RU2685575C1 - Method of continuous diagnosis of technical condition of support bearings of primary and secondary shafts of gearboxes of transmissions of kamaz in operation - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to the field of metrology, in particular to the gearbox parts diagnostics methods. Method of continuous diagnosis of technical condition of support bearings of primary and secondary shafts of gearbox KAMAZ in operation consists in measurement of radial runout of secondary shaft. At that, deviation from the nominal reference value of radial runout of the end of the secondary shaft of the KAMAZ gearbox is measured by means of a strain gauge supported by a support surface of wear-resistant material on secondary shaft through outer surface of speedometer drive worm mounted in cover of rear shaft of KAMAZ gearbox secondary shaft at technically required distance L from bearing, and diagnosis of degree of wear and destruction of support bearings of primary and secondary shafts of gearbox KAMAZ in operation is carried out by precession axis of secondary shaft caused by fracture of common axis of shafts during wear of bearings.

EFFECT: technical result of invention is enabling continuous diagnostics of technical condition of support bearings of primary and secondary shafts of KAMAZ gearbox.

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Description

The invention relates to the field of diagnostics in operation, and can be used to monitor the wear of gearbox parts, in particular the wear of support bearings supporting the primary and secondary shafts of a KAMAZ gearbox in rotation.

The closest in technical essence is a method for detecting damage to at least one engine support bearing, which comprises the following steps: during the entire measurement period P, read the current vibration signal (Vc) of the mechanical vibration of the engine components; during period P, the signal (Vc) is sampled; the signal is synchronized with respect to changes in the N mode; the signal is converted into a frequency signal to obtain frequency spectral bands, ordered by mode N; calculate the average amplitude of the spectral bands to obtain the current vibration signature (Sc) of the engine; calculate the degree of deviation (Δ) between the signature (Sc) and the normal control vibration signature (Ss); and the degree of deviation (Δ) is compared with the indexes of defects in a pre-formed database, combining theoretical damage to the engine bearings, to determine potential damage to the support bearing (RF Patent No. 2558007 C2, 03.11.2010, G01M 13/04). The technical result consists in the possibility of carrying out diagnostics in real time and improving the accuracy of detecting defects in various modes of rotation of the motor shaft.

The prototype uses a method for detecting wear of support bearings, in which the vibration signal of a gas turbine engine is measured to calculate the vibration energy of a signal using a statistical method.

The principle on which the invention is based (RF patent No. 2558007 C2, 03.11.2010, G01M 13/04) is that in a highly noisy environment the frequency resulting from bearing damage is proportional to the speed of rotation of the rotating shaft supported by the bearing, and that this frequency is transmitted to the acceleration sensor through the engine components, which themselves vibrate, in particular, at the fundamental frequencies.

The prototype has several disadvantages. Measurements of vibration sensors are distorted on a high-speed operating mode of a gas turbine engine with a natural vibration environment, which makes it difficult to recognize the vibration levels characteristic of damage.

This method (patent of the Russian Federation No. 2558007 С2, 03.11.2010, G01M 13/04) provides for the reading of a vibration signal coming from vibration sensors, which can detect all vibrations emanating from components of a gas turbine engine. In this case, the detection of damage to the support bearing is carried out on the basis of the identification of vibration levels that exceed the threshold predetermined for a normal bearing, and for which the same factor is identified. This requires a defect database that combines all damage to the engine bearings.

To identify defects, the signal is measured during a change in the engine mode, that is, during a change in the modes of rotation of the shafts.

The degree of deviation is compared with the indexes of defects in a pre-formed database that combines damage to the engine support bearings.

The application of this method (RF patent No. 2558007 C2, 03.11.2010, G01M 13/04) is possible under stationary conditions if there is a pre-formed database that combines damage to the engine bearings by carefully analyzing the data obtained by the degree of deviation from the norm. In addition, each process of diagnosing provides for obtaining a vibrosignal while changing the operation modes from idle to intermediate, which is impossible to perform while working on real modes, which implies the unsuitability of the method for on-board diagnostics.

The technical result of the present invention is to provide the possibility of continuous diagnosis of the degree of wear and destruction of the support bearings of the primary and secondary shafts of a KAMAZ gearbox in operation by comparing the received signal from a strain gauge, such as an inductive position sensor installed in the rear bearing cap of the secondary shaft, with a reference one.

