Motor/pump unit having a single elastic diaphragm

A motor/pump unit for supplying pressure to a pneumatic brake booster, wherein:

• the motor/pump unit is constructed as a diaphragm pump having a single elastomer diaphragm, and
• the diaphragm is moved by an electrically operated motor unit by an eccentric drive,
• the motor/pump unit comprising a pump housing and an operating space cover and the diaphragm is clamped at a radial outer edge thereof between the pump housing and the operating space cover in a sealing manner so that between the diaphragm and the operating space cover an operating space with a variable volume is constructed,
• the operating space cover is constructed in several parts with an upper cover and a lower cover and an inlet valve and outlet valve which are arranged between the upper cover and the lower cover and which control the air circulation through the operating space,
• wherein a sound-damping unit for the noise-reducing discharge of the air from the operating space into the atmosphere is provided, the sound-damping unit arranged on the operating space cover, the sound-damping unit having a filter element of a porous material and a non-return valve, the non-return valve arranged in the air flow direction between the filter element and the atmosphere, the non-return valve clamped in the sound-damping unit between the filter element and a wall with an air outlet opening.