Hydraulic apparatus including rotary valve

Hydraulic apparatus comprising:

• a. a valve casing having a body portion formed with at least one intake opening, at least one discharge opening, and a return opening;
• b. a distributor having a front face and a rear face;
• c. securing means securing said distributor to said body portion for angular movement relative to said body portion about an axis and for limited axial movement, said faces of the secured distributor extending radially relative to said axis;
• d. operating means for moving said distributor about said axis,
• 1. said body portion having a planar face, said planar face and said front face being formed with respective recesses alignable for connecting said at least one intake opening with said at least one discharge opening in a predetermined angular position of said distributor for flow of fluid between said intake and discharge openings in a first path through said valve casing;
• and
• e. cover means spacedly enveloping said distributor in sealing engagement with said body portion, said cover means and said rear face of said distributor bounding therebetween a chamber,
• 1. said planar face and said front face defining axially therebetween a first, annular, throttling gap offset radially outward from said recesses and connecting said intake opening with said chamber,
• 2. a face of said cover means and a portion of said rear face substantially coplanar with said planar face defining axially therebetween a second throttling gap connecting said chamber to said return opening,
• 3. said intake and return openings, said gaps, and said chamber defining a second path of fluid flow through said valve casing,
• 4. the effective flow section of said second path being smaller than the effective flow section of said first path.