Abstract: The disclosure provides a motor with a deceleration mechanism capable of suppressing disengagement of gears even when a large external force is applied to an output shaft. A backup member 70 maintaining engagement between a pinion gear 61 and a helical gear 62 is provided on a side of the pinion gear 61 opposite to the side of the helical gear 62 in a gear case 20. Thus, even when a large external force is applied to the output shaft, disengagement of the gears (disengagement of the pinion gear 61 and the helical gear 62) can be suppressed. Therefore, damage to the pinion gear 61 and the helical gear 62 (deceleration mechanism 60) can be prevented for a long period of time, and consequently the life of the motor 10 with the deceleration mechanism can be extended.

Abstract: The invention provides a grease composition for a speed reducer part of an on-vehicle electric component, the grease composition containing a base oil and a thickener, wherein the base oil is poly-?-olefin or a mixed oil of poly-?-olefin and mineral oil having a kinematic viscosity of 4 to 19 mm2/s at 100° C. and a pour point of ?30° C. or lower, the thickener is a mixture of a diurea compound expressed by formula (1) and a diurea compound expressed by formula (2) R1—NHCONH—R2—NHCONH—R1??(1) R3—NHCONH—R2—NHCONH—R3??(2) wherein R1 is a straight-chain alkyl group having 8 or 18 carbon atoms, R2 is a divalent aromatic hydrocarbon group having 6 to 15 carbon atoms, and R3 is an aryl group having 6 to 7 carbon atoms, and a penetration of the grease composition is 220 to 280.