Abstract: The invention is a passenger compartment heating system for a bus heating system having a closed circuit through which there flows a heat transfer medium. A heat exchanger which is fed on the primary side by a heat-generating unit is used as heat-absorbing part. The inlet temperature and the heat transfer medium are matched to one another in such a way that there is a two-phase liquid/vapor mixture in the passenger heaters, which are arranged in series. The heat exchanger is designed as a capillary block or as a capillary-active porous wall into which the heat is fed on the primary side. The porous wall furthermore divides the vapor-only side from the liquid-only side of the closed circuit of the passenger compartment heating system and, in this region, has virtually only capillary-active channels.

Abstract: An engine unit adapted to be lubricated by a liquid lubricant with a lubricant reservoir as well as a lubricant cooling. The cooling takes place by way of at least one heat pipe, with the heat pipe having a heat absorbing portion adapted to be exposed to the lubricant and a heat transmitting portion adapted to be exposed to surrounding air. The engine unit may be an internal combustion engine, a gear system such as a change-speed transmission or differential transmission of a vehicle drive axle.

Abstract: A transverse guide roller arrangement for a vehicle which can be guided mechanically along a guide track or the like provided on the side of a lane. The transverse guide roller arrangement includes at least one rolling surface which is approximately vertical when the guide roller is in an operating position. The rolling surface is formed by a rubber tire mounted on a rim having a hub rotatably supported on a fixed journal attached to an end of a supporting arm or the like. The hub forms radially, without transistion on an outside thereof the rim without a wheel disk, spokes, screw on flange, or the like. The hub and rim are combined structurally into one piece, with the journal being exchangeably attached to the supporting arm.