# US 2018/0320686 A1 · Gear pump device for rubber extrusion

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

- Number: US 2018/0320686 A1
- Document ID: US20180320686A1
- Status: Published application
- Kind: A1
- Application number: 15/770,639
- Filed: 2016-10-03
- Published: 2018-11-08
- Earliest claimed: 2015-11-05
- Assignees: Sumitomo Rubber Industries, Ltd.; Nakata Engineering Co., Ltd.
- Applicants: Sumitomo Rubber Industries, Ltd.; Nakata Engineering Co., Ltd.
- Inventors: Hiroyuki ONIMATSU; Nozomu NISHIOKA; Hiroshi IHARA; Noboru ISHIHARA; Naoyasu NAKAO
- Web page: https://patentgrep.com/patent/US20180320686A1

## CPC

- F04C 2/18: with similar tooth forms (F04C2/16 takes precedence)
- F01C 19/005: {Structure and composition of sealing elements such as sealing strips, sealing rings and the like; Coating of these elements (vane construction F01C21/0809; piston rings and ring sealings of similar construction in general F16J9/00)}
- F04C 2/16: with helical teeth, e.g. chevron-shaped, screw type {(for non-parallel axes of movement F04C3/00)}
- F04C 13/002: {for homogeneous viscous liquids}
- F04C 15/0015: {of resilient material}
- F04C 15/0038: {Shaft sealings specially adapted for rotary-piston machines or pumps}
- F04C 15/0019: {Radial sealing elements specially adapted for intermeshing-engagement type machines or pumps, e.g. gear machines or pumps}
- F04C 2240/56: Bearing bushings or details thereof
- F04C: ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS (engines F03C); ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F01C: ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES (internal-combustion aspects F02B53/00, F02B55/00)

## Abstract

In a gear pump device for rubber extrusion, prolongation of the maintenance intervals is intended by preventing rubber scorch occurring at the gear support-shaft portion. It has a bushing ring 5 inserted in a gear-housing bore 3 of a housing 4. The bushing ring 5 rotatably supports a support-shaft portion 7 of a gear 2 accommodated in the gear-housing bore 3. The bushing ring 5 has a bearing 15 and a sealing means 16 built-in. The sealing means 16 includes a seal ring 22 of which cross section is ]-shaped and which has a first lip portion 22i contacting with the outer peripheral surface of the support-shaft portion 7, a second lip portion 22o disposed outside thereof in the radial direction, and a side wall portion 22m connecting between outer ends in the axial direction, of the first and second lip portions 22i, 22o.

## Claims

### Claim 1

A gear pump device for rubber extrusion,
which has a pair of gears engaged with each other, a housing having a gear-housing bore housing a pair of the gears, and a bushing ring inserted in the gear-housing bore at end portions thereof in the axial direction, and
which is characterized in that
the gear has a gear portion and a shaft portion concentrically extending from the gear portion toward both sides in the axial direction,
the bushing ring has a bearing and a sealing means built-in, the bearing rotatably supporting the support-shaft portion, and the sealing means disposed inward of the bearing in the axial direction and sealing between it and the outer peripheral surface of the support-shaft portion, and
the sealing means includes a sealing ring which is formed from a rubber elastic body whose cross section is ]-shaped and which has a cylindrical first lip portion contacting with the outer peripheral surface of the support-shaft portion, a cylindrical second lip portion disposed outside thereof in the radial direction, and a side wall portion connecting between axially outer ends of the first and second lip portions.

### Claim 2 (depends on 1)

The gear pump device for rubber extrusion as set forth in claim 1, which is characterized in that
the bushing ring has a ring-shaped bushing base portion concentrically inserted in the gear-housing bore, and
the inner peripheral surface of the bushing base portion has a circumferential-groove-shaped bearing-retaining groove accommodating the bearing, and a circumferential-groove-shaped sealing-means-retaining groove accommodating the sealing means and formed inside thereof in the axial direction in succession.

### Claim 3 (depends on 2)

The gear pump device for rubber extrusion as set forth in claim 2, which is characterized in that
the sealing means has a ring-shaped holder concentrically inserted in the sealing-means-retaining groove,
the inner peripheral surface of the holder is provided in its inside in the axial direction with a circumferential-groove-shaped seal-ring-retaining groove accommodating the seal ring, and
an inner end in the axial direction, of the seal-ring-retaining groove opens in the inside surface in the axial direction, of the holder.