Bevel gear load balance in a hydrostatic transmission

A hydrostatic transmission comprising:

• a housing defining a cavity;
• a conduit disposed in said cavity;
• a variable displacement radial piston type hydraulic pump rotatably disposed on said conduit, said hydraulic pump including a cylinder block radially disposed on said conduit and in fluid communication therewith;
• a bevel gear being one of integral with and attached to said cylinder block;
• an input shaft having an input bevel gear, said input bevel gear enmeshing with and rotatably driving said bevel gear;
• and
• hydrostatic pressure means disposed adjacent said cylinder block for applying a counterbalancing force to said cylinder block in reaction to loads exerted on said cylinder block by said input bevel gear during operation of said hydraulic pump, such that said cylinder block concentrically rotates about said conduit, said hydrostatic pressure means disposed in constant fluid communication with an interior of said conduit.

A hydrostatic transmission comprising:

• a housing defining a cavity;
• a conduit disposed in said cavity;
• a variable displacement radial piston type hydraulic pump rotatably disposed on said conduit, said hydraulic pump including a cylinder block radially disposed on said conduit and in fluid communication therewith;
• a bevel gear being one of integral with and attached to said cylinder block;
• an input shaft having an input bevel gear, said input bevel gear enmeshing with and rotatably driving said bevel gear;
• and
• a hydrostatic piston formed in said conduit adjacent an inner surface of said cylinder block exerting pressurized hydraulic fluid against said cylinder block for applying a counterbalancing reaction force to said cylinder block linearly proportional to loads exerted on said cylinder block by said input bevel gear during operation of said hydraulic pump, such that said cylinder block is caused to concentrically rotate about said conduit, said hydrostatic piston disposed in constant fluid communication with an interior of said conduit.

A hydrostatic transmission comprising:

• a housing defining a cavity therein;
• a conduit disposed in said cavity;
• a variable displacement radial piston type hydraulic pump rotatably disposed on said conduit, said hydraulic pump including a cylinder block radially disposed on said conduit and in fluid communication therewith, said cylinder block including a first bevel gear fixed thereto;
• an input shaft extending through said housing and into said cavity for transmitting rotational motion to said hydraulic pump;
• a second bevel gear disposed on said input shaft within said cavity, said second bevel gear meshed with said first bevel gear to impart rotational motion from said input shaft to said cylinder block, said gear exerting a tilting load against said cylinder block;
• and
• a hydrostatic piston utilizing pressurized hydraulic fluid from said conduit and disposed in constant fluid communication with an interior of said conduit, said hydrostatic piston orientated accordingly for applying a counterbalancing force against an inner surface of said cylinder block in reaction to the tilting load imparted to said cylinder block by said input bevel gear, said hydraulic piston comprising a recess in an outer surface of said conduit disposed radially under an inner surface of said cylinder block.