How are the inner and outer ring raceways of a double row ball slewing ring processed?

What is double row ball slewing ring?

As the key component to realize the rotary motion of the equipment, the double row ball slewing ring is usually composed of the inner ring, the outer ring, two rows of steel balls and the holding frame, and the steel balls placed in the raceway of the inner and outer rings are evenly separated by the cage, and this structure enables it to bear large axial force, radial force and overturning moment at the same time; Its working principle is based on rolling friction, the inner ring and the outer ring rotate relative to each other when rotating, and the steel ball rolls in the raceway, through the reasonable design of the raceway curvature and the diameter of the steel ball, the load can be evenly distributed to improve the bearing capacity and service life. The bearing has significant performance advantages, not only because the double-row ball structure has a high bearing capacity, suitable for heavy-duty conditions, but also because of the high-precision raceway and steel ball processing to meet the high-precision operation needs of the equipment, and high-quality materials and reasonable design make it have a long life, reduce maintenance and replacement costs, and at the same time the structure is relatively simple, easy to install and disassemble.

Features of double row ball slewing bearings

Large bearing capacity: due to the double-row steel ball structure, it can withstand large axial force, radial force and overturning moment at the same time, and is suitable for slewing equipment that bears heavy loads.

High rotation accuracy: the machining accuracy of the raceway and steel ball is high, which can ensure the accuracy of the slewing ring in the rotation process and reduce the shaking and deviation.

Small friction coefficient: The rolling friction between the steel ball and the raceway is small, which can reduce energy loss and improve the transmission efficiency of the equipment.

Long life: After reasonable design and material selection, as well as strict processing technology control, the double row ball slewing ring has a long service life and can operate stably in harsh working environments.

How are the inner and outer ring raceways of a double row ball slewing ring processed

The machining of the inner and outer ring raceways of double row ball slewing rings is a complex process that usually includes the following main steps:

Forging blanks

First of all, according to the size and performance requirements of the slewing ring, select the appropriate steel, such as medium carbon steel or medium carbon alloy steel, etc., and process the steel into the approximate shape of the inner and outer ring blanks through the forging process. Forging can improve the internal structure of the steel, increase the strength and toughness of the material, and at the same time make it close to the shape of the final product, reducing the subsequent machining allowance.

rough machining

Turning the outer circle and end face: The outer circle and end face of the blank are turned with a lathe to achieve preliminary dimensional accuracy and surface flatness, which provides a benchmark for subsequent raceway machining.

Boring the inner hole: For the inner ring, it is necessary to use a boring machine to boring its inner diameter to ensure the dimensional accuracy and cylindricity of the inner hole, and to ensure the accuracy of the fit with other components.

Rough turning of raceway: use a special lathe or CNC machining center to rough turn the raceway with suitable tools, preliminarily form the contour shape of the raceway, and leave a certain machining allowance for subsequent finishing.

Heat treatment

The heat treatment of the inner and outer rings after rough machining is carried out, and the commonly used heat treatment methods include quenching and tempering. The hardness and wear resistance of the raceway surface can be improved through quenching, and the tempering can eliminate the quenching stress, improve the toughness of the material, and make the raceway have good comprehensive mechanical properties.

Finishing

Grinding of the outer circle and end face: Use a grinding machine to grind the outer circle and end face for higher dimensional accuracy and surface finish, providing an accurate positioning reference for the final machining of the raceway.

Raceway grinding: This is a key process in raceway machining, usually using high-precision CNC grinding machines. Through a special grinding wheel, the raceway is ground according to the pre-set parameters, and the curvature radius, width, surface roughness and other parameters of the raceway are precisely controlled to meet the design requirements. In the grinding process, it is necessary to use sophisticated measuring instruments to monitor the dimensional and shape accuracy of the raceway in real time, and make timely adjustments and corrections.

Superfinishing: In order to further improve the surface quality and accuracy of the raceway, sometimes superfinishing operations are carried out, such as grinding or polishing, to finely trim and treat the raceway surface to reduce the surface roughness and improve the wear resistance and fatigue resistance of the surface.

Surface treatment

According to the use environment and performance requirements, the raceway surface is treated accordingly, such as hard chrome plating, blackening treatment, etc. Hard chrome plating can improve the hardness and corrosion resistance of the raceway surface, and blackening can increase the rust resistance of the surface while improving the appearance.

Quality inspection

A variety of testing methods are used to carry out comprehensive quality inspection of the processed inner and outer ring raceways, including dimensional accuracy measurement, shape error detection, surface roughness testing, hardness testing and flaw detection testing, etc., to ensure that all indicators of the raceway meet the design standards and use requirements.

Supplier of double row ball slewing rings

LZTC Double Row Ball Slewing Rings provides a series of services such as R&D, design, production and sales of double row ball slewing ring products. If you are looking for a double row ball slewing ring supplier, please contact us for the latest quote.