Dismantled parts from PC200LC-8M0 C15621.
The Swing Machinery Assembly of a Komatsu PC200LC-8M0 excavator is a crucial component responsible for the rotational movement (swing) of the upper structure of the excavator. This assembly allows the operator to rotate the machine’s cabin, boom, arm, and bucket around the base (undercarriage), providing 360-degree movement. The swing mechanism is vital for positioning the machine during excavation, loading, and other operations.
Here’s a detailed description of the Swing Machinery Assembly:
1. Swing Drive Motor
- The swing drive motor is a hydraulic motor that powers the swing mechanism. It converts hydraulic pressure from the machine's main hydraulic system into rotational motion.
- The motor is typically a high-torque, low-speed motor, designed to provide smooth and controlled movement.
- When hydraulic fluid is pumped into the swing motor, it generates the force needed to rotate the excavator's upper structure.
2. Swing Reduction Gearbox
- The swing reduction gearbox is located between the swing motor and the swing pinion (gear). Its purpose is to reduce the high-speed rotational output of the motor to a slower, more powerful rotation.
- This multi-stage planetary gearbox ensures smooth and controlled movement, allowing the operator to precisely position the excavator’s upper structure.
- The reduction in speed increases torque, which is essential for rotating the heavy components of the excavator, such as the boom, arm, and attachments.
3. Swing Pinion Gear
- The swing pinion gear is a small gear that connects the swing motor and reduction gearbox to the swing circle (large gear).
- It engages with the large swing ring gear (swing circle) to convert the motor’s rotational motion into the rotation of the upper structure.
4. Swing Circle / Ring Gear
- The swing circle, also known as the swing bearing or ring gear, is a large circular gear mounted at the bottom of the upper structure, connecting it to the undercarriage.
- It interfaces with the swing pinion gear to rotate the upper structure. The ring gear is typically mounted horizontally and is designed to withstand the heavy loads associated with swinging the entire upper part of the excavator.
- The swing circle includes bearings that allow smooth rotation and reduce friction between the rotating and stationary parts of the machine.
5. Swing Bearing
- The swing bearing sits between the upper and lower structures of the excavator and allows for smooth, continuous rotation.
- This large bearing is designed to handle axial and radial loads, as well as the tilting moments that occur when the upper structure swings under load.
- It supports the weight of the upper structure and allows the excavator to rotate with minimal friction.
6. Swing Brake
- The swing brake is a critical safety feature in the swing machinery assembly. It can be applied to stop or hold the upper structure in position when the swing movement is not needed.
- The brake is either a mechanical or hydraulic brake, and it engages when the operator releases the swing control lever or in emergency situations to prevent unintentional rotation.
- The swing brake ensures the machine stays in a stable position, even on inclines or in high-load situations.
7. Swing Lock (optional)
- Some excavators are equipped with a swing lock mechanism, which locks the upper structure in place when it is not rotating. This prevents unintended movement during transportation or while working on uneven ground.
8. Hydraulic Lines and Valves
- The swing machinery is powered by the hydraulic system of the excavator. Hydraulic lines deliver pressurized fluid to the swing motor, while control valves regulate the flow of hydraulic fluid to ensure smooth and controlled operation.
- The valves are controlled by the operator through the swing control lever in the cabin.
Function:
The Swing Machinery Assembly allows the upper structure of the excavator to rotate 360 degrees around the undercarriage. This rotation is essential for performing a variety of tasks, such as:
- Positioning the Boom: The operator can swing the boom to different locations without moving the entire machine, making excavation more efficient.
- Loading and Unloading: The swing mechanism enables the operator to load trucks from different angles or move materials around the job site without needing to reposition the entire machine.
- Excavating Trenches or Holes: Continuous rotation is essential when digging or leveling over a large area.
Operation:
- Swing Left or Right: When the operator moves the swing control lever, hydraulic fluid is directed to the swing motor. The motor rotates, driving the swing pinion gear, which engages with the swing circle (ring gear), causing the upper structure to rotate left or right.
- Precise Control: The swing reduction gearbox slows down the motor’s rotation, providing high torque and allowing for precise, controlled movement of the upper structure.
- Stopping and Holding: When the swing lever is released, the swing brake engages, stopping the rotation and holding the upper structure in place until further input from the operator.
The Swing Machinery Assembly is essential for the versatility and efficiency of the excavator, allowing it to perform tasks in confined spaces, reposition materials, and complete excavation tasks without moving the entire machine. Its robust construction and smooth operation are critical for heavy-duty construction tasks.