Centerless Grinding Technology Of Bearing Ring Outer Circle

1. High speed grinding technology

The general production efficiency can be increased by 30%60%. The durability of the grinding wheel can be increased by about 0.71 times. High-speed grinding can achieve the two goals pursued by modern manufacturing technology to improve product quality and labor efficiency. Practice has proved that: if the grinding speed is increased from 35m/ h to 5060m/ h. The workpiece surface roughness parameter value is reduced by about 50%.

To achieve high speed grinding is an important measure to increase the power of the grinding wheel drive system and improve the rigidity of the machine tool. The high speed spindle unit is the most critical component of high speed grinding machine. In high speed grinding, the grinding wheel should not only have sufficient strength, but also need to ensure good grinding performance in order to obtain high grinding effect.

2. CBN grinding wheel grinding technology

The grinding wheel made by it is called CBN grinding wheel, and cubic boron nitride abrasive is referred to as CBN abrasive. It mainly has the following characteristics:

(1) High hardness, high thermal conductivity, good thermal stability, can withstand 1300-1500°C high temperature.

(2) High durability, small wear, grinding ratio up to 4000:10000. Grinding ratio refers to the ratio of the amount of workpiece material removed during grinding to the amount of grinding wheel wear.

And the ordinary corundum grinding wheel is only 50-80°C, the use of CBN ring grinding processing is a new processing technology, for the bearing industry in our country. The application prospect is very broad, but the following technologies need to be studied and solved: CBN grinding wheel manufacturing technology, dressing technology, special bearing grinder and grinding coolant, etc. The use of CBN grinding wheel for bearing ring grinding has been developed and applied in production abroad, because CBN grinding wheel has good processing characteristics. Called it “a revolution in production and processing technology” since 1982, CBN grinding wheel has been widely used in Japan, and rapid growth.

3. External surface grinding wheel automatic dynamic balance technology

Because the grinding wheel is large and heterogeneous, the outer surface is grinded. The center of gravity of the grinding wheel system always deviates from the center of the spindle, and the vibration of the grinding wheel system and the whole machine tool will be caused when the grinding wheel system rotates at high speed, which will directly affect the service life of the machine tool.

After starting up quickly and directly close to the most balanced position, the grinding wheel of the machine tool. Directly installed on the mechanical or other means of automatic balance device. The breakthrough of this technology promotes the development of grinding technology, and can greatly extend the life of grinding wheel, dressing diamond and spindle bearing, reduce the vibration of machine tool, and temporarily adhere to the original precision of machine tool.

4. The technology of quickly eliminating the empty path of inner surface grinding

The level of the inner surface grinder is symbolic. This is mainly because the grinding aperture limits the grinding wheel size and the corresponding system mechanism set parameters in all bearing grinding equipment. The rigidity of the process system is fundamentally limited, and the machining accuracy is required to be high. All these require me to conduct in-depth research on the process of internal and external grinding. In addition to maximizing the cutting capacity of machine tools and grinding wheel, reducing auxiliary grinding time is the key to improve grinding efficiency, because the grinding space accounts for about 10% of the entire grinding time.

5. CNC technology and AC servo technology

Servo amplifier can be connected to form a servo system, AC servo motor and PLC programmable controller positioning module. The servo motor itself is equipped with optical rotary encoder, and the output signal is fed back to the servo amplifier to form a semi-closed loop control system. High speed (3000rpm and low speed operation can ensure the positioning accuracy, the use of servo system can complete the fast jump, fast direction, dressing and making up, coarse and fine grinding, so that the machine tool feed mechanism greatly simplified, performance reliability greatly improved.

6. AC frequency conversion speed regulation technology

The ratio of the linear velocity at the beginning to the end is about 3:2. At present, the linear velocity of the grinding wheel decreases gradually with the consumption of the grinding wheel. High line speed grinding has been adopted in the field of grinding wheel grinding. In order to improve the grinding efficiency and ensure the consistency of grinding quality, the programmable controller calculation function is used to calculate the radius of the grinding wheel after each dressing of the grinding wheel, and then calculate the input frequency of the frequency converter to maintain the constant linear speed of the grinding wheel, and transmit it to the AC frequency converter to ensure the constant linear speed of the grinding wheel.