1. Working principle of hydrostatic bearing
Start the oil supply pump first? Oil enters the oil chamber through the oil filter and throttle, which is on the surface of the main journal.
Produce an oil film? Support, lubricate and cool the spindle? Because of the throttle, the oil is lifted.
Spindle? The oil returns to the oil tank through the oil return hole and the oil return pump. Then start the grinding head motor? axis
Turn around. Which is easy to produce dynamic pressure effect with wedge-shaped oil cavity structure? The spindle rotates stably at high speed.
After that? Form a dynamic oil film with strong stiffness? Used to balance the workload under high-speed operation.
Structural form and characteristics: integral sleeve structure, convenient installation; High precision: due to bearing oil
Homogenization of membrane? Make the spindle have high rotation accuracy: radial jump and axial movement of the spindle.
Dynamic ≤2μm? Or ≤ 1μm high stiffness? Due to the unique oil cavity structure of shafting? Bearing system
Working? The spindle floats by a layer of pressure oil film? Is the spindle a pure hydrostatic bearing when it is not rotating?
When the spindle rotates, dynamic pressure naturally forms in the bearing due to the step effect of the shallow cavity in the bearing hole.
Bearing oil film? Thereby forming a hydrodynamic sliding bearing with a pressure field? This structure improves the bearing.
Stiff? The axial stiffness can reach 20-20-50kg/1μ m? The radial stiffness can reach100 kg/1μ m.
High carrying capacity? Because the dynamic pressure effect is naturally formed? No need for extra motivation? Such a main bear
The bearing capacity is greatly improved. Long service life? Theory of infinite service life under normal use.
In this case? Very little maintenance.
2. Characteristics and application examples of dynamic and static pressure SKF bearing.
In addition to the rolling bearing, the air inlet bearing of the grinder spindle? Commonly used is hydrodynamic sliding bearing?
It is characterized by smooth movements? Good earthquake resistance? High speed. However, hydrodynamic sliding bearings must be used in
Pressure oil film can only be produced at a certain operating speed? Realize pure liquid friction? Therefore, it is not applicable.
For spindle parts with low running speed? Such as a spindle of a headstock of a workpiece. Besides? The spindle is starting.
Stop. Because of the slow speed? Can't build a pressure oil film? So it's inevitable
Direct contact between journal and bearing metal surface? Cause wear.
Large starting torque at the same time? NSK bearings are prone to heat. Is the spindle running? axis
The offset of will vary with working conditions, such as external load and speed. Rotational accuracy and stability
There are certain restrictions. Is the hydrostatic bearing different? Because it relies on an external hydraulic system to supply pressurized oil.
Forming a pressure oil film? The stiffness of the oil film depends on the structural size parameters and joints of the bearing itself.
Performance of the flow device, etc. External load independent of spindle speed? Therefore, it can be ensured that the bearings are in different positions.
It is in a stable pure liquid friction state under working conditions. Bearing wear is small? Long-term guarantee
Maintain working accuracy.
Besides? When a variable throttle is used. Is the oil film stiffness of SKF bearing large? When the load changes
The spindle axis position has not changed much? And high rotation accuracy can be maintained. Lack of hydrostatic bearing
What's the point of needing a special oil supply system? Higher manufacturing cost? Covers a large area?
And the filtration requirements for lubricating oil are very strict? Maintenance is more complicated. There have been many in recent years.
Does the spindle bearing of grinder adopt dynamic bearing or hydrostatic bearing? Good results have been achieved. example
Like what? M 1080, M 10 100 and MGl040 high-precision centerless grinders? Its main axis is
Use dynamic FAG bearings? And is a five-piece dynamic pressure bearing.
Mzlll00 automatic wide grinding wheel centerless grinder? Besides using hydrodynamic bearings? Static is also used
Press the railing? Improve the sensitivity and accuracy of feed? Can you do 0? The feed speed is 0015 mm.
Especially in high-precision centerless grinder or large centerless grinder, hydrostatic bearing is often used as grinding wheel.
Frame spindle bearing. By the way. Imported centerless grinder? Except its grinding wheel spindle
With the above two kinds of bearings? Is there a precision roller bearing as the spindle bearing? Sweden, for example,
France and Japan, etc. Section 5 Common faults and troubleshooting of centerless grinder; The centerless grinder is in use.
In the process? There will be some faults? Must be ruled out in time? In order to continue to work normally. at present
Common faults are described as follows?
In actual production, the phenomenon of trailing guide wheel often occurs? The main reason is often that the grinding amount exceeds a certain value.
The latter value? The cutting force of grinding wheel on workpiece overcomes the problems of workpiece and pallet, workpiece and guide wheel.
Friction between them? The workpiece in turn drives the guide wheel to rotate? There is a phenomenon that the guide wheel is dragged backwards. fall down
Drag phenomenon appears? Not only affect the quality of workpiece processing? But also the idling motor is in a no-load state.
Status? Sometimes it even leads to accidents.
3. The working principle of hydrostatic lubrication sliding bearing.
Static lubricated sliding bearings are called hydrostatic bearings. The principles of static lubrication and dynamic lubrication are different.
