# US 11,993,902 B2 · Work machine having a breather device for gear case

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,993,902 B2
- Document ID: US11993902B2
- Status: Granted
- Kind: B2
- Application number: 18/322,808
- Filed: 2023-05-24
- Published: 2024-01-18
- Granted: 2024-05-28
- Earliest claimed: 2022-07-18
- Assignees: Honda Motor Co., Ltd.
- Applicants: Honda Motor Co., Ltd.
- Inventors: Takuya Matsumoto; Yoshitaka Ota; Atsushi Moroi
- Web page: https://patentgrep.com/patent/US11993902B2

## CPC

- E01H 5/04: Apparatus propelled by animal or engine power; Apparatus propelled by hand with driven dislodging or conveying {levelling} elements, conveying pneumatically {for the dislodged material}(E01H5/10, E01H5/12 take precedence)
- F16H 57/027: characterised by means for venting gearboxes, e.g. air breathers
- F16H 57/031: characterised by covers or lids for gearboxes
- F16H 57/039: Gearboxes for accommodating worm gears
- F16H 2057/02034: {Gearboxes combined or connected with electric machines}
- F16H 2057/02082: {for application in vehicles other than propelling, e.g. adjustment of parts}
- E01H: STREET CLEANING; CLEANING OF PERMANENT WAYS; CLEANING BEACHES; DISPERSING {OR PREVENTING} FOG IN GENERAL {CLEANING STREET OR RAILWAY FURNITURE OR TUNNEL WALLS}(cleaning in general B08B)
- F16H: GEARING

## Abstract

A breather device (140) for a gear case (82) defining a gear chamber (83) therein, comprising a breather chamber (146) defined in a part of the gear case; a breathing hole (152) formed in a wall part defining an upper part of the breather chamber so as to communicate the breather chamber with outside; a communication hole (148, 150) formed in a wall part separating a lower part of the breather chamber from the gear chamber so as to communicate the breather chamber with the gear chamber; and a separating wall (154) extending partly across the breather chamber so as to define a circuitous passage between the breathing hole and the communication hole.

## Claims

### Claim 1

A work machine, comprising
a lower body equipped with a travel unit;
an upper body equipped with a work unit, and pivotally supported by the lower body around a laterally extending pivot shaft for vertical adjustment of the work unit;
a lift device fixed to the upper body, which includes a gear case mounted on the upper body and an output shaft connected to the lower body via a link mechanism and provides the power required for raising the upper body relative to the lower body; and
a breather device provided on the gear case defining a gear chamber therein,
wherein the breather device comprising
a breather chamber defined in a part of the gear case;
a breathing hole formed in a wall part defining an upper part of the breather chamber so as to communicate the breather chamber with outside;
a plurality of communication holes formed in a wall part separating a lower part of the breather chamber from the gear chamber so as to communicate the breather chamber with the gear chamber; and
a separating wall extending partly across the breather chamber so as to define a circuitous passage between the breathing hole and the communication holes, and
wherein the plurality of communication holes includes a front communication hole and a rear communication hole provided in a front and a rear part of the wall part separating the lower part of the breather chamber from the gear chamber, respectively.

### Claim 2 (depends on 1)

The work machine according to claim 1, wherein the breather chamber is elongated in a prescribed direction, and the separating wall includes a first section extending vertically from an upper wall part of the breather chamber, and a second section extending from a lower end of the first section in the prescribed direction so as to be interposed between the breathing hole and the communication holes and define a gap between a tip end of the second section and an opposing peripheral wall part of the breather chamber.

### Claim 3 (depends on 2)

The work machine according to claim 2, wherein the gear case is configured to be mounted on the work machine that tilts in a fore and aft direction during operation, and the prescribed direction coincides with the fore and aft direction of the work machine.

### Claim 4 (depends on 3)

The work machine according to claim 3, wherein the breathing hole is positioned in a part of the breather chamber adjacent to an upper end and a front end of the breather chamber.

### Claim 5 (depends on 1)

The work machine according to claim 1, wherein the rear communication hole is provided with a larger opening area than the front communication hole.

### Claim 6 (depends on 1)

The work machine according to claim 1, wherein the gear case is provided with an upper extension defining a recess separated from the gear chamber and having an open side facing sideways, and the open side of the recess is closed by a lid plate so as to define the breather chamber jointly with the upper extension.