Maintenance of grinder hydrostatic bearing
#1
Maintenance of grinder hydrostatic bearing
There are a lot of static pressure grinding machine and the static pressure kong boring head, made some exploration and attempt to repair, several experiences have been obtained.Maintenance of grinder hydrostatic bearing
1. The hole choke:
1) and equipped with pressure gauge pressure inferior vena instantly. Make maintenance convenient, change the internal throttling to external throttling. Especially can easily be regular cleaning, this is an internal choke
2), according to many years of experience in 1.25 is preferred. So in the maintenance, the throttling ratio. Throttling than the theoretical value is between 1.2 1.5 beta. Need of the Bearing Construction shell before and after the geometrical precision of the spindle, geometric accuracy, alignment, roundness and taper of strict control, in order to ensure the beta. Determined according to bearing capacity of the machine tool for e (eccentricity) to the center of the main shaft and bearing shell geometry make best beta.
3) the oil outlet oil column must agree (observation) if not consistent, the oil cavity in the spindle when loading. Should be taken to change the choke aperture method, to change its flow. 4 cavity, for example, generally, left, right cavity under the oil column, between 20 to 25 mm hole diameter is 0.25 0.4 mm
2. The film feedback choke:Maintenance of grinder hydrostatic bearing
Practice that film feedback throttle bearing stiffness is very big but in also often appear in the operation of the machine tool watts, the phenomenon such as hair, drop pressure. Thin-film feedback key. Bearing lock, the main reason is that (1) that pulls film caused by plastic deformation; (2) feedback slowly. External load mutation, film also have no reaction, shaft and tile has friction (3) thin film fatigue. Film with long time, fatigue deformation, equivalent to change the feedback parameters.
All can get good result. Usually adopt rigid film, preload lotus, reserved aperture method. Specific approach is to 1.4 mm thick film instead of 4 mm thick membrane rigidity, increasing the thickness of the film and use some fatigue resistant material. Inferior vena mat 0.05 mm thick tin foil paper, make the main shaft to adjust to than the ideal place to 0.05 mm high position. Objective when the main shaft bearing (after grinding wheel weight, cutting force), just returned to the ideal center.Maintenance of grinder hydrostatic bearing
3. The improvement of fuel supply system:
In addition to the coarse and fine filter, hydrostatic bearing oil supply system. The rest of the various components of hydrostatic bearing plays a protective role. Based on the original system to improve the oil supply system.
1) in order to immediately stop, throttle plate after the oil outlet pressure relay and pressure gauge (originally in front of the accumulator) can make the operator to see the size of the cavity pressure and the inlet pressure. When the pressure difference is greater than a certain value. In order to avoid bearing lock. Such as inlet pressure 2 MPa in the oral cavity pressure 1.2 1.6 MPa below 1.6 MPa will stop.
2) increase the digital detection device, during which the oil has a certain resistance, static pressure bearing is 0.04 0.05 mm clearance between shaft and bush. Detecting the change of the resistance, it can be learned that period gap size. For spindle, bearings for other, measure the resistance changes. To the signal disposal of backwardness to photoelectric amplifier alarm and control system, control of the spindle motor start-stop, to avoid friction shaft with tile.Maintenance of grinder hydrostatic bearing
1. The hole choke:
1) and equipped with pressure gauge pressure inferior vena instantly. Make maintenance convenient, change the internal throttling to external throttling. Especially can easily be regular cleaning, this is an internal choke
2), according to many years of experience in 1.25 is preferred. So in the maintenance, the throttling ratio. Throttling than the theoretical value is between 1.2 1.5 beta. Need of the Bearing Construction shell before and after the geometrical precision of the spindle, geometric accuracy, alignment, roundness and taper of strict control, in order to ensure the beta. Determined according to bearing capacity of the machine tool for e (eccentricity) to the center of the main shaft and bearing shell geometry make best beta.
3) the oil outlet oil column must agree (observation) if not consistent, the oil cavity in the spindle when loading. Should be taken to change the choke aperture method, to change its flow. 4 cavity, for example, generally, left, right cavity under the oil column, between 20 to 25 mm hole diameter is 0.25 0.4 mm
2. The film feedback choke:Maintenance of grinder hydrostatic bearing
Practice that film feedback throttle bearing stiffness is very big but in also often appear in the operation of the machine tool watts, the phenomenon such as hair, drop pressure. Thin-film feedback key. Bearing lock, the main reason is that (1) that pulls film caused by plastic deformation; (2) feedback slowly. External load mutation, film also have no reaction, shaft and tile has friction (3) thin film fatigue. Film with long time, fatigue deformation, equivalent to change the feedback parameters.
All can get good result. Usually adopt rigid film, preload lotus, reserved aperture method. Specific approach is to 1.4 mm thick film instead of 4 mm thick membrane rigidity, increasing the thickness of the film and use some fatigue resistant material. Inferior vena mat 0.05 mm thick tin foil paper, make the main shaft to adjust to than the ideal place to 0.05 mm high position. Objective when the main shaft bearing (after grinding wheel weight, cutting force), just returned to the ideal center.Maintenance of grinder hydrostatic bearing
3. The improvement of fuel supply system:
In addition to the coarse and fine filter, hydrostatic bearing oil supply system. The rest of the various components of hydrostatic bearing plays a protective role. Based on the original system to improve the oil supply system.
1) in order to immediately stop, throttle plate after the oil outlet pressure relay and pressure gauge (originally in front of the accumulator) can make the operator to see the size of the cavity pressure and the inlet pressure. When the pressure difference is greater than a certain value. In order to avoid bearing lock. Such as inlet pressure 2 MPa in the oral cavity pressure 1.2 1.6 MPa below 1.6 MPa will stop.
2) increase the digital detection device, during which the oil has a certain resistance, static pressure bearing is 0.04 0.05 mm clearance between shaft and bush. Detecting the change of the resistance, it can be learned that period gap size. For spindle, bearings for other, measure the resistance changes. To the signal disposal of backwardness to photoelectric amplifier alarm and control system, control of the spindle motor start-stop, to avoid friction shaft with tile.Maintenance of grinder hydrostatic bearing
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