Same? Hydrostatic bearing is provided with pressure oil by external lubricating oil pump, forming pressure oil film? bear
Load. Although many hydrodynamic bearings also use lubricating oil pump to supply pressure oil? But they are different in nature.
what's up The most obvious difference is the oil supply pressure? The oil supply pressure of hydrostatic bearing is higher than that of dynamic bearing.
A lot.
One of the main characteristics of hydrostatic bearing? Is it a completely static state? You can also establish orientation.
Oil film? Can ensure that the two surfaces of the friction pair are not in direct contact at the start-up stage? This is in the dynamic pressure shaft
Commitment is absolutely impossible.
So what? When starting the rotor with hydrostatic bearing? The hydrostatic lubrication system must be started first.
Is the hydrostatic bearing running? Because of the relative motion of the friction pair? So it may also produce dynamic pressure effect?
When the dynamic pressure effect reaches a certain share? The bearing becomes a hybrid bearing of dynamic and static pressure.
What are the advantages of hydrostatic bearing?
1. When starting and running, the friction pair is separated by pressure oil film? Sliding resistance only comes from fluid viscosity.
Sex? Low friction coefficient and long service life.
2. Does the hydrostatic bearing have the function of "balancing" errors? Can reduce the influence of inaccuracy in manufacturing?
Therefore, the requirement for manufacturing accuracy is lower than that for dynamic bearings.
3. Is the pressure on the surface of the friction pair relatively uniform? The reliability and service life of the bearing are high.
4. The expected bearing performance can be accurately obtained.
5. Is the temperature distribution of the bearing uniform? The problem of thermal expansion is not as serious as that of hydrodynamic bearing.
Hydrostatic bearings are suitable for various working conditions. From precision instruments in grams to loads in numbers.
Thousands of tons of heavy equipment use hydrostatic bearings.
Sliding bearing? Sliding bearing A bearing that works under sliding friction. Sliding bearing worker
Make it stable, reliable and noiseless. Under liquid lubrication conditions? The sliding surfaces are separated by lubricating oil.
No direct contact? Can also greatly reduce friction loss and surface wear? Oil film reflux
Have certain vibration absorption ability. But the starting friction resistance is large. The part of the shaft supported by the bearing is called
Diary? The part that matches the journal is called the bearing bush. In order to improve the friction characteristics of the bearing surface
The antifriction material layer cast on its inner surface is called bearing liner. Material system of bearing bush and bearing liner
Called sliding bearing material. Commonly used sliding bearing material is bearing alloy? Also known as Babbitt.
Or white alloy? Wear-resistant cast iron, copper-based and aluminum-based alloys, powder metallurgy materials, plastics, rubber
Glue, hardwood and carbon graphite? Teflon? Teflon? , modified polyformaldehyde? POM？ Wait.
There are many kinds of sliding bearings. (1) according to the direction of the load can be divided into radial? Centripetal slide
Bearing and thrust? Axial? There are two types of sliding bearings. ② According to lubricant types, it can be divided into oil-lubricated shafts.
Bearings, grease lubricated bearings, water lubricated bearings, gas bearings, solid lubricated bearings, magnetic fluid shafts.
There are 7 categories of bearings and electromagnetic bearings. ③ According to the thickness of lubrication film, it can be divided into thin film lubrication bearing and thick film lubrication.
Two kinds of bearings. ④ Bearing materials can be divided into bronze bearing, cast iron bearing, plastic bearing and precious metal bearing.
Stone bearing, powder metallurgy bearing, self-lubricating bearing and oil-bearing etc. (5) According to the load-bearing structure, it can
It is divided into circular bearing, elliptical bearing, three-blade bearing, step bearing, tilting pad bearing and foil bearing.
Bearing, etc.
When the sliding bearing works, friction will occur due to the contact between the journal and the bearing bush. Cause superficial hair
Fever, wear and tear or even "bite"? What about when designing bearings? A sliding shaft with good antifriction should be selected.
Is bearing material used as bearing bush? Choose the right lubricant and adopt the right supply mode? Improved shaft
The bearing structure obtains thick film lubrication, etc.
Sliding bearings are generally used under low speed and heavy load conditions? Or maintenance and addition.
Lubricating oil is difficult to inject into running parts.
Combined with the above introduction, both hydrostatic bearing and hydrodynamic bearing belong to the category of sliding bearing? all
Is it divided according to its working principle?
There are two kinds of bearings? One is a rolling bearing? One is a sliding bearing.
General rolling bearings are divided into four parts? Inner ring, outer ring, ball? Needle? And a cage. have
Some bearings also have side covers.
"Dynamic bearing" and "hydrostatic bearing"? These two concepts are only available in sliding bearings.
They all have the same principle? Define the position of workpiece in radial direction in the form of sliding friction.
Settings.
Sliding bearings need lubrication? The lubrication methods of dynamic bearing and hydrostatic bearing are different.
Generally speaking? Is the performance of hydrostatic bearing better than that of dynamic bearing? But the formation of hydrodynamic bearings
This is a little lower.