One of the factors which determined fibre quality and the productivity of fibre-spinning machines is the operational reliability of the mechanism for delivery of the spinning solution to the spinneret [i, p. 63].In the preparation of various viscose fibres, both in the ShA-25IR flow lines for ordinary viscose, and also in the PL-25I flow lines for highmodulus fibre, gear pumps of type 13NSh-40I, made in accordance with All-Union State Standard 6443-79, are used to deliver the viscose to the spinneret.In the process of operating these pumps, a random slippage of the intermediate pump gear takes place into the gap between the gears which are located on the pump shaft of the spinning machine and the gears which are located on the gear pump shaft.One result of this slippage may be damage to the pump bars of the spinning machine on which the gear pumps are fastened, and bending of the pump shaft of the machine.While slippage of the intermediate gear causes unplanned stoppage of only one spinning position in the period of scheduled planned repair of the spinning machine, damage to the gear bar and bending of the pump shaft lead to accidental stopping of not less than six spinning positions or to stopping of the entire machine.In turn, this leads to a diminution in fibre quality (undrawn fibre and "tails" in the preparation of high-modulus fibre, for example), and also to an increase in the amount of waste and a reduction in productivity of the flow line.Therefore it is advisable to find out the reasons for damage to the pump bars and bending of the spinning machine pump shaft.From the scheme of the forces (Fig. I) which act in engagement of the drive gears of a type 13NSh-40I pump to the intermediate gear, it is evident that all the forces which arise in engagement of the drive gears are absorbed by the arm on whose axis the intermediate gear is installed.Therefore, the component of the resultant of all forces which is directed along the normal to the lengthwise axis of the arm draws the intermediate gear into the gap between the drive gears [2], and the component of the resultant of all forces which acts along the arm axis is absorbed by the housing and acts through it on the pump bar. In conformity with this scheme, the lengthwise force, Pi, which acts on the lever, is given bywhere TI =PI tan e and T2 =P2 tan a are the radial forces which arise during engagement of the intermediate gear with the gears on the machine shafts and the gear pump gears, respectively, in N; ~ is the engagement angle of the involuted wheels, which is 20°; 8 is the angle between the lengthwise axis of the pump arm and the line of centers of the intermediate gear and the gear on the gear pumpshaft, which is 103°; and PI and P2 are the circumferential forces which arise on engagement of the intermediate gear with the gears on the sbafts of the spinning machine and of the gear pump, respectively, in N.One of the conditions for reliable operation of the mechanism for delivery of spinning solution to the spinneret is the presence of a lubricant o...