Compressor crankshaft aligning installation method

Abstract

According to the compressor crankshaft aligning installation method, a machine frame is included, an assembly hole is formed in the machine frame, an aligning piece is placed in the assembly hole, and the aligning piece and the assembly hole are in running fit; a shaft hole is formed in the middle of the aligning piece, firstly, a core rod of a corresponding specification is selected according to the size of the shaft hole, a corresponding false rotor is selected according to the specification of the core rod, and the core rod is inserted into the false rotor; then fixing a rack on a stator mounting seat, inserting a core rod into a shaft hole of a self-aligning piece, and pressing a false rotor into an inner hole of the stator; and then welding and fixing the aligning piece and the rack, withdrawing the core rod and the false rotor after welding, mounting the crankshaft into the shaft hole, and then thermally sleeving or cold-pressing the rotor into the crankshaft, thereby finally completing the assembly. The core rod and the false rotor are used for adjusting the positions of the self-aligning bearing and the rack and are welded and fixed, so that the machining difficulty of the rack can be greatly reduced, the machining equipment investment of the rack is also reduced, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, and in particular to a method for self-aligning and installing a compressor crankshaft. Background Technology

[0002] Currently, during compressor assembly, the frame is fixed to the stator mounting base, with a shaft hole in the middle of the frame. The crankshaft's main shaft passes through the shaft hole and the rotor's inner hole, and the rotor is placed inside the stator's inner hole. To ensure the uniformity of the air gap between the stator and rotor, the air gap between the stator and rotor inside the motor needs to be uniform. During machining, the machining accuracy of the frame needs to be improved to ensure the perpendicularity of the stator mounting surface to the shaft hole, and the difference in the thickness of the stator steel plate needs to be controlled to ensure the perpendicularity of the stator mounting surface to the stator's inner hole. Ideally, the uniformity of the air gap can be guaranteed by controlling these two dimensional and positional tolerances. However, in actual machining, machining tolerances are allowed, and these two dimensional and positional tolerances will cause unevenness in the air gap.

[0003] Uneven air gaps increase magnetic pull, which in turn increases power consumption and bearing load, reducing reliability. The reverse force of the magnetic pull is provided by the bearing structure, which is a cantilever beam structure. Excessive magnetic pull can cause swirl wear between the rotor and stator inner bores, leading to serious quality problems. Therefore, the frame supporting the bearing structure must have sufficient rigidity. Most existing compressor frames are die-cast, resulting in complex machining processes requiring specialized machines and incurring high costs. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a method for self-aligning compressor crankshaft installation, which can ensure the uniformity of the air gap between the stator and rotor, reduce the requirements for machining accuracy and strength, and lower production costs.

[0005] Therefore, the technical solution of the present invention is: a method for self-aligning installation of a compressor crankshaft, comprising a frame, an assembly hole on the frame, and a self-aligning component placed in the assembly hole, the two being rotatably engaged; the self-aligning component has a shaft hole in the middle; the self-aligning installation steps are as follows:

[0006] 1) Select the corresponding mandrel according to the size of the shaft hole, select the corresponding dummy rotor according to the specifications of the mandrel, and insert the mandrel into the dummy rotor;

[0007] 2) Secure the frame to the stator mounting base;

[0008] 3) Insert the mandrel into the shaft hole of the self-aligning component and press the dummy rotor into the inner hole of the stator;

[0009] 4) Weld and fix the self-aligning components and frame;

[0010] 5) Remove the mandrel and dummy rotor;

[0011] 6) Install the crankshaft into the shaft hole, and then heat-fit or cold-press the rotor into the crankshaft;

[0012] 7) Complete assembly.

[0013] Based on the above scheme and as a preferred embodiment of the above scheme: in step 1), the gap between the mandrel and the shaft hole is 0.002-0.003mm.

[0014] Based on the above scheme and as a preferred embodiment of the above scheme: in step 1), the gap between the mandrel and the dummy rotor is 0.002-0.003mm, and the outer diameter of the dummy rotor is 0.03mm smaller than the design minimum value of the stator inner hole.

[0015] Based on the above scheme and as a preferred option: in step 3), the self-aligning component and the frame are fixed by circumferential welding or by spot welding at no less than 2 points.

[0016] Based on the above scheme and as a preferred embodiment of the above scheme: the mounting hole of the frame is provided with a first mating part, and the self-aligning part is provided with a second mating part on the outside, and the first mating part and the second mating part are rotatably mated.

[0017] Based on the above scheme and as a preferred embodiment of the above scheme: at least one surface between the first mating part and the second mating part is a spherical structure, wherein the spherical structure is a single sphere, or is composed of several concentric spheres of the same diameter with a distribution range exceeding 180 degrees.

