Claims
- 1. A pump for conveying a liquid polymer melt comprising:a pump housing having a melt inlet and a melt outlet, conveying means mounted in the housing for conveying a liquid polymer melt from said melt inlet to said melt outlet, said conveying means including a drive shaft which extends through a bearing bore in said housing and which includes an external end for connection to a drive, and a cooling sleeve tightly mounted to the pump housing and coaxially surrounding the portion of the external end of the drive shaft which is adjacent said housing so as to form a narrow annular gap therebetween which communicates with said bearing bore, and the cooling sleeve defines a free end spaced from the housing, and with the cooling sleeve having at least one annular cooling rib mounted adjacent said free end of the cooling sleeve with the annular cooling rib being configured to retain any melt which leaks through said narrow annular gap.
- 2. The pump as defined in claim 1 wherein the cooling sleeve has an axial length which at least equals the diameter of the drive shaft.
- 3. The pump as defined in claim 2 wherein the one cooling rib includes an annular collar so that the cooling rib forms a receptacle adapted to retain any melt which leaks through said annular gap.
- 4. The pump as defined in claim 2 wherein the cooling sleeve has an internal bore, and wherein one of the drive shaft and the internal bore includes a helical groove which is configured to advance the melt in the gap back toward the bearing bore during operative rotation of the drive shaft.
- 5. The pump as defined in claim 2 wherein the cooling sleeve has an internal bore which includes a helical groove which is configured to advance the melt in the gap back toward the bearing bore during operative rotation of the drive shaft.
- 6. The pump as defined in claim 2 wherein the conveying means comprises at least one pair of meshing gears.
- 7. The pump as defined in claim 2 wherein a plurality of annular cooling ribs are mounted to the exterior of the sleeve in an axially spaced apart arrangement.
- 8. The pump as defined in claim 7 wherein at least one of said annular ribs is mounted to the exterior of the sleeve so as to be axially adjustable.
- 9. The pump as defined in claim 2 wherein a pressure relieving connection extends through the housing from the bearing bore to the melt inlet.
- 10. The pump as defined in claim 9 further comprising an annular chamber formed in one of the pump housing and the cooling sleeve adjacent the juncture of the bearing bore and the annular gap, and with said annular chamber communicating with said pressure relieving connection.
- 11. A multiple gear pump for distributing a melt flow of a liquid polymer melt received from a pressurized melt line, comprisinga pump housing, a plurality of planetary gears mounted on respective planetary shafts within the pump housing, a drive shaft mounting a sun gear within the pump housing which is in operative engagement with each of said planetary gears so as to form a plurality of distributor gear pumps, a plurality of distribution channels extending from a melt inlet in the housing to respective distributor gear pumps, a plurality of outlet channels extending from respective distributor gear pumps to respective melt outlets in the housing, said drive shaft extending through a bearing bore in said housing and including an external end for connection to a drive, and a cooling sleeve tightly mounted to the pump housing and coaxially surrounding the portion of the external end of the drive shaft which is adjacent said housing so as to form a narrow annular gap therebetween which communicates with said bearing bore, and the cooling sleeve defines a free end spaced from the housing, and with the cooling sleeve having a heat dissipating annular rib mounted adjacent said free end of the cooling sleeve, with the heat dissipating annular rib being configured to retain any melt which leaks through said narrow annular gap.
- 12. The pump is defined in claim 11 wherein the heat dissipating rib includes an annular collar so that the rib forms a receptacle adapted to retain any melt which leaks through the annular gap.
- 13. The multiple gear pump as defined in claim 11 wherein the cooling sleeve has an axial length which at least equals the diameter of said drive shaft.
- 14. The pump as defined in claim 13 wherein a plurality of heat dissipating annular ribs are mounted to the exterior of the cooling sleeve in an axially spaced apart arrangement.
- 15. The pump as defined in claim 14 wherein the cooling sleeve has an internal bore, and wherein one of the drive shaft and the internal bore includes a helical groove which is configured to advance the melt in the gap back toward the bearing bore during operative rotation of the drive shaft.
- 16. The pump as defined in claim 15 wherein a pressure relieving connection extends through the housing from the bearing bore to the melt inlet.
- 17. The pump as defined in claim 16 further comprising an annular chamber formed in one of the pump housing and the cooling sleeve adjacent the juncture of the bearing bore and the annular gap, and with said annular chamber communicating with said pressure relieving connection.
Priority Claims (1)
Number |
Date |
Country |
Kind |
198 55 943 |
Dec 1998 |
DE |
|
CROSS-REFERENCE TO RELATED APPLICATION
The present application is a continuation of international application No. PCT/EP99/09383, filed Dec. 1, 1999 and designating the U.S.
US Referenced Citations (8)
Foreign Referenced Citations (8)
Number |
Date |
Country |
24 44 843 |
Apr 1975 |
DE |
149 834 A2 |
Jul 1985 |
EP |
0 189 670 B1 |
Aug 1986 |
EP |
602 357 A1 |
Jun 1994 |
EP |
0 636 190 B1 |
Feb 1995 |
EP |
4-164180 |
Jun 1992 |
JP |
10-131872 |
May 1998 |
JP |
WO9419516 |
Sep 1994 |
WO |
Continuations (1)
|
Number |
Date |
Country |
Parent |
PCT/EP99/09383 |
Dec 1999 |
US |
Child |
09/618931 |
|
US |