Hitachi Construction Machinery Co., Ltd.

Other

Hitachi Chemical Company, Ltd.

Hitachi Powdered Metals Co., Ltd.

Nippon Valqua Industries, Ltd.

Hideki Akita

Osamu Gokita

Shigeyuki Sakurai

Akira Kurasako

Yoshiya Hamamachi

Kotaro Ogura

Hiroshi Nishimura

Hideaki Kawata

Motohiro Miyasaka

Hidekazu Tokushima

Daisuke Fukae

Makoto Sugaya

Kazuyoshi Hatano

Tatsuo Takamure

Osamu Mawatari

Ryohei Suzuki

Kazuo Maruyama

Michiharu Mogami

Teruo Nakamura

Hiroshi Onose

Manabu Ogasawara

Hatsuhiko Usami

Yoshiaki Sekiguchi

Hiromasa Muraki

Yuuji Igawa

Noriyuki Ando

Hiroki Takami

Katsutoshi Hakozaki

Akiko Sato

Makoto Ota

Yasuchika Nagai

Hidekazu Motoki

Wataru Minami

Tomiyoshi Yamazaki

Minoru Fujisaki

Hajime Maezawa

Shuichi Kobayashi

Hideaki Nakatani

Eiji Negoro

Nobuo Yanaka

Hideyuki Fujiya

Akiko Satou

Junichi Kobayashi

Provided is a sliding component having a low coefficient of friction and capable of exerting stable sliding characteristics from the initial stage of sliding, and a manufacturing method capable of easily manufacturing the sliding component. A sliding component () includes an iron substrate (), in which graphite particles () are dispersed in an iron base (), and a tin coating () formed on the iron substrate (), the tin coating () including tin as a main material. The graphite particles () of the sliding component () are exposed through the tin coating (). The manufacturing method includes: a preparation step of preparing an iron substrate () including graphite particles () dispersed in an iron base (); and a film forming step of forming a tin coating () on the surface of the iron substrate (), the tin coating () including tin as a main material. The film forming step forms the tin coating () so that the graphite particles () are exposed through the tin coating ().

Sliding component and method for manufacturing same

It is made possible to prevent damage to hydraulic parts of a work machine due to a decrease in performance of a hydraulic fluid even when the hydraulic fluid of a hydraulic system is changed and the hydraulic fluid becomes a mixed oil in which a mineral oil and a biodegradable oil are mixed with each other. For this purpose, a storage device stores, in advance, oil change history information of the hydraulic fluid, oil kind determination values for determining whether the hydraulic fluid is either the mineral oil or the biodegradable oil or the mixed oil of the mineral oil and the biodegradable oil, and abnormality determination values for respective kinds of the hydraulic fluid. A controller checks whether the oil change history information includes oil change information for which oil kind determination has not been made. When there is oil change information for which oil kind determination has not been made, the controller determines a kind of the hydraulic fluid on the basis of the respective values of a plurality of oil properties detected by an oil sensor and the oil kind determination values. The controller determines an abnormality in the hydraulic fluid by using abnormality determination values corresponding to a result of determination of the kind of the hydraulic fluid.

Work machine management system

A computer for a manufacturer includes: a storage device storing amount-of-change determination values specified for respective amount-of-change indexes indicative of tendencies of temporal changes in pieces of sensor data A, B, and C, about a plurality of oil properties including a viscosity, a density, and a dielectric constant of oil; an abnormality determining section determining abnormality of the oil on the basis of the pieces of sensor data A, B, and C about the plurality of oil properties and abnormality determination values SAh, SAl, SBh, and SCh prescribed for the respective pieces of sensor data A, B, and C about the plurality of oil properties; a cause identifying section identifying, when the abnormality determining section determines the oil to be abnormal, the cause of the abnormality on the basis of the type of the oil property determined to be abnormal and the amount-of-change determination value of the oil property.

Oil diagnosis system

A diagnostic system for a work machine includes a data storage device () in which sensor information (A) input from a sensor (A) that senses an oil property of oil used for operation of the work machine and an abnormality degree determination value defined for each kind of the sensor information (A) are stored, and an arithmetic processing device () that executes first processing of discriminating the degree of abnormality level of the oil based on the sensor information (A) and the abnormality degree determination value, second processing of determining whether or not necessity to carry out oil analysis involving oil extraction exists based on the degree of abnormality level of the oil discriminated in the first processing, and third processing of outputting information indicating that the oil analysis is necessary to other terminal if it is determined that the oil analysis is necessary in the second processing.

Oil properties diagnostic system for work machine

A sliding bearing assembly for joints of construction equipment can be provided, in which production cost is reduced by decreasing the used amount of Cu and sulfides having high fixability to a matrix are dispersed. The sliding bearing assembly for joints of construction equipment, includes at least a shaft and a bush made of an iron-based sintered material which functions as a sliding bearing, in which the bush has the overall composition of, by mass %, 0.1 to 10% of Cu, 0.2 to 1.2% of C, 0.03 to 0.9% of Mn, 0.36 to 1.68% of S, and the balance of Fe and inevitable impurities, a metal structure has pores dispersed in a matrix mainly including a martensite structure and sulfide particles precipitated and dispersed, and the sulfide particles are dispersed at 1 to 7 volume % in the matrix.

