Papers by Keyword: Grinder

Abstract: The paper analyzes the precision coaxial processing requirements and the characteristics of high automatic online compensation, and builds the electric control system based on Delta series products. The system uses a bus controller and absolute encoders servo constitute nearly closed-loop servo control system, combined with torque limiting grading feeding, dressing real-time compensation, stable and high-speed precision machining ceramic ferrule.

Abstract: Lignocellulosic biomass (LB) sources which are readily available in abundance are widely considered as a potential future sustainable raw materials for biofuel production. Typically, biofuel production involved several chemical and mechanical steps consisting of pretreatment, hydrolysis, fermentation and separation. The pretreatment step is considered as one of the most vital part of the whole processing scheme due to the impact it had on the efficiency of the subsequent processing steps. In this study we reviewed the mechanical pretreatment of LB focusing mainly on the size reduction technique by grinding process. Grinding is one of the proven preliminary pretreatment techniques employed in biomass conversion to liquid biofuel. However, this technique is known to be costly due to high energy consumption. In view of this, an efficient and cost effective pretreatment technology is required in order for the biofuel to be produced at a competitive level. At the same time, the impact on environment caused by the conventional pretreatment processes can be minimized. Thus, a new combined chemical-mechanical pretreatment is considered whereby a green ionic liquid (IL) solvent is introduced.

Abstract: Aiming at corrugated surface, scratches, BUE defects and wrong grinding size of blank sheet of high cobalt cemented carbide exists in the traditional grinding process, the reason for these problems are analyzed. Constant feed motion mode is provided for related reason, transmission design and pneumatic speed control loop design are processed; the point-contact online synchronization measurement system is researched and designed to achieve a real-time synchronous detection of the blank sheet grinding; the electric control system of tool is designed based on PLC, automation of tool is achieved. Production efficiency is increased effectively, the labor intensity of workers is improved.

Abstract: Establish the finite element model for high precision grinding machine which takes joint surface into consideration and then carrys out the static and dynamic analysis of the grinder. After the static analysis, modal analysis and harmonic response analysis, the displacement deformation, stress, natural frequency and vibration mode could be found, which also helps find the weak links out. The improvement scheme which aims to increase the stiffness and precision of the whole machine has proposed to efficiently optimize the grinder. And the first natural frequency of the optimized grinder has increased by 68.19%.

Abstract: To increase the lower order natural frequency of MM7140 grinder’s support parts is an effective measure to improve structural rigidity, avoid resonance and reduce amplitude. The finite element models of MM7140's lathe bed and column, were established by 3-D software UG, and led into ANSYS for modal analysis. Then, found the column was the weak link based on the modal analysis results, and brought out the more effective improvement program. This paper offers a reliable basis for the design and renovation of MM7140 grinder.

Abstract: It is necessary to develop complex helical drill point grinders in order to improve drilling quality and efficiency. In this paper, a new type of cutting tool grinder in which there is the tripod universal moving platform is developed, and complex helical drill grinding using the grinder is presented. In addition to complex helical drills, other cutting tools also can be ground using the grinder.

Abstract: This study was focused on the theoretical modeling and numerical simulation about the shear effect and gyroscopic effect of spindle system of high-speed grinder. Based on the rotor dynamics, a theoretical model was established using the transfer matrix method. The moment balance equations, and the transition matrix, the state vector, field matrix of spindle system of ultra-high speed grinder were analyzed and calculated. The results showed that shear effect reduced the critical speed in various orders, and its influence on higher orders was more severe than on lower orders. Furthermore, it could be seen that gyroscopic effect increased the critical speed in various orders, and it was sensitive in higher orders. It could be found that the increase of fifth order critical speed reached 16.6% due to gyroscopic effect, while the minimum increase of critical speed was 1.8% due to gyroscopic effect.

Abstract: This study was focused on the theoretical modeling and numerical simulation about the unbalanced response of spindle system of ultra-high speed grinder. Based on the rotor dynamics, a theoretical model was established using the transfer matrix method. The moment balance equations, and the transition matrix, the state vector, field matrix of spindle system of ultra-high speed grinder were analyzed and calculated. The results showed that the amplitude of unbalance response increased by the same multiple as that of the amount of unbalance at different locations and at different speeds. Furthermore, the first order amplitude increased first and then decreased, and the maximum unbalance was located at the middle of the rotor; second order amplitude decreased first and then increased, and the maximum unbalance was located at the front end of the spindle; the third order amplitude decreased first and then increased, and the maximum unbalance was located at the back end of the spindle.

Abstract: This paper presents the effects of spindle system configuration on the dynamic and static characteristics of high speed grinding. A 3D physical mode of high-speed grinding motorized spindle system with rotation speed of 150m/s was provided. The motorized spindle system consists of bearings, rotor, stator, spindle housing and grinding wheel. Based on the finite element method (FEM), the static characteristics, dynamic and the transient response are analyzed based on the finite element analysis software NASTRAN. It is shown that the spindle overhanging, bearing span have a significant effort on spindle deflection. The dynamic analysis shows no resonance will happen during its speed range. The methods and solutions for the motorized spindle system design and engineering applications was given in this paper.

Abstract: It is necessary to develop drill point grinders in order to improve drilling quality and efficiency. In this paper, a new type of helical drill point grinder is presented. This grinder is mechanically simple, low cost and easy to be used. There are three axis simultaneous motions by means of two cams during helical drill point grinding process. Moreover, the relationships between the helical drill point parameters and helical grinding parameters are derived. As a result, the flank surfaces of helical drill points are described.