For some of outer spherical bearing maintenance experience

Static pressure spherical bearing with its high rotary precision, good rigidity, high bearing capacity, no wear, high durability and widely used in M210, M131W, 3160 a grinding machine, and 2 a710, FYT10 kong boring head. With the development of the numerical control technology, the static pressure spherical bearing is also widely used in machining center CNC machine tool spindle. Initiated the first factory yituo co. LTD. , has a lot of static pressure grinding machine and the static pressure kong boring head, stopped in maintenance some explore and attempt to get some experience. 1. Small hole choke ( 1) Change the internal throttling to external throttling, and equipped with pressure gauge pressure inferior vena instant manifestation. Make maintenance enjoy lunch, especially regular cleaning, can be easily this is internal choke is unable to compare. （ 2) The throttling ratio. The throttle than & beta; The theoretical value is 1. 2 to 1. Between 5, and based on many years of experience in 1. 25 is preferred. In maintenance, so before and after the demand on the geometry precision of the spindle, the geometry precision of bearing bush, alignment, roundness and taper stop strict control, so as to guarantee & beta; Value. On the basis of the machine tool bearing to certain value (e The center of the spindle and bearing shell geometric eccentricity) To make & beta; Best value. （ 3) Fit in the oil chamber not spindle, the oil outlet oil column essential differences ( Check method) , if not, should be taken to change the choke diameter, changes in the flow. 4 cavity, for example, ordinary down, left and right chamber of the oil column, between 20 to 25 mm hole diameter of 0. 25 ~ 0. 4mm。 2. Membrane reaction choke film throttling outer spherical bearing stiffness is very big, but our machine in the running are often present, the phenomenon such as hair, off pressure. Membrane reaction film, is the most critical theory thought, bearing lock, pulls the main reason is: (1) thin film caused by plastic deformation; (2) the reaction is slow. External load mutation, film hasn't response, the shaft friction and tile once; (3) thin film. Deformation of thin film using a long time, tired, be equivalent to change the reaction parameters. Increasing the thickness of the film and use some data of fatigue resistance, all can get good result. Common is to adopt the rigid film, preload lotus, reserved aperture method. Detailed approach is: 1. 4 mm thick film instead of 4 mm thick membrane rigidity, the inferior vena pad 0. 5 mm thick foil paper, make the spindle adjusting to higher than the ideal position 0. The location of the 5 mm. Purpose is when the main shaft bearing ( Grinding wheel weight, cutting force) Later, just return to the ideal center. 3. The improved static pressure oil supply system outside the spherical bearing oil supply system, in addition to the coarse and fine filter, other various components of static pressure spherical bearing has a maintenance function. In the original system based on stop improvement in fuel supply system. （ 1) After the throttle plate of oil outlet pressure relay and pressure gauge, Originally in front of the accumulator) So that 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 stop immediately, to avoid bearing lock. Such as: inlet pressure 2 mpa, the oral cavity pressure 1. 2 to 1. 6 mpa, less than 1. 2 mpa will stop. （ 2) Add digital detection installation high temperature static pressure spherical bearing between the shaft and bearing is 0. 04 ~ 0. 5 mm gap, during which the oil has a certain resistance, detecting the change of the resistance, 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, in order to prevent the shaft friction with tile. The previous: the solid from the smooth high temperature bearing under the nine big advantage of an article: fine bearing is needs pay attention to what