As
well as conventional electric hoist hanging overhead monorail track
lifting and transport equipment, the multi-use with electric single-beam
cranes and electric single-beam overhead crane support for workshops,
warehouses and other places. With
the expansion of electric hoist performance parameters, since the
1980s, this hoist cranes were no longer confined to a small and light
lifting equipment. From
the weight of a large electric hoist bridge crane with lifting capacity
l0Ot below instead of light, medium and general overhead crane
working-level trend, because this crane, light weight, low building
height. With
the electric hoist structure in the form of updates, especially
electric hoist trolleys appeared in various forms of support and
suspension, greatly promoted the breed type hoist crane increase in
expansion of the scope and application. 80
years in foreign countries, especially Germany, Finland, Japan,
Britain, France and other countries of the manufacturers, have been
developed to produce not only the performance of advanced electric
single beam, suspension and electric hoist bridge crane, also derived
from the application of advanced hoist gantry cranes, hoists grab crane,
hoist hooks grab dual crane hoist hook grabs electromagnetic three
cranes, hoists type jib crane , hoist line style wall cranes, hoist bridge crane and warehouse stacking with hoist ceremony aisle stacking cranes. In the following internationally renowned brands representing Germany STAHL Crane example for analysis and comparison:
Hoist
crane species, type, size continues to expand and the lifting and
transport equipment in the proportion of the increase in various types
of hoist cranes will form a separate and important system of lifting and
transport equipment.
1. Performance Parameters
Performance parameter determines the scope and crane applications. Hoist cranes with lifting capacity, span, work level and lifting speed four basic performance parameters. Domestic
hoist crane with very few manufacturers to introduce foreign
technology, the vast majority of companies still produce the mid-1960s
the joint design of products, performance parameters only light small
lifting equipment performance parameters. If
nominal weight series G = 0.5 ~ l0t, span S = 5 ~ 22.5m, lifting speed
Vn = 8m/min, crane operating speed Vk = 20 ~ 75m/min, lifting height H =
6 ~ 30m , working-level assessment system at work, almost only a
working system - Intermediate working system (JC = 25%). Foreign
hoist crane in the mid 1980s as the product structure updates, expanded
the scope of its performance parameters continue to expand the scope of
development, such as shown in the table in Germany STAHL crane hoist
company performance parameters.
2. Machine Features
Hoist crane mainly consists of metal structures, institutions and electrical control of three parts. The characteristics of these three parts constitute the machine features.
(A) three-dimensional full-duplex speed
Domestic
hoist cranes almost all the agencies working speed single speed, if
two-speed, lifting the motor structure is generally picture motors. Its institutional complex, heavy, prone to accidents failure, maintenance cumbersome. German
crane hoist STAHL latest dual-winding motor of the motor, so that the
direction of the lifting crane (Z), carts running longitudinal direction
(Y) and transverse direction of the car (x) can achieve speed
dual-speed operation, to achieve the x, Y , z three directions
dimensional full two-speed operation, welcomed by users.
(2) split-type structure
For
ease of processing, storage and transport, in particular to make the
export of marine transportation, the latest foreign hoist cranes are
used between the main beam and the side beams bolted split structure. As
the "triple play" The emergence and application of operating agencies,
end beam to become independent parts, such as the German company owned
STAHL crane factory has specialized production end beam device (side
beam metal structure plus "triple play" operating agencies), annually
producing about 10,000 pairs of side beam device sold around the world. End
beam for easy shipping, the main beam can be user inconvenience due to
transportation or local collaborative manufacturing, which is engaged in
production STAHL company's new strategy.
(3) the form of a variety of car
To
meet the hoist crane species increased need, electric hoist trolleys
structure and connections are constantly increasing, rigid support or
hanging in the original car, based on the emergence of flexible
suspension car, can reduce the minimum radius of curvature of the track
Articulated trolley, angle and low building height trolley car. Low
construction height of the hoist trolley can be fixed to the side wall
in the car, the electric hoist greatly reduced the required height of
the building, which appeared correspondingly low building height
electric single-beam cranes and hoisting crane, to meet the low plant
requirements.
