SU1673763A2 - Drive shaft - Google Patents

Abstract

The invention relates to mechanical engineering and can be used to transfer rotation from one mechanism to another. The purpose of the invention is to improve performance when operating in conditions of significant temperature differences. The shaft consists of its own shaft 1 of supporting elements, made, for example, in the form of bearings 4, drive elements 5 and intermediate sleeves 6. The shaft is formed into a flat spiral until the elastic tape fits tightly between the turns. The material of the inner active layer of the tape has a greater coefficient of thermal expansion than the outer layer. Variable thickness of the layers provides a guaranteed tension of the shaft with the female part at temperature differences. 1 hp f-ly, 4 ill.

Description

The invention relates to mechanical engineering and can be used to transfer rotation from one mechanism to another.

The purpose of the invention is to improve performance when operating in conditions of significant temperature differences.

FIG. 1 schematically shows a shaft, a longitudinal section; FIG. 2 shows a section A A in FIG. one; in fig. 3 shows the node I in FIG. 1 (increased); in fig. 4-node II in FIG. 2 (increased).

The device consists of a shaft 1, made hollow in the form of an elastic bimetallic tape of layers 2 and 3 rolled into a flat spiral, supporting elements in the form of bearings 4, driving elements such as gear wheels 5, as well as intermediate spacer sleeves 6. has a higher temperature coefficient of linear expansion than the outer layer 2 (Fig. 3). Layer thickness may vary.

The supporting and driving elements form a frame in which a tightly twisted spiral is installed - a hollow shaft 1. The driving and supporting elements, made in the form of bearings, encompass the spiral (Fig. 1).

The drive shaft is assembled as follows.

The bimetallic tape is twisted in a spiral with the active layer inward to a diameter less than the diameters of the mounting holes of the drive and support elements. In this twisted state, shaft 1 is driven into gears 5, spacers 6 and bearings 4.

The tension in conjunction depends on the degree of twist of the elastic helix and the operating temperature. As the temperature decreases, due to the attempt to twist the bimetallic tape, the tension will decrease, which will prevent the structure from being brittle. With an increase in temperature, nat g will

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increase The magnitude of the tension change can be adjusted by changing the ratio of the thickness of the tape layers. The greater the difference in the thickness of the layers, the less the tension will change depending on the temperature change. The use of a tape with different layer thicknesses makes it possible to avoid the complete disappearance of tension at considerable low temperatures.

Example. The inner active layer consists of brass L62 (temperature coefficient of linear expansion a 20.5) and has a thickness of 0.1 mm, the outer passive layer consists of steel 36H (temperature coefficient of linear expansion oz 1 ° С 1) and has a thickness of 0, 1 mm. The width of the tape is 200 mm, the length of the tape in the scan is 1600 mm. The shaft is designed to install parts with a minimum hole diameter d 17 mm and a maximum D 45 mm. With a diameter of 17 mm, the shaft has 30 turns of the tape (wall thickness 6 mm), with a diameter of 45 mm - 11.5 turns (wall thickness 2.2 mm).

Lowering the temperature from normal + 20 to -70 ° С (ДТ 70 ° С - (- 200С) 90 ° С) causes the tape to twist with the formation of tensile stresses in the outer layer and compressive in the inner (active) layer. Wives are opposite in sign to the initial compressive stresses of a twisted layer of 36N steel carrying the main load. The torque of the twisting when cooled to a temperature of -70 ° C is 0.35 Nm and is suppressed by the initial twisting of the tape when assembled in the order of 0.6 Nm, as well as the compression of the shaft-mounted parts

When heated, the voltage changes in reverse order.

Claims (1)

Invention Formula 1 Drive shaft according to model no. 1326796, characterized in that, in order to improve performance characteristics when operating under conditions of significant temperature differences, the tape covering the shaft is bimetallic, and the tape material of the inner layer has a higher temperature coefficient of linear expansion than the tape material outer layer 2 Val according to any one of the preceding claims, from which it is made of a different thickness.  g xLi $ Shh Ј & $ t K3Sa5SSiS && S35Ss & iiiSss & ssisssiii h g, h t- f -. i. -3 te / Feed FIG. 2 Fig.b