Abstract:
A lubricating oil for a compression-type refrigerator using a hydrofluorocarbon refrigerant including a polyvinyl ether-based compound containing in the molecule an alkylene glycol unit or a polyoxyalkylene glycol unit and a polyvinyl ether unit and having a molecular weight in the range of 300 to 3,000, and a refrigeration apparatus using the lubricating oil.The present invention can provide a lubricating oil for a compression-type refrigerator having good compatibility in the atmosphere of a hydrofluorocarbon and a high viscosity index, and a refrigeration apparatus using such a lubricating oil.
Abstract:
A lubricating oil for compression-type refrigerator includes, as a main component, a polyoxyalkyleneglycol derivative represented by the general formula: R1(OR2)m-OR3]n wherein R1 is a methyl group, R2 is a propylene group, R3 is a methyl group, n is an integer of 1 and m is an integer of 12 to 80, and 1,1,1,2-tetrafluoroethane. The derivative has a kinematic viscosity of 5 to 50 cSt at 100° C.
Abstract:
A hydraulic drive apparatus in which a hydraulic pressure motor is driven and rotated depending on an operation position entered from an operation lever. An oil pressure control circuit and method which detect pressures of operation oils capable of driving the hydraulic pressure motor to rotate and a pressure of an operation oil supplied from a hydraulic pump to a directional control valve. The oil pressure control circuit varies a set pressure of a main relief valve in a manner that feeds current to an electromagnetic relief valve and varies a set pressure of an electromagnetic relief valve. As a result, the oil pressure control circuit carries out such a control that a pressure of an operation oil received from the hydraulic pump is higher than a pressure of an operation oil for driving and rotating the hydraulic pressure motor by a predetermined pressure.
Abstract:
There is provided an electrohydraulic motor that has a spool valve 110 for switching from each of drive positions (111, 112), in each of which a corresponding one of a main oil passage 230 and a return oil passage 240 is connected to a hydraulic actuator 130, to a neutral position, in which the hydraulic actuator 130 and each of the main oil passage 230 and the return oil passage 240 are disconnected, and vice versa. There is also provided a connection switch valve 140, which is connected to the main oil passage 230 and the return oil passage 240, for changing the connection between the main oil passage 230 and the return oil passage 240 in the neutral position 113. In response to an operation of the spool valve 110, the connection switch valve 140 connects the main oil passage 230 to the return oil passage 240 in the neutral position 113 and also disconnects the main oil passage 230 from the return oil passage 240 in the drive positions (111, 112).
Abstract:
Disclosed is a lubricating oil for compression-type refrigerator comprising, as a main component, a polyoxyalkyleneglycol derivative represented by the general formula: R1[(OR2)mOR3]n wherein symbols are as defined in the specification. Said lubricating oil has a favorable compatibility with refrigerants and an excellent lubricating property, and is utilized as the lubricating oil for compression-type refrigerator employing hydrogen-containing fluorocarbon compound refrigerants including R-134a or fluorocarbon compound refrigerants without hydrogen.
Abstract:
A method of production of an ether compound from an acetal compound or a ketal compound which is excellent in conversion and selectivity and does not cause corrosion of apparatuses and a novel useful polyvinyl ether compound as lubricating oil for compression-type refrigerators, electric insulation oil and the like are disclosed. The method of production of the present invention comprises reaction of an acetal compound or a ketal compound with hydrogen in the presence of a solid catalyst having acidic property and hydrogenation ability to produce the corresponding ether compound. The polyvinyl ether compound of the present invention comprises the constituting unit expressed by the general formula: ##STR1## (characters in the general formula are the same as those described in the specification), contains none of unsaturated bond, acetal structure and aldehyde structure in the molecule and has weight average molecular weight in the range of 300 to 3000.
Abstract:
The present invention relates to a process for producing glycol monoesters by reacting carboxylic acid, olefin and oxygen in the presence of a catalyst containing (A) a palladium component, (B) an oxygen-containing nitrogen compound, and (C) a metal halide in the specified ratio of (A), (B), (C).According to the present invention, the regeneration of the catalyst through reduction is easy and the catalyst of high activity can be used repeatedly.
Abstract:
An engine cooling device comprises an oil jacket surrounding a cylinder portion of an engine, an oil gallery supplying high-pressure oil to various parts of the engine, and an oil pressure regulator disposed between the oil jacket and the oil gallery to reduce the pressure of the high-pressure oil supplied from the oil gallery and to supply the oil at a reduced pressure to the oil jacket. Thus, the required mechanical strength of the oil jacket can be decreased to decrease the weight of the engine cylinder block.
Abstract:
Adamantane compound is obtained by isomerizing a tricyclic saturated hydrocarbon having 10 to 14 carbon atoms in the presence of an X- or Y-type zeolite catalyst subjected to ion exchange with one or two kinds of metal ions selected from the group consisting of ions of rare earth metals, calcium and magnesium. The preferred catalyst is a catalyst which is further loaded with 1 to 4 kinds of metals selected from the group consisting of germanium, platinum, rhenium, nickel, cobalt, copper, iron ruthenium and rhodium. This isomerization reaction is preferably carried out in the presence of hydrogen gas.
Abstract:
The present invention provides a polyvinyl ether compound containing an alkylene glycol or polyoxyalkylene glycol unit and a vinyl ether unit in a molecule and having a molecular weight in the range of 300 to 3,000. It shows high volume resistivity and a high viscosity index, so it can be favorably used as lubricating oil for a compression refrigerator.