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.
