2. FUNCTION 1) MAIN PUMP The pumps may classified roughly into the rotary group performing a rotary motion and working as the major part of the whole pump function: the swash plate group that varies the delivery rates: and the valve cover group that changes over oil suction and discharge. (1) Rotary group The rotary group consists of drive shaft (F)(111), cylinder block(012), piston shoes(151,152), set plate(153), spherical bush(156), and cylinder spring(157). The drive shaft is supported by bearing(123,124) at its both ends. The shoe is caulked to the piston to from a spherical coupling.
It has a pocket to relieve thrust force generated by loading pressure and the take hydraulic balance so that it slides lightly over the shoe plate(211). The sub group composed by a piston and a shoe is pressed against the shoe plate by the action of the cylinder spring via a retainer and a spherical bush. Similarly, the cylinder block is pressed against valve plate(313) by the action of the cylinder spring. 313 012 156 153 151 152 157 111 211 123 50072MP01 (2) Swash plate group The swash plate group consists of swash plate(212), shoe plate(211), swash plate support(251), tilting bush(214), tilting pin(531) and servo piston(532).
The swash plate is a cylindrical part formed on the opposite side of the sliding surface of the shoe and is supported by the swash support. If the servo piston moves to the right and left as hydraulic force controlled by the regulator is admitted to hydraulic chamber located on both sides of the servo piston, the swash plate slides over the swash plate support via the spherical part of the tilting pin to change the tilting angle( 531 548 214 212 251 211 532 ) 2-7 (210-7) 2-8