Balance beam pin part number 1563100003 156-31-00003 is for bulldozer SD32 spare parts.

Balance beam pin part number 1563100003 156-31-00003 is suitable for bulldozer SD32 spare parts.

The balance beam pin is a key connecting component in the excavator chassis travel system. Its core function is to securely connect the balance beam (or "track carrier" or "track frame") to the excavator's underframe (main frame/chassis), while allowing the balance beam to swing at a certain angle on rough terrain.

1. Location and Structure

Location: Located inside the track travel system on both sides of the excavator. One end connects to the excavator's underframe (chassis body), and the other end passes through the mounting hole of the balance beam.

Structure: Typically a large, robust cylindrical alloy steel shaft. Its dimensions and strength are designed according to the excavator's tonnage to withstand enormous impact loads and shear forces. The pins typically have threads or grooves at both ends for mounting and securing nuts, snap rings, baffles, or locking devices to prevent accidental dislodgement during operation.

Matching Components: Wear-resistant bushings (or bushings, copper bushings) are installed between the pin and the mounting holes of the balance beam. The pin surface is usually hardened or designed with lubrication channels. Bushings or wear plates are also installed at the connection between the pin and the frame. Seals (oil seals) are required at both ends to prevent dirt and water from entering and to prevent lubricant leakage.

2. Core Functions

Connection and Load Bearing: This is the most fundamental function. The pins firmly fix the balance beam to the frame, directly bearing the load transmitted from the excavator's entire weight to the tracks and the ground (especially when the machine is parked on uneven ground), as well as various dynamic loads (impact, vibration, torsional forces) generated during travel, steering, and operation.

Providing Swing Freedom: The balance beam design allows it to swing at a certain angle around the pin axis in the vertical plane. This is the key mechanism by which the excavator's travel system adapts to uneven terrain:

When one track encounters a bump or depression, the balance beam on that side can swing up or down.

The other track maintains better ground contact, ensuring overall machine stability and even track ground pressure, reducing bumps, and improving mobility.

Transmitting driving/braking forces: During travel, the balance beam bears driving or braking forces from the drive/idler wheels, which are transmitted to the chassis via pins.

The balance beam pin is a crucial "joint" component in the excavator's travel system. It robustly connects the balance beam and the main frame, withstands significant static and dynamic loads, and allows the balance beam to swing to adapt to the terrain, ensuring the excavator's smoothness, mobility, and safety. Regular, proper lubrication is key to maintaining its lifespan; any abnormal wear or damage must be addressed promptly to avoid serious consequences.