

  The present invention is intended to solve such a problem, and is provided with a through hole for ventilating the fin side of the rotor near the rotation center of the rotor and the opposite side, that is, the back side. By the above method, the brush cutter can take in cooling air from the drum side of the centrifugal clutch.

The invention's effect

As described above, since the rotor of the present invention can effectively discharge the heat generated from the drum of the centrifugal clutch to the outside of the machine, no special measures are required for the clutch cover.
Therefore, a small, lightweight, low-cost resin clutch cover can be used to reduce the size and weight of the prime mover as a whole. Lighter and smaller size such as hammering machine is realized.

  Furthermore, since the operator's fatigue and burden at the time of carrying, carrying and carrying these work machines can be reduced, there is an effect that comfortable work can be performed.

  In addition, since cooling air can be taken in from two directions, even when grass or the like, which was a conventional defect in a brush cutter, is clogged in the air intake part on the fin side, it passes through the through hole from the centrifugal clutch side. The effect which can be taken in is also acquired.

  A heavy and expensive rotor cover such as a magnesium alloy is also unnecessary. Even when a high horsepower motor is used, it is possible to use a rotor cover made of a synthetic resin that can be processed at low cost and can be reduced in weight.

  Furthermore, since the conventional heat countermeasure technology can be used in combination, a more effective heat countermeasure can be achieved. In adopting the method of the present invention, it is possible to produce an inexpensive product without requiring any special technique or material.

    Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2.

  In FIG. 1, 11 is a rotor main body of the present invention, 21 is a fin thereof, 31 is a through hole thereof, and 41 is a clutch shoe mounting portion.

  The operation of the above configuration will be described below. The rotation from the prime mover starts to rotate by acting with the rotor 11 fixed to the shaft, and the cooling air flows from the rotation center portion on the fin side toward the outer periphery of the rotor due to the increase in engine rotation. At the same time, it flows from the back side of the rotor through the through hole 31 toward the outer periphery of the rotor.

  For the above reasons, the cooling air taken into the rotor fins can be secured from two directions. At the same time, the heat of the centrifugal clutch shoe and clutch drum attached to the back side surface of the rotor is effectively exhausted.

The front view and AA sectional drawing of the rotor which show embodiment of this invention Sectional drawing which shows the direction through which the cooling air of the conventional rotor flows

Explanation of symbols

11, the rotor 21 of the present invention, the fin 31 thereof, the through hole 41 thereof, the clutch shoe mounting portion 1, 2 thereof, the conventional rotor and its fin

Claims (1)

  A rotor for a prime mover, characterized in that an appropriate number of through holes for taking air from the opposite side of the rotor fin to the fin side are arranged near the center of rotation.

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