6ton Compact High Efficiency Single Girder Bridge Crane

• After-sales Service: on Time
• Warranty: 1 Year
• Certification: GS, ISO9001
• Model NO.: LDA
• Condition: New
• Operation Form: Remote Control
• Maximum Lifting Height: 15-20m
• Maximum Lifting Weight: <20t
• Main Girder Form: Single Girder
• Type: Ordinary
• Quality: Top
• on Time Delivery: Yes
• Transport Package: Sea Worthy Package
• Specification: 40′ / 20′ OT / GP
• Origin: China
• HS Code: 84261120
• Production Capacity: 50000 Set / Year

Product Description

LD Type Electric Single Girder Overhead Crane



LD type single girder crane designs,manufacture standard and inspection standard
1,GB3811-83       Crane Design Standard
2,GB6067-85       Crane Safety Specification
3,JB/T1306-94      Electric Single Girder Crane
4,JB/ZQ8012-88     Electric Single Girder Crane, Quality Grade
5,GB5905-86       Crane Test Standard and Procedures 
6,GB5972-86       Crane Tool Steel Wire Inspection and Discard Practical Standard.
7,GB10051-88       Crane Hook  

Mechanical
I.  Brief Introduction 
The electric single girder bridge crane is designed and manufactured according to the standard JB1306-94 and the CD1 form electric hoist is combined to become one kind the small crane which travels along rail.
II.  Material and Craftsmanship
1,Main load-bearing components as: main girder, end girder, use in the GB700-88 standard the Q235-B steel products, Min board thick≥-6mm,the non- stress component uses the Q235-BF steel products,The welding craft and the welded joint inspection strictly observes the corresponding standard and used the ultrasonic to the welded joint not to damage crack detection,The steel products surface carries on blasting treatment,The surface derusting of steel plate achieved in GB8923 the Sa2.5 level section is the St3 level, other parts achieve the Sa2 level or the St2 level,And paints the pretreatment primer, the film thickness each is 25-35μm,total thickness is:75-105μm,film Adhesion according to a GB9286 stipulation level of quality requirement.
2,the wheel material is 45# steel forging the small wheel with is not lower than in GB699 the 45# steel manufacture, and the quenching and tempering treatment, the gear material is 45# steel 42CrMo,20CrTi and so on.
3,Wheel processing degree of hardness: In roller face and wheel rim side degree of hardness(HB)>300-380,depth 20mm place degree of hardness(HB)≥260.
4,The hook material is DG20# steel.
5,the crane for the metal structure the carbon structural steel according GB700, the low-alloy structural steel selects according to the GB1591 or is not lower than in the table:

Component Type		Important component		Other Components
Work Environment Temperature		Not under -20ºC	under -20~25ºC	-25ºC~+40ºC
Steel Size	δ≤20 δ>20	Q235-BF Q235-B	Q235-D	Q235-A.F
			16Mn

III,Metal Structure
1,main girder is made up by pressed u shape steel which is welded together with I-beam steel. Carriage beam is made with U shape steel and then welded. In order to make storage and transportation convenient, in middle of the main girder, there is lift ring. main girder and the carriage beam (the 45# steel) are connected by M24 bolt(code 45# steel).
2,The girder has camber of F which should be within (1/1000-14/1000). The middle camber should be controlled smaller than S/10(S means span).
3,girder curving in level f should be smaller than S/2000. f should be measured on web plate 100mm away from main girder top. span deviation △ S should be within ±2mm when span is smaller than 10m, and span deviation △ S should be within ±[2+0.1(S-10)]mm, when span is over 10m.
IV. Lift Mechanism
1,The lift mechanism is CD₁ electric hoist which includes reducer, electric motor, wire drum shell sheave and so on. Electric motor is special cone electric motor for crane, the rated voltage is 380V, the rated frequency is 50HZ, the insulation grade is the H level, and the protection grade is IP54.
2,The brake works through fan brake wheel and friction bush. Brake is often closed, when it works, the fan brake wheel is open; when it does not work, the fan brake wheel is closed.
3,steel wire is special type of 6W(19) for crane, its structure is dense, intensity is high, the life is long, which meets the hoist crane normal use needs.
V. Trolley Traversing Mechanism
1, The trolley travel mainly is composed of the hoist wall plate ,the auxiliary wall plate, the bolt and so on. Electric motor and reducer is installed on the main wall plate, the electric motor is special type of ZDY cone-shape for the crane, rated voltage 380V, rated frequency is 50HZ, the insulation grade is H level, and protection grade is IP54.
2,break device and electric motor are one unit, when travel mechanism does not work the brake is closed, when it start to work, the fan brake wheel automatically opens.
3,wheels on main wall plate and aux wall plate are the mono wheel rim, buffers are located in both girder ends, buffer uses rubber block.
VI. Crane Traveling Mechanism
1,The crane travel mechanism uses separate drives which are composed by drive wheel set, idle wheel set, reducer and cone-shape electric motor.
2,The crane wheel has double wheel rims, buffers are located in both carriage girder ends, buffer is rubber block.
3,crane brake and the movement electrical machinery are one unit, when crane start working , fan brake wheel will automatically start, when it does not work, the fan brake wheel closes.
Electric Part
I. Electric single girder crane travel motor has single speed cone-shape cage motor to be used for running speed of 30m/min and the cone-shape electric motor.
II. The crane power supply uses slide conductor.
III. The electric hoist travel power is supplied through electric cable supported by galvanized steel wire. Inside bridge raceway, cable protect device is installed and has wiring joint. All crane electric cables and electric wire uses copper core, the control loop wire sectional area is not smaller than 1.5 mm².
IV. All of the electric device shell for crane , completely grounding, the total grounding resistance is not bigger than 4Ω.
V. The power source uses three-phase, 380V50HZ,power source is the 380V50HZ control loop power source is 36V, 50HZ, illumination power source is 220V, 50HZ.
VI. The power distribution system provides by control and protect box of crane and electric hoist protect box, which has main circuit breaker, main power source contactor , over current load relay and various mechanism auto-switch, fault circuit can be cut off for repair.
VII. Protection and instruction
The crane travel and lift mechanism have limit switches. Rope guide is installed on hoist drum and rope guide is connected by rod with break off limit in up movement. Crane is equipped with travel limit switch and safety ruler could be impacted to cut off power supply and ensures protective function.