Patent ID: 6435235
Filing Date: 2002-08-20
Classification: A01G

Abstract:
A coupling for connecting a tree harvester head structure to a mounting structure, comprising:a bearing capable of carrying axial and radial load supporting said tree harvester head structure on said mounting structure for rotation about a bearing axis including a radially outer member rigidly secured to one of said mounting and head structures and a radially inner member rigidly secured to the other of said mounting and head structures and an annular fluid powered rotary actuator disposed on one of the radially inner and outer sides of said bearing including an annular housing component including walls defining an annular groove and a vane forming a dam in said groove and an annular reaction component in fluid sealing engagement with said walls of said housing component including a vane extending radially into said groove, said vanes being circumferentially spaced from one another to divide said groove into two pressure chambers, said vanes having circumferential thicknesses sufficiently small to permit in excess of 220 degrees relative rotation between said housing component and said reaction component, one of said housing and reaction components of said rotary actuator being rigidly secured to said mounting structure and the other of said housing and reaction components being connected for rotation with said head structures.