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: Disclosed is a lubricating oil for compression-type refrigerator comprising, as a main component, a polyoxyalkyleneglycol derivative represented by the general formula: R1&Brketopenst;(OR2&Parenclosest;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.

Abstract: An electro-hydraulic servomotor includes: an electric motor (41) which rotates a drive shaft (51) in response to an inputted signal; a hydraulic motor (60) which rotates an output shaft (61) using hydraulic pressure of operation oil; a first geared shaft (53) rotatable along with the output shaft (61); a second geared shaft (52) threadingly engaged with the drive shaft (51) and meshed with the first geared shaft (53); and a spool (71) axially movable along with the second geared shaft (52) depending on a rotational difference between the drive shaft (51) and the first geared shaft (53), to control supply and discharge of the operation oil to and from the hydraulic motor. (60).

Abstract: Disclosed is a lubricating oil for compression-type refrigerator comprising, as a main component, a polyoxyalkyleneglycol derivative represented by the general formula: 1

Abstract: There is disclosed a lubricating oil for compression-type refrigerators comprising a polyvinyl ether compound which contains a constituting unit represented by the general formula (I), a polyvinyl ether compound which contains constituting units represented by each one of the general formulae (I) and (II), or a mixture of these polyvinyl ether compounds, as the main component thereof. Ratio by mol of carbon to oxygen in the above polyvinyl ether compounds is 4.2 to 7.0. Also disclosed is a lubricating oil for compression-type refrigerators comprising a polyvinyl ether compound containing constituting units which are both represented by the general formula (I) but between which R.sup.5 is different.

Abstract: A method of production of polyvinyl ether compound by which the polyvinyl ether compound having a desired degree of polymerization is produced reliably, safely and efficiently and a novel polyvinyl ether compound useful as lubricating oil for compression-type refrigerators, electric insulation oil and the like are disclosed. The method of production of the present invention is a method of producing a polyvinyl ether compound which comprises polymerizing a vinyl ether compound in the presence of a Lewis acid catalyst and a specific acetal or a method of producing a polyvinyl ether compound which comprises forming an acetal by reaction of a vinyl ether compound with a specific alcohol in the presence of a Lewis acid catalyst, then adding the vinyl ether compound to the acetal and polymerizing the vinyl ether compound. The polyvinyl ether compound of the present invention is homopolymer or a copolymer of an alkyl vinyl ether comprising the constituting unit expressed by the general formula: ##STR1## (R.sup.

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: A polyoxyalkylene glycol derivative which has at least one constitutional unit represented by the general formula: ##STR1## wherein R.sup.1 to R.sup.4 are each hydrogen, a monovalent hydrocarbon group having 1 to 10 carbon atoms or a group represented by the general formula: ##STR2## wherein R.sup.5 and R.sup.6 are each hydrogen, a monovalent hydrocarbon group having 1 to 10 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms, R.sup.7 is an alkylene group having 2 to 5 carbon atoms, a substituted alkylene group having 3 to 5 total carbon atoms with an alkyl group as a substituent, or a substituted alkylene group having 4 to 10 total carbon atoms with an alkoxyalkyl group as a substituent, n' is an integer of 0 to 20 and R.sup.8 is a monovalent hydrocarbon group having 1 to 10 carbon atoms with at least one of R.sup.1 to R.sup.4 being a group represented by the general formula (II).

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.

Abstract: A lubricating oil for compression-type refrigerators which comprises as the main component thereof a polyvinyl ether compound having excellent compatibility with a hydrofluorocarbon or a hydrochlorofluorocarbon, such as 1,1,1,2-tetrafluoroethane and the like, which can be used as the refrigerant to replace compounds causing environmental pollution, such as dichlorofluoroethane and the like, and having an excellent lubricating property is disclosed. The lubricating oil for compression-type refrigerators comprises as the main component thereof a polyvinyl ether compound having the constituting units expressed by the general formula: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 are H or a hydrocarbon group of C.sub.1.about.8, R.sup.4 is a bivalent hydrocarbon group of C.sub.2.about.10, R.sup.5 is a hydrocarbon group of C.sub.1.about.10 and m is 0.about.10.

Abstract: A lubricating oil for compression-type refrigerators which comprises as the main component thereof a polyvinyl ether compound having excellent compatibility with a hydrofluorocarbon or a hydrochlorofluorocarbon, such as 1,1,1,2-tetrafluoroethane and the like, which can be used as the refrigerant to replace compounds causing environmental pollution, such as dichlorofluoroethane and the like, and having an excellent lubricating property is disclosed. The lubricating oil for compression-type refrigerators comprises as the main component thereof a polyvinyl ether compound having the constituting units expressed by the general formula: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 are H or a hydrocarbon group of C.sub.1.about.8, R.sup.4 is a bivalent hydrocarbon group of C.sub.2.about.10, R.sup.5 is a hydrocarbon group of C.sub.1.about.10 and m is 0.about.10.

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: Disclosed is a lubricating oil for compression-type refrigerators comprising, as a main component, a polyoxyalkylene glycol derivative which has at least one constitutional unit represented by the general formula: ##STR1## wherein R.sup.1 to R.sup.4 are as defined in the specification. Said lubricating oil for compression-type refrigerators has good miscibility with refrigerants including R-134a.

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: A continuous granulator of the double-screw type includes a mechanism by which the degree of kneading can be controlled, and prevents lateral communication between the screw ends. A gear pump connected after the screw cylinders delivers the material to the cutting unit.

Abstract: An engine cooling apparatus separately cools a cylinder head and a cylinder block which are positioned around upper and lower portions of an engine combustion chamber. For increased engine output power, the engine cooling system cools the cylinder head to a relatively low temperature and the cylinder block to a relatively high temperature. The cylinder block includes cylinder liners disposed in an oil jacket which is supplied with oil from an oil circulating system via a pressure reducing valve. Oil in the oil jacket returns through a return path into an oil reservoir in the engine, and air bubbles in the oil jacket are returned to the oil reservoir via an air bubble return passage which develops a pressure difference between its opposite open ends.

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: A process for introduction of styrenes in the side chain of substituted aromatic compounds, said side chain containing at least one hydrogen atom in the .alpha.-position thereof, is disclosed, comprising reacting the styrenes and the substituted aromatic compounds in the presence of (A) an alkali metal and (B) a compound containing a benzyloxy group or alkyl and/or aryl-substituted benzyloxy group. Use of (A) and (B) as a reaction accelerator permits to introduce the styrenes in the side chain of the substituted aromatic compounds in high yield and selectivity.

Abstract: The invention provides a novel class of compounds dicyclohexylcyclopentanes or, in particular, 1,3-dicyclohexyl-1-methyl cyclopentane which is synthesized by the hydrogenation of 1-methyl-1,3-diphenyl cyclopentane which in turn is obtained by the dimerization reaction of .alpha.-methylstyrene in the presence of metallic sodium as the catalyst. The compound is useful as a fluid for traction drive.