Eccentric Roller Research Articles

Study on productivity of eccentric roll crusher based on theory and experiment

Productivity, as one of the key indicators for assessing the performance of a crusher, holds significant importance in guiding production practices. It refers to the quantity of materials processed or the quality of output materials within a given time frame. However, there is currently limited research on eccentric roller crushers, and the calculation method for productivity is unclear, failing to consider the motion characteristics between the roller and the materials. To address these issues, this study analyses the motion mode of the crushing roller and establishes a dynamic model for the roll and a flow model for the material. Furthermore, a particle size distribution at the choke level has been established using the breakage model. Based on these models, a productivity calculation method for eccentric roll crushers is proposed. Then, the effectiveness of the method is verified through laboratory experiment. The results indicate that the proposed calculation method can effectively estimate the productivity of eccentric roll crushers.

Research results for eccentric tillage rollers

An innovative double-drum eccentric roller has been developed. The proposed roller allows you to effectively destroy soil lumps and evenly compact the soil surface. Its main advantage is the varying effect on the same areas of soil with its working surfaces, due to which the maximum result of crushing of soil lumps is achieved. The roller is tested in the field with the quality control of its tillage in accordance with agro-technical requirements. As an optimization criterion, we adopted the coefficient of conformity to the standard ks. It characterizes the quality of soil cultivation by the proposed roller from the position of conformity of the structural composition of the soil to agrotechnical requirements. A comparison of the processing quality of the proposed roller and ring-spur roller was made. When the structural composition of the soil fully complies with the agrotechnical requirements ks = 1. Experimental studies of the eccentric roller made it possible to determine its optimal parameters for which the coefficient of compliance with the standard ks = 0.72, which is 20 % better than the ring-spur roller KKSh-6G-02 (ks = 0.52). The achieved quality of soil cultivation by the eccentric roller made it possible to increase the yield of spring wheat by 320 kg/ha in comparison with a ring-spur roller, which provides a profit of 3593 rubles per 1 ha.

Нагрузочная способность эксцентриковых подшипников качения

Eccentric roller bearings are commonly used in engineering and serve as actuating links in mechanical drives of various machines. Load capacity is one of the main parameters of such bearings. This paper presents possible kinematic schemes of an eccentric roller bearing and the specifics of the actual radial load distribution when it is applied to the driving ring between the rolling bodies. It is established that the load capacity of the eccentric roller bearing depends on the actual stress occurring when the rolling body of the minimal radius and the inner ring raceway are in contact. Equations are obtained for calculating the permissible radial load that the rolling body of the minimal radius with a raceway can bear. The limiting load is determined that satisfies the conditions of contact strength of the bearing’s assembly units and ensures performance of the bearing in a mechanical drive of a machine. The results of determining the limiting load of the eccentric roller bearing and the results’ analysis are presented using a specific example. To ensure the performance of the bearing, the optimal ratio of the inner ring radius to the minimum rolling body radius is determined.

The results of studies of eccentric tillage roller

Developed by eccentric tillage rink, which ensures the desired quality of the soil and increase the yield of crops. As a result of theoretical studies, an expression for determining the dynamic force that increases the intensity of crumbling soil lumps, depending on the regime parameters of the rink. In addition, the relationship between the power required when driving the rink, its parameters. The factors influencing the process of tillage by the developed roller are determined. As a criterion of optimization, the adopted coefficient of compliance with for the density soil of benchmark, which characterizes the quality of soil rolling from the position of compliance of soil density with agrotechnical requirements. As a result of experimental studies, the parameters and operating modes of the roller are optimized, at which the required quality of soil treatment is achieved.

Методика и результаты экспериментальных исследований эксцентрикового катка

Методика и результаты экспериментальных исследований эксцентрикового катка

Governing Equations for Web Tension and Web Velocity in the Presence of Nonideal Rollers

Since rotating machinery is used to transport flexible materials (commonly known as webs) on rollers, it is common to observe periodic oscillations in measured signals such as web tension and web transport velocity. These periodic oscillations are more prevalent in the presence of nonideal elements such as eccentric rollers and out-of-round material rolls. One of the critical needs in efficient transport of webs is to maintain web tension at a prescribed value. Tension regulation affects almost all key processes involved during web transport including printing, registration, lamination, winding, etc. Governing equations for web tension and transport velocity that can accurately predict measured behavior in the presence of nonideal rollers are beneficial in understanding web transport behavior under various dynamic conditions and the design of suitable web tension and speed control systems. The focus of this paper is on modeling the effect of eccentric rollers and out-of-round material rolls on web tension and web transport velocity. The new governing equations for web velocity on an eccentric roller and web tension in spans adjacent to the eccentric roller are presented and discussed; a web span is the free web between two consecutive rollers. To solve these governing equations, the location of the entry and exit point of the web on the eccentric roller as it rotates and the length of the web spans adjacent to the eccentric roller are required; a procedure for obtaining this information is described. To corroborate the models and the developed approach, data from experiments on a large experimental web platform are compared with data from model simulations, and a representative sample of the results are presented and discussed.

