The TYWZ2-400 series foot - operated hydraulic drum brake is a normally - open, foot - controlled hydraulic drum brake, mainly used for small and medium - sized cranes, light - duty lifting equipment, and other machinery that requires manual, reliable braking and has no power supply. It is an upgraded version of the TYW - 400, featuring a more stable structure and an automatic gap - balancing device. Below is a detailed introduction covering its core parameters, structure, working principle, applications, maintenance, and troubleshooting.
Core Technical Parameters
| Parameter | TYWZ2 - 400 Standard Value |
|---|---|
| Drum diameter | 400 mm |
| Rated braking torque | 0-800 N·m (adjustable) |
| Hydraulic system pressure | 2-5 MPa |
| Brake shoe clearance | 0.8-1.2 mm (auto - balanced) |
| Friction lining | Non - asbestos semi - metallic, original thickness 14 mm (replace when ≤3 mm) |
| Foot pedal stroke | 150-200 mm (adjustable) |
| Recommended oil type | ISO VG 32/46 hydraulic oil |
| Operating environment | -20℃ to +50℃, relative humidity ≤90% |
| Weight | ~84 kg |
| Compliance standard | JB/T 6406-2006 |
Structural & Design Features
Foot - Hydraulic Integrated Control: It has a foot - operated hydraulic pump unit (with pressure relief valve and return spring) connected to the brake body via a high - pressure hose, no external power needed.
Auto - Balancing Clearance Device: The interlocking shoe clearance balancing and auto - aligning devices keep the two - side shoe clearance equal, avoiding one - side dragging and reducing manual adjustment.
Fail - Safe Spring & Parking Lock: A built - in return spring enables emergency braking when the hydraulic system fails. The foot pedal is equipped with a locking pin for parking.
Quick - Change Linings: The clip - on friction linings can be replaced without disassembling the entire brake body, saving time.
Self - Lubricating Hinges: Hinge points use self - lubricating bearings to minimize wear and maintenance frequency.
Working Principle
It adopts a normally - open, hydraulically closed working mode, suitable for manual on - demand braking:
Braking (Pedal Pressed): Pressing the foot pedal makes the hydraulic pump generate pressure. The pressure is transmitted to the brake cylinder, pushing the brake arms to open the shoes and clamp the drum for braking. The pressure relief valve adjusts the maximum braking force.
Release (Pedal Released): Releasing the pedal lowers the hydraulic pressure. The return spring resets the pump, and the brake's return spring pulls the shoes back, separating them from the drum.
Emergency/Parking: If the hydraulic system fails, the return spring triggers braking. The pedal locking pin can lock the released state for parking.
Typical Applications
It is ideal for scenarios requiring manual, reliable braking without power access, such as small/medium gantry cranes, jib cranes, workshop trolleys, light - duty conveyors, and mobile maintenance platforms. It provides stable deceleration and accurate positioning for load lowering and parking.
