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US H749 HGranted
Oil seal
AssigneeKioritz Corporation
InventorAkira Nagashima
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AssigneeKioritz Corporation
InventorAkira Nagashima
Estimating the term…
An oil seal disposed between a device having a rotary shaft and the rotary shaft. The oil seal comprises an annular supporting member supported within the fixed structure of the device and an annular elastic sealing member disposed in contact with the outer peripheral surface of the rotary shaft in such a manner as to allow relative sliding rotation therebetween. The annular supporting member has a peripheral supporting portion with a cup-shaped section taken along a plane including the axis of the rotary shaft, and the cup-shaped section opens to the outside of the device in the axial direction thereof. The annular elastic sealing member is fixed to an annular, radially-inwardly projecting portion of the annular supporting member.
An oil seal disposed in a device which includes a rotary shaft and a fixed structure thereabout, said oil seal comprising:
Dependencies are inferred from the claim text.
From the US filing history. Foreign family members aren’t listed.
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USPTO file history isn’t available for this patent, so only indexed dates are shown.
1. FIELD OF THE INVENTION
The present invention relates to an oil seal, and more particularly to an oil seal which is suitable for sealing the gaps between a crankcase and a crankshaft of a crankcase pre-compression type two-cycle internal combustion engine.
2. DESCRIPTION OF THE PRIOR ART
The single drawing is a cutaway sectional view through essential parts of a crankcase pre-compression type internal combustion engine of a chain saw, to which an oil seal in accordance with an embodiment of the present invention is applied.
The present invention will be described with respect to an embodiment thereof illustrated in the single drawing.
In the illustrated embodiment, the present invention is applied to, for example, a crankcase pre-compression type two-cycle internal combustion engine of a chain saw. An oil seal 1 in accordance with the present invention is provided for the purpose of sealing the gaps between a crankcase 2 and a crankshaft 3 of the two-cycle internal combustion engine. The crankcase 2 has a stepped opening 4 formed at one end thereof in such a manner as to open in the axial direction. The opening 4 in turn has a smaller-diameter opening portion 6 in which a rolling bearing 5 such as a ball bearing is disposed, and a larger-diameter opening portion 7 which is formed on the axially outer side of the smaller-diameter opening portion 6 in a concentrical manner, and in which the oil seal 1 is disposed. The crankshaft 3 is rotatably supported by the bearing 5 and extends from the opening 4 to the outside of the crankcase 2. A fixed part 8 including an oil pump device is disposed around the portion of the crankshaft 3 that extends from the crankcase 2 to the outside thereof in juxtaposition with the end of the crankcase 2 in which the opening 4 is formed.
The oil seal 1 has an annular supporting member 9 formed of a material such as metal, and an annular elastic sealing member 10 supported by the supporting member 9 and formed of an elastic material such as rubber.