Self-lubricating bushings are crucial components in hydraulic
systems, designed to provide smooth and efficient operation while
minimizing friction and wear. These bushings are coated with a
lubricant that continuously releases a thin film of lubrication
onto the contact surfaces, ensuring consistent and reliable
performance.
The self-lubricating feature of these bushings significantly
reduces the need for regular lubrication and maintenance, making
them a cost-effective and convenient solution. They are also able
to withstand high pressures and temperatures, ensuring reliable
performance even in extreme operating conditions.
Additionally, these bushings are made from high-quality materials
that are resistant to corrosion and wear, further enhancing their
durability and lifespan. This makes them a suitable choice for a
wide range of hydraulic applications, including pumps, valves, and
cylinders.
In summary, self-lubricating bushings for hydraulic components
offer a reliable and efficient solution for reducing friction and
wear, minimizing maintenance requirements, and ensuring smooth
operation of hydraulic systems.
www.bronzegleitlager.com professionally developed bearings can meet the special application
requirements of the fluid power industry. Under the condition of high load and high speed, the BIMETAL BEARINGS solution is stable and reliable and supports most fluid power
applications.
A Reliable, Lighter, Greaseless Bearing Solution
Viiplus Low-Friction Pump Bearing Solution
The aluminum bushing block serves several purposes, which include
supporting the gear shafts, acting as a thrust bearing and providing a sealing function to ensure good contact with the faces
of the gears. SICAL®3D alloy is highly effective under a wide range of load,
speed, temperature and fluid viscosity conditions.
Sealing efficiency can be compromised under shaft loading due to
internal leakage resulting from deformation and changes in geometry
of the side face of the bushing block. The superior mechanical
strength of SICAL®3D resists this deformation which significantly improves the volumetric efficiency of external gear pumps and
motors.
Hydraulic applications:
Hydraulic pumps are used in hydraulic drive systems and can be
hydrostatic or hydrodynamic. A hydraulic pump is a mechanical
source of power that converts mechanical power into hydraulic
energy (hydrostatic energy i.e. flow, pressure).
In the hydraulic market viiplus provides solutions for various
applications.
The typical applications are:
- Piston pumps and motors
- Gear pumps and motors
- Vane Pumps
- Cylinders
Piston pumps and motors
The bushing blocks geometry plays the main role in the process of
defining functional and
mechanical parameters related to the performance of the pump (high efficiency, low noise level,
assembly ability).
Other piston pump applications
viiplus bimetal bushes are composed of two metal strips, in two different materials; the first is normally in steel, the second is normally
constituted by an alloy containing copper, which when coupled with
the steel strip acts as an internal covering. Furthermore, some
sizes also have an external relubrication hole.
Characteristics
BIMETAL BUSHING
! Capable of supporting high specific
loads
! Excellent fatigue strength under dynamic
and shock load conditions
! Superior performance under oscillating
movement
! Steel backing provides strength and
rigidity
! Thin wall construction permits compact
bearing assembly
! Indents in the bearing surface provide a
reservoir for grease and thus allow ex
tended re-greasing intervals
! Tolerant of relatively poor mating surface
finish
BIMETAL BUSHING
! Bush bore may bored, reamed, broach
ed or ball burnished in situ to control the
assembled bearing clearance
! Suitable for oil or grease lubrication
! Steel backing provides strength and
rigidity
! Hardened shafts are not required
! Thin wall construction permits compact
bearing assembly
4 Performance
4.2 Typical Applications
BIMETAL BUSHING
High load, oscillating conditions as for
example agricultural machinery, earthmo
vers, small end bushes, m
BIMETAL BUSHING
High speed applications where good emer
gency running is required as for example in
echanical hand- oil pump bearings, gearbox bushes, steer
ling and lifting equipment, hydraulic cylin- ing gear, power
steering, pedal bushes,ders, off highway equipment etc. king-pin
bushes, tailgate pivots, brake caliper bushes, mechanical handling
and lifting equipment, machine slides, hydraulic
cylinders, hydraulic motors, pneumatic
equipment, textile machinery, agricultural equipment etc.
Advantages
The special construction of these bushes means they have good resistance against wear, in particular at medium speed with a
medium load, or at low speed with a high load.
Special Techincal Features
The internal surface of the viiplus bimetal bushes can include
different types of channels, so as to satisfy the various types of applications and lubrication
conditions in which the bushes may be used.
