Yamashin-filter Corp.

Tatsuhiro Oshita

Makoto Ishizuka

Meiho Taku

Nobuki Sasaki

Megumi Nomoto

A leakage of liquid inside a differential pressure detection device is reliably preventable. A diaphragm portion that detects a differential pressure as a pressure difference between a high pressure side and a low pressure side includes an annular member, a strain gauge provided in a hollow portion of the annular member, and a first plate and a second plate provided such that the annular member and the strain gauge are sandwiched. The first plate and the second plate each abut on a first annular packing. A first groove and a second groove (the first annular packing) overlap with the annular member when viewed from a first direction along an axis of the first hole.

Differential pressure detection device

A tank for storing oil includes a suction strainer with first and second filtration portions. The first filtration portion has a substantially cylindrical shape and formed by bending a thin plate into a pleated shape. The second filtration portion is provided on the outer side of the first filtration portion. The second filtration portion has a substantially cylindrical shape and is formed of a material having a plurality of spaces formed in a surface and interior of the material.

Suction strainer

When a lid covers an opening portion formed at an upper end of a filter case with a bottomed substantially cylindrical shape inside which a filter element is disposed, the internal space between the lid and the filter case is formed. A bypass flow path connecting the internal space and outside space is formed in the lid, and a relief valve disposed moveably between a position closing the bypass flow path and a position opening the bypass flow path includes an air bleeder formed from a porous material.

Filter device

A return filter is provided in a tank, for removing bubbles from hydraulic oil before returning the hydraulic oil to the tank. A vortex forming portion that includes a spiral-shaped blade member is provided in an outflow portion that has a substantially cylindrical shape and communicates with a hollow portion of a filter element. Thus, a vortex forms in the hydraulic oil flowing through the outflow portion and bubbles contained in the hydraulic oil are collected.

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Kanagawa, Japan

Tatsuhiro Oshita