The ceramic ball bearing has been used to exact machine for its good properties such as heat-resistant, corrosion-resisting, and wear-resisting. The old grinding methods of ball bearing spend much time and power. Although the magnetic fluid grinding method economizes time, but cost much money. This study research the effects of spindle speed, grit size, load, and the material of float-ring and fixed-ring on the grinding characteristics by using a new ultra-precision ball grinding machine which developed by our lab. Search the optimum operating conditions of this machine for the requirement of industrial circles. Experimental results show that the converge rate of the saturated value for the sphericity, surface roughness (Ra), and the removal rate are increased with increasing spindle speed, grit size, or load. The sphericity and surface roughness (Ra) are increased when spindle speed, grit size, or load is increased. The sphericity and surface roughness (Ra) are increased with increasing removal rate in using the same grit size and load. Under a certain operating parameter of grinding process, the mean diameter and removal rate are decreased with increasing grinding time. The sphericity and surface roughness (Ra) are better when using the plastic than the float-ring and fixed ring of aluminum, but its removal rate is lower than aluminum¡¦s. First, let the average sphericity achieve saturated value by using diamond grind disk to grinding the Al2O3 ceramic ball. Then, the optimum sphericity can achieve 0.7£gm and the surface roughness (Ra) can achieve 0.1£gm by using the B4C grits of 0.5£gm to grinding.

A general closed-form analytical solution is derived for the lapping tracks with its kinematics for the concentric V-groove lapping system. The lapping tracks on the ball surface for the three contact points are fixed circles, and their lengths of the lapping tracks are linearly proportional to , , and , respectively. In practice, if the orientation is randomized as the ball enters the lap again, then the distribution of the lapping tracks are dense after many cycles, and the larger the lapping length in each cycle, the smaller is the number of cycles required achieving the maximum lapped area ratio. In the geometry design of ball lapping, the V-groove half-angle should be larger than 45¢X, but to prevent the splash of abrasives, it should be less than 75¢X. Since the spin angular speed with its angle continuously varies with time for the eccentric lapping system, lapping tracks are not fixed circles. In practice, the lapped areas are complementary at the contact points of A and B. The total lapped area ratio is higher than 87% for a slip ratio less than 0.5. Hence, it is possible to lap all the surface of a ball by changing the slip ratio during the lapping process. Moreover, the larger the V-groove half-angle, the less is the eccentricity to achieve the optimum lapped area ratio. In order to understand the ball motion and ball lapping mechanism in the magnetic fluid lapping system, the forces and moments equilibrium equations are derived and numerical methods are analyzed. As the balls traveling in a train are assumed to be the same size, only one ball is considered in the dynamic analysis. Results show that as the ball separates from the shaft and the float, the spin angle increases quickly and approaches to 90¢X. Hence, the ball changes its attitude and thereby generates a new lapping tracks on the ball surface. Consequently, after repeating many cycles, lapping tracks would be scoping out more space and this is one of the spherical surface generation mechanisms. Surface waviness of ball causes a variation in the lapping load. When , it is possible to cause the ball separated from float and the lapping load is zero during the separation period. No matter how the ball separates from float, the spin angle always varies in a small range. Hence, only a very small region can be grounded due to the effect of the surface waviness. Therefore, it is not the main lapping mechanism of the spherical surface generation. In fact, during the lapping process, many balls with different diameters are lapped. To understand the ball¡¦s lapping mechanism of the spherical surface generation, it is necessary to consider a batch of balls. For a batch of balls with different diameters, the applied load on each should be different from each other. Generally, the larger the diameter of a ball, the larger is the friction force between the ball and shaft and the ball circulation speed. Therefore, it is possible to cause the collision between the larger and the smaller balls. To understand the interaction between balls traveling in a train, the dynamic analysis of multiple balls is developed. As the ball interacts with each other, it is possible to change the spin angle, and thereby to achieve the larger variation range of the lapping tracks. During the lapping process of a batch of balls, it is also possible to cause the separation between the shaft and the ball, and it causes the ball to change its attitude and to achieve more uniform lapping tracks.

The thesis is focus on design solutions of automatic tool changer for CNC vertical milling machine SLV 300 in cooperation with the design company IMC/Engineering s. r. o. The main goal of theses is the creation of several design variants based on the critical research of similar machinery and the subsequent choice of the most appropriate solution. The assessment of the various options is done with amount of the changes caused on the existing design of the machine. It is essential the suitability of the solution from the perspective of the customer's company SolidVision s. r. o. Design solution is being designed for the possibility of a presentation device with unique features in its class, which is meant to be a simple maintenance free design with the possibility of easy service access For the chosen solution of the automatic tool changer are by calculation verified by the most exposed part of the device. In the thesis is also design documentation, for a better understand of the design solution.