Gear pump applications
Gear pumps (with external teeth) (fixed displacement) are simple and
economical pumps. The swept volume or displacement of gear pumps
for hydraulics will be between about 1 to 200 millilitres. They
have the lowest volumetric efficiency ({displaystyle eta _{v}approx
90%} eta_v approx 90 % ) of all three basic pump types (gear, vane
and piston pumps).
lined self-lubricating bearing also called bushing, dry bushing, bearing, bushing, coated bearing,SF-1 oilless
bearing, liner metal polymer composite bearing and based plain
bearing. This type of bush takes layer as sliding layer which makes
products can perform very well under dry condition or oil
condition.
Material Structure
These materiais consist of metal backing bonded to a porous bronze
sintered layer with based polymer bearing layer.The metal backing
provides mechanical strength, while the bronze sinter layer provides a strong mechanical
bonding between the backing and the bearing lining,the based
polymer offers exceptional low friction even under dry condition.
Advantages
Improved energy efficiency with the low friction performance of -enriched overlay;
Extended service life with a high wear-resistant bronze layer;
Zero maintenance as self-lubricating bearings can operate dry without grease;
Greater reliability than bimetallic bearings by avoiding potential
shaft/bearing seizure under boundary lubricated conditions and
frequent stop/start operation;
Compact, lightweight designs with thin-wall bearing construction;
Reduced noise with no metal-to-metal contact between the bearing and the shaft;
Quick, simple assembly without expensive mounting tools.
Gear pump bearing block type
Shafts in gear pumps. A low operating bearing clearance is essential for the high build-up of pressure and for low gear-pump leakage. To ensure a fault-free hydrodynamic operating state, the plain
bearings must exhibit a bearing clearance tailored to the operating
medium. The plain bearings come into direct contact with the
operating medium. Aggressive media may be used, depending
on the application. The plain bearings must therefore offer high resistance to abrasion, good resistance to erosion, chemical
compatibility and low swelling tendency.
Advantage: Reliable function of the bearing with plain bearings
Hydrodynamic operation
Sliding speed up to 10 m/s
High media compatibility
Low operating bearing clearance
High resistance to abrasion
High resistance to erosion
Good chemical resistance
Low swelling tendency
Low level of wear, even at high engine speeds and mixed friction
Pump Bearing Application Requirements
External gear pumps and motors mounted with hydraulic bushing
blocks are widely used in many industries such as construction,
agriculture, automotive and material handling equipment and
chemicals.
Built with few components, these reliable, lightweight, robust
pumps provide outstanding performance in volumetric efficiency.
When assembled with low-friction bearings, they can provide fixed-flow efficiencies of greater than 95% to hydraulic
systems.
Viiplus Pump Bearings - Benefits
Compared to standard aluminum alloys SICAL®3D offers:
High mechanical strength and when combined with high precision VIIPLUS machining, improved volumetric efficiency, especially in the medium pressure range
Low friction between the gear and the bushing block faces for reduced energy
losses
Good bearing properties which, depending on the operating
conditions, allow designs without metal-polymer bearings
High precision machining for reduced clearances and quiet operation
Vane Pumps
The vane rotor is supported by bearings at the front and back
plates.
When mounted in the back plate, needle roller bearings can fail due
to oil starvation, particularly after long periods of rest in
different climatic conditions or during repeated stop-start
operation.
To improve pump reliability, viiplus metal polymer cylindrical
bearings underwent trials to determine the feasibility of replacing
the needle roller bearings.
The rigorous, extensive testing program included operation at full
pump power and different engine regimes from 500 to 7 000 rpm under
boundary, mixed and hydrodynamic lubrication, stop/start operation
and oil starvation.
The results of these tests confirmed that the metal polymer composite cylindrical bushings provide superior pump reliability thanks to their excellent tribological performance of under dry,
marginal and hydrodynamic lubricated operating conditions.
Hydraulic cylinder applications
Viiplus provides high quality components with competitive prices.
We have years of experience with OEMs and Tier One suppliers to
give them an innovative edge in the market. Viiplus engineer teams
are here to help you to design the product you need at the lowest cost.
We have wide range of customer support including worldwide local
supply and R&D.
Viiplus offers:
A wide variety of high performance bearings and solutions to give our customers an edge in the market.
Great customer support from Viiplus teams who provide technical
support for any kind of bearing questions.
An incredible strategic partner with local support. We provide our
customer with the right products that offer high quality at a lower cost. Worldwide network that makes on-site support anywhere in the
world possible.
