Abstract:
The present invention provides a magnesium alloy member and a method for manufacturing a magnesium alloy member capable of achieving a mechanical strength and a high-temperature fatigue strength sufficient to apply them to mechanical parts of a compressor for automotive air conditioners. The invention also provides a compressor for air conditioners using, as a mechanical part thereof, a magnesium alloy equipped with a necessary mechanical strength and high-temperature fatigue strength. More specifically, a magnesium alloy member is formed by subjecting a cast material of a magnesium alloy containing, on the basis of mass%, from 0.3% to 10% calcium (Ca), from 0.2% to 15% aluminum (Al), and from 0.05% to 1.5% manganese (Mn), and containing calcium (Ca) and aluminum (Al) at a calcium/aluminum mass ratio of from 0.6 to 1.7, with the balance being magnesium (Mg) and inevitable impurities to plastic working (extrusion processing) at from 250°C to 500°C. This makes it possible to obtain a magnesium alloy member having a room-temperature 0.2% proof stress of 300 MPa or more and a 150°C fatigue strength of 100 MPa or greater. The magnesium alloy member used for the formation of mechanical parts of a compressor for automotive air conditioners contributes to a reduction in the weight of the compressor.
Abstract:
The invention relates to a lubricant pump (1), in particular for an internal combustion engine of a motor vehicle, comprising a housing (3) in which at least one pair (4) of intermeshing gear wheels (5) is disposed for delivering lubricant, wherein a first of the gear wheels is rotatably mounted on a drive shaft and the second of the gear wheels (5) is rotatably mounted on an axially displaceable displacement unit (6) for adjusting a variable volume to be delivered, and further comprising a control piston (16) which can be moved axially in a receptacle (15) of the housing (3) for hydraulically adjusting the position of the displacement unit (6), wherein the control piston (16) has a central longitudinal axis (17) and cylinder rings (18-21) enclosing control edges (18', 18"; 19', 19") for exposing or closing control channels (12, 13) opening into the receptacle (15). To this end, the control piston (16) is designed as a composite component (31), wherein the cylinder rings (18-21) are produced from a material which reduces friction and/or wear with respect to the receptacle (15), and the central longitudinal axis (17) is produced at least in some sections from a material which has a coefficient of thermal expansion that corresponds at least substantially to that of the receptacle (15). The invention further relates to a control piston for a lubricant pump.
Abstract:
A piston (1) has a piston body (10) made of a material selected from any one of aluminum, an aluminum alloy, magnesium, and a magnesium alloy containing 12-25% silicon. An entire surface or a predetermined portion of the surface of the piston body (10) is covered with a plasma oxide film (17) by a microarc-oxidation process.
Abstract:
Ein Zylinderkurbelgehäuse für eine flüssigkeitsgekühlte Brennkraftmaschine ist in einem Verbundguss auszubilden, wobei ein Aluminium-Triebwerksblock von einem Magnesium-Gehäuse umgossen ist. Das Zylinderkurbelgehäuse ist derart konzipiert, dass der Alu-Triebwerksblock wesentlich der Kraftverteilung zwischen Zylinderkoop und den Kurbelwellen-Lagerdeckeln dient sowie der Kühlwasserführung, wobei das Magnesium-Gehäuse frei von einer Kühlwasser-Führung überwiegend der Schmierölführung dient und im übrigen zur anteiligen Versteifung gegen Biegeund Torsionsbelastungen entsprechend durchgebildet ist.
Abstract:
A swash plate type compressor (10) having a cylinder block (12, 14) with cylinder bores (18) disposed parallel to the axis of the cylinder block. A rotary shaft (22) rotatably mounted within the cylinder block carries an aluminium swash plate (20). The swash plate (20) is fixed in the rotary shaft (22) and has two facial surfaces (26) and an end surface (28). The swash plate (20) has a coating layer of at least 0.2 wt.% cobalt and the balance being tin. A piston (16) reciprocally fitted within the cylinder bore (18) contains shoes (24) which slideably intervene between the piston (16) and the swash plate facial surfaces (26). The shoes (24) transfer the rotational motion of the swash plate (20) to the linear motion of the piston (16). The coated surfaces (26) of the swash plate (20) are in slidable contact with the shoes (24). The coating on the swash plate (20) permits the use of low silicon alloy aluminium without the need of metal plating or high finish polishing.
Abstract:
A swash plate type compressor (10) having a cylinder block (12, 14) with cylinder bores (18) disposed parallel to the axis of the cylinder block. A rotary shaft (22) rotatably mounted within the cylinder block carries an aluminium swash plate (20). The swash plate (20) is fixed in the rotary shaft (22) and has two facial surfaces (26) and an end surface (28). The swash plate (20) has a coating layer of at least 0.2 wt.% cobalt and the balance being tin. A piston (16) reciprocally fitted within the cylinder bore (18) contains shoes (24) which slideably intervene between the piston (16) and the swash plate facial surfaces (26). The shoes (24) transfer the rotational motion of the swash plate (20) to the linear motion of the piston (16). The coated surfaces (26) of the swash plate (20) are in slidable contact with the shoes (24). The coating on the swash plate (20) permits the use of low silicon alloy aluminium without the need of metal plating or high finish polishing.
Abstract:
In einen preßgegossenen Leichtmetallkolben für Verbrennungskraftmaschinen sind partiell Faserformkörper aus keramischen Kurzfasern, die parallel zu einer Ebene ausgerichtet sind, eingegossen. Zur Verbesserung der Verschleißfestigkeit des aus einer warmfesten Magnesiumlegierung bestehenden Kolbens weist der Kolbenschaft wenigstens im Bereich seiner Reibflächen eine 10 bis 30 µm dicke, eine Härte von 740 bis 850 HV 0,01 besitzende metallische, chemisch oder galvanisch abgeschiedene Laufschicht auf.
Abstract:
A piston is manufactured by incorporating a reinforcement which is formed at least in part by a fibre material and which is so non-uniform as to provide differing characteristics in the cast piston in predetermined differing regions of the piston. For example, the volumetric density of the fibres may be different in one region of the reinforcement as compared with another region in order to produce a more resistant region in the cast piston. Additionally or alternatively, the reinforcement may hold finely divided materials which combine with the piston material during casting to give improved properties. Examples of this are the incorporation of particles of silicon, silicon carbide or silicon nitride to improve wear and/or the incorporation of molybdenum disulphide and tungsten disulphide or graphite to improve lubrication.