[0018] Based on the above scheme and as a preferred embodiment of the above scheme: the contact method between the first mating part and the second mating part is point contact, having three or more contact points; or, the contact method between the first mating part and the second mating part is line contact, having three or more contact lines; or, the contact method between the first mating part and the second mating part is surface contact, with the two completely fitted together or having two or more contact surfaces.

[0019] This invention utilizes a mandrel and a dummy rotor to replace the actual crankshaft and rotor used in the installation. The gaps between the mandrel and the shaft hole of the self-aligning component, and between the mandrel and the inner hole of the dummy rotor, are adjusted to 0.002-0.003 mm. The dummy rotor is installed in the inner hole of the stator used for installation, and then the air gap between the dummy rotor and the inner hole of the stator is adjusted. During adjustment, the self-aligning component rotates relative to the mounting hole of the frame. When the air gap reaches uniformity, it indicates successful alignment. At this point, the self-aligning component is welded and fixed to the mounting hole of the frame. When the mandrel and dummy rotor are removed and the actual crankshaft and rotor are installed, the air gap between the stator and rotor is also uniform.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: by setting the frame as a split structure, the self-aligning component where the shaft hole is located can rotate relative to the frame itself. The position of the self-aligning bearing and the frame is adjusted and fixed by using a mandrel and a dummy rotor, which can greatly reduce the processing difficulty of the frame, reduce the investment in the processing equipment of the frame, and reduce the production cost. After self-aligning by using the self-aligning component, the influence of form and position tolerance can be greatly eliminated, resulting in a smaller and more uniform air gap and improving the working efficiency of the motor. Attached Figure Description

[0021] The following detailed description, in conjunction with the accompanying drawings and embodiments of the present invention, will provide further information.

[0022] Figure 1 This is a flowchart of the self-aligning installation process of the present invention;

[0023] Figure 2 This is a schematic diagram of the self-aligning installation of the present invention;

[0024] Figure 3 for Figure 2 Structural sectional view;

[0025] Figure 4 This is a schematic diagram of the structure of the frame and self-aligning component of the present invention;

[0026] Figure 5 This is a structural cross-sectional view of the frame and self-aligning component of the present invention;

[0027] Figure 6 This is an actual assembly drawing of the present invention.

[0028] The markings in the diagram are as follows: Frame 1, Assembly Hole 11, First Mating Part 12, Crankshaft 2, Stator 3, Stator Mounting Base 31, Rotor 4, Self-aligning Part 5, Shaft Hole 51, Second Mating Part 52, Mandrel 6, Dummy Rotor 7 Detailed Implementation

[0029] In the description of this invention, it should be noted that the directional terms such as "center", "horizontal (X)", "longitudinal (Y)", "vertical (Z)", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this invention.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. Thus, the use of "first" and "second" to define a feature may explicitly or implicitly include one or more of that feature. In the description of this invention, "several" or "a number" means two or more, unless otherwise explicitly specified.

[0031] See the attached drawings. The compressor crankshaft self-aligning installation method described in this embodiment involves a frame 1, a crankshaft 2, and a motor. The motor includes a stator 3 and a rotor 4. The frame 1 has a through mounting hole 11, and a first mating part 12 is provided inside the mounting hole 11. It also includes a self-aligning component 5, which has a shaft hole 51 in the middle and a second mating part 52 on its outer circumference. When not welded and fixed, the first mating part 12 and the second mating part 52 can be rotatably engaged.

[0032] At least one surface between the first mating part and the second mating part is a spherical structure. The spherical structure can be a part of a complete sphere or a structure composed of multiple concentric spheres of the same diameter. The distribution range of these concentric spheres of the same diameter exceeds 180 degrees, and the concentric spheres of the same diameter can be connected by connecting surfaces such as planes and arcs.

[0033] The shape of the first mating part 12 within the frame is not limited, as long as it satisfies any one of the following:

[0034] ① The contact method between the first mating part and the second mating part is point contact, with three or more contact points. For example, the first mating part is composed of three or more local planes with an angle in the horizontal direction;

[0035] ② The contact method between the first mating part and the second mating part is line contact, with three or more contact lines; for example, the first mating part is a conical surface structure or a frustum structure;

[0036] ③ The contact method between the first mating part and the second mating part is surface contact, and the two are completely fitted together or have two or more contact surfaces. For example, the first mating part has a spherical structure and is completely fitted with the second mating part.

