Axial, lateral and torsional force dampener
A downhole tool for dampening vibrational, lateral, compressive, and tensile forces exerted on sensor equipment inside a drillstring is described. The downhole tool is housed inside the drill string. The tool generally includes a bottom end shaft for connection to the drillstring and that is telescopically engaged within a compression housing and a torsional housing. The torsional housing enables the bottom end shaft to slide axially with respect to the torsional housing whilst preventing torsional movement of the bottom end shaft relative to the torsional housing. The compression housing is connected to the sensor equipment and operatively contains a first spring between the compression housing and the bottom end shaft that absorbs compression forces between bottom end shaft and compression housing.
1. A spring member for dampening axial forces comprising:
an elastomeric ring biased in a resting position and elastically deformable to a compressed position;
a first annular disc having a top surface and a hole in the center;
second annular disc having a bottom surface and a hole in the center;
an inner wall extending around an inner perimeter of the second annular disc; and
an outer wall extending around an outer perimeter of the first annular disc;
wherein the top surface of the first annular disc faces the bottom surface of the second annular disc and the inner wall of the second annular disc faces the outer wall of the first annular disc to align the holes of each annular disc and form a channel between the annular discs, and the elastomeric ring is disposed in the channel;
wherein the spring member is movable between:
a neutral position in which the first and second annular discs are spaced apart to define an outer annular gap between the outer wall and the elastomeric ring, and an inner annular gap between the top surface and the inner wall, such that the inner and outer walls do not contact the annular disc that they are facing;
a compressed position in which the inner and outer walls abut the annular disc that they are facing;
wherein movement from the neutral position to the compressed position causes the elastomeric ring to deform into the outer annular gap and to provide force dampening.
2. The spring member of claim 1 , wherein:
the outer wall extends from the first annular disc top surface; and
the inner wall extends from the second annular disc bottom surface.
3. A spring assembly comprising two or more spring members as defined in claim 1 , the two or more spring members stacked together to align the holes of the first and second annular discs of the two or more spring members.
4. The spring assembly of claim 3 further comprising at least one disc spring adjacent the spring member at an end of the spring assembly.
5. A downhole tool for connection to a drill string to dampen forces in equipment housed inside the drill string, the downhole tool comprising the spring assembly of claim 3 .