Foyer Light is a type of lighting fixture used for decorating and illuminating entrance halls. It is typically installed on the ceiling and can be in the form of a chandelier, Semi-flush Mount, Wall Sconce, or ceiling fan light. The design of Foyer Light is often elaborate, and can be made of materials such as crystal, glass, metal, and can feature intricate patterns and decorations. It not only provides ample lighting, but also adds a touch of elegance and sophistication to the entrance hall.
The specific choice of Foyer Light also depends on the type of decoration effect suitable for various lamps and lanterns. However, it is generally necessary to meet the effect of the atmosphere and grade, and the current modern and simple Foyer Light is more popular, and the Lighting Fixture material is generally made of metal, stainless steel or acrylic. The installation method can be installed by ceiling or hanging wire, and the selection of lamps and lanterns should also be comprehensively considered from the later maintenance and management methods.
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In the Newtonian fluid, non-Newtonian fluid and gas-liquid two-phase fluid delivery, screw pump has its unique advantages. The most widely used single, double and triple screw pump structure, working principle is very different. From an economic point of view, these three types of screw pumps have other pump can not be replaced applications. Due to the simple profile and low precision of profile, the single screw pump can adopt the high efficiency process without chip processing, so the low price has many advantages in terms of structure and adaptability. In non-lubricating media, including solid media and corrosion Sexual media delivery unique. At present, the domestic production of single screw pump far more than the production of enterprises double and triple screw pump. Single-screw single-screw single screw pump (ie, 1/2 profile) accounted for the vast majority, and the world has gradually promoted the advanced double-headed single screw pump (ie, 2/3 profile). This paper analyzes their advantages and disadvantages and discusses the process route and cross-sectional profile (the formula derivation process omitted), for the promotion of new lines and applications provide a reference. 1 type of line 1.1 conventional type of line (1/2 type cross-section profile shown in Figure l example, referred to as type A, is the oldest type of line, first proposed by the French engineer Myan0 rotor truncated circle. Diameter D = 2 a, eccentricity e, pitch t, ​​single head. The stator truncation is an ellipse with radius a and center distance 4e. Its parameters: pitch T = 2t, double head. Center of gravity e is the radius of the circle in the radius 2e r r is called the so-called Cardanon circle asked planetary motion. The number of rotor head and stator head ratio of 12. 1.2 new line (2/3 profile) horizontal The cross section is shown in Figure l (b) (c), referred to as the B type, C type, is a new type of wire proposed in recent years at home and abroad.B type rotor truncation radius a, the center of the circle 4 e long circle, the diameter D = 2 a, eccentricity e, pitch t, ​​double head .C rotor truncation is an oval, its diameter D = 2a, eccentricity e, the maximum radius b = a +2 e, pitch t, The formation of the truncation is shown in Figure I (d). As with the aforementioned Cardanodon circular motion, the rolling radius is 1.5 e, Symmetrical hypocycloid K). When the rotor is moving, the axis of symmetry is a conjugate with the bone line, and the extension of the rotor profile during the motion is the stator profile. Although the trajectories of the rotor are the same, due to the different truncation of the rotor, Of the stator line is very different, B-type three-petal-shaped C-like triangle-like pitch of its Ding = 1.5 t, three head rotor head number and the ratio of the number of heads is 23. 2 type line equation type AB Rotor line equation is the same i C-type rotor equation is elliptic .New-type line equation is related to the bone line .In Figure 2, rounded on the A1 point, Line equation for the type (I) .B-type stator profile is based on a radius of the bone line isosceles line (LY) and a radius of the circular arc. Lolline equation (2). Pure arc (3) .X0 and Y0 for the cusp point coordinates .C-type stator line equation similar to the B, it is abbreviated. 3 The advantages and disadvantages of each type (1) Type A advantages : Rotor and stator profile is simple, long production history, processing experience, efficient and economical process methods. Such as rotor mining With continuous stamping process hollow screw factory (Figure 3), not only efficient, save material, but also improve the efficiency and life of the pump.Generally, the stator mold and more use of rubber products.However, in the case of high pressure, due to compression deformation of rubber, So that the media back to the pump efficiency dropped sharply, and some high-pressure pump efficiency of only about l.0%. To solve this problem, rigid sleeve is an effective way. Because A-type stator profile is simple, easy to rigid sleeve manufacturing (Figure 3) Disadvantages: Since the relative movement between the rotor and the stator contact surface is not pure rolling, especially in the two linear sections of the stator, the sliding speed is relatively large and easy to wear. In the 2: 2/3 type, Large, so the same volume flow smaller. E.g. . The theoretical flow rate Q (m / r): A type: Q = 1.36 TB type Q = 1.612TC type Q = 1.6041T With the same parameters, A large 2πe2 value, C-type flow slightly smaller than the B type. The rotor is double-headed, so its center-of-gravity offset is half that of Type A. This allows higher speeds and less noise. Each revolution of the chamber by 2x3 instead of 1x2, the pump pulsation decreased more. The increase in chamber also allows the zone of higher slip rate to ask for lower instantaneous velocities than Type A, thereby reducing wear and increasing longevity. In addition, the new surface seal, can improve the volumetric efficiency. In the new line, since the B-type stator profile is derived from a discontinuous equation curve, there are six hard transition points in the profile (bony loophole and cusp arc at the excessive), obviously affect the operational life . However, C-type stator profile is developed by the continuous equation curve, so no such phenomenon. Comprehensive analysis, at present, China should promote C-type pump. It is reported that C-type has been commercialized in some countries, such as the German Alvieh AG company launched the AED series pumps. 4 process discussion. A-type rotor technology is more mature, can be used forming vehicles, mold cars, cyclone milling, continuous stamping and other methods. Continuous stamping is currently one of the best A-type rotor production methods. Foreign multi-axis cavity machining 2/3 type rotor, the higher the cost. Domestic units have introduced its processing machine tools, such as WEIN-GARTNER's VARID five-axis CNC milling machine, can process a variety of types of screw precision profile and single-screw pump rotor, core and rigid sleeve. However, the characteristics of single screw pump structure is mostly hard rotor, soft motion is a complex and not complex (relative double, three screw pump in terms of) products, so if only as a single machine for processing single screw machine, then Obviously excess function. Moreover, this type of medium-sized equipment, priced at about 10 million yuan, is also worth considering. According to the author's empirical analysis, the prototype or small-batch production can be completed by ordinary machine tools with a mastering device. If the mass production is carried out, an imitation milling head is installed on the existing A-type rotor processing machine and the author has completed the structural training to be competent . A-type rubber stator core processing can be car, milling, grinding and other methods, the plant has a wealth of experience. A new type of wire core technology and A type of similar methods. The key is to have the correct line coordinate information linear or nonlinear contraction of the compensatory prosthesis. A-type rigid sleeve can be used to process ordinary universal machine, 2/3-type rigid sleeve processing is extremely expensive equipment. 5 CAD Model Line Design Example This article uses a similar three-screw pump model used to improve the trajectory programming. The method is simple and reliable, without the need to establish the envelope equation, the program has been used for double and triple screw pump profile design. Program for the modular design, the package into the tool design software, not only can calculate the single screw pump rotor, stator end, shaft, cross section, but also calculate the rotor, stator core forming car, milling, rolling, Grinding and other tooling line and the tool shovel grinding wheel process parameters. The program also has various types of rubber core shrinkage compensation function, for the new single screw pump research and production of the old line provides a convenient. Table l is