The YJ type one-way shock absorber (bumper )is a kind of drilling tool . It can effect shock absorbing and shock reduction by means of elastic deforming and anticoagulation produced from hydraulic oil under the outside force . Its advantages such as simple structure , reliable working performance and easy to maintain can well absorb shocking and vibrating load from drill strings during drilling operation. Therefore, using of shock absorber can raise in structure the service life of drill bit and drill pipe , speed up drilling ,get rid of drilling jumping, well protect surface equipments and drilling tools.

Working principle

The hydraulic shock absorber is connected between drill bit and drill collar, the torque is transferred from top drill string to mandrel. The spline transfers torque to spline outer barrel , oil cylinder and lower sub , then drive drill bit to rotate.

The bit weight is from the which of top drill tool so that drill bit insert drill into formation to break rock into pieces. The drilling mud is fed through bore of drill pipe and drill collar into mandrel of shock absorber, tailpipe , lower sub bore and ejected into bottom well .Because of the uneven bottom well conditions and special structure of cone bit, the drill bit and drill string during drilling operation would produce severe vibration. The hydraulic shock absorber , by means of compressible deformation of compressed liquid under the function of pressure , absorb the energy from drill bit and drill string vibration. Thus, the shock

absorber can reduce the vibration and impact load of drill tools.