Hydraulic motor

Claim 2

A hydraulic motor comprising a stationary housing having coaxial high speed and output shafts journaled therewithin; said high speed shaft having a bent axis portion; a hydraulically actuated nutating member within said housing and axially retained and journaled on the bent axis portion of said high speed shaft to cause rotation of the latter and consequent nutation of said nutating member; said nutating member having coaxial bevel gear means which during nutation thereof progressively mesh with bevel gear means fixed in said housing and on said output shaft; the progressively meshing gear means on said nutating member and on said output shaft having at least a one tooth difference to effect low speed-high torque driving of the latter by nutation of said nutating member; said nutating member being hydraulically actuated by a circular array of axially movable pistons in said housing engaged with an inclined end face of said nutating member; and said high speed shaft having an axially outer end portion extending coaxially within said circular array of pistons.

Claim 3

The hydraulic motor of claim 1 wherein said axially outer end portion of said high speed shaft has means externally of said housing for driving the same independently of hydraulic actuation of said nutating member to cause nutation of said nutating member and consequent low speed-high torque driving of said output shaft.

Claim 4

The hydraulic motor of claim 1 wherein said high speed shaft is tubular and surrounds said output shaft said housing having a pinion gear and shaft extending to the exterior of said housing and rotatable therein about an axis parallel to the axis of said high speed shaft with said pinion gear meshing with teeth around the axially outer end portion of said high speed shaft whereby said high speed shaft may be driven by said pinion gear independently of hydraulic actuation of said nutating member to cause nutation of the latter and consequent driving of said output shaft at low speed-high torque.

Claim 5

The hydraulic motor of claim 1 wherein said bevel gear means on said output shaft is at the axially inner end of said output shaft and wherein said bent axis portion of said high speed shaft is at the axially inner end portion of said high speed shaft.

Claim 6

The hydraulic motor of claim 4 wherein said axially outer end portion of said high speed shaft extends through said housing for high speed rotation by means other than hydraulic thus to cause nutation of said nutating member in the event of loss of hydraulic pressure.

Claim 7

A hydraulic motor comprising a housing having inlet and return ports; coaxial high speed and output shafts journaled in said housing; said high speed shaft having a bent axis portion; a nutating member axially retained and journaled on the bent axis portion of said high speed shaft; said nutating member having a face on one side thereof normal to said bent axis portion and bevel gear means on the other side coaxial with said bent axis portion; said housing having a cylinder block with a circular array of cylinder bores coaxial with said high speed and output shafts; pistons reciprocable in the respective cylinder bores and engageable with said face on said one side of said nutating member; valve means effective to alternately communicate said cylinder bores with said inlet and return ports whereby said pistons are moved in one direction against said face of said nutating member by fluid under pressure from said inlet port thus to cause nutation of said nutating member and are moved in the opposite direction by such nutation of said nutating member to return fluid to said return PORT; coaxial bevel gear means respectively fixed in said housing and on said output shaft with which the bevel gear means of said nutating member progressively mesh during nutation of said nutating member, there being at least a one tooth difference in at least one set of the progressively meshing bevel gear means whereby said output shaft is driven by nutation of said nutating member; said high speed shaft having an axially outer end portion extending coaxially within said cylinder block.

Claim 8

A hydraulic motor comprising a housing having inlet and return ports; coaxial high speed and output shafts journaled in said housing; said high speed shaft having a bent axis portion; a nutating member axially retained and journaled on the bent axis portion of said high speed shaft; said nutating member having a face on one side thereof normal to said bent axis portion and bevel gear means on the other side coaxial with said bent axis portion; said housing having a cylinder block with a circular array of cylinder bores coaxial with said high speed and output shafts; pistons reciprocable in the respective cylinder bores and engageable with said face on said one side of said nutating member; valve means effective to alternately communicate said cylinder bores with said inlet and return ports whereby said pistons are moved in one direction against said face of said nutating member by fluid under pressure from said inlet port thus to cause nutation of said nutating member and are moved in the opposite direction by such nutation of said nutating member to return fluid to said return PORT; coaxial bevel gear means respectively fixed in said housing and on said output shaft with which the bevel gear means of said nutating member progressively mesh during nutation of said nutating member, there being at least a one tooth difference in at least one set of the progressively meshing bevel gear means whereby said output shaft is driven by nutation of said nutating member; said high speed shaft having an axially outer end portion extending coaxially within said cylinder block.

Claim 9

The hydraulic motor of claim 6 wherein said tooth difference is between the progressively meshing bevel gear means of said nutating member and said output shaft.

Claim 10

The hydraulic motor of claim 6 wherein said axially outer end portion of said high speed shaft has means externally of said housing for driving the same independently of said pistons to effect nutation of said nutating member and consequent driving of said output shaft.

Claim 11

The hydraulic motor of claim 6 wherein said bevel gear means on said output shaft is at the axially inner end of said output shaft and wherein said bent axis portion of said high speed shaft is at the axially inner end portion of said high speed shaft.

Claim 12

The hydraulic motor of claim 9 wherein said axially outer end portion of said high speed shaft extends through said housing to the exterior thereof for rotation by means other than hydraulic thus to cause nutation of said nutating member in the event of loss of hydraulic pressure.