Sliding bearing assembly

A floating seal () is provided between a mounting bracket () fixed to a side frame () and a roller () rotatable with respect to this mounting bracket (), and lubricant oil (L) collected in the roller () is sealed by this floating seal (). On the other hand, an air permeable plug () provided with an air permeable member () made of a porous material of interconnected cells is provided on a lid member () of the roller (), air and/or water vapor is made to flow between the inside and the outside of the roller () and flow of lubricant oil (L) and/or rainwater and dusts is prevented by the air permeable member () of the air permeable plug (). As a result, the pressure of the inside and the pressure of the outside of the roller () can be made equal all the time.

Rotation device for construction machine

Provided are a novel sliding bearing and a construction machine provided with same, the sliding bearing being capable of maintaining an excellent sliding performance over a long period of time and exhibiting an excellent strength. A sliding bearing includes at least a brush and a shaft part, the shaft part being provided with a grease feeding pathway for feeding grease from the exterior to the sliding surfaces of the shaft part and the bush, the bush being formed from a porous sintered metal, and a decomposition catalyst being adhered to the sliding surface of the bush.

Sliding bearing and construction machine provided with same

A dust seal is provided with a tubular fitting portion, a bush end surface abutting portion, a lip portion and a sealing projection integrally formed. The sealing projection is formed to project in an axially opposite direction to the lip portion from a radial inner section of the bush end surface abutting portion and abuts against a chamfered portion of a bush in such a manner as to overlap the chamfered portion. Therefore, at the time of supplying lubricant between the bush and a connecting pin, the sealing projection can prevent a part of the lubricant from entering between an end surface of the bush and the bush end surface abutting portion of the dust seal to maintain a sealed state therebetween. In consequence, the dust seal can be stably held on the inner peripheral side of a boss member, preventing the pulling-out of the dust seal.

Bearing device

Grease for a slide bearing, which can suppress unusual noise attributable to a slip caused between a shaft and a bearing when a machine is stopped. In slide bearing greasesupplied to between a slide bearingformed of a porous sintered alloy-made bushing having poresimpregnated with lubricating oiland a shaftinserted in the slide bearingand supported to be slidingly rotatable in the circumferential direction, the slide bearing greaseemploys base oil having dynamic viscosity of 10-70 mm/s at 40&#xb0; C. and exuding under a load of the shaftto form an oil filmbetween the slide bearingand the shaft

Grease for slide bearing

An oil-impregnated sintered sliding bearing formed of a porous iron-based sintered alloy with quenched structure and receiving a high surface pressure capable of reducing the number of finishing steps by cutting and grinding and providing a bearing performance equivalent to or higher than that of conventional bearings, wherein a plurality of ridge-and-groove lines having a height difference of 2 to 12.5 &#x3bc;m and extending in circumferential direction are axially arranged in parallel with each other by boring the bearing surface thereof to form a wavy surface in axial direction, and the portion thereof deeper by 10 to 60 &#x3bc;m from the outer layer of the bearing surface is formed dense to seal surface pores so as to reduce the pores opening to the outer surface to 1 to 10 percent by area, whereby the bearing can be used at a surface pressure of 6 kgf/mm(58.5 MPa) or higher and a sliding speed of 2 to 5 cm/s.

Oil-impregnated sintered sliding bearing

A seal () is constituted by an outer lip portion () to be held in abutting engagement with an outer link portion () of a crawler belt (), an inner lip portion () to be held in abutting engagement with a bush (), and an interconnecting bridge portion () bridged and connected between the outer and inner lip portions (). The outer lip portion () on the side of track link, the inner lip portion () on the side of bush, and outer bridge portion (A) and inner bridge portion (B) of the interconnecting bridge portion () are formed in thicknesses (T, T, T' and T&#x2032;), respectively, which are in the relations of (TT&#x2032;&#x3e;T&#x2248;T&#x2032;). A maximum outside diameter portion (C) of the interconnecting bridge portion () is located radially outward of a median point between inner and outer peripheral ends of the lip portion () on the side of bush. The inner lip portion () as a whole is uniformly pressed against an end face (A) of the bush () by the interconnecting bridge portion ().

Crawler belt and seal for use therein

A seal device ( ) for a bearing system ( ) is constituted by first and second seal rings ( ) and ( ). The first seal ring ( ) is constituted by a lip seal ( ) having a lip portion ( B) in sliding contact with an end face ( B) of a bush ( ) which is fitted on a joint shaft ( ), and a slide tube ( ) having a seal surface ( C) on an end face at an axial end away from the lip portion ( B) which is formed integrally with a tubular body portion ( A) of the lip seal ( ). The second seal ring ( ) is fixedly fitted in a boss ( ) radially on the outer side of the first seal ring ( ), and provided with a seal surface ( D) on the inner side of an annular inward collar portion ( C) for sliding contact with the seal surface ( C) of the slide tube ( ).

Sealing device

The improved slide bearing assembly comprises at least a shaft and a bush that is formed of a porous iron-base sintered material and is characterized in that the bush is impregnated with a lubricant oil having a viscosity of 240-1500 cSt. The bearing assembly can be operated in slow- and high-pressure applications without oil refillings for a prolonged period of at least several years. The shaft is preferably formed of an iron or a steel member that have been subjected to a treatment of surface modification. The slide bearing assembly is preferably used in such an environment that the working pressure applied to the sliding surfaces is at least 6.0 kgf/mm.sup.2 and that the sliding speed is in the range 2-5 cm/sec.

Slide bearing assembly

Growing community of inventors

Tsuchiura, Japan

Hideki Akita