# US 12,180,959 B2 · Gear pump with intermeshing gear wheels enclosed by housing with bearing journals arranged on shaft axes and use thereof

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- Number: US 12,180,959 B2
- Document ID: US12180959B2
- Status: Granted
- Kind: B2
- Application number: 18/287,999
- Filed: 2022-03-07
- Published: 2024-06-20
- Granted: 2024-12-31
- Earliest claimed: 2021-04-30
- Assignees: Maag Pump Systems AG
- Applicants: Maag Pump Systems AG
- Inventors: René Triebe; Marc Finkeldei
- Web page: https://patentgrep.com/patent/US12180959B2

## CPC

- F04C 2/18: with similar tooth forms (F04C2/16 takes precedence)
- F04C 18/084: {Toothed wheels}
- F04C 2/08: of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
- F04C 13/002: {for homogeneous viscous liquids}
- F04C 15/00: Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00 (of pumps specially adapted for elastic fluids F04C18/00 - F04C29/00)
- F04C 15/0088: {Lubrication (of machines or engines in general F01M)}
- F04C 29/02: Lubrication (of machines or engines in general F01M); Lubricant separation (separation in general B01D)
- F16C 33/10: Construction relative to lubrication {(lubrication in general F16N)}
- F04C 2240/50: Bearings
- F04C 2240/54: Hydrostatic or hydrodynamic bearing assemblies specially adapted for rotary positive displacement pumps or compressors
- F04C 2240/56: Bearing bushings or details thereof
- F04C 2240/60: Shafts
- F04C: ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS (engines F03C); ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS

## Abstract

Gear pump with intermeshing gear wheels enclosed by a housing with bearing journals arranged on shaft axes, each projecting laterally from the gear wheels, which are mounted in the housing by means of slide bearings, having a slide bearing length, the slide bearings being lubricated with pumped medium. The invention is characterized in that a filling pocket with radial expansion is incorporated in each of the slide bearings in the region of a pump pressure side, the filling pocket being spaced from a gear-side end face of the respective slide bearing by a distance, so that a bar with a bar width with axial expansion corresponding to a slide bearing surface is formed, and in that a lubrication groove with a tampering cross-section is provided in each of the slide bearings, the lubricating groove starting from an end on the gearwheel side towards a slide bearing end and starting at the filling pocket on the gearwheel side and communicating therewith.

## Claims

### Claim 1

Gear pump with intermeshing gear wheels (1) enclosed by a housing with bearing journals (5, 6) arranged on shaft axes (9), each projecting laterally from the gear wheels (1), which are mounted in the housing by means of slide bearings (3), having a slide bearing length (L), the slide bearings (3) being lubricated with pumped medium, characterized in that:
a filling pocket (2) with radial expansion is incorporated in each of the slide bearings (3) in a region of a pump pressure side, the filling pocket (2) being spaced apart from a gear-side end face (7) of the respective slide bearing (3) by a distance (d), so that a bar (11) with a bar width (D) with axial expansion corresponding to a slide bearing surface is formed; and
a lubricating groove (4) with a tampering cross-section is provided in each of the slide bearings (3), the lubricating groove (4) starting from an end on a gearwheel side towards a slide bearing end and starting at the filling pocket (2) on the gearwheel side and communicating therewith.

### Claim 2 (depends on 1)

The gear pump according to claim 1, characterized in that the distance (d) between the gear-side end face (7) of the slide bearings (3) and the respective filling pocket (2) is 5% to 10%, preferably 7%, of the slide bearing length (L).

### Claim 3 (depends on 1)

The gear pump according to claim 1, characterized in that the bar width (D) is at least 1% to 10%, preferably 3%, of the slide bearing length (L).

### Claim 4 (depends on 1)

The gear pump according to one claim 1, characterized in that the filling pocket (2) has a maximum width (Br) in an axial direction with respect to the shaft axis (9) which is 5% to 20%, preferably 10%, of the slide bearing length (L).

### Claim 5 (depends on 1)

The gear pump according to claim 1, characterized in that the filling pocket (2) starts at an angle of 225° to 315°, preferably at 270°, with respect to a plane spanned by the two shaft axes (9) and in a direction of rotation of the gear wheels.

### Claim 6 (depends on 1)

The gear pump according to claim 1, characterized in that the filling pocket (2) ends at an angle of 315° to 360°, preferably at 330°, with respect to a plane spanned by the two shaft axes (9) and in the direction of rotation of a gear wheels (1).

### Claim 7 (depends on 1)

The gear pump according to claim 1, characterized in that a cross-section in a transition region (12) from the filling pocket (2) to the lubrication groove (4) is formed continuously.

### Claim 8 (depends on 1)

The gear pump according to claim 1, characterized in that the lubrication groove (4) runs at an acute angle (γ) with respect to the shaft axis (9) in a direction of the slide bearing end.

### Claim 9 (depends on 1)

The gear pump according to claim 1, characterized in that the lubricating groove (4) extends to the end of the slide bearing.

### Claim 10 (depends on 1)

The gear pump according to claim 1, characterized in that at least one of the journals (5, 6) has, at least over part of its axial extent, a journal diameter (DL) which lies in a range from 90% to 100% of a root circle diameter (DF) of a toothing of an associated gear wheel (1).

### Claim 11 (depends on 1)

Use of the gear pump according to claim 1 for conveying highly viscous conveying medium, such as polymer, with a mass percentage of inorganic fillers in total mass of conveying medium of more than 60%.