Damper apparatus and steering system

A damper apparatus comprising:

• a shaft having a shaft portion and a large-diameter portion having a diameter larger than a diameter of the shaft portion;
• a housing through which the shaft extends so as to be movable relative to the housing in an axial direction, the housing having a tubular shape, and the housing having a restriction portion at a position at which the restriction portion faces the large-diameter portion in the axial direction;
• and
• a shock-absorbing member disposed between the large-diameter portion and the restriction portion, the shock-absorbing member being configured to restrict movement of the shaft relative to the housing and absorb a shock generated due to the restriction when the shaft is moved to an end of a movable range relative to the housing, wherein
• the shock-absorbing member includes:
• a shock-receiving member configured to come into contact with one member when the large-diameter portion is moved to a prescribed position in the axial direction relative to the restriction portion, the one member being one of the large-diameter portion and the restriction portion;
• a pre-compression spring, the pre-compression spring being a spring having elasticity in the axial direction, the pre-compression spring being disposed between the shock-receiving member and another member in a state where the pre-compression spring is compressed in advance in the axial direction, and the pre-compression spring being configured to urge the one member in the axial direction via the shock-receiving member when the large-diameter portion is relatively moved toward the restriction portion beyond the prescribed position, the another member being the other one of the large-diameter portion and the restriction portion;
• and
• an elastic body disposed between the another member and the shock-receiving member, the elastic body being configured to be deformed to absorb a shock while restricting relative movement of the shaft when the large-diameter portion is relatively moved toward the restriction portion beyond the prescribed position.