Hydraulic steering system for boats

Claim 2

A hydraulic steering system comprising a housing, a drive shaft extending into one end of said housing and journaled therein for rotation, a pump mechanism wholly contained within said housing, means connecting said pump mechanism to said drive shaft for actuation thereby, a porting plate for said pump mechanism secured to the other end of said housing, said porting plate having an outer diameter less than the outer diameter of said housing, and a mounting support for said steering system having an opening therein for receipt of said porting plate with said other end of said housing engaging the front side of said mounting support and said porting plate protruding a slight distance behind said mounting support to provide sufficient space therebehind for connection of fluid lines to said porting plate behind said mounting support, and means for securing said housing and porting plate to said mounting support with said other end of said housing engaging the front side of said mounting support and said porting plate protruding behind said mounting support as aforesaid.

Claim 3

The steering system of claim 1 wherein said housing has a counterbore in said other end, and said porting plate has a radial flange which is received in said counterbore for accurately locating said porting plate with respect to said housing.

Claim 4

The steering system of claim 1 wherein said means for releasably securing said housing and porting plate to said mounting support comprises a cup-shaped element surrounding the protruding portion of said porting plate, studs projecting from said protruding portion through openings in said cup-shaped element, and nuts threadedly engaging said studs for drawing said housing and porting plate toward said cup-shaped element and forcing the lip of said cup-shaped element into engagement with the back side of said mounting support.

Claim 5

The steering system of claim 3 wherein the protruding portion of said porting plate has a bore therein, and right-angle fittinGs are connected to the ends of said bore behind said mounting support, said cup-shaped element having slots in opposite sides thereof for extension of said fittings therethrough.

Claim 6

The steering system of claim 1 wherein said pump mechanism comprises a cylinder body keyed to said drive shaft for rotation therewith, said cylinder body having a plurality of circumferentially spaced axially extending cylinder bores open at their outer ends and having flow passages in their inner ends, an inclined swashplate fixed in said housing adjacent the open ends of said cylinder bores, pistons in said cylinder bores, spring means for urging said pistons into engagement with said swashplate, the end face of said porting plate adjacent said pump mechanism being in sliding sealed engagement with said cylinder body, a pair of arcuate grooves in said end face which alternately communicate with said cylinder bores during rotation of said cylinder body, a transverse bore in the protruding portion of said porting plate, check valves in opposite ends of said transverse bore, a pair of passages in said porting plate communicating said arcuate grooves with said transverse bore adjacent said check valves, and a shuttle valve having sliding sealed engagement in said transverse bore between said passages, said shuttle valve having stem portions projecting from the ends thereof for opening of said check valves when urged thereagainst by high-pressure fluid in the opposite end of said bore, and stop means for limiting the movement of said shuttle valve toward said check valve to avoid blocking communication between said check valves and passages by said shuttle valve.

Claim 7

The steering system of claim 1 wherein said pump mechanism comprises a cylinder body keyed to said drive shaft for rotation therewith, said cylinder body having a plurality of circumferentially spaced axially extending cylinder bores open at their outer ends and having flow passages in their inner ends, an inclined swashplate fixed in said housing adjacent the open ends of said cylinder bores, pistons in said cylinder bores, spring means urging said pistons into engagement with said swashplate, the end face of said porting plate adjacent said pump mechanism being in sliding sealed engagement with said cylinder body, a pair of arcuate grooves in said end face which alternately communicate with said cylinder bores during rotation of said cylinder body, passages in said porting plate communicating with said arcuate grooves, and a radial groove in said end face between said arcuate grooves on the suction side of said pump mechanism, said radial groove extending radially outwardly beyond said cylinder body to provide communication with the interior of said housing, said housing comprising a reservoir containing makeup fluid which is supplied to said cylinder bores during rotation past said radial groove.

Claim 8

The steering system of claim 6 further comprising an annular groove in said end face surrounding said arcuate grooves and intersecting said radial groove to provide low pressure fluid completely surrounding said arcuate grooves.

Claim 9

The steering system of claim 5 further comprising ball bearings contained in recesses in the outer ends of said pistons to provide rolling engagement with said swashplate.

Claim 10

A hydraulic steering system comprising a housing, a drive shaft extending into one end of said housing and journaled therein for rotation, a pump mechanism wholly contained within said housing, means containing said pump mechanism to said drive shaft for actuation thereby, a porting plate for said pump mechanism secured to the other end of said housing, said pump mechanism comprising a cylinder body keyed to said drive shaft for rotation therewith, said cylinder body having a plurality of circumferentially spaced axially entending cylinder bores open at their outer ends and having flow passages in their inner ends, an inclined swashplate fixed in said housing adjacent the open ends of said cylinder bores, pistons in said cylinder bOres, means for urging said pistons into engagement with said swashplate, the end face of said porting plate adjacent said pump mechanism being in sliding sealed engagement with said cylinder body, a pair of arcuate grooves in said end face which alternately communicate with said cylinder bores during rotation of said cylinder body, said porting plate containing a pair of passages communicating said arcuate grooves with a bore adjacent check valves in opposite ends of said bore, and a shuttle valve having sliding sealed engagement in said bore between said passages, said shuttle valve having stem portions projecting from the ends thereof for opening of said check valves when urged thereagainst by high-pressure fluid in the opposite end of said bore, and stop means for limiting the movement of said shuttle valve toward said check valves to avoid blocking communication between said check valves and passages by said shuttle valve.

Claim 11

A hydraulic steering system comprising a housing, a drive shaft extending into one end of said housing and journaled therein for rotation, a pump mechanism wholly contained within said housing, means containing said pump mechanism to said drive shaft for actuation thereby, a porting plate for said pump mechanism secured to the other end of said housing, said pump mechanism comprising a cylinder body keyed to said drive shaft for rotation therewith, said cylinder body having a plurality of circumferentially spaced axially entending cylinder bores open at their outer ends and having flow passages in their inner ends, an inclined swashplate fixed in said housing adjacent the open ends of said cylinder bores, pistons in said cylinder bOres, means for urging said pistons into engagement with said swashplate, the end face of said porting plate adjacent said pump mechanism being in sliding sealed engagement with said cylinder body, a pair of arcuate grooves in said end face which alternately communicate with said cylinder bores during rotation of said cylinder body, said porting plate containing a pair of passages communicating said arcuate grooves with a bore adjacent check valves in opposite ends of said bore, and a shuttle valve having sliding sealed engagement in said bore between said passages, said shuttle valve having stem portions projecting from the ends thereof for opening of said check valves when urged thereagainst by high-pressure fluid in the opposite end of said bore, and stop means for limiting the movement of said shuttle valve toward said check valves to avoid blocking communication between said check valves and passages by said shuttle valve.

Claim 12

The steering system of claim 9 further comprising a radial groove in said end face between said arcuate grooves on the suction side of said pump mechanism, said radial groove extending radially outwardly beyond said cylinder body to provide communication with the interior of said housing, said housing comprising a reservoir containing makeup fluid which is supplied to said cylinder bores during rotation past said radial groove.

Claim 13

The steering system of claim 10 further comprising an annular groove in said end face surrounding said arcuate grooves and intersecting said radial groove to provide low pressure fluid completely surrounding said arcuate grooves.