How to disassemble and assemble slewing bearings correctly

2020-02-29

Slewing bearings are not only widely used in machinery and equipment, but also widely used in entertainment venues, ports, and life. So how to disassemble the slewing bearing? What should I pay attention to when disassembling? I believe there are not many people who know about it. Now let’s take a look at the basic guidelines for disassembly and assembly of slewing bearings.

The slewing bearing is closely matched with the shaft, so when disassembling, the bearing and the shaft can be removed from the housing together, and the bearing can be removed from the shaft with a press or other disassembly and assembly tools.

When disassembling the outer ring, it is necessary to install several outer ring extruding screws on the circumference of the shell, which can be disassembled while tightening the screws. These screw holes are usually covered with blind plugs, tapered roller bearings and other separable bearings, set up several stoppers on the housing shoulder, use spacers, use a press to disassemble, or gently tap to disassemble.

The disassembly of the cylindrical bore bearing is generally easier to pull out with a press. But pay attention to let the inner ring bear its pulling force. The oil pressure method is used to disassemble the inner ring of large bearings. Oil pressure is applied through the oil hole provided on the shaft, which is convenient for drawing. The inner ring of NU and NJ cylindrical roller bearings can be disassembled by induction heating. A method of heating a part in a short time to expand the inner ring before drawing.

Disassemble the small bearing with adapter sleeve, support the inner ring with the stopper fastened to the shaft, turn the nut back a few times, and use the spacer to knock it apart with a hammer. For large bearings, it is easier to use oil pressure to disassemble the bearing. The oil is pumped through the oil hole on the tapered shaft to expand the inner ring and disassemble the bearing.

Unloading is a simple and common method of disassembly. The structure of the machine is relatively simple, and the parts are solid or some unimportant parts, and most of them use this method to disassemble. Before disassembling, in order to reduce the resistance, lubricating oil is often used in the joints. Commonly used items for demolition are hand hammers, general fitter hand hammers, punches and pads. When unloading, different methods and steps need to be taken according to different machine structure, and the end face of the bushing being hammered should be padded with a pad. When unloading a small diameter bushing, it is better to use a step punch. The small diameter of the punch matches the inner hole of the bushing. The large diameter of the punch is about 0.5mm smaller than the outer diameter of the bushing. For the disassembly of large-diameter bushes and rolling bearings, casings are often used. Generally, when disassembling small bearing caps, the method of symmetrically driving the inclined pads is often used to open the bearing caps.

Pressure unloading and pulling unloading have many advantages over knock unloading. It applies uniform force, and the magnitude and direction of the force are easy to control. It can disassemble larger parts and parts with larger interference, and this disassembly method damages There are fewer opportunities for parts. However, pressure unloading and pulling unloading require corresponding machinery and things. Pressure unloading requires the use of pressure machine tools. Commonly used pressure machine tools include mechanical presses, interference presses and hydraulic presses.