雙螺桿壓縮機(jī)的設(shè)計(jì)
雙螺桿壓縮機(jī)的設(shè)計(jì),螺桿,壓縮機(jī),設(shè)計(jì)
Screw compressor rotor machining tool wear the geometric calculation method
[Abstract]: screw compressor rotor milling and processing a grinding two methods, usually conducted in two phases processing; first stage is rough, when the workpiece to be processed about its size to the second stage of Finished, when the rotor be processed into its final size when completed. Materials or cutting cushion in the finishing was removed, it is by milling, grinding and cutting tools determined by the design. Taking into account the screw compressor rotor is a spiral shape, in the process of cutting, cutting tool on every point of contact with the rotor of the horizontal length is not the same, therefore, finished at the rate of wear and tear tool of its type along the line is Inconsistent. Envelop the meshing theory be used here in terms of the process of cutting tool on every point and the relative motion between the rotor. To a certain scale, in this relative movement of assumptions, calculated on every point of the tool wear rate. By calculating the results and experimental tool that the rate of wear and tear, we can see that both the conclusions are the same. On this basis, can know how to create a rough time so that semi-processed materials while the thinning tool and thereby facilitate the finishing tool at the same rate of wear and tear. A similar technology is being applied to many of the machines during processing, and forming a variety of knives were also used for these technical.
Keyword: screw compressors; spiral rotor; manufacturing tool
1. Description:
? Screw compressor is a displacement of the rotary volume machines, it mainly by the meshing of a spiral rotor component, in the case, do rotor rotary movement, with its volume of the rotor spinning change. Today's main rotor was a screw-type, used for milling or grinding. In either form of processing by the rotor, rotor can be used to define the coordinates of their geometric characteristics, as shown in Figure 1. To run a good screw compressor rotor must mesh properly, and in the contact line in the rotor to retain a certain seal. This requires suitable for processing such knives, and must be a reasonable process of engagement worked out. Gear envelope of processing methods, if in a particular relative movement of a surface on another envelope, on this surface is meshing the two. Equation (1) the definition of a given surface, the second surface by equation (2) and the equation (3) is given. Rotor in x, y coordinates the work surface for the change function x (t) and y (t). Through the x (t) and y (t) can be defined the type of rotor, Figure 2 is a typical example. Equation (4) is a familiar mating surface. Rotor coordinate their knives and coordinates the derivation can be equation (5). Equation (5) in C on behalf of the rotor shaft centerline the distance between the rotor and tool is the angle between the shaft. h t mean, respectively, and the rotor and tool the surface. These surface of the envelope equation by equation (6) in the rotation angle to function in the form of that out.
Because the surface is generated by the t to define the parameters, the envelope can be used to calculate the other parameters, it is the back corner of the rotor, is generated mesh surface as a factor. Envelope equation in the cross-section of the generation that is part of the plane, but two general points on the relative speed rotary tool is the point of view. Rotor of the lead by each rotor rotary angle to determine;
r (t, )=[]=[xcos-ysin,xsin+ycos,p] (1)
Naming
C Rotor Tool center distance Rotor rotary angle
P Rotor each arc-lead Rotor-point line tan=
R Tool-line coordinate Pressure angletan=
r Vector coordinates Rot Shaft angle
s Measuring Tool Wea Tool perspective
t Rotor parameters
x x Coordinate h Rotor spiral
t y Coordinate hn Surface preparation of the rotor
z z Coordinate n Rotor cross-section preparation
Ms Liu area t Tool
Figure 1 Rotor Tool and the coordinates
(3)
P(t, ,)=[
= (4)
(5)
(6)
(7)
Equation (7) in the equation (6) on the basis of the conditions of engagement, into the specific data can be obtained results. To set a parameter t, cross-section of the rotor coordinate x (t) and y (t) and their derivative known Rafah. Through the equation (1) and (2) and the parameters of the valve can be calculated.
(8)
Meshing conditions show that the spiral in the formation surface, the screw rotor precise tool of a broader and very convenient to use. With related gear envelope production of linear cutter involute line in the example of many in the relevant materials, such as Litin and Fuentes. But Andreev [2] and xing [3] in their recent book by using screw Compressor specific forms of processing tool to screw compressor theory.
Stosic [4] propose a suitable rotation of the screw rotor imbalance and do not intersect axis production methods. And Stosic Etal. [5] not only describes the intersection axis method. Equation (10) gives a reverse tool of the special form of the rotor. It can be used to calculate the impact of screw rotor manufacturing processing equipment deficiencies.
Tool is given the coordinates, the rotor-line through the coordinates of the points equation (4) the inverse operation can be calculated. Algorithms are as follows;
(9)
Angle from the next-calculated parameters:
(10)
Shizi over by equation (!) The inverse operation can be calculated rotor horizontal coordinates x and y. are as follows:
(11)
Here
Once the results worked out along the distribution of the dispersion of meshing tool can be used to calculate the rotor and the coordinates. The same can be identified contact line and the rotor, rotor and contacts between the tool path.
Screw compressor line is sealed by a series of points near the rotor component, usually in the gap between the rotor, a similar, knives and the contact line between the workpiece can be regarded as a rotor of the contact line, redundant Preparation should be removed when the rotor machining. If these remaining tool processing of raw materials have not been out, that gap is often overlooked. In this case, presented by the more than expected, with results to calculate the gap tool wear.
