摘要:
Rotationsverdrängervakuumpumpe, insbesondere Drehschiebervakuumpumpe, mit einem Rotor, wenigstens einem an dem Rotor ausgebildeten Arbeitspumpabschnitt zur Förderung eines Arbeitsmediums entlang eines Mediumförderweges, wenigstens einem an dem Rotor ausgebildeten Steuerpumpabschnitt zur Förderung eines Steuerfluids, einem Sicherheitsventil zum zeitweisen Verschließen des Mediumförderweges, und einer mit dem Steuerfluid betriebenen Druckvorsteuerung für das Sicherheitsventil, wobei für die Druckvorsteuerung ein Überdruckventil vorgesehen ist.
摘要:
Polymers suitable for use as a viscosity index improver for lubricating oil compositions including hydrogenated linear polymers characterized by the formula: Dʹ - PA - Dʺ ; and hydrogenated star polymers characterized by the formula: Dʹ - PA - Dʺ n - X ; wherein D' represents an "outer" block derived from diene having a number average molecular weight of from about 10,000 to about 120,000 daltons; PA represents a block derived from monoalkenyl arene having a number average molecular weight of from about 10,000 to about 50,000 daltons; D" represents an inner random derived from diene having a number average molecular weight of from about 5,000 to about 60,000 daltons; n represents the average number of arms per star polymer formed by the reaction of 2 or more moles of a polyalkenyl coupling agent per mole of arms; and X represents a nucleus of a polyalkenyl coupling agent.
摘要:
Disclosed is a method of manufacturing magnetic disks, comprising a magnetic layer, a protective layer, and a lubricating layer on a substrate. In the process, a lubricant alpha comprising a compound denoted by chemical formula
wherein m and n are natural number, is fractionated by molecular weight to prepare a lubricant a having a weight average molecular weight (Mw) of from 3,000 to 7,000 and a molecular weight dispersion of less than or equal to 1.2; a lubricant beta comprising a compound denoted by the chemical formula
wherein m and n are natural number, is fractionated by molecular weight to prepare a lubricant b having a weight average molecular weight (Mw) of from 2,000 to 5,000 and a molecular weight dispersion of less than or equal to 1.2; a lubricant c comprising a mixture of lubricants a and b is prepared; and a film of lubricant c is formed on a protective layer provided on a substrate to form a lubricating layer. A magnetic disk comprising a magnetic layer, a protective layer, and a lubricating layer on a substrate, in which the lubricating layer has been formed on the protective layer is also enclosed.
摘要:
The present invention provides a grease composition containing a base oil (A), a urea-based thickener (B), and a polymer compound (C), wherein particles that contain the urea-based thickener (B) in the grease composition satisfying the following requirement (I), the polymer compound (C) having a number average molecular weight (Mn) of 30,000 or more and a molecular weight distribution (Mw/Mn) of 2.20 or less, the grease composition being superior in reduction of friction coefficient under conditions of low speed and low load. Requirement (I): the particles have an arithmetic average particle diameter on an area basis as measured by a laser diffraction/scattering method of 2.0 pm or less.
摘要:
Lubricating oil has a kinematic viscosity in a range of 1 mm 2 /S to 7 mm 2 /S at 40°C, has a mass average molecular weight in a range of 150 to 400, and contains 0.5% by mass or more of a high molecular weight component. The high molecular weight component has a mass molecular weight of greater than or equal to 500. A crankshaft serving as a shaft part of a compression element includes a main shaft that includes a sliding surface. In a case where the sliding surface is a single sliding surface, a length of the single sliding surface in an axial direction is a single sliding length L, whereas in a case where the sliding surface is divided into a plurality of sliding surfaces, a length of one of the sliding surfaces in the axial direction, the one sliding surface having a least length in the axial direction among the plurality of sliding surfaces, is the single sliding length L, and a ratio L / D of the single sliding length L to an external diameter D of the main shaft is less than or equal to 2.0.