Gear pump

Claim 2

A gear pump or gear motor comprising a housing of synthetic plastic material having an internal chamber and an inlet and an outlet communicating with said chamber, a pair of meshing gears having opposite end faces provided in said chamber and each including a mounting shaft having journalling pins at its opposite ends; a plurality of cupped metallic journalling sleeves journalling the respective journalling pins for rotation, each of said sleeves having an open side facing into said chamber, a closed side provided with a transverse wall extending at least in part exteriorly of said housing and exposed to the ambient atmosphere, and a transverse flange in engagement with said respective end faces of said gears so as to conduct heat from said gears via said transverse wall to the exterior of said housing; spring clamps having intermediate and transversely extending end portions embedded in the material of said housing, and said transversely extending end portions engaging said flanges at the sides thereof facing away from the respective end faces of said gears for pressing said flanges against said end faces.

Claim 3

A gear pump or gear motor as defined in claim 1, said chamber being in part bounded by a substantially cylindrical surface; and wherein said sleeves have respective flanges each encircling one of said open sides and bounding said chamber together with said substantially cylindrical surface.

Claim 4

A gear pump or gear motor as defined in claim 2, said gears having respective axial end faces; and wherein said flanges are in engagement with respective ones of said end faces.

Claim 5

A gear pump or gear motor as defined in claim 2; further comprising a substantially cylindrical metal-strip insert accommodated in said chamber and overlying said cylindrical surface; said insert having a length corresponding substantially to that of the respective gears.

Claim 6

A gear pump or gear motor as defined in claim 1, one of said shafts having a shaft portion extending to the exterior of said housing; and further comprising a cupped metallic retainer accommodating a shaft seal, said retainer having a transverse wall through which said shaft portion extends, and a circumferential wall which is at least in part exposed to the ambient atmosphere.

Claim 7

A gear pump or gear motor as defined in claim 1, wherein said inlet and outlet are at least in part constituted by tubular elements extending to the exterior of and projecting beyond said housing.

Claim 8

A gear pump or gear motor as defined in claim 1, wherein said sleeves are of aluminum.

Claim 9

A gear pump or gear motor comprising an integral housing of plastic material having an internal chamber and an inlet and an outlet communicating with said chamber; a pair of meshing gears in said chamber and having opposite end faces and each including a mounting shaft having journalling pins projecting outwardly from the respective end faces, one of said journalling pins projecting beyond the outer surface of said housing and the other of said journalling pins ending short of said outer surface; a plurality of metallic journalling sleeves journalling the respective journalling pins and each having an open side at the respective end face, and each of said sleeves for said other of said journalling pins having a side formed by a transverse wall at the outer surface of said housing and exposed to the ambient atmosphere to thereby dissipate heat, each of said sleeves having a transverse flange in engagement with the respective end face of said gears; substantially U-shaped spring clamps embedded in the material of said housing and engaging said flanges at the sides thereof facing away from the respective end faces of said gears for pRessing said flanges against said end faces; and a cup-shaped retainer accommodating a shaft seal and having a transverse wall at said outer surface likewise exposed to the ambient atmosphere and provided with an opening through which said one journal pin projects.

Claim 10

A gear pump or gear motor comprising an integral housing of plastic material having an internal chamber and an inlet and an outlet communicating with said chamber; a pair of meshing gears in said chamber and having opposite end faces and each including a mounting shaft having journalling pins projecting outwardly from the respective end faces, one of said journalling pins projecting beyond the outer surface of said housing and the other of said journalling pins ending short of said outer surface; a plurality of metallic journalling sleeves journalling the respective journalling pins and each having an open side at the respective end face, and each of said sleeves for said other of said journalling pins having a side formed by a transverse wall at the outer surface of said housing and exposed to the ambient atmosphere to thereby dissipate heat, each of said sleeves having a transverse flange in engagement with the respective end face of said gears; substantially U-shaped spring clamps embedded in the material of said housing and engaging said flanges at the sides thereof facing away from the respective end faces of said gears for pRessing said flanges against said end faces; and a cup-shaped retainer accommodating a shaft seal and having a transverse wall at said outer surface likewise exposed to the ambient atmosphere and provided with an opening through which said one journal pin projects.