Governor Balance Weights

Balance weight relates to an internal combustion engine, and more specifically to an engine equipped with a mechanical governor for holding an engine revolution speed at a predetermined value though an engine load varies as well as a decompression device for decreasing a starting torque at the time of starting operation of the engine. 
A valve actuating camshaft and a governor weights are arranged in parallel with a crankshaft. The valve actuating camshaft is interlockingly connected to the crankshaft through a valve actuating cam gear, and the governor shaft is interlockingly connected to the crankshaft through a governor weight. A centrifugal balance weight of the decompression device is supported by one of the opposite side surfaces of the valve actuating cam gear so as to be swingable in the centrifugal direction. A governor weight or balance weight of a mechanical governor is supported by the governor shaft. 
When the mechanical governor weight and the decompression device are installed to the engine, it is necessary to arrange two shafts of the governor weight and the valve actuating camshaft. Therefore, the engine can't help becoming large in overall dimension.

On one hand, in the case that the engine is intended to be made smaller in overall dimension in the above-mentioned construction of the prior art, it is necessary to make both the centrifugal balance weight of the decompression device and the governor weight smaller in size in order to avoid an interference therebetween. Thereupon, the decompression device provides a small centrifugal force for cancellation of the decompression and the decompression capability thereof can't help becoming small correspondingly. Also the mechanical governor weight provides a small governor force and the governor capability thereof is lowered. 
It is an object of the present product to make an overall compactness of an engine compatible with the securement of a decompression capability and a governor weight capability. 
For accomplishing the above-mentioned object, the present product is constructed as follows. 
A centrifugal balance weight of a decompression device is supported by a first side surface, which first side surface faces a valve actuating cam, of opposite side surfaces of a valve actuating cam gear in a swingable manner in the centrifugal direction. A governor weight of a mechanical governor is supported by a second side surface, which second side surface is opposed to the first side surface, of the opposite side surfaces of the gear. A centrifugal force transmission member of the governor weight is supported by a valve actuating camshaft outside the second side surface of the valve actuating cam gear. 
Since the present balance weight is constructed as mentioned above, the following advantages can be provided.

Since, in addition to the centrifugal balance weight of the decompression device, also the governor weight of the mechanical governor is supported by the valve actuating cam gear, the governor weight shaft and the governor gear employed in the conventional construction can be omitted. Therefore, the engine can be made small, and the construction thereof can be simplified.

Further, since the balance weight and the governor weight are disposed on the opposite sides of the cam gear respectively, an interference between both swinging orbits thereof can be prevented. Therefore, governor weight and balance weights can be made large in size. Accordingly, since the decompression device can be equipped with a strong decompression spring by enlarging the decompression cancellation centrifugal force of the centrifugal weight in that way, a sufficient decompression capability can be surely provided. At the same time, since the mechanical governor can exert a strong governor force by enlarging the centrifugal force of the governor weight in that way, the governor weight capability can be kept in a good condition. 
Resultantly, it becomes possible to make the compaction of the engine in overall dimension compatible with the securement of the decompression capability and governor weight or balance weight capability.

Please leave your information to get the latest quotation and product catalogue!