Patent GB-191305741-A (GB)
Title: Improvements in and connected with Fluid-pressure Apparatus.
Inventor: WALKER CHARLES LESLIE
Filed: 1913-03-08
Granted: 1914-03-05
Abstract: 5741. Walker, C. L. March 8. Revolving-cylinder pumps; stroke, varying.- Relates to improvements in fluid-pressure apparatus of the wobbler or swash-plate type and is shown applied to a liquid-pressure transmission system. The pump barrel 8, 8<a> is made in two parts secured together by dowel pins and is provided with a series of double-acting cylinders 17 containing pistons 16, the rods of which are secured through cylindrical bearings to the rods 11<d> of swash-plate 11<b>. The swash-plate is universally jointed to the barrel 8 in the manner shown and is provided with rollers 15, 15<a>, which engage guides 10<c>, 10<d>, which are connected to the barrel and to one another by give-and-take elements as described below in connexion with the motor element of the system. The inclination of the swash-plate is maintained by a sleeve 12, which engages with the swash-plate through radial load bearings 11<c>, is supported on trunnions carried by a sleeve 13, and is provided with a projection 12<a>, which engages a longitudinally adjustable part 14 to vary the piston stroke and direction of flow of the compressed liquid, which is preferably oil. The motor element consists of a barrel 23, 33<a> provided with nine double-acting cylinders containing pistons which are connected to a swash-plate 18<a>, which is universally jointed to the barrel and is provided with anchoring-arms 18<d>, which carry rollers in engagement with guides 25<d>, 25<e>. One pair of guides 25<a>, 25<b>, Fig. 3, is carried by a disk 25 which is loosely screwed on one end of the barrel 23<a>. The other pair is similarly carried by a disk 24 loosely screwed to the other end of the barrel. Both sets of guides are mounted on the ends of levers 26, which constitute give-and-take elements, and which are centrally mounted in holes in flanges 23<b>, 23<c> on the cylinder barrel. The distribution of fluid in the pump and motor is effected by disk valves held in contact with the ends of the cylinder barrels. The plate 6, Figs. 1, 7, and 9, is provided with pressure and return ports P, R in communication with the pump cylinders, which ports communicate with eight pressure and eight return ports in communication with the motor cylinders. A spring 7<a>, Fig. 1, maintains the valve plates 6, 7 in position. The fluid pressure acts in one of two pairs of recesses 7<b>, 7<c> which contain pistons 7<d>, 7<c> having articulated liquid-tight passages 7<f>, 7<a>. In a modified form of barrel, one part contains a recess which contains a fluid-tight disk or piston which rests on the other part. A spring maintains the engaging surfaces in contact, and the fluid pressure on the valve faces is balanced by supplying fluid pressure to the recess. A modified form of valve is described wherein a valve-plate is placed between the casing adjacent to the shaft 8<b> and the cylinder barrel and is acted on by a spring. The construction ensures equal axial pressures acting on each side of the plate. The balancing parts of the pressure and return sides are similar and symmetrically opposite in position. Each consists of a major and two minor disks fitted within liquidcharged recesses in the plate. The disks are connected to one another by ducts. The backs of all the disks are in free communication with non- pressure parts, for example, the interior of the casing. If the plate and its parts are located at the opposite end of the barrel, each disk is placed with its axis in the centre of pressure, in which case the minor disks are dispensed with.