This technical result is achieved by the fact that in the method of continuous diagnosis of the degree of wear and destruction of the support bearings of the primary and secondary shafts of the KAMAZ gearbox in operation, the radial runout of the end of the output shaft of the KAMAZ gearbox from the outer surface of the speedometer drive worm is measured through a wear plate made of wear-resistant material. A strain gauge sensor, such as an inductive position sensor, is mounted in the rear bearing cap of the secondary shaft. and the required distance L from the bearing. The deviation of the signal from the nominal reference value indicates an increased amplitude of the radial runout of the output shaft end of the gearbox due to the formation of precession of the output shaft axis caused by a fracture of the common shaft axis due to wear of at least one support bearing of the gearbox primary and secondary shaft.

FIG. 1 is a diagram illustrating the method of continuous diagnosis of the technical condition of the support bearings of the primary and secondary shafts of a KAMAZ gearbox in operation, where 1 is the rear bearing cap of the output shaft; 2 - inductive position sensor; 3 - support plate (heel) of wear-resistant material; 4 - flange mounting the propeller shaft; 5 - the secondary shaft of the KAMAZ model 142 transmission; 6 - speedometer drive worm; 7 - speedometer drive gear; 8 - the rear bearing of the secondary shaft.

FIG. 2 shows the kinematic layout of the shafts and supports of the power unit, where 9 is the crankshaft; 10 - the block of cylinders; 11 - a flywheel; 12 - clutch unit; 8, 13, 15, 19 - the bearing; 14 - transmission case; 16 - synchronizer IV-V gear; 17 - gear IV transmission; 5 - gearbox secondary shaft; 2 - inductive position sensor; 1 - cover of the rear bearing of the secondary shaft; 6 - speedometer drive worm; 18 - a primary shaft of a transmission.

The method of continuous diagnosis of the degree of wear and destruction of the bearings of the primary and secondary shafts of the KAMAZ gearbox in operation is as follows.

Preliminary, in the rear bearing cover 1 (Fig. 1) of the secondary shaft 5 (Fig. 1) of the gearbox, at the technologically necessary distance L from the bearing, a strain gauge is mounted, for example an inductive position sensor 2 (Fig. 1) to which the support plate 3 is attached ( Fig. 1) of wear-resistant material. The secondary shaft 5 (fig. 2) of a gearbox with serviceable support bearings 8, 15 (fig. 2) has a certain radial runout amplitude, which through a supporting plate 3 (fig. 1) of a wear-resistant material perceives a strain gauge, for example, an inductive sensor position 2 (Fig. 1), from the outer surface of the worm drive speedometer 6 (Fig. 1). The amplitude of the radial runout of the end of the output shaft 5 (Fig. 2) of the gearbox with serviceable support bearings 8, 15 (Fig. 2) during rotation is taken to be the nominal reference value of the serviceable technical condition of the support bearings 8, 15 (Fig. 2) of the primary 18 (Fig 2) and secondary 5 (fig. 2) transmission shafts.

Research has established the process of wear and interaction of elements in the development of failures. During car operation, the temperature in the thrust bearing 19 (Fig. 2) of the input shaft 18 (Fig. 2) is increased by heating the crankshaft 9 (Fig. 2) of the engine from the oil and the cylinder block 10 (Fig. 2), the flywheel 11 ( Fig. 2) due to friction with the clutch disc 12 (Fig. 2) and a rubber sealing ring mounted on the rear end of the crankshaft 9 (Fig. 2), due to the friction force that occurs when the crankshaft 9 rotates (Fig. 2) . The temperature in the support bearing 19 (Fig. 2) of the primary shaft 18 (Fig. 2) during operation is about 150 ° C, which leads to the dilution and leakage of grease from the support bearing 19 (Fig. 2) of the primary shaft 18 (Fig. 2 ). Reducing the amount of grease leads to faster wear and failure of the support bearing 19 (Fig. 2) of the primary shaft 18 (Fig. 2).

Simultaneously, there is an increase in the load on the primary shaft 18 (Fig. 2) of the gearbox due to an increase in clutch imbalance 12 (Fig. 2) arising from a violation of the centering of the middle drive plate, which also contributes to the speedy failure of the support bearing 19 (Fig 2) the input shaft 18 (FIG. 2) installed in the rear end of the crankshaft 9 (FIG. 2).

