Hitachi, Ltd.

Hitachi Construction Machinery Co., Ltd.

Masaya Imai

Kenji Tojo

Masao Shiibayashi

Eiichi Hazaki

Yasuo Takahashi

Masato Ikegawa

Mitsuru Fujiwara

Katsuhiko Kasuya

Tetsuzo Matsunaga

Seiji Watanabe

Eiji Kometani

An oil feeding device for a scroll fluid apparatus including an oil flow passage in the crankshaft providing oil to the crank pin bearing, an intermediate pressure chamber, and the sealed spaces between the scroll members.

Oil feeding device for scroll fluid apparatus

An oil feeding device for plain bearings supporting a crankshaft connected to an orbital scroll member in a scroll fluid apparatus, including axially extending oil flow passages formed on the outer peripheral surface of the crankshaft at portions journaled by the plain bearings but displaced from the lines of action of lateral loads caused by fluid pressure in the sealed space between two scroll members, thereby generating bearing oil film reactions commensurate with the lateral loads, so as to produce an optimum oil film pressure distribution for the bearings at all times.

In a screw rotor including a female rotor member and a male rotor member rotatable about parallel shafts and respectively while meshing with each other, the forward face flank of the female rotor member is composed of a first flank of the forward face formed by a parabolic curve, and a second flank of the forward face formed by a circular arc of a radius R.sub.2, and the backward face flank of the female rotor member is composed of a first flank of the backward face generated by the backward face tooth top flank of the male rotor member having a radius R.sub.5, and a second flank of the backward face formed by a circular arc of a radius R.sub.3 which is smaller than the radius R.sub.2 of the second flank of the forward face flank. The tooth profile of the male rotor member is essentially formed by the forward face flank and the backward face flank of the female rotor member.

Screw rotor with specific tooth profile

An oil-cooled type screw rotor assembly having a female rotor and a male rotor adapted to rotate around parallel axes in meshing relation to each other. The leading side flank of the female rotor is constituted by a first leading side flank formed by an arc of a radius R.sub.1 and a second leading side flank formed by an arc of a radius R.sub.2. Also, the trailing side flank of the female rotor is constituted by a first trailing side flank formed by an arc of the tooth ends of the male rotor having a radius R.sub.5 and a second trailing side flank formed by an arc of a radius R.sub.3 which is smaller than the radius R.sub.2 of the second leading side flank. The configuration of the teeth of the male rotor is materially formed by arcs of the leading and trailing side flanks of the female rotor.

Male and female screw rotor assembly with specific tooth flanks

A scroll-type fluid apparatus including an orbiting scroll member, a stationary scroll member, and a plurality of pockets formed in at least one of the orbiting scroll member and the stationary scroll member to cooperate with the other scroll member for confining liquid therein. When an axially urging force is ecerted on the orbiting scroll member, a liquid pressure commensurate with the axially urging force is produced in the pockets, so that such liquid pressure cancels out a biased axially urging force (moment) exerted on the orbiting scroll member.

Scroll-type fluid apparatus provided with means for counteracting a

A scroll-type fluid machine is provided with a plurality of liquid-confining pockets formed in the sliding surface of the end member of either one of orbiting and stationary scrolls. In operation, a high liquid pressure is generated in the pocket or pockets positioned in the region where a localized high axial urging force is exerted during operation, so that the localized high axial urging force acting on the two scrolls is partially or fully negated.

Scrool-type fluid machine with liquid-filled force-balanced pockets

A mechanical seal comprises, in addition to a rotating seal element, a stationary seal element, and a support ring: means for securing the support ring to a rotating shaft in such a manner that, between a casing and the shaft, the ring remains nonrotatable by the shaft but can travel axially following any axial movement of the shaft. The securing means comprises nonrotational stop means located between the casing and support ring and means located between the ring and shaft to permit the both to rotate relative to each other but keep them from moving axially. The nonrotational stop means is a combination of pins and holes, key ways and keys, or the like, and the means located between the ring and shaft to permit the both to rotate is either a pair of rolling bearings or a plurality of journal bearings plus a thrust sliding bearing.

Mechanical seal

A hydraulic pump or motor having: oil grooves in the internal partial-spherical surface of a piston for introducing pressure oil between said internal partial-spherical surface and a ball; oil grooves in the peripheral surface of the large diameter portion of said piston for introducing pressure oil between the outer peripheral surface of the large diameter portion of said piston and a cylinder; small diameter passages provided through said piston and extending from the upper end of said piston to said oil grooves, while communicating with an oil chamber for said piston; and necked or throttle portions provided in said small diameter passages, respectively, to thereby give rise to pressure drops for oil which is passing through said small diameter passages.

Growing community of inventors

Ibaraki, Japan

Masaya Imai