Kumayambiriro kwa mizere yoyendera mizere, mzere wa ndodo unkayikidwa pansi pa mzere wa skid mbale. Zoyenda zamakono zamakono zimagwiritsa ntchito mfundo yomweyi, kupatula kuti nthawi zina mipira imagwiritsidwa ntchito m'malo mwa odzigudubuza. Chovala chozungulira chosavuta kwambiri ndi chotengera cha shaft, chomwe chimangokhala chitsamba chokhazikika pakati pa gudumu ndi ekseli. Kapangidwe kameneka kanasinthidwa ndi mayendedwe ogudubuza, omwe amagwiritsa ntchito ma cylindrical rollers ambiri kuti alowe m'malo mwa bushing choyambirira, ndipo chilichonse chogudubuza chinali ngati gudumu lapadera.
Chitsanzo choyambirira cha kunyamulira mpira chinapezeka pa sitima yakale yachiroma yomwe inamangidwa mu 40 BC ku Nyanja ya Naimi, Italy: chipilala chamatabwa chinagwiritsidwa ntchito kuthandizira pamwamba pa tebulo lozungulira. Zimanenedwa kuti Leonardo da Vinci adalongosola za mpira wozungulira pafupifupi 1500. Pakati pa zinthu zosiyanasiyana zosakhwima za mayendedwe a mpira, mfundo yofunika kwambiri ndi yakuti mipira idzawombana, ndikuyambitsa kukangana kwina. Koma izi zitha kupewedwa poyika mipira m'makola ang'onoang'ono. M'zaka za zana la 17, Galileo adafotokoza koyamba za "mpira wa khola". Kumapeto kwa zaka za m'ma 1700, gulu la British C. Wallow linapanga ndi kupanga ma bearing a mpira, omwe anaikidwa pa galimoto yamakalata kuti agwiritse ntchito poyesa, ndipo British P Worth adalandira chilolezo cha kunyamula mpira. Njira yoyamba yodzigudubuza yokhala ndi khola inapangidwa ndi wopanga mawotchi John Harrison mu 1760 kuti apange wotchi ya H3. Kumapeto kwa zaka za m'ma 1800, HR hertz waku Germany adasindikiza pepala lokhudza kupsinjika kwa ma berelo a mpira. Pamaziko a zomwe Hertz adachita, Germany's r. Stribeck ndi Sweden a Palmgren ndi ena achita chiwerengero chachikulu cha mayesero, zomwe zathandiza kuti chitukuko cha chiphunzitso kamangidwe ndi kutopa mawerengedwe moyo wa fani anagubuduza. Pambuyo pake, NP Petrov wa ku Russia anagwiritsa ntchito lamulo la Newton la viscosity kuti awerengere kuchuluka kwa kugundana kwake. Patent yoyamba panjira ya mpira idapezedwa ndi Philip Vaughn waku camson mu 1794.
Mu 1883, Friedrich Fisher adapereka lingaliro logwiritsa ntchito makina opangira oyenera pogaya mipira yachitsulo yokhala ndi kukula kofanana ndi kuzungulira kolondola, komwe kudayika maziko amakampani onyamula katundu. O Reynolds adasanthula masamu pa zomwe Thor adapeza ndikupeza Reynolds equation, zomwe zidayala maziko a chiphunzitso cha hydrodynamic lubrication.
Nthawi yotumiza: Sep-01-2022