PURPOSE: To eliminate uneven stay of freezer oil when the pump stops, by forming an intake gas passage chamber with frames below a motor and extending ribs of the frame which are placed between external walls of related cylinders of the passage chamber, up to a level nearly flush with the lower end of a motor coil.
CONSTITUTION: The drawing shows the evolved relation between each cylinder and rib however, actually, the cylinders are arranged in the annular form having a full circumferential length L. Each cylinder 5 is arranged in lower position in the order of A, B, C and D and ribs 14 extend between the cylinders up to levels flush with a level just before the lower face of a motor end coil. Therefore, even if freezer oil contained in circulating gas may be stayed in dents 21 when the pump stops, the oil will not overflow the ribs having the same length as before and stagnate by much amount just before a suction passage of the lowest cylinder as occasionally experienced formerly.