The most important parts of piston bearing, if the bearing clearance presentation, you can not guarantee normal internal pump three pairs of friction pair gap, together will
damage the hydrostatic bearing oil film thickness of each friction pair, down piston pump bearings use life expectancy. According to information supplied to the hydraulic pump factory, using the
average life expectancy of bearings is 10000h, beyond this value will need to replace the new port.
Open bearing down, no professional view instrument is unable to view the bearing clearance, the only use visual, such as found in the outer roller scratches or discoloration, it
is necessary to replace.
When replacing the bearing, should pay attention to the type of original letters and bearing, mostly piston bearing use large load bearing capacity, the best purchase of the
original factory, the original specification of the goods, if the replacement of another brand, you should consult an experienced bearing The staff look-up table on the exchange, the purpose is
to uphold the level of accuracy and load bearing capacity.
3 three pairs of friction pairs View and correction
3.1 plunger rod and cylinder bore
Table 1 is a piston pump replacement parts specification (see Figure 1), when the various voids listed in the table of tolerance, according to the following approach fix:
(1) cylinder inserts copper sleeve, you can choose to replace copper sleeve approach amendment. First, a group of at plunger rod diameter trimmed to a consistent scale, and then
1000 # sandpaper polished than the outer diameter.
Three ways to install copper cylinder sleeve:
(A) loading or copper cylinder plus warm jacket cryogenic extrusion, interference installation; (b) adopt a Loctite adhesive of the installation, which measures demand for copper
coat we have an outer diameter of the outer groove; (c) cylinders hole tapping, threading copper sleeve outer diameter after coating Loctite glue, screw installation.
(2) melting contact information and a copper cylinder sleeve, the correction method is as follows:
(A) selection of ground rods, craft or mechanical way cylinder bore polishing amended; (b) the choice of coordinate boring, boring the cylinder hole scratch; (c) Selection Reamer
correction cylinder bore.
(3) selection of "look engineering skills" approach as follows:
(A) plating skills: the plunger outer layer of hard chrome plating; (b) electrical brush skills: the plunger outer brush wear data; (c) thermal spraying or electric arc spraying
or spray: Spray-carbon Horse s body wear data; (d) laser cladding: the plunger outer cladding alloy powder by high hardness.
(4) cylinder bore no copper cylinder data sets are mostly ductile iron, prepared amorphous thin film or coating on the cylinder wall. Since the cylinder bore wall with this
particular substance, so talent composition hard - hard matching friction deputy. If you blindly grinding cylinder bore, the cylinder bore wall of this layer look out research data, more friction
constructor function has changed. Deputy friction coating is removed, if the use of force, it will dramatically increase the friction surface temperature, the plunger rod and cylinder bore attack
gluing.
Also look at the preparation of the plunger rod a common film with a coating rich in less wear + wearable + smooth function, this group is still a hard practice of friction
deputy - soft pairing, once people change coating, also damaged Best paired friction deputy, repair these special piston pump, it is necessary to a professional repair plant.
3.2 shoe and the swash plate
Sliding friction shoe and the swash plate is a swash plate piston pump three pairs of friction pairs in the most complex pair.
Table 1 lists the plunger rod ball and slipper ball voids (see Figure 2), if the piston and slipper gap tolerance, high-pressure oil in the piston chamber will from the plunger
ball and slipper gap the escape, the shoe and the swash plate film thinning will form hydrostatic bearing failure is grim, the shoe and the swash plate seizure metal touch friction shoe ablation
fall, the plunger swash plate ball head scratching. When the plunger rod ball and slipper ball beyond Gongyi 1.5 times, it is necessary to replace the group.
The plunger rod and the plunger rod cylinder bore diameter φ16 φ20 φ25 φ30 φ35 φ40