英文翻译 液压传动系统设计与计算.docx

1、英文翻译 液压传动系统设计与计算河南农业大学毕业论文（设计）英文翻译翻译题目：液压传动系统设计与计算 学 院 机电工程学院 专业班级 06机制（3）班 学生姓名 陈重 指导教师 魏宗信 2010年 5 月 3 日Hydraulic actuation system design and computation1 is clear about the design request to carry on the operating mode analysis.When design hydraulic system below, first should be clear about the q

2、uestion, and takes it as the design basis.Main engine use, technological process, 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 stabili

3、ty, the commutation pointing accuracy as well as the request which to the system 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

4、 work foundation, should carry on the operating mode analysis to the main engine, 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

5、the oil motor load and the speed change as necessary the rule, below makes the concrete 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 char

6、t (Lt), the speed circulation chart (vt), or the speed and the displacement circulation 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-coordi

7、nate L expression piston moves, the x-coordinate t expression starts from the piston 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 charact

8、eristic 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 show, the hydraulic cylinder starts to make the uniform accelerated motion, then uniform motion,Chart 1.2 speeds circulation chartFinally

9、 uniform retarded motion to end point; The second kind, the hydraulic cylinder preceding 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 cylind

10、er one most above makes the uniform accelerated motion in the overall travelling 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, als

11、o 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 hydraulic cylinders load strength computationsWhen the operating mechanism makes the straight reciprocating motion, the hydraulic cylinder m

12、ust 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; 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 moti

13、on various stages overall load strengthThe hydraulic cylinder cycle of motion various 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

14、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 accelerates to the certain speed, its overall load strength including guide rail friction force, packing assembly friction force (according to cyl

15、inder 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)To the simple hydraulic system, the above computation process may simplify. For example uses the single proportioning pump to supply t

16、he 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 a pair of association pumps for the oil, then only must calculate the fast stage and the labor enters the stage the overall load stre

17、ngth.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 of force Me. The operating duty moment of force is possibly a definite value, also possibly as necessary changes, should carry on the

18、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: (1.7)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

19、 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 formula is: (1.8) In the formula: Is the angle acceleration (r/s2); is the acceleration or decelerates the time (s); J

20、 is revolves the part rotation inertia (),In the formula: 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 cycle various stages load size, then may draw up the oil motor the duty cycle chart2 det

21、erminations 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 motion various stages biggest overall load strength determined, in addition below, but a

22、lso 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 weight is heavy; The pressure chooses high somewhat, then part size small, the weight

23、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, according to cuts the load to elect.If the table 2.1, the table 2.2 shows.The table 2.1 press

24、es 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 execution file the working pressureMechanical typeEngine bedFarm machineryProject machineryGr

25、inderAggregate machine-toolDragon Gate digs the bedBroaching machineWorking pressure/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 fo

26、rce (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 capacity oil motor the maximum current capacity (2.2)In

27、 the formula: 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 pressure. The hydraulic pressure pumpin

28、g 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 pressurep, namely (3.1) loses, the pip

29、eline 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 system p is (2 5) 105Pa, with the

30、 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 pressure part handbook or the prod

31、uct 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)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 s