Destruction of the support bearing 19 (Fig. 2) of the input shaft 18 (Fig. 2) of the gearbox mounted in the rear end of the crankshaft 9 (Fig. 2) causes the gearbox input shaft to lose one support and become cantilever. The cantilever end of the gearbox primary shaft senses the dynamic loads from the unbalance of the clutch 12 (Fig. 2), due to which a precession of the axis of rotation of the input shaft 18 (Fig. 2) of the gearbox caused by a fracture of the common shaft axis when the axis of rotation of the input shaft 18 ( Fig. 2) gradually deviates from the center and begins to describe the cone, in addition to its own rotation of the input shaft 18 (Fig. 2) around its axis. This causes an increase in the amplitude of the dynamic loads, which is transmitted through kinematic connections to the gear coupling of the input shaft 18 (Fig. 2) of the gearbox with the synchronizer IV-V gear 16 (Fig. 2) and to the splined coupling of the synchronizer IV-V gear 16 (FIG. 2) with the secondary shaft 5 (Fig. 2), causing an increase in the wear rate of these surfaces.

During operation, the gearbox is continuously shifted with axial movements of the shafts, especially the secondary shaft 5 (Fig. 2), which leads to axial oscillations of the bearings 8, 15 (Fig. 2) and, due to fretting wear, loses the stationary nature of their fitment in the crankcase 14 (Fig. 2) or on the shafts. At the same time, radial oscillations of the input shaft 18 (Fig. 2) occur under the action of clutch imbalance 12 (Fig. 2), with the occurrence of precession caused by a fracture of the common shaft axis, which also causes fretting wear in the interfaces of bearings 8, 13 (Fig. 2 ) with crankcase and shafts 5, 18 (Fig. 2), resulting in the loss of the fixed nature of these interfaces. After the loss of immobility of the pairing, the radial clearances of the shafts 5, 18 (Fig. 2) intensively increase, which significantly violates the conditions of gear teeth engagement, gear changes. The intensity of the increase in the angular gaps increases due to wear of the elements of the spline mates. Increasing angular gaps in turn intensifies the growth of axial gaps. This is the manifestation of the mutual influence of the technical state of the gearbox elements during operation.

The increase in gaps in the mates causes an increase in the amplitude of dynamic loads, which is transmitted through kinematic connections to neighboring mates, causing an increase in the intensity of their wear, and can be determined by the proposed method.

During wear and destruction of support bearings 8, 13, 15, 19 (Fig. 2) of the primary 18 (Fig. 2) and secondary 5 (Fig. 2) gearbox shafts, apart from the radial runout of the end of the output shaft 5 (Fig. 2), precession will appear caused by a fracture of the common shaft axis, which will lead to a change in the signal of the strain gauge sensor, such as inductive position sensor 2 (Fig. 1), perceived from the outer surface of the worm 6 (Fig. 1) of the speedometer drive through the wear plate 3 (Fig. 1) of wear-resistant material. The deviation of the signal from the nominal reference value indicates an increased amplitude of the radial runout of the end of the output shaft 5 (Fig. 1) of the gearbox due to the failure of at least one support bearing 8, 13, 15, 19 (Fig. 2) of the primary 18 (Fig. 2) and the secondary 5 (fig. 2) of the transmission shafts is an integral parameter of the technical condition of all support bearings, due to the shaft precession caused by the fracture of the common shaft axis, which is taken as a structural parameter in the diagnosis.

The proposed method makes it possible to continuously diagnose the degree of wear and detect the destruction of the support bearings of the primary and secondary shafts at early stages, thus avoiding the increased wear of the remaining parts of the gearbox, namely the output shaft of the gearbox, gears and synchronizers of the output shaft.

Thus, compared with the prototype, due to the identified process of precession formation caused by the fracture of the common shaft axis and using it as a structural parameter, the claimed method allows continuous diagnostics of the degree of wear and destruction of the support bearings of the primary and secondary shafts of the KAMAZ gearbox in operation by receiving a signal from a strain gauge sensor, such as an inductive position sensor mounted in the rear bearing cap of the output shaft.

Claims (1)

A method of continuous diagnosis of the technical condition of the support bearings of the primary and secondary shafts of a KAMAZ gearbox in operation, including measurement of the radial runout of the secondary shaft, characterized in that in order to ensure continuous diagnostics, the deviation from the nominal reference value of the radial runout of the end of the output shaft of the KAMAZ gearbox is measured using a strain gauge a sensor, such as an inductive position sensor, supported by a support surface of a wear-resistant mat The serial on the secondary shaft through the outer surface of the worm drive of the speedometer mounted in the rear bearing cover of the secondary shaft of the KAMAZ gearbox at the technologically necessary distance L from the bearing, and the diagnosis of the degree of wear and destruction of the support bearings of the primary and secondary shafts of the KAMAZ gearbox in operation is carried out by axis precession secondary shaft caused by a fracture of the common axis of the shafts during wear of the bearings.

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