High-precision bearing with large length-to-diameter ratio and its manufacturing method, and water pump rotor and its manufacturing method

Abstract

The invention discloses a large-length-diameter-ratio high-precision bearing, a manufacturing method of the large-length-diameter-ratio high-precision bearing, a water pump rotor and a manufacturing method of the water pump rotor. The water pump rotor comprises a rotor body (1) and the large-length-diameter-ratio high-precision bearing. The large-length-diameter-ratio high-precision bearing comprises a first friction part (2), a second friction part (3) and a structure connecting part (4). The center of the first friction part (2) is provided with a first shaft hole (22). The center of the second friction part (3) is provided with a second shaft hole (33). The first friction part (2) and the second friction part (3) are integrally connected with the two ends of the structure connecting part (4) in an interference fit mode. The first shaft hole (22) and the second shaft hole (33) are finally formed and coaxial through internal grinding precision machining. The inner diameter size of the first friction part (2) is d1, the inner diameter size of the second friction part (3) is d2, the inner diameter size of the structure connecting part (4) is d3, and d1=d2<d3. After the large-length-diameter-ratio high-precision bearing is formed, the rotor body (1) is integrally formed on the periphery of the large-length-diameter-ratio high-precision bearing through injection molding. The water pump rotor is matched with a rotating shaft through the first shaft hole (22) and the second shaft hole (33) in a sliding mode.

Description

technical field [0001] The invention relates to a high-precision bearing with a large aspect ratio and a manufacturing method thereof; in addition, the invention also relates to a water pump rotor and a manufacturing method thereof. Background technique [0002] Bearings are commonly used mechanical parts used to support journals or rotating parts on shafts. According to the working principle of bearings, they can be divided into rolling friction bearings, that is, rolling bearings, and sliding friction bearings, that is, sliding bearings. Rolling bearings are mainly ball bearings. Ball bearings are general-purpose parts. The advantage is long life, but the disadvantage is that they are relatively loud. At the same time, the smaller the bearing, the more difficult it is to process and the higher the cost. Sliding bearings are widely used in the field of micro motors. This kind of bearings are generally manufactured by powder metallurgy technology. The advantages are low cost...

AI Technical Summary

Problems solved by technology

Graphite bearings have the following defects: the bearing cannot be made into a thin-walled structure; after injection molding or pressing into the rotor, its inner diameter is easy to shrink; wear is large; black wear particles are easily produced, causing water pollution

Ceramic bearings have the following defects: the inner hole is difficult to process; since ceramics do not have self-lubricating properties, they cannot be dry-frictioned; the material is brittle and easily damaged; bearings with an aspect ratio greater than 3 are difficult to achieve

[0004] like figure 1 Shown is a schematic diagram of a cross-sectional structure of an existing rotor, which is a rotor of a micro-water pump. The rotor and the bearing are installed by pressing a bearing 20, 30 into each of the two ends of the rotor 10 or by injection molding at one end and pressing at the other end. The disadvantage of this kind of rotor is that there is a problem of concentricity deviation between the two bearings, and the concentricity is difficult to guarantee. At the same time, due to the consideration of concentricity, the tolerance of the bearing is large, and the gap between the shaft and the shaft is large. Deformation and shrinkage due to pressure will have adverse effects on the operation of the rotor. The precision is not enough, and it is easy to cause problems such as jitter and noise, and premature failure.

In addition, the existing rotors of the same type still use ceramic bearings or graphite bearings to be injected in the middle of the rotor. Due to the inherent defects of the above-mentioned type of bearings, their length is limited, and the bearings in the axial middle of the rotor are not as good as the bearings at both ends. Stable, and the friction surface of the bearing is large, it is difficult to ensure the running accuracy of the rotor, and it is easy to cause vibration, noise and other problems

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