Clamp ring detaching method, clamp ring detaching tool, and method of manufacturing magnetic disk device

A clamp ring detaching method of detaching from a motor hub a clamp ring fastened to the motor hub, the clamp ring comprising a plurality of hub pressing portions contacting the outer circumferential surface of the motor hub and connecting portions which connect the hub pressing portions, each connecting portion having a concave portion, the method comprising:

• expanding the connecting portions plastically outwards in a radial direction of the clamp ring in order to remove the clamp ring from the motor hub;
• and
• pressing the outer circumferential surface of the connecting portions expanded, inwards in a radial direction of the clamp ring.

A method of detaching from a motor hub a clamp ring in which a plurality of hub pressing portions contacting the outer circumferential surface of the motor hub and connecting portions which connect the hub pressing portions, each connecting portion having a concave portion are arranged alternately, the method comprising:

• pressing portions at least one of the concave portions, which are displaced to both the sides from a center of the concave portion, outwards in a direction of the clamp ring at the same time in order to remove the clamp ring from the motor hub.

A clamp ring detaching tool to be used when detaching from a motor hub a clamp ring fastened to the motor hub, the clamp ring comprising a plurality of hub pressing portions contacting the outer circumferential surface of the motor hub and connecting portions which connect the hub pressing portions, each connecting portion having a concave portion, the tool comprising:

• a pressing portion which presses those portions of at least one of the concave portions which are displaced from a center of the concave portion, at the same time outwards in a radial direction of the clamp ring.

A method of manufacturing a magnetic disk device, having detaching from a motor hub a clamp ring fastened to the motor hub, the clamp ring comprising a plurality of hub pressing portions contacting the outer circumferential surface of the motor hub and connecting portions which connect the hub pressing portions, each connecting portion having a concave portion, the detaching comprising:

• pressing portions of at least one of the concave portions, which are displaced from a center of the concave portion, outwards in a radial direction of the clamp ring in order to remove the clamp ring from the motor hub.