2. Ms Liu calculated given the coordinates distribution
2.1 more than expected given the coordinates of the rotor
If the rotor from the processing of raw materials out of a given thickness of the rotor to the vertical surface of a normal position, rough when the rotor plane of the corresponding coordinates and finishing at the rotor plane of the corresponding coordinate the different representatives in the process of cutting the rotor and Tool of relative movement. When the rotor in the calculation of rough circumferential, and the equation (6), a related derivative of the r to determine the normal direction of the rotor. Rotor plane method used to calculate the coordinates. It does not include the rotor cross-section coordinates of the remaining preparation of raw materials, is more than the thickness of material calculated as follows:
(12)
Here diameter D calculated from the next –
(13)
Preparation of the horizontal coordinates of the rotor can equation (11) worked out at the point of cutting tools for rough coordinates, finishing tool when the coordinates from the original rotor x and y coordinates to calculate. Rough at the rotor plane of the corresponding coordinates and finishing at the rotor plane of the corresponding coordinate the different representatives in the process of cutting tool and the rotor relative movement. When the rotor in the calculation of rough cross-section coordinates, finishing at the cross-section coordinates x, y,. Can get the same conclusion. The conclusions from the rough, can also coordinate the rotor cutter knives and finishing at the coordinates of that.
2.2 tool wear
The start given the tools, wear parts and tool and the relative motion between the relevant rate. Rough and finishing tool when the coordinates can illustrate this point. Or through the rough when the rotor and finishing at the rotor plane or cross-section of the difference can be seen. The following example is through the rotor in the rough when the cross-section coordinates and finishing of the cross-section.
(14) From the equation (14) can be calculated tool wear, the cutter knives from excessive wear and tear can see the coordinates. The sooner that coordinates changes also wear faster rate. This theory was later used to wear by Cutter calculated by the rotor of the processing line. To wear a specific method is feasible in proportion to gradually enlarge it, stack it to the rotor or tool-line, the right-line position on a reasonable estimate wear.
3. Examples of applications
3. Examples of industrial application of the rotor is a 5-6 tooth meshing of the yin and yang of mutual rotor, plans were set out two of their engagement, map conversion of the diameter of 144 mm, the rotor helix angle, the rotor center distance To 108 mm.
3.1 Cutting tool wear uniform
Figure 2 is given by the rotor meshing situation tells us that screw compressor rotor and its engagement in the forming tool is neither parallel nor intersection of the axis. Equation (7) the solution can be calculated Rotor Tool meshing requirements. When the rotor is finishing cross-section point coordinates x, y and, on the rotor of the spiral can coordinate equation (1) obtained. Use the same method of calculation of rotor rough coordinates can be obtained at the thickness of material for more than 50. The meshing of the yin and yang rotor knives, their rotor knives from the Centre for 180 mm and 200 mm. Roughing and finishing tool is the same. Rotor and tool for the axis angle.
Uniform caused by the cutting tool wear, the preparation was in order gradually increased 50 times, it superimposed on the coordinates of the tool, charts, three representatives of the curve in the coordinates, the cutter knives on the wear and tear from every point leads to the To a certain length of the line said. Tool of wear and tear of the tool along the line is inconsistent. In the rotor-point line all the perspective. Pressure angle is the same. Under such circumstances, the tool is the smallest of wear and tear, no other case of wear and tear than it big.
3.2 more than expected use of cutting tool to reduce the distribution of the wear and tear
Uneven thickness over a certain amount of material was processed out, is what we expect. Because of uneven thickness of the material would cause more than cutter-type knives along the line the direction of wear. If Ms Liu is deemed to be a uniform distribution of more than expected, so the cycle of wear and tear caused can be a tool wear the uniform. Tool wear the uniform from the economic terms, should be the best option. Because it allows tool in the renovation period, or when to use sharp in the longest time. The new rotor coordinates and the old rotor coordinates x, y in comparison to be reflected in Figure 4. Rotor coordinates of a special online every point from a certain length of the line that coordinates the rotor case-by -
Step increases 50 times, wear a result, not all the same.
3.3 experimental verification
Calculated by the type of tool wear and get the actual measurement tool wear-line, on the basis of this production of the 150 twin-screw compressors. Figure 5 is rotor meshing of the yin and yang situation. Theory did not wear a given line of the tolerance zone for the 6, it said that a certain degree of wear and tear. Figure in the actual measurement tool wear-line marked by fine line, calculated type of tool wear line marked by rough line. Taken in line with the statement result of this calculation is correct.
Figure 4
Figure 5
4. Conclusion
Tool wear often occur in the screw compressor rotor machining process. Logically speaking in the hope that the uneven thickness of material from the rotor in the process of being processed out, otherwise it will cause along the tool-wear line thickness inconsistent. If a certain size tool to reverse the processing of surplus materials, will be in uniform thickness of the material, processing tool in the course of a certain rate cutting will produce a uniform tool wear. Gear envelope theory was as a meshing requirements, horizontal helical gears used this to calculate the distribution of preparation, it will cause the finishing tool wear.
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