中英文文献翻译液压传动系统设计与计算文档格式.docx

1、Chart 1.1 displacements circulation chart1.1.2 speeds circulation chart vt （or vL）In the project the hydraulic cylinder movement characteristic may induce is three kind of types. The chart 1.2 is three kind of types hydraulic cylinders v t chart, the first kind of like chart 1.2 center solid lines s

2、how, the hydraulic cylinder starts to make the uniform accelerated motion, then uniform motion,Chart 1.2 speeds circulation chartFinally uniform retarded motion to end point; The second kind, the hydraulic cylinder preceding partly makes the uniform accelerated motion in the overall travelling sched

3、ule, in another one partly makes the uniform retarded motion, also the acceleration value is equal; The third kind, the hydraulic cylinder one most above makes the uniform accelerated motion in the overall travelling schedule by a smaller acceleration, then uniform decelerates to the travelling sche

4、dule end point. Vt chart three velocity curve, not only clearly has indicated three kind of types hydraulic cylinders movement rule, also indirectly has indicated three kind of operating modes dynamic performance.1.2 mechanical analyses1.2.1 hydraulic cylinders loads and duty cycle chart1.2.1.1 hydr

5、aulic cylinders load strength computationsWhen the operating mechanism makes the straight reciprocating motion, the hydraulic cylinder must overcome the load is composed by six parts （1.1）In the formula: Fc In order to resistance to cutting; Ff In order to friction drag; Fi For inertia resistance; F

6、g For gravity; Fm In order to seal the resistance; Fb In order to drain the oil the resistance.1.2.1.2 hydraulic cylinders cycle of motion various stages overall load strengthThe hydraulic cylinder cycle of motion various stages overall load strength computation, generally includes the start acceler

7、ation, quickly enters, the labor enters, quickly draws back, decelerates applies the brake and so on several stages, each stage overall load strength has the difference.（1） starts the acceleration period: By now the hydraulic cylinder or the piston were in from static enough to starts and accelerate

8、s to the certain speed, its overall load strength including guide rail friction force, packing assembly friction force （according to cylinder mechanical efficiency m=0.9 computation）, gravity and so on item, namely: （1.2）（2） fast stage: （1.3）（3） the labor enters the stage: （1.4）（4）decelerates: （1.5）

9、To the simple hydraulic system, the above computation process may simplify. For example uses the single proportioning pump to supply the oil, only must calculate the labor to enter the stage the overall load strength, if the simple system uses the limiting pressure type variable displacement pump or

10、 a pair of association pumps for the oil, then only must calculate the fast stage and the labor enters the stage the overall load strength.1.2.2 oil motors loadWhen the operating mechanism makes the rotary motion, the oil motor must overcome the outside load is: （1.6）1.2.2.1 operating duties moment

11、of force Me. The operating duty moment of force is possibly a definite value, also possibly as necessary changes, should carry on the concrete analysis according to the machine working condition.1.2.2.2 friction moments. In order to revolve the part journal place friction moment, its formula is: （1.

12、7） G is revolves the part weight （N）; F is the rubbing factor, when the start for the factor, after the start for moves the rubbing factor; R is the journal radius （m）.1.2.2.3 moment of inertiaMi. The moment of inertia which in order to revolve the part acceleration or decelerates when produces, its

13、 formula is: （1.8） Is the angle acceleration （r/s2）;is the acceleration or decelerates the time （s）; J is revolves the part rotation inertia （）,In order to rotate the part the flywheel effect （）.Each kind may look up According to the type （1.6）, separately figures out the oil motor in a operating cy

14、cle various stages load size, then may draw up the oil motor the duty cycle chart2 determinations hydraulic system main parameter2.1 hydraulic cylinders design calculations2.1.1 initially decides the hydraulic cylinder working pressureIn the hydraulic cylinder working pressure main basis cycle of mo

15、tion various stages biggest overall load strength determined, in addition below, but also needs to consider the factor:2.1.1.1 each kind of equipment different characteristic and use situation.2.1.1.2 considerations economies and the weight factor, the pressure elects lowly, then part size big, the

16、weight is heavy; The pressure chooses high somewhat, then part size small, the weight is light, but to the part manufacture precision, the sealing property requests high.Therefore, the hydraulic cylinder working pressure choice has two ways: One, elects according to the mechanical type; Two, accordi

17、ng to cuts the load to elect.If the table 2.1, the table 2.2 shows.The table 2.1 presses the load to choose the execution file the working pressureLoad/N50005001000010000200002000030000300005000050000Working pressure/MPa0.811.522.5334455The table 2.2 presses the mechanical type to choose the executi

18、on file the working pressureMechanical typeEngine bedFarm machineryProject machineryGrinderAggregate machine-toolDragon Gate digs the bedBroaching machinea2358810101620322.2 oil motors design calculation2.2.1 computations oil motor displacementUnder oil motor displacement according to the type decid

19、ed that, （2.1） T is the oil motor load moment of force （Nm）;For oil motor import and export pressure difference （n/m3）;is the oil motor mechanical efficiency, the common gear and the plunger motor takes 0.9 0.95, the leaf blade motor takes 0.8 0.9.2.2.2 computations oil motor needs the current capac

20、ity oil motor the maximum current capacity （2.2）is the oil motor displacement （m3/r）;is the oil motor highest rotational speed （r/s）.3 hydraulic pressure parts choice3.1 hydraulic pumps determinations with need the power the computation3.1.1.1 determines the hydraulic pump the biggest working pressu

21、re. The hydraulic pressure pumping station must the working pressure determination, mainly acts according to the hydraulic cylinder in the operating cycle various stages to have most tremendous pressure p1, in addition the oil pump loses Sigma Delta p the oil mouth to the cylinder place always press

22、urep, namely （3.1） loses, the pipeline including the oil after the flow valve and other parts local pressures along the regulation loss and so on, before system pipeline design, may act according to the similar system experience to estimate, common pipeline simple throttle valve velocity modulation

23、system p is （2 5） 105Pa, with the velocity modulation valve and pipeline complex system is （5 15） 105Pa, also may only consider flows after various control valves pressure loss, but ignores the circuitry along the regulation loss, various valves rated pressure loses may searches from the hydraulic p

24、ressure part handbook or the product sample, Also may refer to the table 1.3 selectionsThe table 3.1 is commonly used, the low pressure each kind of valve pressure loses （pn）Valvepn （105Pa）Cone-way valve0.30.538Cross valve1.53233.1.2 determines the hydraulic pump current capacityqBPumps the current capacity basis functional element operating cycle must the maximum current capacity and the system divulges the determination3.1.2.1 At the same time when more than hydraulic cylinders movement, the hydraulic p