MSD 7R SHEARS
About the Attachment Section 2 Page 5
ATTACHMENT GLOSSARY
Lower Shear The lower stationary jaw of the shear. The lower shear contains the lower cutting blades, the guide blade,
and the cross blade.
Main Bearing Hardened bushings that the main shaft of the shear rotates on during operation. There are two main
bearings, bolted in on both sides of the main pivot group.
Main Shaft The shaft on which the upper shear pivots causing the shearing action of the attachment.
Manifold Hydraulic block that directs the excavator’s hydraulic fl ow to the shear cylinder and rotation assembly.
Block
Motor Hydraulic rotation component that drives the turntable bearing or planetary gear box on rotating shears.
Nose Plate Steel plate across the front of the lower shear jaw. The profi le of the nose plate is a very important
maintenance item that must be built up and hardsurfaced to prevent wear of the parent material.
Primary The cutting blades in the shear jaws closest to the shear throat. There is a primary blade in both upper and
Blades lower shear jaws.
Rear Cylinder Pin that anchors the butt end of the shear cylinder inside the rear of the shear. The rear cylinder pin must be
Pin greased according to the instructions in this manual.
Rotation Hydraulic drive assembly allows full 360° continuous rotation of the shear. This option gives greater
Assembly positioning capabilities when processing with the mobile shear.
Secondary The cutting blades in the shear jaws farthest from the shear throat. There is a secondary blade in both the
Blades upper and lower shear jaws.
Shear Hydraulic cylinder that powers the cutting action of the shear. The barrel end of the cylinder attaches to the
Cylinder shear’s upper jaw and the rod end attaches to the rear cylinder lugs. The cylinder rod stays protected from
damage inside the shear.
Shear Stick The main body of the shear that includes the lower shear. This weldment must be regularly inspected for
damage.
Swivel Allows continuous hydraulic fl ow to the shear cylinder during rotation of shear without twisting hoses.
Manifold
Turntable Rotary gear bearing used in rotating shears. It is mounted to the shear stick and is driven by hydraulic
Bearing components in the upper head or mounting bracket. It is sometimes called a slewing ring.
Upper Shear Movable jaw of the shear that contains cutting blades, the Saber Tip, and the wear area for the slide pucks.
The shear cylinder articulates the upper shear into the lower shear to perform the cutting action.
