240 to the sliding-bearings 223 are formed in the rotor-housing 225a so as to supply the oil to the sliding bearings 223 as a lubricant. The oil is supplied to the oil receiver by flying; that is, when the supporting plates 232, 236 rotate, the oil around the supporting plates 232, 236 is flung upward by centrifugal force and flows into the oil receiver 240. The oil supplied to the sliding-bearings 223 is also used for the lubrication of oil seals 242 fit to the outer faces of the shafts 221. The oil returns to the side-housing 226a through the passage 241c.
A pair of the shafts 221 project into the side-housing 226b as shown of the right side in FIG. 5, and meshing gears 245 are fixed tothe ends of the shafts 221, as a result of which the two rotors 221 rotate simultaneously. In the bottom of the side-housing 226b is an oil sump 238' similar to that in the side-housing 226a. The lower part of the lower gear 245 is submerged in the oil within the sump 238'. The oil flung by the gear 245 lubricates the sliding bearings 223' and the oil seals 242'.
For the purpose of preventing a jolt in the thrust direction of the ball bearing 233, it has been proposed to use a double angular ball bearing, however the system has a mechanical loss and is noisy. The sliding bearings 223 and 223' in FIG. 5 support loads only in the radial direction. Additionally, the oil-supplied by flying is