中英文文献翻译液压传动系统设计与计算.docx

1、中英文文献翻译液压传动系统设计与计算英文原文 Hydraulic actuation system design and computation1. clearing about the design request to carry on the operating mode analysis. When design hydraulic system below, first should be clear about the question, and takes it as the design basis. Main engine use, technological process

2、, overall layout as well as to hydraulic gear position and spatial size request; The main engine to the hydraulic system performance requirement, like the automaticity, the velocity modulation scope, the movement stability, the commutation pointing accuracy as well as the request which to the system

3、 efficiency, warm promotes; Hydraulic system working conditions, like temperature, humidity, vibration impact as well as whether has situation and so on corrosiveness and heat-sensitive material existence.In in the above work foundation, should carry on the operating mode analysis to the main engine

4、, the operating mode analysis including the movement analysis and the mechanical analysis, also must establish the load and the operating cycle chart to the complex system, from this understood the hydraulic cylinder or the oil motor load and the speed change as necessary the rule, below makes the c

5、oncrete introduction to the operating mode analysis content1.1 movements analysesThe main engine functional element according to the technological requirement movement situation, may use the displacement circulation chart (Lt), the speed circulation chart (vt), or the speed and the displacement circ

6、ulation chart indicated, from this carries on the analysis to the movement rule.1.1.1 displacements circulation attempts LtThe chart 1.1 is the hydraulic press hydraulic cylinder moves the circulation chart, the y-coordinate L expression piston moves, the x-coordinate t expression starts from the pi

7、ston to the reposition time, the rate of curve expression movement of plunger speed.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

8、hydraulic cylinders v t chart, the first kind of like chart 1.2 center solid lines show, 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 p

9、receding partly makes the uniform accelerated motion in the overall travelling schedule, 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

10、 schedule by a smaller acceleration, then uniform decelerates to the travelling schedule 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

11、 mechanical analyses1.2.1 hydraulic cylinders loads and duty cycle chart1.2.1.1 hydraulic 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

12、to resistance to cutting; Ff In order to friction drag; Fi For inertia resistance; Fg 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 va

13、rious stages overall load strength computation, generally includes the start acceleration, 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

14、hydraulic cylinder or the piston were in from static enough to starts and accelerates 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:

15、(1.2)(2) fast stage: (1.3)(3) the labor enters the stage: （1.4）(4)decelerates: (1.5)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

16、, if the simple system uses the limiting pressure type variable displacement pump or 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, th

17、e oil motor must overcome the outside load is: (1.6)1.2.2.1 operating duties moment 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 mome

18、nts. In order to revolve the part journal place friction moment, its formula is: (1.7)In the formula: 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

19、moment of inertia which in order to revolve the part acceleration or decelerates when produces, its formula is: (1.8) In the formula: Is the angle acceleration (r/s2); is the acceleration or decelerates the time (s); J is revolves the part rotation inertia (),In the formula: In order to rotate the p

20、art the flywheel effect ().Each kind may look up According to the type (1.6), separately figures out the oil motor in a operating cycle various stages load size, then may draw up the oil motor the duty cycle chart2 determinations hydraulic system main parameter2.1 hydraulic cylinders design calculat

21、ions2.1.1 initially decides the hydraulic cylinder working pressureIn the hydraulic cylinder working pressure main basis cycle of motion 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 characte

22、ristic and use situation.2.1.1.2 considerations economies and the weight factor, the pressure elects lowly, then part size big, the 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 hig

23、h.Therefore, the hydraulic cylinder working pressure choice has two ways: One, elects according to the mechanical type; Two, according 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/N500050010000100

24、00200002000030000300005000050000Working pressure/MPa0.811.522.5334455The table 2.2 presses the mechanical type to choose the execution file the working pressureMechanical typeEngine bedFarm machineryProject machineryGrinderAggregate machine-toolDragon Gate digs the bedBroaching machineWorking pressu

25、re/MPaa2358810101620322.2 oil motors design calculation2.2.1 computations oil motor displacementUnder oil motor displacement according to the type decided that, (2.1)In the formula: T is the oil motor load moment of force (Nm); For oil motor import and export pressure difference (n/m3);is the oil mo

26、tor 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 capacity oil motor the maximum current capacity (2.2)In the formula: is the oil motor displacement (m3/r); is the oil motor highest rotat

27、ional 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 pressure. The hydraulic pressure pumping station must the working pressure determination, mainly acts according to the hy

28、draulic 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 pressurep, namely (3.1) loses, the pipeline including the oil after the flow valve and other parts local pressures along

29、 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 system p is (2 5) 105Pa, with the velocity modulation valve and pipeline complex system is (5 15) 105Pa, also may o

30、nly 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 pressure part handbook or the product sample, Also may refer to the table 1.3 selectionsThe table 3.1 is commonly us

31、ed, the low pressure each kind of valve pressure loses (pn)Valvepn (105Pa)Valvepn (105Pa)Valvepn (105Pa)Valvepn (105Pa)Cone-way valve0.30.5Cone-way valve38Cone-way valve1.52Cone-way valve1.52Cross valve1.53Cross valve23Cross valve1.53Cross valve353.1.2 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