Sealed bearings lubricated by a lubricating medium

Claim 1

An electric motor comprising a machine housing having a wall with an opening defining a bearing space, a rotor shaft revolvably traversing said wall opening and space, an antifriction bearing device seated in said space and journaling said shaft, closure means coaxially surrounding said shaft and having elastically deformable glide-ring seals for tightly closing said space on opposite sides of said bearing device, oilair injection means and lubricant drainage duct means communicating from the outside with said bearing space for circulating pressure lubricant through said bearing device, the combination of a cover rigidly mounted on said Machine housing on the inner side thereof and coaxially surrounding said shaft for closing said space and said bearing device from the machine interior, said cover and said shaft forming an annular air gap between each other, an air gap labyrinth serving to dissipate pressure of pressure lubricant entering therein from said bearing space, said labyrinth having fixed parts mounted on said cover and parts fastened to said shaft to revolve together therewith, said respective parts straddling each other and thereby extending the effective length of said air gap, and a glide-ring seal coaxially surrounding and seated on said shaft and having at least one part having at least one surface communicating with said gap and another surface contacting said cover to seal said gap, whereby the remaining pressure of the lubricant in said labyrinth maintains said part against said cover at a minimal pressure.