Pulleys - JRC

Pulleys are the heart of conveyors. A single failure can halt the entire system, demanding exceptional reliability.
To withstand harsh conditions like belt tension and winding, precise design and proper material selection are essential.
JRC thoroughly performs strength calculations based on proprietary standards and provides safe, reliable pulleys through integrated production at specialized factories.

Internal Structure Lineup

Type A

Welds the end plate to the boss, wi th the boss and shaft fixed by shrink fitting. Commonly used for a wide range of load capacities.

Type B

Similar to A-Type, but with a larger thickness difference between the end plate and shell. Reduces stress concentration by minimizing the thickness difference.

Type C

A-Type boss and end plate integrated. Eliminates welding heat effects, suitable for high torque and small diameters where welding is difficult.

Type D

B-Type boss and end plate integrated, reducing shell thickness to minimize stress concentration like B-Type.

Type E

C-Type and D-Type fur ther integrated to the shell’s outer end. Welding is performed at low-stress areas to reduce strength loss. Primarily used for heavy-load applications.

Type S

B-Type’s boss and end plate integrated. The shell thickness is reduced towards the outer side to min imize stress concentration, similar to B-Type.

Type P

Boss and shaft secured by fasteners (e.g., Powerlock). Allows for shaft replacement and supports heavy loads and high torque. (*End plate shape can be A, B, C, or D.)

Precise Centering for Accurate Weld Positioning

Inaccurate centering can cause rotation irregularities, leading to premature damage of parts. This can result in increased costs and reduced efficiency. JRC’s solution to these problems is thorough precision centering.

Suppresses vibration and noise
Extends bearing life

Full Penetration Welding

When welding the (pulley) End Plate to the Shell or Boss, the joint surface of the End Plate is intentionally ground at an angle. The ground area is then filled by welding, fusing the previously separate materials together into a single unit.

Shrink Fit

The pulley employs a “heat-shrink fit” method for securing the shaft. This critical connection between the End Plate (Boss) and shaft requires precise machining to ensure dimensional accuracy. The Boss is heated with a burner to expand the bore, allowing the shaft to be inserted. As it cools, the bore contracts, creating a tight, secure fit. This design prevents unnecessary stress on the shaft.

Precision Machining

Shafts, shells, End Plate, and Boss are machined with micron-level precision—tighter tolerances than millimeters—where required, based on a thorough understanding of the necessary accuracy levels. This results in precision pulleys with minimal variation.