Excavator is one of the important equipment in modern engineering construction. The excavator can rotate left and right during work, which is inseparable from the credit of the slewing mechanism. It is one of the important components of the hydraulic excavator. The slewing mechanism is connected with the walking device through a slewing support, and the slewing drive device makes the platform rotate relative to the walking device and drives it to rotate around its central axis of rotation. Today, the editor will tell you about the existence and working principle of excavator slewing bearings for everyone to learn and understand.
1. The existence of slewing ring
1) rotary column slewing bearing
In the structure of the slewing column type slewing bearing, the rotating body and the supporting shaft form a rotating column, which is inserted into the bearing of the bearing seat. The bearing seat is bolted to the frame. The shell of the swing cylinder is also fixed on the frame, and its output shaft is inserted into the lower bearing. The rotating body is driven to rotate relative to the frame. The working device is hinged on the revolving body and revolves with the revolving body, and the rotation angle is not more than 180°.
- Rolling bearing type slewing ring
Rolling bearings are compared with ordinary bearings. The speed is very slow, and the commonly used structure has two types: single-row ball and double-row ball. The single-row ball slewing bearing is mainly composed of inner ring, outer ring, isolator, rolling element and upper and lower sealing devices. The steel balls are separated by rolling elements, and the inner ring or outer ring is processed into an inner ring or an outer ring.
The inner gear ring is fixed on the walking frame, and the outer ring is firmly connected with the rotary platform. The slewing drive device is fixedly connected to the slewing platform and generally consists of a slewing hydraulic motor, a planetary reducer, and a slewing drive pinion. Through the meshing transmission of the driving pinion and the ring gear, The rotary device revolves around the inner ring gear while rotating. Thereby driving the platform to rotate 360°.
- Working principle of transmission
When the excavator is working, the position of the combined force of the upper part of the turntable and the load is constantly changing, and is biased towards the direction of the load. In order to balance the load moment, each device on the turntable needs to be reasonably arranged, and a counterweight is set at the tail to improve the force of the lower structure of the turntable, reduce the wear of the slewing bearing, and ensure the stability of the whole machine.
As the speed increases, the flow rate required by the swing motor also increases. When all the oil of the hydraulic pump is supplied to the swing motor, the start phase ends. The accumulator releases its energy at this moment, so the hydraulic pump and the oil from the accumulator are supplied to the slewing motor together, which speeds up the speed of the slewing motor. This is the second stage of starting.
The above is a brief introduction to the existence form and working principle of the excavator slewing bearing. Here is a reminder that after the excavator is used for a period of time, its slewing bearing is prone to noise, impact and other faults. The operator should pay attention to observe and check in time to eliminate malfunction. Only correct and reasonable maintenance and maintenance of the slewing ring can ensure its normal operation, give full play to its performance and extend its service life.