| 摘要 |
PROBLEM TO BE SOLVED: To provide an actuator which is provided with a plastic gear device capable of uniting reduction of noise and a long life of the device, in particular, is suitable for an HVAC system and exhibits such an effect in a low-temperature environment.SOLUTION: An actuator includes: a stepping motor; a multi-stage gear device in which each stage gear including a first step gear attached to a rotation shaft of the motor is engaged with a subsequent step gear respectively; and a base member for installing the stepping motor and the multi-stage gear device thereon. Therein, the multi-stage gear device is configured such that a grease composition for resin is applied to at least a bearing part of either gear and to an engagement part between gears, the grease composition for resin includes base oil (a) which comprises poly-alpha-olefin oil and has a dynamic viscosity of 4 to 6 mm/s at 100°C, thickening agent (b) as lithium soap, thickener (c), solid lubricant (d) and wear-resistant agent (e), the consistency number of the composition being NLGI consistency No. 00, No. 0, No. 1 or No. 2. |
