Tham khảo tài liệu 'bearing design in machinery episode 2 part 10', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Volume of a Sphere V r sphere 4 pr 3 Vsphere 4 p 3 cm3 Mass of the Ball mr pV g cm3 X cm3 g kg The shaft and inner ring angular speed is 2pN o - 7 60 o 30 000 X 1mn X ỈẸỊd 3142 d s min 60 s 1 rev Angular Speed of Rolling Elements and Cage Oc oshaft m x 3142 rad s 1227 rad s C Rin Rout m m 1 Centifugal Force Fc Fc mro2CRr kg x 1227 rad s 2 X m 530 N Thrust Force Component at Outer Ring Contact S Fx 0 Woa Wa 200 N Radial Component of Inner Ring Contact Wir c tan ai Wia Wir 200 X ctan40 N Copyright 2003 by Marcel Dekker Inc. All Rights Reserved. Radial Component of Outer Ring Contact S Fy 0 Wor Wrr Fc Wor 530 N Outer Ring Contact Angle W tan ao W or 200 N tan a TOWN 0 26 ao Resultant Force on Outer Ring Contact The resultant force on the outer ring race Wo is in the direction normal to surface as shown in Fig. 12-22. It has two components in the axial and radial directions Woa Wo Wo Normal Contact Force on Inner Ring Race The resultant force on the inner ring race Wi is in the direction normal to surface as shown in Fig. 12-22. It has two components in the axial and radial directions W a Wo W sin 200 N N sin sin 40 200 N sin 40 Example Problem 12-9 An angular contact ball bearing has a contact angle with the inner ring of ai 30 . The thrust load of W 11 500 N is divided evenly on 14 balls. The ball has a diameter of dr 18 mm. The shaft speed is N 33 000 RPM. The conformity ratio Rr . The diameter of the outer race at the contact point with the balls is 118 mm. The balls and rings are made of steel having the Copyright 2003 by Marcel Dekker Inc. All Rights Reserved. following properties modulus of elasticity E 2 X 1011 N m2 Poisson s ratio V density p 7870 kg m3. a. Find contact angle ao with the outer ring. b. Find the contact force with the inner and outer rings. c. Find the centrifugal force of each rolling element. d. Find the maximum pressure at the
