Conical Rollers Research Articles

On the Dynamic Characteristics of Radial-Axial Ring Rolling Processes

An analytical model is presented to describe the dynamic characteristics of the radial-axial ring rolling process. Growing motions of rolled ring are analyzed in relation to the actions of pressure roll and conical roll, and the variations of both rolling forces are also discussed. In this developed model the interaction between pressure roll and conical roll motions as well as the temperature variation of rolled material which critically affects the deformed state of the ring is considered. To verify the validity of this dynamic model, the simulation results are compared with those obtained experimentally. Experiments were carried out with AISI 1045 steel blanks in hot condition. The theoretical results are found to coincide well with the experimental results.

An Adaptive Control Approach to the Ring Geometry Control for Radial-Axial Ring Rolling Processes

This paper considers the radial-axial ring rolling process control and treats the problem of controlling the pressure roll and conical roll motions which are critical to final dimensional accuracy of rolled products. Since the process dynamics reveals non-linear characteristics and parameter uncertainty, an adaptive controller design method is proposed for the pressure roll and conical roll motion control, taking into consideration the process dynamics variation. The effectiveness of the proposed controller has been verified by computer simulation. The simulation results show that the ring rolling process with this adaptive controller is insensitive to variation of process parameters and yields desirable dimensional accuracy of rolled ring products.

A new rotary speed converter

A new rotary speed converter without a source of noise and speed irregularity such as gears and belts has been developed. It is transmitted by a friction force working between two ferromagnetic bodies attracting each other by a magnetic force. A spherical or cylindrical idler is put across a gap between two ferromagnetic cylindrical rolls fixed parallel each other. Large attractive forces are produced between the idler and the rolls by magnetic flux passing through their contacts, and generate large friction forces between the idler and the rolls which can transmit a torque. There is almost no noise and slip in this torque transmission mechanism. Therefore, it is suitable to use this system for an application such as a turntable drive of a record player for which noise and slip are fatal. A stepless rotary speed converter is also realizable by combining an idler and two conical rolls placed in parallel and opposite direction. This is very useful as a small size stepless rotary speed converter for which there has been no good method.

Introduction of indented conical rolls on the piercing mill of the 140 tube-production unit

Introduction of indented conical rolls on the piercing mill of the 140 tube-production unit

Excavación de galerías en rocas duras mediante máquina tuneladora (minador continuo)

This article studies the most outstanding characteristics of continuous boring machines and their drilling tools, giving in hard rock excavation a sizable economy of 30 to 50% relative to the hammering and blasting techniques. The paper goes through the development of these machines from the simple grinding wheel, to the conical roller bit, the excavating crown with an approximate diameter half of the gallery being excavated, the spiral pitch instead of the circular pitch, etc., each providing a number of advantages over the preceding step.

Selection of the size and shape of tower intakes

1. Minimum local head losses in an intake are observed with a horizontal arrangement of the intake opening sill (ϕsill=0°). In the case of small intake opening heights (t/ dw≤0.25) the ceiling and conical roller gate bottom of these intakes should be inclined at angle ϕceil=22–30° to the horizontal to reduce the head losses. 2. For relative heights of the intake openings t/dw≥0.3 the intakes withϕsill≤25° and conical roller gate bottom have the same head losses. 3. To reduce the head losses in an intake withϕsill>25° (when t/dw<0.7) the ceiling and conical cylindrical gate bottom should be inclined at angleϕceil=ϕsill+(7–10°) to the horizontal.

SOME RECENT EXPERIMENTS ON DIRECT WEFT PROJECTION

This paper describes three types of experimental equipment for projecting weft by means of solid-body friction and the results of some preliminary experiments. The theory is given of the way to use two Hooke's couplings most effectively to produce a decelerated delivery with cylindrical delivery discs and several desirable design features to be borne in mind are discussed. Some experiments with conical delivery rollers are described which show the extent of the variation in the length of yarn delivered on each pick and in the deviation of the direction of projection of the yarn from the nominal. The investigation of the ancillary use of relatively low-speed air-streams has been initiated with the aid of a closed-circuit wind-tunnel in association with constant-speed yarn delivery.

On Conical Roller Expander

From a study of the working of a conical roller expander, the authors have derived formulas for calculating the state of contact between cloth and expander, tension on cloth, and the degree of expansion. The area of contact of cloth with the expander roller reaches a maximum at both ends of the roller, when a very close contact is obtained. The ends of the roller, then, contribute most to the expanding action. The speed of cloth is nearly equal to the surface speed of the ends of the roller; a considerable amount of slip between cloth and roller is inevitable in the middle of the roller. Here the expanding action is weak and the cloth relaxes. Cloth relaxation is difficult to control.

コニカルローラ幅出装置

From a study of the working of a conical roller expander, the authors have derived formulas for calculating the state of contact between cloth and expander, tension on cloth, and the degree of expansion. The area of contact of cloth with the expander roller reaches a maximum at both ends of the roller, when a very close contact is obtained. The ends of the roller, then, contribute most to the expanding action. The speed of cloth is nearly equal to the surface speed of the ends of the roller; a considerable amount of slip between cloth and roller is inevitable in the middle of the roller. Here the expanding action is weak and the cloth relaxes. Cloth relaxation is difficult to control.