(4) a new operating concept
Domestic electric single-girder crane operation mode with the ground and the cab operation of the points, but
the electric single beam crane poor rigidity, with a single beam crane
cab rigidity of the connection is poor, so the operation with cab poor
performance. Abroad,
the main beam of a new generation of single hoist crane cab operation
is no longer forms, such as running speed is larger, or need cab
operations are rigid better electric hoist bridge crane instead of a
single beam cranes. Domestic
hoist cranes ground handling mostly follow the style manipulation, ie
flashlight door hanging in the hoist switch box, easy to operate when
heavy collision operator. Foreign
ground operation in the form of this product have already switched to
non-follow operation, ie flashlight door hanging in a single slide, you
can leave the weight in a relatively safe place to operate.
3. Metal structure
Hoist crane metal structure including the main beam, side beam and the main beam of the connector end of three parts. Both
at home and abroad in the past due to light and small crane hoist
lifting equipment, the main beam multi-beam combination using ordinary
hot-rolled girders, beams mostly end welded channel group, the main end
beam welding and connecting more for less containing flange plus
ordinary bolts. Since
the 1960s in particular, gas shielded welding automatic welding
technology, welding technology for ease of use of automatic main beam
box girder structure began to develop. In
the 1970s the international community with the rolling technology, the
emergence of hot-rolled steel H cranes and hoists Lord The beams make a
major change. 1980 German production hoist cranes, Germany STAHL company, has ordinary use of H-steel as the main beam.
Before
the end of the girder hoist crane rolling multi-channel group using
welded, with the rolling technology development, foreign direct use
began rolling thin wall rectangular cross-section beam fasting tube
production side, so that the welding work considerably reduced, and the
single-cylinder lightweight structure, is a new trend.
Main
side beam welded connections between form, recently in foreign
countries has been articulated connections and bolted connections and
other forms replaced. Bolt
flange connection form by shedding load pin plus or minus bolted
connection form form to the development of high-strength bolts, hoist
cranes currently abroad have adopted a new generation of high strength
bolts. This
connection is connected to the primary end beam pull, no direct
contact, but through the outer diameter of 50mm, 10mm thick shim plate
end beam, respectively, with the main local processing flat contact
surface of the contact pads at both ends not only increase the exposure
area, but also to overcome the shortcomings of previous contact with
uneven, with taper pin positioned to facilitate the assembly and
disassembly, is an ideal form of connection.
4. Agency
Most only lifting crane hoist and run by the two institutions.
(1) Lifting mechanism
As
electric hoist hoisting mechanism mainly consists of motor, brake,
reducer, extract and winding equipment and electrical control system. Germany
STAHL company's SH type electric hoist, appeared in the overall layout
of the major changes, the use of "triple play" that drives the motor
shaft brake system speed shaft gear reducer as the motor, brake and gear
three as one, arranged in one end of the roll device, the electrical
switch box fixed to the gearbox, this U-shaped structure makes the
overall layout is more compact electric hoist, thus breaking the
traditional structure and layout. In
addition, SH-type electric hoist with box-shaped bracket instead of a
circular drum shell, the frame-shaped bracket, down, left, and right
directions are processing a trolley running connection used to connect
the mounting holes, electric hoist can be installed on the same in a
variety of forms of operation small car, hoist composition of different
types of cranes.
(2) "triple play" operating agencies
The
drive (motor), the brake (brake) and transmission (gearbox) three kinds
of devices into one, called the "triple play" drives, such as the wheel
assembly is coupled with the "triple play" run institutions. A
"triple play" Run agency is today the foreign hoist crane one of the
most prominent features, with a compact, lightweight and beautiful, easy
disassembly, easy to adjust, smooth operation, supporting wide range of
advantages. Germany
STAHL company's end tooth positioning connection type "triple play" run
institutions, not only applied to the traveling mechanism, the current
has been more widely used.
5. Electrical appliances
(A) motor
Hulu
current domestic manufacturers have adopted conical brake motors, and
foreign manufacturers to use more cylindrical hoist brake motor as the
driving and braking agencies device, due cylindrical motor with double
winding, it is very suitable speed dual-run speed and the speed
frequency use. Motor
Insulation Class E-Class has also increased to F, as STAHL wire rope
hoist the German company Siemens lifting equipment developed
specifically for electric motors, working-level are 4m, long life, is
also buried thermistor thermostat protection.
