BRUSH AND BRUSH HOUSING ARRANGEMENT TO MITIGATE HYDRODYNAMIC BRUSH LIFT IN FLUID-IMMERSED ELECTRIC MOTORS

A direct current electric motor brush and brush housing arrangement, comprising means to significantly reduce the effect of brush lift in a brushed motor containing viscous fluid. The means enable viscous fluid to avoid momentum transfer into the brushes by providing two or more pressure relief channels that provide the fluid with direct means of radial exit along the direction of the brush, potentially reducing the brush lift due to the fluid being forced between a rotating commutator and its associated brushes. The pressure relief channels may be located in the housing immediately adjacent to the brush, being radially disposed to the leading face (or leading and trailing faces) of each brush, or in the leading face (or leading and trailing faces) of each brush itself, and may comprise additional channels in the housing near but not immediately adjacent the brushes.