The material of bimetallic shaft sleeve parts is a patented product, which is a new material of special-shaped and standardized shaft sleeve products. Mainly for all kinds of shaft sleeve processing enterprises, general machinery factories and mechanical repair enterprises to provide near-net-shape materials. With this bimetallic shaft sleeve part-shaped material, it can be directly installed as a shaft sleeve product with only a little mechanical processing (such as chamfering, drilling, turning or oil pressing). Its technical features are described as follows:
1. At present, there are two industrial batch blank-making and sleeve-making processes for steel-copper alloy bimetallic shaft sleeves:
1. 1. Cast a circular shaft sleeve made of copper alloy on the inner wall of seamless steel pipe.
Casting a copper alloy full-circle shaft sleeve on the inner wall of seamless steel pipe is more common in Europe, and the mechanical properties such as stiffness and strength of the parts are good. The disadvantages are complex production process, large material waste and high manufacturing cost.
1.2. Steel sintered copper alloy is cold rolled into bimetallic rolled shaft sleeve.
Compared with the casting sleeve, the sleeve rolled with this bimetallic plate improves the production efficiency and is also one of the more widely used sleeves at present. However, when manufacturing bimetallic plates, there are still many production equipment, long process flow, large area and large energy consumption. When rolling into a shaft sleeve blank, the material must go through cutting, pre-bending, rounding, shaping and other processes, which still wastes materials, man-hours and molds, increases the processing cycle and product production cost, and generally requires a certain scale.
This rolling sleeve technology still has two disadvantages:
Copper alloy sintered on (1) bimetallic plate is generally cold-rolled by rolling mill, and its relative density is ≤97%, so it cannot be used as high-performance parts.
(2) The bushing is rolled with cracks, whether butt joint or lap joint, which makes the bushing maintenance accuracy poor. These two defects directly affect the mechanical properties and service performance of casing.
2. Bushing made of bimetallic bushing parts (patented technology product)
2. 1 Manufacturing technology of bimetallic bushing parts materials
In order to overcome the above two types and three types: (two types: casting type and sintering type; Three types: casting full-circle shaft sleeve, rolling butt shaft sleeve and rolling buckle shaft sleeve. ), improve the mechanical and technical performance of the shaft sleeve, save metal materials, especially non-ferrous metal materials, save processing procedures, save manufacturing equipment, and save tooling molds and machine tools for processing the shaft sleeve. In the invention, the copper alloy is sintered on the inner wall of the seamless steel pipe, and the inner lining of the sintered copper alloy is made denser than or equal to 98% by using a radial rotary forging machine, thus meeting the performance requirements of mechanical structural parts. The production process method of manufacturing steel sintered copper alloy full-circle bimetallic shaft sleeve parts-"sintering rotary rolling method" was pioneered.
2.2 Technical characteristics of "sintering rotary rolling method":
The material characteristics of the bimetallic shaft sleeve parts manufactured by this process are: (1), round structure, good rigidity and good maintenance accuracy, and easy to realize automatic assembly on the automatic production line; (2) the production efficiency is high (the average man-hour for completing a shaft sleeve is 4 seconds), the processing procedures are few, the molds and process equipment required by cutting the traditional sintered bimetallic plate and coil into coils are omitted, the used equipment is few, only two sets of main equipment are needed, and the occupied area is small; (See the comparison table) (3) The material utilization rate is high, and it is made according to the required specifications. The utilization ratio of steel and copper alloy is close to 100%, which saves materials and energy and has low manufacturing cost. (4) With this bimetallic shaft sleeve part-shaped material, the shaft sleeve product can be directly installed with only a little processing (such as chamfering, drilling, turning or oil pressing).
Double ball bearings are relatively high-grade bearings. There are several tiny steel balls around the axis of the bearing. When the fan blade or axis rotates, the steel ball rotates with it. Because they are all spheres, the friction is small, and there is no problem of oil leakage. The advantage of double-ball fan is long service life, about 50000- 100000 hours; Good anti-aging performance, suitable for high-speed running fans. The disadvantage of double ball bearings is high manufacturing cost, and the noise of the same speed class is the biggest (because the friction point of ball bearings has increased by 2 times). Double ball air bearing and hydraulic bearing have good sealing performance, especially double ball bearing. Double ball bearings are completely embedded in the fan, and the rotating parts are not in direct contact with the outside world. In a sealed environment, the working environment of the bearing is relatively stable. Therefore, almost all 5000 rpm large-caliber fans use double ball bearings. Hydraulic bearings have a unique oil return circuit, so the possibility of lubricating oil leakage is very small.