Provided is a variable displacement pump which includes a cylinder block including a plurality of cylinder bores formed in a rotation shaft in a circumferential direction and rotating together with the rotation shaft, a piston provided inside each of the plurality of cylinder bores to be slidable, and a swash plate supported to be tiltable with respect to the rotation shaft while a distal end portion of the piston is slidable thereon and which sucks and discharges a working fluid by moving the piston in a reciprocating manner with a stroke in accordance with an inclination angle of the swash plate, the variable displacement pump including: a control piston which includes a piston portion pressing the swash plate and controls the inclination angle of the swash plate; a piston accommodation portion which is formed in the housing and accommodates the piston portion; and a hollow cylindrical guide portion which is disposed between the piston accommodation portion and the piston portion and includes an inner peripheral surface supporting the piston portion to be slidable thereon, in which the housing is formed of a material having higher fatigue strength than the guide portion and the guide portion is formed of a material harder than the housing.

A connector plate, for mechanically and hydraulically connecting a hydraulic machine with a hydraulic attachment part, includes a plurality of hydrostatic connector recesses. Each recess has a first side that includes a first orifice opening to the hydraulic attachment part, and a second side with a second orifice opening to the hydraulic machine. The plurality of orifices are arranged so as to open in a substantially axially parallel manner with respect to a drive shaft of the hydraulic machine. A hydraulic machine includes such a connector plate, and a hydrostatic unit includes such a hydraulic machine and a hydraulic attachment part.

A hydraulic pump includes: a valve plate including a suction port and a delivery port; a valve cover to which the valve plate is mounted; and a cylinder block that slides on the valve plate. The valve cover includes a suction passage and a delivery passage. The valve cover includes: a first chamber that communicates with the delivery passage through a communication passage and functions as a Helmholtz resonator; and a second chamber that communicates with the delivery passage, or with the first chamber, through an introduction passage including a restrictor. In the valve cover and the valve plate, a supply passage extends from the second chamber to a bottom dead center-side sealing surface of the valve plate, the bottom dead center-side sealing surface being a surface located between the suction port and the delivery port. The supply passage includes a restrictor.

A hydrostatic axial piston machine includes a pot-like housing, a connection plate that closes the pot-like housing, a rotatably mounted cylinder drum, and pistons arranged in cylinder chambers of the cylinder drum. The cylinder chambers are each alternately connected via a cylinder chamber opening to a low-pressure control opening and a high-pressure control opening of a resting control part. The control part has two switching regions located between the low-pressure and high pressure control openings. A piston reverses its movement direction in a dead center within the two switching regions. In the switching region, the cylinder chambers are connected via a connecting line to a fluid volume arranged in the housing. The fluid volume extends between the connection plate and the housing such that it is sealed to an interior by the connection plate and the housing.

A housing assembly for a side-by-side (SBS) piston pump may define a pump cavity enclosing first and second piston pumps having parallel longitudinal axes. The housing assembly may include a shroud partially or wholly separating the piston pumps to substantially reduce churning of lubricating fluid flow flowing around the piston pumps and pooling in a fluid intersection area between the piston pumps. The shroud may be a planar shroud plate extending between the piston pumps, or a curved shroud plate between the piston pumps and having sections partially encircling each of the piston pumps. The shroud may alternatively be first and second shroud portions extending inwardly from the cavity walls and directing the lubricating fluid flows the merge in a combined lubricating fluid flow area.

Mounting structure for housing-free hydraulic axial piston machines of the bent axis or swash plate design, having a closing plate on which a cylinder block unit with displacing pistons arranged therein is supported, and having a drive or driven shaft. The mounting structure here is designed in the manner of a basket and has a receptacle for the drive or driven shaft and at least two struts which are in each case connected at one end to the receptacle and at the other end to the closing plate in such a manner that the closing plate, the cylinder block unit and the drive or driven shaft are heldanalogously as in a housingin a functionally ready position.

The devices comprises a distributor (16) that presents distribution ducts opening out into a radial distribution face (16A), and a distributor-counterpart engaged in each other in such a manner that two main enclosures (18, 20) are provided between their opposite axially-extending faces. The device comprises a cylinder-capacity selector comprising two slides (24, 26) arranged after the other in a bore (22) of the element engaged in the other, to which are connected the main enclosures (18, 20) and at least some of the distribution ducts (30, 31). The slides are able to adopt at least three distinct configurations establishing different connections between the main ducts (18, 20) and the distribution ducts via the main enclosures, in order to be able to obtain at least three distinct operating cylinder capacities.

An example method of cooling a compressor section of a gas turbine engine includes diverting a flow from a compressor through a heat exchanger, the flow moving from the compressor in a first direction, and moving the flow from the heat exchanger back to the compressor in a second direction. An example spacer for a compressor of a gas turbine engine includes a first side portion, a second side portion spaced apart from the first side portion, and a middle web arranged between the first and second side portions. At least one of the first and second side portions and the middle web include at least one orifice to communicate flow in a direction that is different from a core flowpath flow direction. An example compressor including the spacer is also disclosed.

An integrated electro-hydraulic unit has a hydraulic machine, an electric machine encircling the hydraulic machine and a housing at least partially surrounding the electric machine and the hydraulic machine. The hydraulic machine includes a rotary working group configured to pump a fluid. The electric machine includes a stator and a rotor coupled to the rotary working group such that the rotor drives the rotary working group. The housing includes a front cap and an end cap each having a plurality of tie rod openings. The housing includes a plurality of tie rods and a housing shell encircling the electric machine and positioned between the front and end caps. The tie rods extend through the openings in the front cap and end cap. Nuts are tightened on the tie rods such that the front cap, the end cap, and the housing shell are compressed via tension in the tie rods.

An integrated electro-hydraulic unit has a hydraulic machine, an electric machine encircling the hydraulic machine and a housing at least partially surrounding the electric machine and the hydraulic machine. The hydraulic machine includes a rotary working group configured to pump a fluid. The electric machine includes a stator and a rotor coupled to the rotary working group such that the rotor drives the rotary working group. The housing includes a front cap and an end cap each having a plurality of tie rod openings. The housing includes a plurality of tie rods and a housing shell encircling the electric machine and positioned between the front and end caps. The tie rods extend through the openings in the front cap and end cap. Nuts are tightened on the tie rods such that the front cap, the end cap, and the housing shell are compressed via tension in the tie rods.