Sealing gasket with one or more positioning protrusions

1 . A sealing gasket for a vacuum pump, the sealing gasket comprising:

a first surface;

a second surface opposite to the first surface;

opposing side walls disposed between the first and second surfaces;

a first sealing member defining a first closed shape;

a second sealing member defining a second closed shape;

a first longitudinal sealing member connected between a first facing axially inner face of the first sealing member and a second facing axially inner face of the second sealing member; and

a second longitudinal sealing member connected between the first facing axially inner face of the first sealing member and the second facing axially inner face of the second sealing member, wherein

the sealing gasket is a moulded, deformable, one-piece gasket,

the first sealing member, the second sealing member, the first longitudinal sealing member, and the second longitudinal sealing member have a square or rectangular cross section, and

one or more protrusions extend radially outwards from the first sealing member from the first surface that defines a radially outer wall of the first sealing member.

2 . The sealing gasket of claim 1 , comprising a plurality of protrusions extending from the first surface spaced apart from one another at discrete positions across the first surface.

3 . The sealing gasket of claim 1 , wherein the one or more protrusions extend perpendicularly from the first surface.

4 . The sealing gasket of claim 1 , wherein each of the protrusions has a cross section, the shape of which is a rounded polygon, a rounded square or a rounded rectangle.

5 . The sealing gasket of claim 1 , wherein each of the one or more protrusions comprises:

a proximal end at which the protrusion is connected to the first surface; and

a distal end opposite to the proximal end; and wherein:

a length of the protrusion between the proximal end and the distal end is between 1 mm and 6 mm.

6 . The sealing gasket of claim 1 , wherein each of the one or more protrusions comprises:

a proximal end at which the protrusion is connected to the first surface; and

a distal end opposite to the proximate end; and wherein:

the proximal end is spaced apart from one or both of the opposing side walls in a direction from one side wall to another side wall.

7 . The sealing gasket of claim 6 , wherein:

the proximal end is spaced apart from a first side wall in the direction from one side wall to another side wall by a distance of less than or equal to 0.4 mm; and/or

the proximal end is spaced apart from a second side wall in the direction from one side wall to another side wall by a distance of less than or equal to 0.4 mm.

8 . The sealing gasket of claim 1 , wherein the sealing gasket is an elastomer.

9 . The sealing gasket of claim 1 , wherein the first sealing member and the second sealing member define a respective closed shape of an annulus, a circle, an oval, an ellipse, a stadium, a rounded polygon, a rounded square, a rounded rectangle, or a squircle.

10 . The sealing gasket of claim 1 , wherein the first sealing member and the second sealing member each comprise a respective plurality of the protrusions which extend outwardly from a respective radially outer wall of the first sealing member and the second sealing member.

11 . The sealing gasket of claim 1 , wherein the vacuum pump, comprising comprises:

shell stators defining at least one pumping chamber;

end pieces mountable at either end of the shell stator; and

the sealing gasket, wherein

the shell stators or the end pieces define one or more seal grooves in which the sealing gasket is located;

the one or more seal grooves comprise one or more voids extending from a side wall of the seal grooves; and

the one or more protrusions are received in respective voids.

12 . The sealing gasket of claim 11 , wherein the voids are slots.

13 . The sealing gasket of claim 11 , wherein for each protrusion and the respective void in which it is received, the length of that void from an open end of the void to a closed end of the void is greater than the length of the portion of that protrusion that is within the void, thereby to allow for expansion of the protrusion within the void in the direction along the length of the protrusion.

14 . The sealing gasket of claim 11 , wherein for each protrusion and the respective void in which it is received, the width of that void in a direction that is perpendicular to the direction from an open end of the void to a closed end of the void is less than or equal to the width of the portion of that protrusion that is within the void, thereby to provide an interference fit of the protrusion in the void.