(2) Electric
Plane
collector or pulley collector in foreign countries has been eliminated,
the current widespread use of novel structure and secure the
introduction of concealed trolley line power supply unit. Hoist
trolley is also rampant power introduced by the taut wire suspension
cable into the power goes flat cable slide introduction and further
development of the trolley line power supply for the interior
introduced.
Ground
operation by hand switches the emergence of new dual-speed flashlight
door, it can also be installed on the hoist digital device, with a total
safety switch key and buzzer, etc., and full use of low-voltage
operation (usually 48v).
Hoist
switch box for the whole model, the electrical components concentrated
in one, and arranged in the hoist side, in order to facilitate
maintenance. With delay function using new electronic overload limiter, and has accumulated and photoelectric display load value function.
6. Use of new materials
In
addition to the main hoist cranes using H-beam steel, side beams of
rectangular steel tube and the guide rope with wear new materials, the
use of seamless steel rolls, die-cast aluminum motor housing, pulleys
and wheels with cast iron, but also Current foreign hoist crane
application of new materials trend. If
STAHL's electric hoist trolley wheels are made of high overall
performance of ductile iron, high tensile strength than ordinary steel,
fatigue strength equivalent to 45 steel, iron and steel can be to cast
on behalf of forging, because iron containing graphite, with
lubrication, the wheel wear, wheel pressure is not great on the hoist
crane with wear-resistant, anti-fatigue, technology and good ductile
iron wheels are ideal.
7. New design and test methods
In the use of modern design methods, the German STAHL company chose a modular design approach. Modular
design enables breed product design with a strong ability to respond,
to minimize the derived non-standard product design cycles, accelerated
capital operation. Modular design must have a modern design tools and modernization of technical information management system associated with it. The
design is based on statistical analysis of market surveys and previous
forecast of accumulated data, charts, chart line rule, under strict
guidance of scientific theory, develop crane structures, institutions,
standardization of parts and other multi-level modular units.
The use of laser technology to detect hoist bridge crane geometric accuracy, speed, both fast and high accuracy. For
the assessment of hoist cranes reliability and service life, the German
company uses STAHL hoist perfect life test methods, test procedures and
supporting the use of special equipment, including automatic detection
of fatigue test recorder can automatically record the test of time and
electrical Cumulative Cumulative number of contacts and so on.
8. Introduction of new technology
To improve the performance of reducer, box using machining center, gear hobbing machine with high precision machining. And
sections for cutting sheet metal processing, using a photoelectric
tracking cutting new technology; pretreatment process has been developed
with a sand drying a continuous spray primer and finish of the new
technology; taken in the welding aspect of mixed units dumped gas
shielded arc welding, the welding quality, high efficiency nor splash.
9. Development to the special environment
To
meet the special needs of the application environment, such as
explosive, anti-corrosive and electrically insulated spaces need to be
provided with a special performance of the hoist cranes. STAHL
produced as proof hoist cranes, has developed a gas-proof and
dust-proof full range of products, not only to provide ZONE1 area
(ATEX), can also provide ZONE2 area (ATEX) a full range of
explosion-proof electric hoist, explosion-proof single beam, suspension, double girder cranes . Such
proof equipment class subdivision, greatly reducing the company's cost
of production, but also for end customers to provide more economical,
more rational lifting and transport equipment.
To
be elected to three insulated hoist cranes in foreign countries has
come out, and corrosion from Mongolia nit Gourd, at home and abroad have
been no official development and production.
10. Conclusion
10.1 Performance Comparison
China
Domestic: Starting weight up to 32 tons, lifting height up to 30
meters, the lifting speed is generally single speed, Sector level M3,
electrical protection class IP44, maintenance of high frequency, Crane
weight capacity, crane installation space is high, the noise Large
(85dB), the overall power consumption of a high crane (in 32-ton crane,
for example, power 92kw), product standard GB14405-1993 "General
overhead crane."
