Background technology

Elevator machinery is to realize production process mechanization, automation in modern industry enterprise, alleviate heavy physical labor, the important tool of raising labour productivity and equipment.Hoisting crane is the important substance basis of do mechanization operation, is fixed assets main in some industrial enterprises.For industrial and mining enterprises, port and pier, warehouse, station, building operation building site, and the department such as ocean exploitation, space travel, hoisting crane has become main essential elements of productive forces, carrying out aborning work efficiently, forming the basis of rationalization's batch manufacturing and mechanized continuous productive process, is one of important symbol of modern production.Increase by one or two weight-lifting equipment on some key post, the growth that labor efficiency will be at double.

Elevator machinery is comprised of movable machinery, load carrier, propulsion source and control convenience and safety equipment, signal designation equipment etc.; A kind ofly in the batch operation mode, material is hoisted, descended and the handling machinery of parallel motion.The operation of elevator machinery is usually with the character of repetitive cycling.Complete work cycle generally comprises and gets thing, hoists, translation, decline, unloading, then returns to the links such as original place.Elevator machinery is widely used in the each department of national economy such as transportation, building industry, business and agricultural and people's daily life.

And in actual production, we always can run into some by weight as track of the case ﹑ down-hole of machine bed ﹑ heaviness etc. in the situation that the situation that does not have lifting appliance to move or lift, only depending on the workman to operate is to be difficult to realize, at this moment we just need to use jack.Jack and our life are closely bound up, in all trades and professions, as built the departments such as Zhu﹑ iron road ﹑ vehicle maintenance and repair, all be widely used, so the development of jack technology will directly or indirectly have influence on normal operation and the work of these departments.Jack is again erector, top heavy-duty machine, jack etc., is that the smaller power of a kind of use just can, the simple crane tool of weight jacking, decline or displacement, also can be used to the deviation of dent removal equipment installation and the distortion of member etc.Jack is mainly used in the departments such as factories and miness, communications and transportation as work such as Mechanical Help and other lifting, supports.Its structure is firm, flexibility and reliability lightly, and a people is portability and operation.Jack is to lift part as equipment by rigid top, the light little weight-lifting equipment of jacking weight in little stroke by top bracket or bottom claw, the top lifting height of jack is generally 400mm, and jacking speed is generally 10-35mm/min, and the load-carrying ability maximum can reach 500t.

At present, on market, general jack, by the difference of its structure and principle of work, is divided into mechanical type and fluid pressure type usually, and mechanical jack has again rack-and-pinion and spiral two kinds, and wherein screw jack and fluid pressure type jack are comparatively commonly used.

Fluid pressure type jack structure compactness, stable working, have self-locking action, therefore use extensively.But the top driven shortcoming of hydraulic jack is: the factors such as leakage of oil in (1) hydraulic jack system, motion-affecting stationarity and correctness, make the hydraulic jack transmission can not guarantee strict transmitting ratio.(2) the hydraulic jack transmission is more responsive to the variation of oil temperature, and during temperature traverse, liquid viscosity changes, and causes the variation of motion characteristics, makes the stability of work be affected, so it should not be worked under the environmental conditions very large in temperature traverse.(3) in order to reduce leakage, and, in order to meet the requirement on some performance, the related parts accuracy of manufacture of Hydraulic Elements is had relatively high expectations, and processing technology is more complicated.(4) the hydraulic jack transmission requires that the independent energy is arranged, easy to use unlike power supply.(5) the hydraulic jack system et out of order is difficult for checking and getting rid of.

The main shaft appearance of lifting screw is processed and can be increased service life with chromium; It is highly low, is applicable to the job requirements of general crawl space, and Yang Cheng is short, padded use that can be repeatedly, it be by manpower by the screw pair transmission, its compact conformation, cost is lower, uses and carries more for convenience; Can support for a long time weight, the biggest lifting capacity has reached 100 tons, uses more extensive.

Hydraulic jack mainly is comprised of grease chamber, oil pump, shoe cream room, piston and crank etc., during work, with the hand crank of jack, drives oil pressure pump, and working oil is pressed into to grease chamber, and promote piston and rise or descend, and then jack-up or whereabouts weight.When engineering construction, YQ type Manual hydraulic jack (or claim move slip jack) is the double-acting hydraulic gear of a kind of internal liquid return.Use more.This jack quality is light, and efficiency is high, uses and carries also more conveniently, and it can be divided into again general and special-purpose two classes.

The dedicated hydraulic jack makes special-purpose tensioner, when making prestressed concrete member, deformed bar is applied to tension force.The dedicated hydraulic jack mostly is double-acting type.Commonly used has feedthrough and bores two kinds of anchor formulas.Use feedthrough in the time of large absolutely.

Centre-hole jack is applicable to tension reinforcing steel bar bundle or bundled steel wires, and it mainly presses piston and spring etc. partly to form by tension cylinder, top-bearing jar, top.Its feature is: a punching duct is arranged along the stretcher axle center, after reinforcing bar (or steel wire) penetrates by the instrument anchoring of afterbody.

Screw jack is divided into again: fixed type screw jack, fixed type LQ type lifting screw and mobile jack screw three major types.(1) fixedly screw jack has two kinds of plain type and ratchet-types, when operation, before the unloading, can not make planar movement; (2) fixed type LQ type lifting screw compact conformation, light and handy, easy to use.It is comprised of ratchet group, large bevel pinion, jacking sleeve, serration screw rod, body frame etc.; When back and forth moving handle, the support tooth promotes ratchet group intermittent-rotation, and bevel pinion drives bevel gear wheel, makes the rotation of serration screw rod, thereby makes jacking sleeve increase or descend.Because thrust baring rotates flexibly, friction force is little, thereby manual dexterity, high efficiency

Mobile jack screw be a kind of in the jacking process transportable jack, when operation, its movement is mainly that the horizontal screw bolt by its bottom rotates, thereby the weight of jack-up or decline is together moved horizontally together with jack.Therefore, mobile jack screw just uses easily in the equipment installation.

The jack structure that the utility model relates to is mainly to be applied to automotive field, and current domestic simple automobile jack extensively adopts manually, or the driven by motor mechanics is by automobile jack-up.Hand jack labour intensity is high, and activity space has certain limitation, and need to use certain external force and could lifting play vehicle, is not suitable for especially the women and uses.Adopt the mechanics of driven by motor, there is the shortcomings such as transmission of power is not steady, and do not have can be effectively mobile function.