Washing machine including damper for damping vibration of tub

A washing machine comprising:

• a housing;
• a tub which is relatively movable in the housing;
• a drum rotatably disposed in the tub;
• and
• a damper disposed between the housing and the tub, the damper comprising:
• a damper frame including an end which is supported by one of the housing and the tub;
• a rod including:
• an end which is supported by a remaining one of the housing and the tub;
• and
• an opposite end which is inserted into a support portion of the damper frame, the rod being movable with respect to the damper frame according to a relative movement between the housing and the tub;
• a rotation movement member provided around the rod in the damper frame and rotating with respect to the damper frame, the rotation movement member being movable with respect to the damper frame in an axial direction of the rod;
• a friction member which is disposed between the support portion of the damper frame and the rotation movement member in the axial direction and applies a friction force to the rod by contacting an outer circumferential surface of the rod;
• and
• a switching unit which switches, by rotating the rotation movement member, a state of the damper between a first state in which the friction member is movable together with the damper frame with respect to the rod and a second state in which the friction member is movable together with the rod with respect to the damper frame, wherein the switching unit comprises:
• a motor;
• a transmission member which includes a gear which engages with a gear portion of the rotation movement member, and transmits a driving force of the motor to the rotation movement member;
• and
• a sensor which detects a rotation angle of the rotation movement member.

A washing machine comprising:

• a housing;
• a tub which is relatively movable in the housing;
• a drum rotatably disposed in the tub;
• and
• a damper disposed between the housing and the tub, the damper comprising:
• a damper frame including an end which is supported by one of the housing and the tub;
• a rod including:
• an end which is supported by a remaining one of the housing and the tub;
• and
• an opposite end which is inserted into a support portion of the damper frame, the rod being movable with respect to the damper frame according to a relative movement between the housing and the tub;
• a rotation movement member provided around the rod in the damper frame and rotating with respect to the damper frame, the rotation movement member being movable with respect to the damper frame in an axial direction of the rod;
• a friction member which is disposed between the support portion of the damper frame and the rotation movement member in the axial direction and applies a friction force to the rod by contacting an outer circumferential surface of the rod;
• and
• a switching unit which switches, by rotating the rotation movement member, a state of the damper between a first state in which the friction member is movable together with the damper frame with respect to the rod and a second state in which the friction member is movable together with the rod with respect to the damper frame, wherein
• the switching unit comprises a sensor which detects a rotation angle of the rotation movement member by detecting a plurality of protrusions disposed at the rotation movement member and protruding in the axial direction, and
• the plurality of protrusions is spirally arrayed at regular intervals.