[en] The development of a rotary microactuator supported on encapsulated microball bearings and driven by electro-pneumatic actuation is reported. The encapsulated bearing provides full support to an encased rotor, while an electro-pneumatic thrust balance is used to minimize rotor normal load. By minimizing normal load, bearing friction is reduced leading to increased speed and performance. Experimental results show that the microactuator is capable of repeatable operation and continuous 360° motion at speeds of 5–2000 rpm. This is the first demonstration of a ball bearing supported electrostatic microactuator with a fully encased rotor, capable of direct mechanical attachment or reliable interaction with external media

[en] In this paper, the novel approach for the fault diagnosis of the bearing equipped with rotational mechanical facilities was studied. As research works, by applying the ball bearing used extensively in many industrial fields, experiments were conducted in order to propose the new prognostic method about the condition monitoring for the rotational bodies based on the condition analysis of infrared thermography. Also, by using the vibration spectrum analysis, the real time monitoring was performed. As results, it was confirmed that infrared thermography method could be adapted into monitor and diagnose the fault for bearing by evaluating quantitatively and qualitatively the temperature characteristics according to the condition of the ball bearing

[en] Deep groove ball bearings (DGBB) are widely applied in the supporting structure of a variety of rotating machineries. A high rotating accuracy should be maintained for a more stable rotor system, which requires a carefully designed DGBB. For a designing purpose, dynamic behaviors of the DGBB under different structural parameters need to be investigated. Its dynamic responses are essentially excited by the contact forces induced by external loads. Besides the relative displacement between the inner- and the outer-raceway, and the clearance, ring waviness is the major factor that affects the values of the contact forces and the deformations of different rolling elements. Therefore, the control of ring waviness order and its corresponding amplitude is of great significance for the design of a high-precision DGBB and moreover a rotor system with high rotating accuracy. In this work, the effects of different waviness order and waviness amplitude are investigated to study the dynamic behavior of a DGBB under different waviness parameter. (paper)

[en] Skidding is a phenomenon that frequently occurs in ball–raceway contact areas of bearings and often leads to their early failure. This paper presents a skidding analysis of angular contact ball bearings (ACBBs) subjected to various boundary conditions. A five degrees-offreedom quasi-static model for ACBBs was employed to investigate skidding with ball and race contact forces and inertial loading by rotational speed. The model provided the internal load distribution of all rolling elements, which was subsequently used for the skidding prediction. Hirano’s criterion was used as a theoretical basis for the skidding analysis of ACBBs. Simulations were performed to investigate the influence of external loading, rotational speed, and angular misalignment on the bearing skidding. The effects of the preload method and initial contact angle on the skidding were also considered. As a result, this study provided an in-depth observation of skidding in ACBBs subjected to various operating conditions.

[en] In order to avoid the horizontal backward swing necessary when the transfer unit of a manipulator, consisting of a grab arm with a gripping device, is moved backwards, it is proposed to form the grab arm as a stationary guide tube provided with a driving motor and to further install one or several guide tubes which may be moved into and out of the first guide tube like a telescope by means of a worm drive. Hollow as well as ball spindles may be used. (UWI)

[en] A method is proposed for calculating the load capacity of a radial ball bearing with increased radial clearance.

[en] A spectrometer cuvette handle is described designed for operation at a speed of 50 c/s. It consists of minimally one fixed handle body and one rotary cuvette carrier. The handle is supported in an antifriction bearing whose antifriction bodies are made of electrically and magnetically nonconducting material, such as sapphire. (H.S.)

[en] The main application problems of expert systems are considered. Special requirements on expert systems for technical diagnostics are formulated. The special role of the 'blackboard system approach' in the considered applications of expert system techniques is pointed out and some examples are presented. An inference engine for production-quality controlling diagnostics of ball bearings is proposed. (author)

[en] In this study, a non-destructive evaluation (NDE) method is proposed for ball bearings contaminated with micro foreign substances, which were inserted into a ball bearing to create a defective specimen. The non-contact quantitative infrared thermographic technique was applied for NDE condition monitoring. Passive thermographic experiments were conducted to perform early fault diagnosis, for bearings operated at optimized torque status under a dynamic load condition. The temperature profiles for normal and defective specimens were quantitatively compared, and the thermographic data analyzed. Based on the NDE results, the temperature characteristics and abnormal fault detection of the ball bearing were quantitatively analyzed according to the rise in temperature.

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