Filter device

Patent metadata

Field	Value
Publication number	US-10821377-B2
Application number	US-201816210030-A
Country	US
Kind code	B2
Filing date	Dec 5, 2018
Priority date	Jun 29, 2016
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

An air vent hole includes a substantially columnar hole main body portion, a first hole portion formed on the upper side of the hole main body portion, and a second hole portion formed on the lower side of the hole main body portion. Each of the first hole portion and the second hole portion partly has, in a cross section of the hole portion substantially orthogonal to a first direction that is a longitudinal direction of the hole main body portion, a cross-sectional area smaller than a cross-sectional area of a cross section of the hole main body portion substantially orthogonal to the first direction. A float inserted into the air vent hole is movable between a position where the float occludes the first hole portion and a position where the float occludes the second hole portion. The float occludes the first hole portion under the weight of the float. However, the float is pushed up by air. Furthermore, the float is formed of a material having a smaller specific gravity than a liquid to be filtered. Thus, the float is pushed up by the liquid to occlude the first hole portion.

First claim

The invention claimed is:

1. An oil tank comprising a filter device, wherein the filter device is disposed inside the oil tank, and comprises:
a filter case including a substantially cylindrical side surface member, a bottom surface member covering a lower end of the side surface member, and a lid member covering an upper end of the side surface member, the filter case being internally provided with a substantially cylindrical interior space, wherein the filter case has a filter inside;
an air vent passage passing through an inside of the lid member and
an air vent portion assembled in a concavity of the lid member, the air vent portion being detachable from the lid member,
wherein the air vent portion includes:
an air vent hole allowing the interior space to communicate via the air vent passage with an exterior space of the filter case and including
a substantially columnar hole main body portion,
a first hole portion formed on the upper side of the hole main body portion and partly having, in a cross section of the first hole portion substantially orthogonal to a first direction that is a longitudinal direction of the hole main body portion, a cross-sectional area smaller than a cross-sectional area of a cross section of the hole main body portion substantially orthogonal to the first direction, and
a second hole portion formed on the lower side of the hole main body portion and partly having, in a cross section of the second hole portion substantially orthogonal to the first direction, a cross-sectional area smaller than the cross-sectional area of the cross section of the hole main body portion substantially orthogonal to the first direction; and

a float inserted into the air vent hole to be movable between a position where the float occlude the first hole portion and a position where the float occludes the second hole portion, the float being formed of a material having a smaller specific gravity than oil to be filtered,
wherein:
a minimum inner diameter of the cross section of the first hole portion is smaller than a maximum outer diameter of a cross section the float substantially orthogonal to the first direction;
a minimum inner diameter of the cross section of the second hole portion is smaller than a maximum outer diameter of a cross section the float substantially orthogonal to the first direction; and
the float is raised by the oil in the air vent hole, wherein the concavity of the lid member comprises:
a first cavity disposed on a lower end surface of the lid member, the lower end surface of the lid member being abutted on the filter case;
a second cavity having a smaller diameter than that of the first cavity is disposed on an air flow downstream side of the first cavity;
an opening of the air vent passage having a smaller diameter than that of the second cavity is disposed on an air flow downstream side of the second cavity;
wherein the air vent portion is fitted into the second cavity; and
wherein the air vent portion includes a lower end surface positioned above the lower end surface of the lid member.

2. The oil tank according to claim 1 , wherein
the first hole portion is a first tapered hole portion formed to have a diameter gradually decreasing upward,
the second hole portion is a second tapered hole portion formed to have a diameter gradually decreasing downward, and
the float has a substantially spherical shape having a diameter that is smaller than a diameter of the cross section of the hole main body portion substantially orthogonal to the longitudinal direction and that is larger than a diameter of a thinnest section of the first tapered hole portion and a diameter of a thinnest section of the second tapered hole portion, and the float is inserted into a space formed by the hole main body, the first tapered hole portion and the second tapered hole portion.

3. The oil tank according to claim 1 , wherein
the side surface member includes an inflow hole formed in a vicinity of the lid member to cause the oil to flow from a tangential direction at any point on a side surface of the filter case into the filter case, and
the air vent portion is provided at a position including a center axis of the interior space.

4. The oil tank according to claim 2 , wherein
the side surface member includes an inflow hole formed in a vicinity of the lid member to cause the oil to flow from a tangential direction at any point on a side surface of the filter case into the filter case, and
the air vent portion is provided at a position including a center axis of the interior space.

5. The oil tank according to claim 2 , wherein
the air vent portion includes a lower end surface positioned above a lower surface of the lid member.

6. The oil tank according to claim 3 , wherein
the air vent portion includes a lower end surface positioned above a lower surface of the lid member.

7. The oil tank according to claim 1 , wherein:
the air vent portion has a columnar shape with a flanged lower end; and
an upper end of the float is not allowed to move up beyond an upper end of the air bent portion.

8. The oil tank according to claim 7 , wherein:
a bottom surface of the flanged lower end is entirely flat.

Assignees

• Yamashin Filter Corp

Inventors

• Sasaki Nobuki
• Kitajima Nobuyuki
• Tsurusaki Yoshinori

Classifications

• B01D35/147 Primary

  Bypass or safety valves · CPC title

• B01D2201/64

  Filters having floating elements · CPC title

• F15B1/26

  Supply reservoir or sump assemblies · CPC title

• B01D36/001

  Filters in combination with devices for the removal of gas, air purge systems · CPC title

• B01D29/908

  provoking a tangential stream · CPC title