Bearing in grinding process, the working surface is carried out by high-speed rotating grinding wheel, so if you do not press the operating instructions for operation and adjust equipment, there will be all kinds of defects at the time of grinding the bearing surface, which affects overall quality of the bearing. Bearing in precision grinding, due to rough demanding, work the surface grinding traces can often be observed to surface grinding marks are the following naked eye. Reason cross spiral traces traces manifestations happen mainly due to the wheel bus straight poor, uneven phenomenon exists, when the grinding wheel and the workpiece is only partial contact, when the workpiece or grinding wheel several times back and forth movement, workpiece performance will be reproduced and cross helix can be observed visually. Pitch and speed of the workpiece table of these spirals, the size of workpiece speed, but also with the wheel axis is not parallel to the rail line and the table-related.
   Mainly due to (a) helix form

    1. Dresser bad, not chamfered corners, unused coolant trimmed;
    2. The table guide rail lubricating oil too much, resulting floating table;
    3. The machine precision is not good;
    The grinding pressure is too big.

   Having reasons (two) spiral formed

    1.V shaped track rigidity is bad, when an offset grinding wheel, but the wheel in contact with the edge of the work surface;
    2. trimming noisy round table commutation speed instability, accuracy is not high, so that the wheel a little less edge trimming;
    3. The piece itself poor rigidity;
    There grinding broken down too flaking iron grit and workpiece surface plot attached to the wheel 4. wheel, to this end should be a good dressing wheel wash or scrub clean with cold water;
    5. Dresser bad, there are local projection and so on. Mainly due to the surface of scaly scaly surface traces of reproduction is due to the wheel cutting edge sharp enough, the occurrence of "eating to live" phenomenon at the time of grinding, when vibration is large.
 
    Specific causes scaly surface marks appear are:

    1. The grinding wheel surface was rubbish and oil;
    2. No dressing wheel round;
    3. The wheel becomes dull. Dressing sharp enough;
    The diamond frame is not firmly fastened, diamond or diamond quality is not good not shaking sharp;
    5. Wheel hardness uneven. The main reason Face nap napped surface traces reproduction is due to coarse-grained abrasive shedding, abrasive sandwiched between the workpiece and the grinding wheel caused.

    The specific reasons for the surface grinding was napping in are:

    1. kibble legacy traces, not worn when grinding;
    2. The coolant filter coarse grains and tiny grains not clean;
    3. coarse-grained abrasive grinding wheel just fall off easily when trimmed;
    4. toughness validity or wheel too soft;
    5. abrasive workpiece material toughness and tenacity with improper surface straight waveform trace our workpieces milled cut a cross section perpendicular to the axis and zoom, you can see its surrounding approximates a sine wave. Along its center axis of rotation without translation, the track is the sine waveform surrounding cylinder, which is also known as a polygon.

    The reason is straight waveform generation mobile wheel pressure relative to the workpiece or grinding wheel on the workpiece by cyclically changing exigencies caused by vibration. Such vibrations may be forced vibration, it may be self-excited vibration, and therefore often more than one straight wave frequency on the workpiece.