VACUUM PUMP FOR A MOTOR VEHICLE ENGINE

• US 20100196187A1
• Filed: 07/03/2007
• Published: 08/05/2010
• Est. Priority Date: 07/03/2007
• Status: Active Grant

• Current Assignee: O.M.P. Officine Mazzocco Pagnoni S.R.L.
• Original Assignee: O.M.P. Officine Mazzocco Pagnoni S.R.L.
• Inventors: De Rango, Alessandra, Pazzi, Giovanni, Pachetti, Carlo, Lo Biundo, Giuseppe
• Granted Patent: US 9,670,928 B2
• Time in Patent Office: Days
• US Class Current: 418/259
• CPC Class Codes: F01C 21/0881 the vanes consisting of two or more parts
• CPC Class Codes: F04C 18/3442 the surfaces of the inner and outer member, forming the inlet and outlet opening
• CPC Class Codes: F04C 2220/10 Vacuum
• CPC Class Codes: F04C 27/001 Radial sealings for working fluid

Abstract

A vacuum pump for a motor vehicle engine which has a stator and a chamber, has a side wall, and the side wall has a transversal section with a predetermined shape. The rotor mounted in the chamber is capable of rotating around a rotation axis parallel to the side wall. The vane mounted on the rotor is free to slide in a direction at right angles with respect to the rotation axis of the rotor, and the vane has a predetermined length and two opposite end portions that substantially slide along the side wall of the chamber. At least one of the end portions of the vane has at least one part that has a bend radius substantially equal to that of a part of the side wall, when the one vane is at a reference operating position.

Claims

1. A vacuum pump for a motor vehicle engine, comprising:

a stator;

a chamber defined inside said stator, said chamber having a side wall whose transversal section has a predetermined shape;

a rotor mounted in said chamber and capable of rotating around a rotation axis parallel to said side wall;

at least one vane mounted on said rotor and free to slide in a direction at right angles with respect to the rotation axis of said rotor, said at least one vane having a predetermined length and two opposite end portions that substantially slide along the side wall of said chamber;

at least one of said end portions of said at least one vane comprised of at least one part having a bend radius substantially equal to that of a part of said side wall, when said at least one vane is at least one reference operating position.

2. The vacuum pump according to claim 1, wherein said at least one reference operating position is defined at a configuration of maximum stress of the end portions of said at least one vane against the side wall of the chamber.

3. The vacuum pump according to claim 1, wherein said at least one vane is free to slide in a direction passing through the rotation axis, of said rotor, the external circumference of said rotor is tangential to the side wall of the chamber along a tangential line parallel to the rotation axis of the rotor, and the side wall comprises a part shaped as a circumferential arc having a predetermined radius, each of said end portions of said at least one vane comprising at least two parts having respective bend radii that are different from one another.

4. The vacuum pump according to claim 3, wherein each of said end portions of said at least one vane comprises two opposite parts which are symmetrical with respect to a longitudinal axis of said at least one vane and having respective bend radii substantially equal to said predetermined radius.

5. The vacuum pump according to claim 3, wherein each of said end portions of said at least one vane comprises a first part having a bend radius substantially equal to said predetermined.

6. The vacuum pump according to claim 5, wherein each of said end portions of said at least one vane comprise a second part substantially parallel to a longitudinal axis of said at least one vane.

7. The vacuum pump according to claim 5, wherein said first parts of said end portions are positioned on opposite sides with respect to the longitudinal axis of said at least one vane.

8. The vacuum pump according to claim 3, wherein said parts of each of said end portions of said at least one vane are radiused, at a longitudinal axis of said at least one vane, by an arc of circumference.

9. The vacuum pump according to claim 8, wherein the diameter of the ideal circumference that defines said arc of circumference is smaller than the thickness of said at least one vane.

10. The vacuum pump according to claim 9, wherein the ratio between the diameter of the ideal circumference that defines said arc of circumference and the thickness of said at least one vane ranges between about ⅕

and about ¼

.

11. A vane for a vacuum pump for a motor vehicle engine, comprising:

a central body and two opposite end portions that are substantially adapted to slide on a side wall of a chamber provided inside a stator of said vacuum pump;

at least one of said end portions of said vane comprises at least two parts having respective bend radii that are different from one another.

12. The vane according to claim 11, wherein each of said end portions comprises two opposite parts symmetrical with respect to a longitudinal axis of said vane and having respective bend radii substantially equal to a predetermined radius.

13. The vane according to claim 11, wherein each of said end portions comprises a first part having a bend radius substantially equal to a predetermined radius, and a second part substantially parallel to a longitudinal axis of said vane.

14. The vane according to claim 13, wherein said first parts of said end portions are positioned opposite the longitudinal axis of said vane.

15. The vane according to claim 11, wherein said parts of each of said end portions are radiused, at a longitudinal axis of said vane, by an arc of circumference.

16. The vane according to claim 15, wherein the diameter of the ideal circumference that defines said arc of circumference is smaller than the thickness of the vane.

17. The vane according to claim 16, wherein the ratio between the diameter of the ideal circumference (CI) that defines said arc of circumference and the thickness of the vane ranges between about ⅕

and about ¼

.