Analysis of the compound seismic system consisting of ERFPS system and dish spring

A theoretical analyzing approach about ERFPS (Eccentric Rolling Friction Pendulum System) is presented. It starts from formulation of the governing equation according to relative kinematics energy theorem in multiply body dynamics. This system consists of an eccentric roller which is placed in vicinity of two circular concave curve slides to form non-indented contacts. Computation results show that it has the three kinds of necessary capabilities required for an effective isolation system. The relatively long vibration period provides the seismic isolation capability, the gravity provides the reposition capability, and the rolling friction forces at contacting surface on top and bottom plate respectively, provides energy dissipation capability. It is shown that the inter-storey drift resulted from seismic action could be drastically decreased on buildings equipped with ERFPS system. If the rolling friction coefficient is about 0.01, the seismic isolation effectiveness could be as high as 90%. When the coupling effect in two directions is so small that it could be neglected and the dynamic responses could be calculated with respect to each of the individual direction in earthquake engineering.

Eccentric roller type total artificial heart creating interatrial shunt.

Creating an interatrial shunt to achieve left-right flow balance and modification of the blood chambers to improve the basic performance of the device were performed in developing an eccentric roller type total artificial heart (ERTAH). Smaller blood chambers reduce friction loss and increase durability and energy efficiency. We changed the left blood chamber volume of 60 ml to 40 ml and the right blood chamber volume of 53 ml to 35 ml compared with previous types. Designs of inlet and outlet ports were modified to prevent backflow. In the mock circulatory system, redesigning the blood chambers resulted in a 20% increase in energy efficiency, about a two-fold increase of cardiac output and improved durability compared to the previous type. In an animal experiment, the ERTAH operated at a driving rate of 160 rpm with a left flow rate of 6.0 L/min and a right flow rate of 5.4 L/min. Interatrial shunt flow rate was 250-400 ml/min.

Flow balance between the left and right cardiac output of an eccentric roller type total artificial heart.

We have made an eccentric roller type total artificial heart (ERTAH). The ERTAH is a positive-displacement device comparable to a DeBakey roller pump. Its left and right outputs are determined by the size of its blood chambers, and the ratio of its left and right output is almost constant. We focused on an interatrial shunt to achieve left-right balance. We have conducted numerical simulation, a mock test, and an acute animal experiment to analyze left-right heart balance during ERTAH operation. Numerical simulation was performed under conditions in which the flow of the left artificial heart was fixed at 6 L/min, the flow of the right artificial heart was varied from 4.8 to 6 L/min, and the interatrial resistance was also varied. The relationship between the interatrial shunt flow rate and the output of the left and right artificial hearts was balanced when the flow of the right artificial heart was at 5.45 L/min. In a mock test, 2 DeBakey roller pumps were connected to the left and right sides of a Donovan mock circulatory system, and an interatrial shunt was created between the inlet ports of the left and right roller pumps. The interatrial resistance of the mock system was varied from 7.7, to 4.3, and to 2.9 mm Hg x min/L when the inner diameter of the interatrial shunt was 6, 8, and 10 mm, respectively. As in the mock test, 2 roller pumps were used to bypass the right and left hearts of a goat weighing 60 kg. The flow rate of the left heart was almost constant (4.7 L/min). The flow of the right heart was approximately 4.1 L/min when the interatrial shunt flow rate was zero. A leading consideration was that the left to left shunt through the bronchial arteries in this goat was approximately 0.6 L/min. In developing the ERTAH, we considered that creating an interatrial shunt between the inlet ports of the ERTAH as well as making a difference between the chamber volumes might be effective in balancing the left-right sides of the artificial heart.

Eccentric roller type total artificial heart designed for implantation.

In the process of developing a completely implantable total artificial heart system, we have made an eccentric roller type total artificial heart and evaluated it by means of a mock circulatory system and by an acute animal experiment. The actuator of the artificial heart consists of 2 cylindrical drum type rollers which squeeze 2 blood chambers. The blood chambers are made of silicone rubber and are torus in shape. There is no valve used in this artificial heart. The artificial heart appears to be a nearly circular cylinder, approximately 10 cm in length and 8 cm in diameter. In the Donovan mock test, the artificial heart worked at a roller speed of 100-125 rpm with flow rates of 2.5-3.0 L/min for the right side and 3.2-3.8 L/min for the left side, respectively. The electric power consumption was 19.0-24.7 W. Our artificial heart is characterized by an ejection of blood alternatively in the pulsatile mode without need for reversing the motor. In the ex vivo evaluation, circulation of an adult sheep was maintained with this artificial heart for 4 h.

Trial manufacture of eccentric roller type total artificial heart.

