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The surface of INA bearing rubs and pares the reason which presents the defect

13th November 2013 Bearing Technology 0 Comments

INA bearing, in the course of rubing and processing, job its surface to go on, rub, sharpen through high-speed emery wheel that rotate, so does not carry on operation and adjust the apparatus while rubing and paring according to the homework guide book, will work in INA bearing the surface presents all sorts of defects, so that the quality wholly on the influence INA bearing. INA bearing, when accurate to rubs and pares, because of coarse to expect very much, job whom surface appear rub, sharpen trace, can observe surface he waste, have the following aspects to sharpen the trace mainly with naked eye often.

Display and cross the helix trace

Appear the reason of trace because bus bar of emery wheel flat and straightforward and poor mainly, the unsmooth phenomenon exists, while rubing and paring, emery wheel and work piece keep in touch partly, after the work pieces or round sports for several times of emery wheel, will reappear to cross in the helix when displaying in work pieces and the naked eye can be observed. Pitch and work piece a speed, rotational speed of work piece of the helix are relevant in size, not parallel and relevant with axis thread and working bench guide of emery wheel at the same time.

1 Main reason why the helix forms

1.It is bad for emery wheel to repair, corner pour angle, use and cool liquid to go on and repair;

2.The working bench guide leads too much lubricating oil, cause the working bench to float;

3.The lathe is not good in precision;

4.Rub and pare the pressure too big, etc.

2 Forming of helix has reasons

1. V -shaped rigidity is good of guide,when rubing and paring last skew emery wheel, but keep in touch emery wheel edge as job surface;

2.The working bench is unstable in reversing speed while repairing the noisy wheel, the precision is not high, make a certain edges of emery wheel slightly repaired little;

3.Own rigidity of the work piece is bad;

4.Break sand one and work piece peeling off very much to rub and pare the iron filling under to accumulate and attach to surface of the emery wheel on the emery wheel, for this reason the emery wheel that should repair is washed or scrubed clean with the cooling water;

5.It is fine for emery wheel to repair, have some and protruding, etc.

The surface presents the fish scale

The surface reproduces main reason of the trace of the fish scale because the cutting edge of the emery wheel is not sharp enough, happen while rubing and paring ” Gnaw ” The phenomenon, it is relatively great to shake at this moment. Lead to the fact the surface of the work piece presents the fish scale the concrete reason of the trace is:

1. There are rubbish and oil filth on the surface of the emery wheel;

2. The emery wheel has not repaired the round;

3. The emery wheel is dull. Do not repair sharply enough;

4. It is not firm that diamond fastens the shelf, diamond is waved or diamond quality is not very sharp;

5. Hardness irregularity of the emery wheel,etc..

The working range draws the hair

The surface reproduces the main reason for drawing the hair trace to take off the backwardness because of the grit of thick granularity, the grit is inserted to cause between work piece and emery wheel.

The surface of the work piece is the concrete reason for drawing the hair while rubing and paring:

1. The trace left over at the time of rough grinding, has not ground off while finishing grind;

2. Thick grit and small grit can not be filtered clean to cool in the liquid;

3. The grit was easy to loss when the thick granularity emery wheel was just repaired well;

4. Material toughness validity or emery wheel is too soft;

5. Grit toughness cooperates with work piece material toughness improperly etc..

There are straight wave form traces on the surface of the work piece

We hang down the intersection of axis and line, cut cross section and enlarge work piece that rub, can see perimeter its similar to sinusoidal wave. Make its centre not rotate and translate along the axis thread, the sinusoidal wave and peripheral orbit is a cylinder of wave form, also call this the polygon.

So. This kind of vibration may be to force to be shaken, or surge and shake by oneself, so the straight wave on the work piece is often more than one kind frequently.

The concrete reason for producing the straight wave form trace is:

1. The main shaft interval of emery wheel is too big;

2. The emery wheel is too tall in hardness;

3. The emery wheel is too quiet to equilibrate well or the emery wheel is dull;

4. The work piece is too high in rotational speed;

5. The horizontal Qi’s knife is too large

6. The main shaft INA bearing of the emery wheel is abraded, it is too big to cooperate with the interval, the radial emerges to beat;

7. The emery wheel compresses tightly the organization or working bench ” Creep ” When.

The surface of the work piece reproduces and burns the trace

The surface of the work piece will often be burnt in the course of rubing and paring, burn several kinds of types, first, burn it in the direction that the emery wheel is processed, it is a black dull patch piece; Second, take the form of the lines or intermittent lines.

The surface of the work piece is burnt in the course of rubing and processing, sum up and have the following reasons:

1. The emery wheel is too hard or too detailed organization of granularity is too dense;

2. It is too big to enter the giving amount, it is insufficient in supply to cut the liquid, the heat-dissipating condition is bad;

3. The work piece is too low in rotational speed, the emery wheel is too fast in rotational speed;

4. The emery wheel shakes the pendulum too big, burn because of rubing and paring the depth and changing constantly;

5. The emery wheel is not repaired in time or not repaired well;

6. Diamond is sharp, the emery wheel is not repaired well;

7. It is too deep to burn at the time of the rough grinding of the work piece, it is too small to finish grind the allowance, has not ground off;

8. It is insufficient that the work piece clamps the strength or suction, under rubing and paring strength function, the work piece stops transferring to phenomenon,etc..

Then how does the surface of work piece know whether to burn out in the course of rubing and paring? This should be through can check out while pickling regularlying.

After the work piece is pickled, when the surface is wet, should estimate under the astigmatism light and examine immediately, the normal surface is even and dark and gray. If clicked by the software, cloud black dull spot appear, and the circle is indefinite and whole in week; If take off carbons, it is piebald to appear ashen or black dull; If rub and process the crackle, then the crackle is full of cracks in shape, burn in this way, first, black dull patch piece appears in the direction that the emery wheel is processed on the surface, second, the lines or intermittent lines appear.

Present, burn the phenomenon while being above-mentioned in the course of rubing and processing, must analyze the reason in time, take the effective measure to solve, stop to burn in batches.

The surface roughness can not reach the requirement

The surface roughness of INA bearing part has standard and technological requirement, but in rubing processing and ultra precise course, because of various reasons, can not often reach the requirement of ones that stipulate. Lead to the fact the unqualified main reason of the surface roughness of the work piece is:

1. Rub, sharpen speed to be too low, enter, give speed to be too fast, feed quantity to be too big, have, enter, give, rub, sharpen time to be too short;

2. The work piece is too high in rotational speed or work piece axle and emery wheel axle are shaken too big;

3. The emery wheel is too thick or too soft in granularity;

4. It is too fast or repairs the interval of organization too big to repair the speed the emery wheel;

5. Diamond which is repaired the emery wheel is not sharp or quality is not good;

6. Ultra to use the intersection of oilstone and quality to be bad while being precise, erection site incorrect;

7. Can’t meet the quality requirement ultraly and smartly with the kerosene;

8. Extremely precise time is too short,etc.;

So long as we operate and check conscientiously according to the homework guide book strictly, go wrong and analyze the reason in time, and solve, these defects can be avoided, thus has guaranteed the whole quality of the products.

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