1. Scratch (two-body abrasive wear)
The
hard particles moving with the shaft diameter are in contact with the
friction surface, which is the lower contact stress between the
particles and the metal surface. They draw linear injuries on the
surface of the pad; the hard particles on the surface of the pad are
also on the surface of the shaft Draw a line of scars, are called scratches. Scratch is a two-body abrasive wear, the direction of the linear wound and the direction of movement of the same axis.
Lubricating oil film rupture, shaft diameter surface of the hub peak
will also scratch the bearing, there are many linear scars, it is also
two body abrasive wear.
Hard particles embedded in the bearing surface and fall off, causing scratches of scratches.
Most of the above particles are iron and sand.
Scratch causes the friction surface to roughen, thereby reducing the
carrying capacity of the lubricating oil film, and will form a new
scratchable friction surface of the hard particles and hub peaks,
resulting in a vicious circle.
2. (three body) abrasive wear
Into
the bearing gap between the smaller hard particles, wandering between
the two friction surfaces, in the friction surface to produce high
contact stress, constitute three body abrasive wear, similar to the
grinding effect, so that the bearing and shaft diameter surface wear. The high contact stress between the hard particles and the frictional
surface causes plastic deformation or fatigue damage to the frictional
surface of the ductile metal, causing the frictional surface of the
brittle metal to crack or peel.
Abrasive wear scar is also linear, the direction of movement with the axis of the same direction.
When the edge of the contact, the lack of oil or oil film rupture, etc. will produce severe abrasive wear. Abrasive wear will lead to shaft diameter and / or bearing geometry
and shape changes, the accuracy of loss, bearing clearance increases, so
that the performance of sliding bearings in the life expectancy before
the rapid deterioration.
3. Bite stick (glued)
In
the lubricating oil film rupture or lack of oil in the state, a large
friction factor resulting in a lot of friction heat, bearing
temperature. At
high temperatures, a fusible surface of the low melting point of the
metal due to softening and adhesion to the other friction surface, with
the rotation of the shaft shape of the role of shear, the adhesion of
metal from the original surface from the transfer to another friction
surface, Resulting in frictional surfaces with obvious pits and bumps. This damage is adhering to wear.
When the bite occurs, the friction increases sharply, the bearing temperature is further increased, forming a vicious circle. When the adhesion is serious, the shaft diameter of the power can no
longer cut the bond point, will make the axis of movement to terminate,
commonly known as "bearing shaft", bearing completely damaged.
Fatigue wear
Fatigue wear is also known as fatigue damage. Under
the repeated action of the cyclic load, fatigue cracks appear on the
friction surface in the direction perpendicular to the sliding
direction. The crack develops perpendicularly to the surface of the
bearing pad, and extends to the lining and the backing surface, and
extends to the friction surface parallel to the friction surface, The final material is peeled off from the friction surface, causing pound damage.
5. stripping
When
the bearing pad is manufactured, if the lining force is insufficient or
the bonding is insufficient, the material of the local lining will be
peeled off from the bearing during the operation of the bearing. Peeling and fatigue flaking are somewhat similar, but fatigue peeling
around the perimeter of the pit irregular, combined with poor adhesion
caused by the surrounding relatively smooth pits.
6. Corrosion
Lubricants in the course of continuous oxidation, oxidation often
produce weak organic acids, it is the casting material, especially the
casting of lead and lead alloy lead is corrosive, which is characterized
by lead-like drop off, so that the surface becomes rough.
Strong inorganic acids are more susceptible to corrosion of steel journal surfaces.
Tin
in the tin-bearing alloy is oxidized, the surface of the pad to form a
layer of SnO2 and SnO composed of black hard coating, hardness in the
range of 200 ~ 600HS. This cover is extremely harmful to the bearing, it is very hard, can
scratch the journal surface, and make bearing clearance smaller.
7. Erosion
(1) cavitation
Cavitation is the surface damage that occurs when the solid surface is
in contact with the liquid and is subjected to relative movement.
When
the oil in the oil film low pressure area, the oil will form bubbles,
the bubble movement to the high pressure area, the pressure under the
bubble collapse, in the moment of collapse to produce great impact and
high temperature, solid surface in this Impact of the repeated role, the material fatigue off, so that the
friction surface appears small pits, and then developed into sponge-like
scars.
Heavy load, high speed, and the load and speed changes in the larger sliding bearings, often cavitation.
(2) fluid erosion
The intense impact of the fluid on the solid surface can cause fluid
erosion, so that the surface of the solid surface scars, the surface of
the damage more smooth.
(3) electric erosion
As the motor or electrical leakage, in the friction between the
surface of the spark, in the friction surface caused by dot-like scars,
which is characterized by damage reciprocating on the hard journal
surface.
8. fretting wear
In
the bonding surface between the lining and the backing, the bearing pad
and the bearing seat, there are three forms of adhesive wear, oxidation
(corrosion) wear and abrasive wear due to the combination of micro
vibration (slip) and oxidation between the metal surfaces Composite wear, known as fretting wear, will cause spot punches on the joint surface.
CATEGORIES
Latest news
- Ferrofluid Vacuum Feedthrough Seals us
- SF-1 Carbon Steel Self-lubricating Bea
- Ball transfer unit
- Motorcycle suspension bushing
- Bimetal Flange Bush Bearing
- Selection standard for dimension refer
Contact us
- ADD: No.503,Hunan International Commerce Center, Jintai Square,Changsha 410001,Hunan
- TEL: 86-731-84770165
- FAX: 86-731-84770163
- E-mail: sales2@slide-bearing.com
> Industry news