Germany
STAHL Company: Starting weight up to 100 tons, lifting height up to 120
meters, the lifting speed is generally two-speed or frequency, Sector
level is generally M5, electrical protection class IP55, maintenance
frequency is low, since the lightweight crane, cranes installation space
and low noise (74dB), crane overall power consumption low (in 32-ton
crane, for example, power 33kw), product standard DIN15018.
10.2 Cost Analysis
Premise:
In the plant 110 meters long, 24 meters wide inside, install a starting
weight of 32 tons, span 22.5 m, lifting height of 10 meters hoist
double girder overhead cranes. Crane working hours according to 3 hours / day, 250 days / year, working-level A5. Electricity
price of 1.2 yuan / kWh, plant construction cost is 2000 yuan / m 2,
plant life of 10-year period, comparing the German STAHL SH-type hoist
double girder cranes and using domestic QD double girder crane costs
incurred.
| Compare contents | The SH type using German STAHL hoist double girder crane | Using domestic double girder crane |
| Vehicle weight (t) | 16 | 39.8 |
| Vehicle power (kw) | 33 | 92 |
| Maximum wheel load (t) | 20.6 | 31.1 |
| Crane at the top of the track tread height (mm) | 1600 | 3300 |
| Hook left limit position to the wall (mm) |
Left Limit: 1120 |
Left Limit: 2050 |
| Right Limit: 1120 | Right limit 1800 |
(1) electricity cost analysis:
Since
both cranes, power consumption differ by as :92-33 = 59kw, so the use
of the German STAHL SH-type hoist double girder crane electricity
savings of 10 years as follows:
(92-33) kw X 3 hours / day X 250 days / year X 10 years X 1.2 yuan / kWh = 531,000 yuan
(2) Plant Cost Analysis:
Since
both the top of a crane to the track away from the tread surface height
:3300-1600 = 1700 (mm) = 1.7 meters and a hook to the wall to the left,
away from the right limit position is: (2050 +1800) - (1120 +1120) =
1610 (mm) = 1.61 m according to this data, to calculate the work area
for various additional construction cost is:
2000 yuan / m 2 X 110米X (1.7 +1.61) m = 357,600 yuan
Since
both cranes crane vehicle weight and maximum wheel pressure difference,
with the amount of steel steel construction plant, using the German
STAHL SH-type hoist double girder cranes than using domestic QD double
girder crane steel savings of 10% less per square meter can be reduced
by 200 yuan, so the construction cost savings as follows:
200 yuan / m 2 X 110米X 24 meter = 528,000 yuan
(3) Labor Cost Analysis:
As
Germany's SH type STAHL hoist double girder crane design light
structure, round pressure is small, so even such a large tonnage crane
cab and without manipulation, and made such cranes generally usually
cab manipulation, and manipulation To obtain this type of crane drivers
relevant state agencies accredited induction certificate. It can be launched by the German STAHL the SH type hoist double girder crane can save labor costs as follows:
According to every qualified drivers who operate a monthly 2,000 yuan monthly salary / month, or 10 years can be calculated:
2000 yuan / month X 12月X 10 years = 240,000 yuan
(4) Other hidden cost analysis:
As
a result of the German STAHL SH-type hoist double girder crane design
of the plant, the plant construction area of conservation and other
related expenses incurred, such as: lighting equipment costs,
electricity for lighting, heating costs, plumbing fees, fees not
statistical calculations in this section, but you can guarantee that
with the growth of plant life, this part of the hidden cost savings back
to the more obvious
Cost savings table:
Electricity cost analysis: 531,000
Plant Cost Analysis: 35.76 +52.8 = 885600
Labor Cost Analysis: 240,000
Other cost analysis: 100,000 (estimate)
10.3 final recommendation
Through
the above analysis, although the crane in the procurement of parts, its
first purchase cost is higher than the domestic component costs, but
the total cost, including construction costs, maintenance costs,
operating costs were lower than the same indicators of domestic crane. In
addition, for the German STAHL Crane Safety and reliability are
increased, and the use of performance indicators is much higher than
domestic cranes, it is recommended that customers in the economy as
permitted under German STAHL Crane preferred to enjoy the world-class
cranes to customers with to convenience!
