Grinding Tools

Grinding tools

Understanding the working principle of centerless grinding is the basis for maintenance

In centerless grinding, the workpiece is supported by a supporting plate, and the processing work needs to be completed between the grinding wheel and the guide wheel. When the guide wheel axis and the grinding wheel axis are adjusted to a skew state with each other, and the skew angle is in the range of 1° to 6°, the workpiece will automatically feed axially while rotating. This through-grinding method is very suitable for external cylindrical surface processing. If the axes of the guide wheel and the grinding wheel are parallel, plunge grinding will be used, and the forming surface can be processed. When grinding the inner circle, the outer circle is used as a positioning reference and is centered by rollers or support blocks. The grinding wheel will extend into the hole for processing.

After knowing these working principles, maintenance can be targeted. For example, through-grinding and plunge grinding have different requirements for the angle adjustment of the guide wheel. During maintenance, it is necessary to check whether the axis of the guide wheel is accurate. In 2025, an auto parts factory caused the bearing cylindrical grinding accuracy to decrease by 0.02 mm due to ignoring changes in the guide wheel angle, resulting in more than 200 products being scrapped.

The pallet is the key component to support the workpiece

The workpiece is directly in contact with the pallet and is subject to friction and pressure for a long time. Every 8 hours of work, the surface wear of the pallet must be checked with a micrometer. If the wear exceeds 0.03 mm, it must be replaced or repaired in time. The contact surface between the pallet and the workpiece must be kept clean. After each specification change, it must be wiped with a dust-free cloth to prevent iron filings from scratching the surface.

The accuracy of the installation height of the pallet must be guaranteed. Once the deviation exceeds 0.01 mm, it will inevitably directly affect the roundness of the workpiece. Operator Li Ming grinding equipment maintenance plan , during a routine inspection in March 2026, he noticed that the fastening bolts of the pallet were loose. After recalibration, the cylindrical runout of the workpiece was reduced from 0.025 mm to 0.008 mm. This way, the production of batch defective products was avoided.

Maintenance and management of grinding wheels and guide wheels

The core tool used for grinding is the grinding wheel, which needs to be stored in a dry and constant temperature environment, and the ambient humidity should be controlled below 50% to prevent moisture from affecting its hardness. Before a new grinding wheel is installed, a static balance test must be carried out. If the imbalance exceeds 0.5 gcm, it will cause vibration during the grinding process. After every 500 workpieces are ground, a diamond dresser must be used to dress the surface of the grinding wheel to restore its cutting performance.

The guide wheel is responsible for driving the workpiece to rotate and feed. The bearings and drive belts need to be replaced with lubricating oil every quarter. In April 2026, there must have been a situation where the guide pulley belt became loose, and the feed speed of the workpiece was in an unstable state, causing the surface roughness to rise from Ra0.4 to Ra0.8. It was not until the belt was tightened again that it returned to normal conditions.

The cooling and lubrication system cannot be ignored

When grinding the workpiece, the flow rate of the coolant must reach more than 20 liters per minute, so that the heat can be effectively taken away and the grinding debris can be washed away smoothly. The concentration of the coolant needs to be maintained at 5% to 8%, that is, within the range of 5% to 8%. A refractometer must be used for testing every three days, and the filter must be cleaned every shift to prevent clogging, which may cause the temperature rise to lose control and adjustment and cause abnormal situations.

The coolant replacement cycle should not exceed 30 days. If used for a long time, bacteria will breed and produce odor. In November 2025, due to the deterioration of the coolant in a bearing factory, the temperature in the grinding area increased to 45°C, which eventually caused thermal deformation of the workpiece, and the roundness error exceeded 0.015 mm. The problem was solved after replacing with new coolant and cleaning the pipes.

Regular inspection of electrical and control systems

The motor terminals need to be inspected every two weeks to prevent loosening and thereby avoid heating problems caused by increased contact resistance. The cooling fan of the inverter must be replaced every other year to ensure that the cooling effect is maintained. The input and output modules of the PLC controller need to use industrial alcohol to clean the contacts every three months. This is to prevent dust accumulation from causing signal misjudgment.

The protective switch and emergency stop button need to be functionally tested once a month. In January 2026, a situation occurred in a precision machinery factory. Due to poor contact in the emergency stop button, when the grinding wheel chuck broke down, the shutdown operation could not be achieved immediately, causing the operator's arm to suffer scratches. Subsequent measures were taken to replace all emergency stop buttons and strengthen daily testing.

Daily maintenance records and fault prevention

Operators on each shift are required to fill out a maintenance record form, which covers data such as plate wear, number of times the grinding wheel has been dressed, and coolant concentration. Summarize one week as a cycle and analyze the data to explore trends. For example, if the wear rate of the pallet accelerates, this may indicate that the feed amount is too large, or the hardness of the blank has changed.

Create a fault prevention list , grinding processing equipment maintenance plan, grinding processing equipment maintenance plan , and develop processing procedures for common problems such as guide wheel deviation and grinding wheel cracks. In May 2026, a company based on historical data pre-replaced the guide wheel bearing that was about to reach the end of its life, avoiding losses caused by shutdowns and production shutdowns, and saving about 8,000 yuan in maintenance costs at a time.

What happens when you encounter an extremely difficult fault while maintaining your centerless grinding device? Welcome to share your experience in the comment area, and don’t forget to like and bookmark this article so you can always look forward to it when you encounter problems!