Cradle bearing and cradle bearing support

Abstract

A cradle bearing for supporting a swashplate of a variable hydraulic axial piston. The cradle bearing is of an angular ball bearing type or includes, with respect to the bearing axis, a tapered inner race and/or a tapered outer race. A swashplate for a variable hydraulic axial piston unit including a first and a second cradle bearing zone spaced to each other in axial direction of a swashplate tilt axis, suitable for supporting the swashplate in a housing of a variable hydraulic axial piston unit, wherein the first cradle bearing zone is inclined with respect to the swashplate tilt axis. A variable hydraulic axial piston unit of the swashplate type including a swashplate which is supported rotatable in the housing of the variable hydraulic axial piston unit at a first bearing zone by a tapered bearing and at a second bearing zone by regular cylindrical cradle bearing or a journal bearing whose axis is aligned with the swashplate tilt axis.

What is claimed is: 
     
         1 . A swashplate for a variable hydraulic axial piston unit comprising a first and a second cradle bearing zone spaced to each other in axial direction of a swashplate tilt axis, for supporting the swashplate in a housing of the variable hydraulic axial piston unit, wherein the first cradle bearing zone is inclined with respect to the swashplate tilt axis. 
     
     
         2 . The swashplate according to  claim 1 , wherein a central axis of the second cradle bearing zone is aligned with the swashplate tilt axis. 
     
     
         3 . The swashplate according to  claim 1 , wherein the swashplate comprises receiving means at a distal end in direction of the swashplate tilt axis for receiving a support element. 
     
     
         4 . The swashplate according to  claim 1 , wherein the first cradle bearing zone essentially faces towards the distal end comprising the receiving means. 
     
     
         5 . The swashplate according to  claim 1 , wherein a distal end comprising the receiving means is arranged remote from the first cradle bearing zone. 
     
     
         6 . A variable hydraulic axial piston unit of the swashplate type comprising a swashplate according to  claim 1 , which is supported rotatable in a housing of the variable hydraulic axial piston unit at a first cradle bearing zone by means of a tapered cradle bearing for supporting a swashplate of a variable hydraulic axial piston unit, wherein the cradle bearing is of an angular ball bearing type or comprises, with respect to the bearing axis, a tapered inner race and/or a tapered outer race and at a second cradle bearing zone by means of a regular cylindrical cradle bearing or a journal cradle bearing whose axis is aligned with the swashplate tilt axis. 
     
     
         7 . The variable hydraulic axial piston unit according to  claim 6 , wherein at one distal end of the swashplate in direction of the swashplate tilt axis a support element is disposed between the swashplate and the housing or the housing comprises a support surface for supporting the swashplate in direction of the swashplate tilt axis. 
     
     
         8 . The variable hydraulic axial piston unit according to  claim 6 , wherein the swashplate comprises a displacement pin for tilting the swashplate, wherein the first cradle bearing zone is located closer to the displacement pin than the second cradle bearing zone. 
     
     
         9 . The variable hydraulic axial piston unit according to  claim 6 , wherein the swashplate comprises a displacement pin for tilting the swashplate, wherein the second cradle bearing zone is located closer to the displacement pin than the first cradle bearing zone. 
     
     
         10 . The variable hydraulic axial piston unit according to  claim 6 , wherein the support element is made of bronze, plastic material or any other material capable of reducing friction forces at the distal end of the swashplate and/or capable of supporting an axial force in the direction of the swashplate tilt axis. 
     
     
         11 . The variable hydraulic axial piston unit according to  claim 6 , wherein the support element at least in direction of the swashplate tilt axis is capable of dampening vibration forces of the hydraulic unit and/or is capable of balancing temperature dilatations or hysteresis of the swashplate, the cradle bearings, and/or the housing of the hydraulic unit. 
     
     
         12 . The variable hydraulic axial piston unit according to  claim 6 , wherein the support element is manufactured as a single-part out of bronze, rubber, plastic or reinforced rubber or plastic material. 
     
     
         13 . The variable hydraulic axial piston unit according to  claim 6 , wherein the support element is a hydraulic tappet.