PS50 Hydraulic Operated Disc Brakes for JC50 DRAWWORK

JC50 Disc Brake Actuator consists of brake disc, service calipers (normally open calipers), safety calipers (normally closed calipers) and caliper bracket. It provides service braking and safety parking braking functions.

1. Brake Disc

Installation location: Both sides of the JC50 drum shaft. The unilateral wear limit is 5 mm. Structure: Available in water-cooled and air-cooled types, serving as the reference surface for friction braking.

2. Service Calipers (Normally Open Calipers: 2 pcs per side for JC50)

Structure: Caliper body + single-acting hydraulic cylinder + brake pad + return spring. Hydraulic cylinder principle: Driller’s brake lever → proportional hydraulic oil supply. Rising oil pressure extends the cylinder piston and pushes the brake pads to clamp the brake disc; falling oil pressure retracts the brake pads via the return spring to release the brake. Function: Stepless speed control for normal tripping and drilling feed. The clamping force changes continuously with the handle oil pressure. Working oil pressure: 0～7.5 MPa. Clearance adjustment: The normal clearance between brake pad and disc surface is 1.0～1.5 mm.

3. Safety Calipers (Normally Closed Calipers: 1 pc per side for JC50)

Structure: Caliper body + disc spring cylinder + brake pad. Brake release state: Pressurized oil supplied to the safety oil circuit compresses the internal disc springs, separating brake pads from the brake disc. Braking state (pressure loss / power failure / emergency): Upon hydraulic pressure loss, disc springs release elastic force to force brake pads to lock onto the brake disc, realizing emergency braking and drum parking lock (preventing traveling block drop). Key feature: Braking is triggered automatically by mechanical force of disc springs in case of power cut, hydraulic pump failure or oil cutoff. The safety calipers of JC50 adopt an independent accumulator to maintain pressure for emergency braking.

4. Caliper Bracket Assembly

It is bolted onto both sides of the JC50 drawworks frame, fixing all service calipers and safety calipers respectively. It ensures brake pads are aligned facing the end face of brake disc and provides limiting function to prevent offse

PS40 and PS50 disc brake devices are equipped to drilling rig ZJ40 and ZJ50 , with drilling depth of 4000-5000 meters, maximum hook load of 2250KN-3150KN, with 6 sets of brake clamps, including 4 sets of working clamps, 2 sets of safety clamps, working brake torque of 90KN·M-115KN·M, and parking brake torque of 60KN·M-85KN·M

ZJ40-ZJ50 Actuator