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Patent Searching and Data


Title:
BENT AXIS TYPE HYDRAULIC ROTATING MACHINE
Document Type and Number:
WIPO Patent Application WO/2011/162128
Kind Code:
A9
Abstract:
On the surface of a cylinder block (6), a surface treatment layer (15) is formed in such a way as to cover the entire surface including a center hole (7) and a plurality of cylinder holes (8). The surface treatment layer (15) consists of a manganese phosphate chemical conversion coating (18) and a nitrided layer (17) which is formed by applying nitriding-based heat treatment to the base material (16) for the cylinder block (6), said base material (16) being formed using an iron-based material such as cast iron, cast steel, or the like. The chemical conversion coating (18) is such that a phosphate manganese chemical conversion coating is formed on the surface of the nitrided layer (17). This chemical conversion coating (18) excels in initial adaptivity with respect to sliding members such as tapered pistons (10) and the like. Therefore, it is possible to restrain wear in areas of contact between the tapered pistons (10) and the cylinder holes (8) in the cylinder block (6).

Inventors:
NUMAGUCHI KAZUHIRO (JP)
NIIDOME TAKASHI (JP)
TSUBO TAKAHIRO (JP)
OKUNO NAOYUKI (JP)
Application Number:
PCT/JP2011/063586
Publication Date:
March 08, 2012
Filing Date:
June 14, 2011
Export Citation:
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Assignee:
HITACHI CONSTRUCTION MACHINERY (JP)
NUMAGUCHI KAZUHIRO (JP)
NIIDOME TAKASHI (JP)
TSUBO TAKAHIRO (JP)
OKUNO NAOYUKI (JP)
International Classes:
F04B1/24; F03C1/24; F04B53/00; F04B53/14; F04B53/16
Attorney, Agent or Firm:
HIROSE KAZUHIKO (JP)
Kazuhiko Hirose (JP)
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Claims: