Custom CNC Turning Bronze Parts
Product material: bronze
Product introduction: This part is a bronze bushing on the crusher for fixed connection together with a crusher to the crusher to bear the drive shaft. As a high precision part on the equipment and with a precision grade of IT6, this part requires CNC turning. Because of long time friction, moving parts must be replaced when the gap between the shaft and the hole has been worn to a certain content. Therefore, during design, the designer uses a material with low hardness and good abrasion resistance for the shaft sleeve or lining to reduce shaft and seat abrasion. The shaft sleeve or lining is replaced when being worn to a certain content, which can save the cost of shaft or seat replacement. Generally, interference fit is used for the shaft sleeve and lining, and clearance fit is used for the shaft. Abrasion is inevitable no matter how, but the service life can be prolonged, and shaft parts are easier to machine relatively.
Application fields of the lining part
The lining part is applicable to packing machinery, textile machinery, mining machinery, metallurgical machinery, printing machinery, tobacco machinery, forging machinery, various machine tools and interchangeable mechanical drive coupling, including belt pulleys, chain wheels, gears, propellers, large fans, and other various couplings. Featuring large torque, high precision, easy assembly and disassembly, simple operation, good positioning, reduced scrappage of mated shafts and hubs, re-usability, and no mating surface damages, it is the ideal and most economic selection currently.
Key technologies of the lining
1.The allowances for different different sections of a lining is +0.018 – 0.09, with upper deviation and requiring the adapter sleeve’s taper angle difference to be only large. This means that the big end the the taper must coordinate to contact but the small end allows a small amount of clearance. With poor taper hole coordination, the mating self-aligning roller bearing will have a single raw of rollers subjected to forces, which leads to unstable operation, big vibration, loud tone, tendency of looseness, and a short bearing service life. The taper angle difference of a high precision adapter sleeve should be ≤0.005, with a mating contact area not less than 90% guaranteed.
2.The radial play eccentricity of the outer conical surface of an adapter bushing to the inner hole (commonly called wall margin) must be high precision. Otherwise, the rotating shaft produces a centripetal force due to the fair amount, and fails for bumping operation with big vibration and a loud tone. The ideal state is 0 wall margin. According to up to international standards, the dimensional section of a bearing with the maximum inner diameter of below 65 is about half of its maximum standard group clearance, and 1/10 of the maximum clearance value of grade C precision. Therefore, the adapter sleeve products up to international standards cannot be used for fine large-load bearing mating.
3.The adapter sleeve’s outer conical surface and inner hole surface must have good linearity, that is good form and location tolerance and high cylindricity precision. This is not specified in national standards, and any single sectional dimension within the allowance range is qualified. This leads to loose control of linearity of the formed outer conical surface. Especially during cut-in grinding of outer conical surface machining, if the blank has poor linearity itself and the grinding wheel gives poor correction, the surface linearity will not be high. Common companies do not have contourgraphs for inspection. Therefore, this is a big product problem in the adapter sleeve industry of China, which seriously affects mating precision and mating stability and leads to poor bearing functions.
4.The lock nut axially moves and squeezes the bearing lining’s end surface to compress the internal taper between the adapter sleeve and the bearing’s inner hole. In this way, the mating bearing for the screw-threaded coupling function of an adapter sleeve fixes the bearing to the rotating shaft. Therefore, the bearing nut must be in good coordination with the adapter bushing’s threads, meeting the requirements of national standards for common threads.