Hydrostatic pressure worm-rack devices

In a hydrostatic pressure worm-rack device of the type comprising a worm formed with operating oil supply openings at opposite flanks of respective teeth of the worm, a rack meshing with said worm, opposite flanks of respective teeth of said rack being formed with hydrostatic pressure oil pockets, drive means for driving a shaft of said worm, and means for supplying the operating oil to said supply openings of said worm, the improvement which comprises:

• an oil distributor mounted on one end of said worm shaft for supplying oil to mating surfaces and non mating surfaces of the teeth of said worm and said rack and for supplying pilot oil to pilot oil supply ports provided for flanks of teeth at the opposite ends of said worm which firstly mate with the teeth of said rack;
• oil passages provided through said worm shaft and through respective teeth of said worm for independently supplying said operating oil and said pilot oil;
• flow quantity adjusting valve means installed between said operating oil supply means and said oil distributor, said flow quantity adjusting valve means having a constant flow quantity characteristic;
• and
• adjusting pins having a length of a lead angle of said worm and respectively threaded into ends of said oil passages.