Power transmission apparatus for four-wheel drive vehicle

A power transmission apparatus for four-wheel drive vehicle comprising:

• a housing fixed to the vehicle;
• an hydraulic pump having a casing rotatably supported within said housing and connecting front and rear wheels or left side and right side wheels of the vehicle by oil pressure produced therein corresponding to a rotational speed difference between said front and rear wheels or said left side and right side wheels,
• adjusting means outside of said housing for introducing the oil generated in said hydraulic pump thereinto, adjusting the oil pressure and returning said oil to said hydraulic pump,
• first sealing means provided between the inner periphery of said housing and the outer periphery of said casing to prevent the operating oil of said hydraulic pump from leaking through a gap between both said inner periphery and said outer periphery;
• second sealing means disposed at a side of the discharge side oil passage nearer said hydraulic pump than said first sealing means to prevent the operating oil of said hydraulic pump from leaking through a gap between both said peripheries.

A power transmission apparatus for a four-wheel drive vehicle comprising:

• a housing fixed to the vehicle body;
• a differential gear mechanism in said housing responsive to the rotational speed difference between the front and rear wheels or the left side and right side wheels of the vehicle;
• a hydraulic pump having a casing mounted within said housing and rotatably supported with its outer periphery adjacent the inner periphery of said housing and restraining operation of said differential gear mechanism by oil pressure produced therein corresponding to a rotational speed difference between front and rear wheels or left side and right side wheels of the vehicle;
• and
• a variable throttle, provided outside of said housing for introducing the oil generated in said hydraulic pump thereinto, adjusting the oil pressure and returning said oil to said hydraulic pump.

A power transmission apparatus for a four-wheel drive vehicle, comprising;

• a housing fixed to the vehicle body;
• a differential gear mechanism provided in said housing to respond to a rotational speed difference between the front and rear wheels or the left side and right side wheels of the vehicle;
• an hydraulic pump for restraining operation of said differential gear mechanism;
• adjusting means provided at the outer periphery of said housing so as to introduce the oil generated in said hydraulic pump thereinto, adjust the oil pressure and return said oil to said hydraulic pump, and
• wherein said differential gear mechanism and said hydraulic pump are integral with each other.

A power transmission apparatus for a four-wheel drive vehicle comprising:

• a housing fixed to the vehicle body;
• a hydraulic pump having a casing mounted within said housing and rotatably supported with its outer periphery adjacent the inner periphery of said housing and connecting front and rear wheels or left side and right side wheels of the vehicle by oil pressure produced therein corresponding to a rotational speed difference between said front and rear wheels or said left said and right side wheels;
• a variable throttle outside of said housing for receiving the oil generated in said hydraulic pump within said housing, adjusting the oil pressure and returning said oil to said hydraulic pump;
• and
• means for introducing into said variable throttle oil pressure of oil supplied to a power cylinder disposed in a steering mechanism, as operating oil pressure to said variable throttle.