Working toward a completely implantable total artificial heart, we have designed an eccentric roller type total artificial heart. The actuator of this artificial heart is a drum type eccentric roller that squeezes the blood chambers. The blood chambers are made of silicone rubber and are torus in shape. The shape of the artificial heart is an almost circular cylinder, and its length and diameter are 10 cm and 8 cm, respectively. The 2 main characteristics of this artificial heart are that it discharges blood in a pulsatile mode and that it requires no reversing of the motor. Because we have not completed the artificial heart yet, we have tested the eccentric roller mechanism on the prototype with an overflow type mock circulation with a 100 mm Hg afterload. The prototype worked at the roller speeds of 50, 100, and 150 rpm with flow rates of 1.7, 3.7, and 5.4 L/min, respectively. Next the prototype was connected to a Donovan type mock circulatory system and worked at roller speeds of 88-214 rpm with flow rates of 3.0-8.4 L/min against mean afterloads of 82-120 mm Hg.

Effect of Mechanical Processing Variables in Drawing on Sliver Irregularity

The present work examines the influence of draft distribution at the drawframe upon sliver irregularity under varying conditions of drawframe processing. The investigations were made at the first and second passage of drawing in carded mixings and at post-combed drawings in combed mixings, on slow-speed drawframes with Shirley draft distribution and high-speed Whitin drawframes. Eccentricity of top roller is shown to be one of the causes of slippage and sliver irregularity in slow-speed drawframes. Increasing the top roller loading is helpful in overcoming to some extent the deterioration in irregularity caused by an eccentric top roller. Roller slip at the front position caused by eccentricity in the roller has the most detrimental effects on sliver irregularity. Use of lower break draft under these conditions increases the sliver irregularity considerably. Eccentricity in the top roller in the second and third position causes more slippage, but the effect on irregularity of sliver is only marginal. Reduction of break draft increases slippage of front, second, and third top rollers even when they are true, but it does not affect sliver irregularity. The optimum roller setting at the front zone in conventional and high-speed drawframes depends upon the break draft and lies at a higher level at lower break draft. Thus, at close front zone setting, higher break draft gives a more regular sliver, while at wide setting, lower-break draft gives better results. The sliver irregularity at the optimum setting is, however, not much affected by the break draft.

LEVELLING THE UNEVENESS OF SLIVER ON THE FALSE TWIST DRAFTING

The drafting system of woollen ring spinning with false twisting has its objective to achieve such a drafting effect as in woollen mule spinning. This is an idea of levelling the uneveness of a sliver by concentrating twists on its thin portion to give greater draft to its less twisted, thick portion.The previuos report pointed out a marked difference between the twist densities in the regions from back rollers to a tube entrance and from the tube entrance to the front nip. The twist density is smaller at the part from the tube entrance to the front nip than in the other. It may be said, therefore, that the operation of levelling the sliver may be performed only in this narrow zone.This report deals in detail the operation of levelling the uneveness of a sliver by experimenting the influences of the thickness upon a variation in twists in the false twisting zone.(1) In the false twist drafting, the drafting is given mainly in the less twisted zone between the tube and the front nip. (Fig. 1 and 2)(2) In the case of twisting at one place, a sliver is twistless in the zone between the tube and the front nip in steady state. When an unven sliver enters this zone, the S twist and the Z twist appear alternately. (Fig. 5)(3) In the case of twisting at two places, there are twists in a sliver in the main draft zone in the steady state. When uneven sliver enters the zone, a variation occurrs in such a way that its thick portion is less twisted and its thin portion more twisted. (Fig. 6)(4) The evenness of a sliver is improved by false twist drafting in the zone between the tube and the front nip. The uneven sliver prepared by eccentric rollers was false twist-drafted and examined. It was found that its less twisted and thick portion is more elongated than its more twisted part. (Fig. 7)(5) The wave length of uneveness of a sliver has a close connection with length of the zone L2. (Fig. 8)

New Autmatic Thread Rolling Machine using the Rolling Dies of Eccentric Roller Type

Results of experimental studies on a new-deviced thread rolling machine using a pair of rolling dies of eccentric roller type are described. (1) By a new thread rolling machine, the rolling dies were fixed slghtly eccentric on each axis of rolling dies, which was fixed at any desired distance during the rolling operation. (2) The outside of the rolling dies is circular form and not relived, so the accuracy and the durability of rolling dies are satisfactory compared with those of the thread rolling machine of hydraulic type. (3) The construction and the operation of the new thread rolling machine are very simple and so the full automatic operation could be realized very easily. (4) During the operation, the rolling pressure changes very gradually and the rolling forces are not unbalanced, so the rolling action is very smooth and not causes any accident. (5) Diameters of threads which can be rolled by this type of machine range from 2 mm to 16 mm and up to the length of 60 mm. (6) The work pieces were fed automatically to the rolling dies and the thread rolling could be completed in a few seconds, the work piece being made 5∼12 revolutions by thread rolling according to the diameter. (7) The accuracy of the rolled threads is so high as the grade JIS 1 st class. (8) By this machine, the threading action must be completed during about half revolution of the rolling dies, so the diameter of the rolling dies is comparatively large, say 140∼160 mm.