Products for Steel Production Equipment Drive shafts for steel production/ industrial equipment JTEKT JTEKT JTEKT CORPORATION

Drive shafts for steel production/ industrial equipment Preface Throughout the manufacturing industry the pursuit of greater power output at higher efficiency is a priority. Under such circumstances, highly sophisticated and economical drive shafts that fit in a limited space are in great demand for use in various equipment and machines. Drive shaft lineup is certain to satisfy your requirements in various applications, including iron manufacturing machines, rolling mills, construction machines, and rolling stock. We thank you in advance for your support of our drive shafts. ■ Introduction to...

Introduction to drive shafts Position of each series of universal joints Functions A drive shaft is a revolving shaft used to transmit the Torque capacity power of a motor to a machine. Since it is installed in a limited space, the axes are seldom aligned. However, by using a universal joint, the input axis and the space, enabling smooth torque transmission. Each universal joint has four rolling bearings (cross & bearing), realizing low friction and minimizing torque losses. Plate mills Hot/cold strip mills Rod/wire rod mills, etc. D/U/T series General industrial machines, etc. KF/EZ series Universal...

Structural features Retainer ring Retainer washers Weld yoke Spline sleeve Bearing cup Thrust washer Rollers Roller guide Oil seal Felt seal Slinger Cross Oval bore yoke Cylindrical bore yoke Cross & bearing Weld yoke Propeller tube Spline shaft Retainer ring Retainer washers Weld yoke Spline sleeve Bearing cup Thrust washer Bearing holders Rollers (double row) Oil seal Slinger Cross Felt seal Flange yoke Cross & bearing Hexagon head bolts Flange keys Hexagon socket head cap bolts Weld yoke Propeller tube Spline shaft Retainer cap Retainer washers Bearing cups Weld yoke Spline sleeve Felt seal...

Because the cross is an elastic cantilever beam and the bearing has some radial clearance, the load on the cross generally becomes heavier toward to the end of the cross. In order to improve this phenomenon, load on the roller is made uniform by designing the roller to have a minutely smaller diameter at the very close end, which would improve flaking life, (figure on the right). It is required that the detailed investigation takes into account multitude of JTEKT records and the technology of theoretical analysis by FEM, when this would be applied. Unequal loads Load distribution Equal loads...

Thermal spraying coat of tungsten carbide (WC) on bearing cup key To avoid corrosion on the side face of bearing cup key applying carburizing heat treatment, one possible method is to apply thermal spraying coat of tungsten carbide (WC) on these surfaces. The following effects are expected in case the generation of clearance due to corrosion at the key area is restrained. (1) The bending stress of bolt can be alleviated, which leads to the restraint of strength reduction. (2) The heavier load on raceways at the end of the cross can be restrained, which expects longer fatigue life for cross &...

Periodic inspection The greasing amount varies depending on the sizes of the cross & bearing and spline part. Apply the amount of grease specified by JTEKT. ®Cross bearing (bearing cup part or cross body) ■ Greasing positions Apply grease in the positions shown in the figure below. ■ Cycles of periodic greasing * Be sure to apply grease with correct intervals and amount. - Hot strip mills: Once a month The grease to be applied should be the one specified in the drawing. - Cold strip mills: Every 3 months Use of insufficient or different grease may lead to early damage. - Others: Every 3 months...

Overhaul ■ As a rule, conduct overhaul of the major parts every year   after the start of operation. ■ Cross & bearing     nicks, or rusting, etc. of the cross and bearing cup. Thrust washer Checks Rollers Roller guide Slinger Bearing set bolts ■ Bearing set bolt   - Check for bending, looseness, cracks, or rusting of the bolt. Yoke Check   - Check for cracks, nicks, or rusting, etc. of each part.     attaching part for signs of the above. ■ Others   Checks Check ＊ ＊The next page shows some examples of failures of each part. Inspection/repair ■   Long-term use leads to failure of the product,...

(2) Insufficient tightening torque © Flaking of cross raceway surface ® Flaking of bearing cup raceway surface <Part> Cross <Cause> - Flaking occurred at the bottom of the cross due to insufficient lubrication <Measure> - Periodic greasing <Treatment> - Repair by re-grinding <Part> Bearing cup <Cause> - Flaking occurred on the bearing cup inlet side due to insufficient lubrication <Measure> - Periodic greasing <Treatment> - Repair by re-grinding <Part> Bearing set bolt <Cause> - Flat fracture shape because the axial force did not act on the bolt <Measures> - Tighten with the proper tightening...

h\ r\ © Brinelling on raceway surface <Measures> - Review the usage conditions - Apply an appropriate load - Reduce the bending stress acting on the bolt <Treatment> - Replace with a new part <Part> Cross <Cause> - An excessive load acted on the raceway surface <Measures> - Review the usage conditions - Apply an appropriate load <Treatment> - Repair by re-grinding <Part> Yoke key way <Cause> - An excessive load acted on the key way <Measures> - Review the usage conditions - Apply an appropriate load <Treatment> - Repair by weld overlaying 7 Flaking of raceway surface r\ © Oval bore wear <Part>...

The driving shaft and driven shaft intermediated by a universal joint has the following relationship between their rotational angles: 02 = cos# ■ tan --(I) Rotational angle of driving shaft : Rotational angle of driven shaft : Shaft operating angle (Fig. 1) Driven shaft \ Shaft \ operating angle© \ This means that, even if the rotational speed and torque of the driving shaft are constant, the driven shaft is subject to fluctuation in rotational speed and torque. The speed ratio between the driving shaft and driven shaft can be obtained by differentiating equation (1) with respect to time...