Return filter

Patent metadata

Field	Value
Publication number	US-10272373-B2
Application number	US-201715843072-A
Country	US
Kind code	B2
Filing date	Dec 15, 2017
Priority date	Jun 18, 2015
Publication date	Apr 30, 2019
Grant date	Apr 30, 2019

Abstract

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.

First claim

The invention claimed is:

1. A return filter provided in a tank, comprising:
a filter element including a filtration member having a substantially cylindrical shape;
a filter case having a bottomed substantially cylindrical shape and provided with the filtration member therein;
an inflow portion configured to allow an inflow of oil and to communicate with a space between the filter case and the filter element;
an outflow portion having a substantially cylindrical shape and provided to a bottom surface of the filter case, the outflow portion being configured to communicate with a hollow portion of the filter element; and

a vortex forming portion provided in the outflow portion, the vortex forming portion including a blade member having a spiral shape,
wherein:
the vortex forming portion includes a tubular portion having a substantially cylindrical shape with a covered upper end, the tubular portion being formed extending along an axis of the blade member at a substantial center of the vortex forming portion;
the blade member includes, on a lower side thereof, a passage that crosses the blade member in a radial direction; and
the tubular portion and the outflow portion each include a hole that communicates with the passage.

2. A return filter provided in a tank, comprising:
a filter element including a filtration member having a substantially cylindrical shape;
a filter case having a bottomed substantially cylindrical shape and provided with the filtration member therein:
an inflow portion configured to allow an inflow of oil and to communicate with a space between the filter case and the filter element;
an outflow portion having a substantially cylindrical shape and provided to a bottom surface of the filter case, the outflow portion being configured to communicate with a hollow portion of the filter element;

a vortex forming portion provided in the outflow portion, the vortex forming portion including a blade member having a spiral shape;
an outflow pipe provided protruding downward from a bottom surface of the filter case, the outflow pipe being configured to communicate with the outflow portion; and
a lower end of the outflow pipe being covered by a lower end surface having a substantially truncated cone shape that increases in height and decreases in width toward a center, and a side surface of the outflow pipe in a vicinity of the lower end surface including a plurality of holes.

3. A return filter provided in a tank, comprising:
a filter element including a filtration member having a substantially cylindrical shape;
a filter case having a bottomed substantially cylindrical shape and provided with the filtration member therein;
an inflow portion configured to allow an inflow of oil and to communicate with a space between the filter case and the filter element;
an outflow portion having a substantially cylindrical shape and provided to a bottom surface of the filter case, the outflow portion being configured to communicate with a hollow portion of the filter element;

a vortex forming portion provided in the outflow portion, the vortex forming portion including a blade member having a spiral shape;
a lid configured to cover an upper end of the filter case;
a valve provided to the lid and configured to open and close depending on a difference in a pressure on an outer side of the filtration member and a pressure on an inner side of the filtration member; and
a bypass strainer configured to allow passage of the oil after passing through the valve, the bypass strainer including a frame having an inner peripheral surface to which the valve is fitted;
the filter element further including an upper plate that covers an upper end of the filtration member; and
the upper plate and the frame being integrated with each other.

4. The return filter according to claim 1 , further comprising an outflow pipe provided protruding downward from a bottom surface of the filter case, the outflow pipe being configured to communicate with the outflow portion,
a lower end of the outflow pipe being covered by a lower end surface having a substantially truncated cone shape that increases in height and decreases in width toward a center, and a side surface of the outflow pipe in a vicinity of the lower end surface including a plurality of holes.

5. The return filter according to claim 1 , further comprising:
a lid configured to cover an upper end of the filter case;
a valve provided to the lid and configured to open and close depending on a difference in a pressure on an outer side of the filtration member and a pressure on an inner side of the filtration member; and
a bypass strainer configured to allow passage of the oil after passing through the valve, the bypass strainer including a frame having an inner peripheral surface to which the valve is fitted;
the filter element further including an upper plate that covers an upper end of the filtration member; and
the upper plate and the frame being integrated with each other.

6. The return filter according to claim 2 , further comprising:
a lid configured to cover an upper end of the filter case;
a valve provided to the lid and configured to open and close depending on a difference in a pressure on an outer side of the filtration member and a pressure on an inner side of the filtration member; and
a bypass strainer configured to allow passage of the oil after passing through the valve, the bypass strainer including a frame having an inner peripheral surface to which the valve is fitted;
the filter element further including an upper plate that covers an upper end of the filtration member; and
the upper plate and the frame being integrated with each other.

7. The return filter according to claim 4 , further comprising:
a lid configured to cover an upper end of the filter case;
a valve provided to the lid and configured to open and close depending on a difference in a pressure on an outer side of the filtration member and a pressure on an inner side of the filtration member; and
a bypass strainer configured to allow passage of the oil after passing through the valve, the bypass strainer including a frame having an inner peripheral surface to which the valve is fitted;
the filter element further including an upper plate that covers an upper end of the filtration member; and
the upper plate and the frame being integrated with each other.

Assignees

• Yamashin Filter Corp

Inventors

• Taku Meiho
• Ishizuka Makoto
• Oshita Tatsuhiro

Classifications

• B01D29/925

  containing liquid displacement elements or cores · CPC title

• B04C3/06

  Construction of inlets or outlets to the vortex chamber · CPC title

• F15B1/26

  Supply reservoir or sump assemblies · CPC title

• B01D35/147

  Bypass or safety valves · CPC title

• F15B21/04

  Special measures taken in connection with the properties of the fluid · CPC title