Vacuum suction cups and clamping devices have been used for a variety of purposes in many industries, from lifting packaging to clamping items for machining. With the large-scale production (wooden furniture, plastic and other non-magnetic materials) of CNC engraving machine, large workpieces need to be clamped on the flat CNC engraving machine workbench. Mechanical clamping is not an option because it can damage the workpiece and cannot meet the need to place the object on the workbench quickly and clamp it immediately.
The solution is to use vacuum to compress the workpiece, providing immediate pressing and removal. The CNC engraving machine table has a machined flat surface with grooves (or channels) in the whole area and rubber gasket. The metallurgical progress of the planer tool head allows high-speed machining, which produces a lot of force on the parts on the worktable, so it is necessary to apply a lot of pressure vacuum force on these parts. The vacuum provides the means to produce these forces.
Like most woodworking machines, performance will degrade over time, and failure is always an option. Then, you are forced to consider repairs, overhauls, or replacement options, resulting in downtime.
The key component of CNC engraving machine is vacuum pump, which is used to fix the material on the fender or in the fixing device. Therefore, it is important to have and follow a preventive maintenance plan to extend its service life. The most important operation is to keep the filter between the vacuum distribution system and the pump clean, dry and intact.
A physical check is a way to check the condition of the filter. The other is an instrument or sensor that measures vacuum and / or air flow. The measured value of the instrument shall be recorded every day. When the vacuum or airflow drops below a certain range, the sensor will sound or the router can be disabled.
Finally, the filter must be replaced according to the manufacturer’s recommendation or inspection failure. But the cost is minimal, especially compared to the downtime caused by the disabled vacuum pump.
Some vacuum pumps only need to change oil regularly in dusty environment. It is not important that the pump is well protected or isolated. The small dust produced by the CNC engraving machine will even penetrate into the smallest cavity. The continuous accumulation of impurities will reduce the viscosity of the oil, which will cause damage to the pump bearings and other mechanical parts.
It is better to overhaul the vacuum pump. The suite can be widely used to accomplish tasks, but experts have the advantage of the right tools and rich experience. Experts may also provide warranty.
The liquid ring vacuum pump will hardly fail or shut down due to any unscheduled maintenance. This is because the offset pump rotor installed in the pump body has gaps that provide vacuum on the input side and compression on the output side. The rotor is immersed in liquid (usually water) and cannot contact the housing. The liquid acts like a piston, compressing air into the space between the blades. This area between the blades can be considered as an irregular cylinder that forces compressed air through the outlet. The only parts that need to be replaced are externally mounted bearings, seals, and washers.
The liquid ring pump can run for decades without maintenance, and the price is relatively low. These pumps have high vacuum degree and low air flow, which are more suitable for CNC engraving machine to process small parts. The vacuum surface area of these parts is smaller.
Rotary vane vacuum pumps are probably the most widely used. They typically have a horsepower rating of 0.25 to 30 and a high vacuum rating of 20 to 30 inches of mercury. However, compared with the single-stage regenerative blower, the air flow is lower in the range of 500 to 700 CFM, 150 to 400 CFM.
The rotary vane vacuum pump is also very suitable for processing small parts and is an ideal choice for the vacuum chuck on the rotating shaft. But again, it’s best to have an overhaul done by an expert. A typical overhaul begins with cleaning the outside of the pump and removing the paint. After removal, the technician will look for abnormal wear patterns. The motor was tested and the pump was reassembled with new shaft seals, O-rings, washers, valves and vanes. Finally, test the air flow and vacuum of the pump.
Although the choice of vacuum pump depends on what you need to do, please do not neglect the maintenance and reconstruction.