[0037] During the alignment installation, mandrels 6 and dummy rotors 7 of various specifications are also required. The size of the mandrels and dummy rotors is slightly larger than that of the crankshaft and rotor used in the time, so as to achieve a tighter fit with the shaft hole and the inner hole of the stator, thereby completing the alignment work.

[0038] The specific steps are as follows:

[0039] 1) Obtain the dimensions of the shaft hole in the self-aligning component, accurate to 0.001 mm;

[0040] 2) Select the corresponding mandrel according to the size of the shaft hole, and the gap between the mandrel and the shaft hole should be 0.002-0.003mm;

[0041] 3) Select the corresponding dummy rotor according to the specifications of the mandrel, and insert the mandrel into the dummy rotor; the gap between the mandrel and the dummy rotor is 0.002-0.003mm, and the outer diameter of the dummy rotor is 0.03mm smaller than the design minimum value of the stator inner hole;

[0042] 4) Fix the frame 1 to the upper end face of the stator mounting base 31 with screws;

[0043] 5) Insert the mandrel 6 into the shaft hole 51 of the self-aligning component and press the dummy rotor 7 into the stator inner hole;

[0044] 6) Since the mandrel and the self-aligning component, and the dummy rotor and the stator are in a transitional fit state, the relative position of the self-aligning component and the frame is the optimal self-aligning position. Therefore, use a welding torch to weld and fix the self-aligning component 5 and the frame 1 together. The welding here can be a full weld on the circumference where the self-aligning component and the assembly hole fit tightly, or spot welding at no less than 2 points. Just fix the two together.

[0045] 7) After welding is completed, remove the mandrel 6 and the dummy rotor 7 from the shaft hole and the stator inner hole;

[0046] 8) Reinstall the crankshaft 2 that actually needs to be installed into the shaft hole, and then press the rotor 4 into the crankshaft through hot fitting and cold pressing; thus completing the assembly of the crankshaft, stator and rotor.

[0047] Compared to the unaligned stator-rotor air gap, the stator-rotor air gap is smaller and more uniform at this time, which can greatly improve the working efficiency of the motor; the entire alignment and installation process is very convenient and can be completed quickly, which greatly reduces the assembly difficulty and improves the assembly efficiency of the compressor.

[0048] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for self-aligning installation of a compressor crankshaft, comprising a frame, characterized in that: The frame is provided with mounting holes, and a self-aligning component is placed in the mounting holes, with the two rotating together; the self-aligning component has a shaft hole in the middle; the self-aligning installation steps are as follows: 1) Select the corresponding mandrel according to the size of the shaft hole, select the corresponding dummy rotor according to the specifications of the mandrel, and insert the mandrel into the dummy rotor; 2) Secure the frame to the stator mounting base; 3) Insert the mandrel into the shaft hole of the self-aligning component and press the dummy rotor into the inner hole of the stator; 4) Weld and fix the self-aligning components and frame; 5) Remove the mandrel and dummy rotor; 6) Install the crankshaft into the shaft hole, and then heat-fit or cold-press the rotor into the crankshaft; 7) Complete assembly.

2. The compressor crankshaft self-aligning installation method as described in claim 1, characterized in that: In step 1), the gap between the mandrel and the shaft hole is 0.002-0.003 mm.

3. The compressor crankshaft self-aligning installation method as described in claim 1, characterized in that: In step 1), the gap between the mandrel and the dummy rotor is 0.002-0.003 mm, and the outer diameter of the dummy rotor is 0.03 mm smaller than the minimum design value of the stator inner hole.

4. The compressor crankshaft self-aligning installation method as described in claim 1, characterized in that: In step 3), the self-aligning component and the frame are fixed by circumferential welding or by spot welding at no less than 2 points.

5. A compressor crankshaft self-aligning installation method as described in claim 1, characterized in that: The frame has a first mating part inside the mounting hole and a second mating part on the outside of the self-aligning component. The first mating part and the second mating part are rotatably mated.

6. The compressor crankshaft self-aligning installation method as described in claim 5, characterized in that: At least one surface between the first mating part and the second mating part is a spherical structure. The spherical structure is a single sphere or is composed of several concentric spheres of the same diameter with a distribution range exceeding 180 degrees.

7. A compressor crankshaft self-aligning installation method as described in claim 5, characterized in that: The contact method between the first mating part and the second mating part is point contact, with three or more contact points.

8. A compressor crankshaft self-aligning installation method as described in claim 5, characterized in that: The contact method between the first mating part and the second mating part is line contact, having three or more contact lines.

9. A compressor crankshaft self-aligning installation method as described in claim 5, characterized in that: The first mating part and the second mating part are in surface contact, and the two are completely fitted together or have two or more contact surfaces.

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