RU2446330C2 - Twin gear unit with one drive gear wheel and equalised load paths - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: twin-gear unit comprises drive gear 1, its bearings being fitted on dampers. Compliance of said dampers is defined from parameters of the unit gears, drive gear rpm and power transmitted. Drive gear compliance allows it to displace toward unloaded path by required amount, hence, equalising load by feedback principle.

EFFECT: optimum overall dimensions and weight, simple and reliable operation.

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Description

The invention relates to mechanical engineering and can be used, for example, for a two-line two-stage gearbox, which is an airplane propeller drive with a shaft offset from the axis of the engine.

Known dual-flow gearbox, where load balancing is obtained due to the accuracy of manufacturing parts and assembly of the gearbox [1].

The main disadvantage of such a reducer is that the equalization of flows is carried out individually for each reducer by adjusting the contact spot of the engagement of each stream, which is quite difficult and time-consuming.

The objective of the invention is a dual-flow gearbox with one driving gear and equalized flow load with a simple and reliable principle of alignment.

This is achieved by the fact that the bearings of the drive gear of the gearbox, transmitting power to two streams, are mounted on malleable bearings (dampers) with a value of the static malleability of the bearings Δ equal to:

,

,

where ε is the total error of asymmetric manufacture and assembly of gears of flows;

z ₁ - the number of teeth of the pinion gear;

m ₁ - the module of the teeth of the pinion gear;

n is the number of revolutions of the pinion gear;

N is the power transmitted by the gearbox;

α is the angle of the profile of the teeth of the pinion gear;

β is the angle of the gears of the flows;

To _p - the coefficient of uneven distribution of load flow;

K is the correction factor determined when the gearbox is being refined.

Fig. 1 shows the kinematic diagram of the gearbox, and Fig. 2 shows a cross section of its drive gear assembly.

The gearbox consists of a pinion gear 1, which is mated on both sides with gears 2 mounted on the left and right shafts of the two flows, on which gears 3 are also mounted on the other end, paired with the output gear 4.

The bearings of the pinion gear are mounted on dampers 5, and its internal slots are interfaced with the external slots of the engine output spring 6.

The gearbox operates as follows (Fig. 1): the torque from the output spring 6, for example, from the gas turbine engine is supplied to the drive gear of the gearbox 1 and through the right and left shafts (two streams) of the gearbox, each of which has two gears 2 and 3, coupled with gears 1 and 4, respectively, at points 1, 2 and 3, 4, is transmitted to the output gear 4, from which it is removed.

The load is balanced by the flows due to the suppleness of the bearings A and B of the bearings of the pinion gear and the gear moving towards the unloaded flow with the static flexibility of the bearings - Δ, which leads to the alignment of two forces normal to the tooth surfaces at points 1 and 2 and, as a result, the load is balanced by flows .

The advantages of such a gearbox are optimal dimensions, weight, simplicity and reliability for operation.

Example: Given N = 500 liters. from.; ε = 0.09 mm (with a gear manufacturing accuracy of 6–5–5, ε ₁ = 0.016 mm, ε ₂ = 0.024 mm, ε ₃ = 0.05 mm [2]); K = 1; K _P = 1.05; z ₁ = 21; m = 2.25 mm; n = 32,000 rpm; α = 25 °; β = 27 °. Substituting the given values in the formula for determining Δ, we obtain:

,for two dampers

,

.for one damper

.

[3].These values correspond to the real compliance of the plate dampers.

[3].

Information sources

1. L.N. Reshetov. "Designing rational mechanisms." Ed. 2nd revised and expanded, M .: Mechanical Engineering, 1972

2. "Multi-threaded gearboxes." Under. general edition of I.P. Gorobets. Kiev, Technics, 1983

3. V.F. Stolyarov. "Oscillations of an unbalanced rotor on elastic-damping supports", works of NAMI, issue 36, 1961

Claims (1)

A dual-flow gearbox with one driving gear and with an equal load on the flows, comprising a drive gear, characterized in that the bearings of the drive gear of the gearbox, transmitting power to two flows, are mounted on malleable bearings (dampers) with a static flexibility of supports A equal to:

where ε is the total error of asymmetric manufacture and assembly of gears of flows;
z ₁ - the number of teeth of the pinion gear;
m ₁ - the module of the teeth of the pinion gear;
n is the number of revolutions of the pinion gear;
N is the power transmitted by the gearbox;
α is the angle of the profile of the teeth of the pinion gear;
β is the angle of the gears of the flows;
To _P - the coefficient of uneven distribution of load flow;
K is the correction factor determined when the gearbox is being refined.

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