Claims
- 1. A two-stage positive displacement pump, said two-stage pump (1) being configured as a hybrid pump (3) comprising a reciprocating pump (5) and a diagram pump (10), said reciprocating pump being located on a side of the hybrid pump where pumping medium enters the hybrid pump, said reciprocating pump (5) having a comparatively large displacement volume (6) and a piston-cylinder space (7) which is sealed off with respect to a crank area (8) by means of a sealing membrane (9), and said diaphragm pump (10) being connected in series behind the reciprocating pump (5), said diaphragm pump having a displacement volume (11) which is appreciably smaller than that of the reciprocating pump (5).
- 2. A two-stage positive displacement pump according to claim 1, wherein the displacement volumes (6, 11) of the hybrid pump (3) are at least approximately matched to each other in such a way that, at a given operating vacuum, the reciprocating pump (5) has an expulsion volume which is at least approximately equal to the suction volume of the diaphragm pump (10).
- 3. A two-stage positive displacement pump according to claim 1, wherein at least one pump (5, 10) of the hybrid pump (3) comprises a floating piston (18, 19).
- 4. A two-stage positive displacement pump according to claim 1, wherein the reciprocating pump (5) of the hybrid pump (3) has a piston head with a sealing collar that, upon insertion into the piston-cylinder space (7), takes on a U-shaped cross-section.
- 5. A two-stage positive displacement pump according to claim 1, wherein the diaphragm pump (10) of the hybrid pump (3) has a molded membrane (22), with a front side (24) which faces an adjacent pumping area wall (23) and is matched in shape to it.
- 6. A two-stage positive displacement pump according to claim 1, wherein the reciprocating pump (5) and the diaphragm pump (10) of the hybrid pump (3) are driven by a common crankshaft (26).
- 7. A two-stage positive displacement pump according to claim 6, wherein the pumps (5, 10) are aligned in the direction of the hybrid pump's longitudinal axis (L).
- 8. A two-stage positive displacement pump according to claim 1, wherein the hybrid pump (3) is provided with at least an approximate balancing of mass of all of moving masses in rigard to the reciprocating pump (5) and the diaphragm pump (10).
Priority Claims (2)
Number |
Date |
Country |
Kind |
9305554 U |
Apr 1993 |
DEX |
|
43 20 963.7 |
Jun 1993 |
DEX |
|
CROSS-REFERENCE TO RELATED APPLICATION
This application is a division of U.S. application Ser. No. 08/226,165, filed Apr. 11, 1994, now U.S. Pat. No. 5,387,090.
US Referenced Citations (10)
Foreign Referenced Citations (4)
Number |
Date |
Country |
2302425 |
Aug 1976 |
FRX |
2903786 |
Aug 1979 |
DEX |
8808819 |
Oct 1988 |
DEX |
3710782 |
Oct 1988 |
DEX |
Non-Patent Literature Citations (3)
Entry |
English Translation of portions of German Office Action dated Jan. 10, 1994 in couterpart German Priority Application P 43 20 963.7-15. |
"LABOVAC.RTM. Linear-Membranpumpen und Kolbenpumpen" Brochure of SASKIA Hochvakuum und Labortechnik GmbH. |
"LABOVAC.RTM. D 65-D Dry Trochen Sec" Brochure of SASKIA Hochvakuum und Labortechnik GmbH. |
Divisions (1)
|
Number |
Date |
Country |
Parent |
226165 |
Apr 1994 |
|