Rotor blade non-counterbored retention assembly via a sliding clamped bushing

A retainer assembly for use in a rotor blade retention assembly having a retainer cavity, the retainer assembly comprising:

• an upper bushing slidably disposed within the retainer cavity, the upper bushing comprising an upper counterbored portion;
• a lower bushing slidably disposed within the retainer cavity, the upper bushing and the lower bushing cooperating to define a bushing inner cavity;
• an outboard blade pin disposed within the bushing inner cavity, the outboard blade pin comprising a blade pin inner cavity;
• a first fastener disposed within the upper counterbored portion;
• and
• a second fastener extending through the blade pin inner cavity and coupled to the first fastener such that the first fastener, the outboard blade pin, and the second fastener are configured to cooperatively clamp the lower bushing and the upper bushing to a spool disposed therebetween.

A method for installing a retainer assembly of a rotor blade retention assembly having a central hub, a rotor blade having a blade hole, a blade inner cavity and a proximal end coupled to the central hub, and a strap member disposed within the blade inner cavity and including a distal end receiving portion, the retainer assembly having an upper bushing with an upper counterbored portion, a lower bushing, and a bushing inner cavity, a first fastener, a second fastener, and an outboard blade pin including a blade pin inner cavity, the method comprising:

• inserting the distal end receiving portion of the strap member into the blade hole,
• inserting, after inserting the distal end receiving portion of the strap member into the blade hole, the upper bushing and the lower bushing into the blade hole;
• inserting, after inserting the upper bushing and the lower bushing into the blade hole, the outboard blade pin into the bushing inner cavity and through the distal end receiving portion;
• inserting the first fastener into the upper counterbored portion of the upper bushing;
• inserting the second fastener through the blade pin inner cavity;
• and
• coupling the first fastener to the second fastener such that the first fastener, the outboard blade pin, and the second fastener cooperatively clamp the lower bushing and the upper bushing to the strap member.

A rotor blade retention assembly comprising:

• a central hub,
• a rotor blade comprising an upper outer surface, a lower outer surface, a blade hole, and a proximal end coupled to the central hub;
• a strap member extending along a portion of the rotor blade such that a distal end receiving portion of the strap member extends into the blade hole;
• a retainer assembly disposed within the blade hole and coupled to the strap member, the retainer assembly comprising:
• an upper bushing slidably disposed within the blade hole and extending between the strap member and the upper outer surface of the rotor blade, the upper bushing comprising an upper counterbored portion,
• a lower bushing slidably disposed within the blade hole and extending between the strap member and the lower outer surface of the rotor blade, the upper bushing and the lower bushing cooperating to define a bushing inner cavity,
• an outboard blade pin disposed within the distal end receiving portion of the strap member, the outboard blade pin comprising a blade pin inner cavity, and
• a protective layer disposed within the blade hole, wherein a first portion of the protective layer is disposed between an inner wall of the blade hole and the upper bushing and extends from the strap member to the upper outer surface, and wherein a second portion of the protective layer is disposed between the inner wall of the blade hole and the lower bushing and extends from the strap member to the lower outer surface.