RU2843812C1 - Tractor automatic transmission friction clutches testing bench - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: invention relates to the field of mechanical engineering and can be used for incoming inspection of a friction disc pack of an automatic transmission (AT) of a tractor. Device includes electric motor, on output shaft of which there fixed is drive pulley of belt gear, the driven pulley of which and drive part of clutch are fixed on the shaft, driven part of clutch and inertial mass are fixed on the shaft that is connected to input shaft of the case by a coupling. At that, drive gear of crankcase is fixed on shaft, driven gear freely rotates on shaft, and drive part of friction package rotates on shaft and is rigidly connected to driven gear, driven part of friction package is connected to the shaft connected to the post.

EFFECT: enlarging the range of facilities providing performance of resource tests at acceptance inspection of friction discs of automatic transmission to confirm the quality of investigated friction discs.

1 cl, 1 dwg

Description

The invention relates to the field of mechanical engineering and can be used for incoming inspection of a friction disc pack of an automatic transmission (AT) of a tractor.

The following inertial stands are known.

An inertial test rig for testing friction clutches (see SU 274431 A1, G01M 13/00, published 24.06.1970), comprising a drive, an inertial mass and a clutch being tested with a movable support, mounted on a common frame.

However, with such a design of the inertial mass unit, a lot of time is spent on the selection and connection of flywheels of the required moment of inertia with the leading (or driven) shaft of the clutch, especially when testing clutches of various vehicles or during tests, the program and methodology of which provide for a change in the moment of inertia during one test.

A test rig for testing a friction clutch (see SU 617698 A1, G01M 13/00, published 30.07.1978), comprising a frame on which an electric motor, a gearbox, a test unit, flywheel inertial masses and a brake are sequentially mounted in a kinematically interconnected manner.

The disadvantage of this stand is that it does not provide a complete simulation of the operation of the tested clutch under operating conditions, since the kinematics of the stand does not allow simulating the moment of resistance on the shaft of the tested clutch and the moment of interaction of the drive of the operating machine with the soil.

These stands are designed to test dry friction clutches operating in braking mode. They contain an electric drive, an inertial mass, and a dry clutch being tested, mounted on the stand frame. Inertial stands are the main type of stands for testing friction units of vehicles. The degree of loading of the clutch being tested depends on the acceleration or deceleration of the inertial mass of a certain moment of inertia, simulating the mass of the vehicle.

With this design of these dry clutch friction test rigs, it is not possible to test a separate friction pack of a vehicle's automatic transmission (AT) to verify its stated characteristics.

The technical result is an expansion of the arsenal of means for carrying out resource tests during incoming inspection of friction discs of an automatic transmission to confirm the quality of the friction discs being tested.

The technical result is achieved due to the fact that the test stand includes an electric motor, on the output shaft of which the driving pulley of the belt drive is fixed, the driven pulley of which and the driving part of the clutch are fixed on the shaft, the driven part of the clutch and the inertial mass are fixed on the shaft, which is connected to the input shaft of the crankcase by a clutch, wherein the driving gear of the crankcase is fixed on the shaft, the driven gear rotates freely on the shaft, and the driving part of the friction pack rotates on the shaft and is rigidly connected to the driven gear, the driven part of the friction pack is connected to the shaft connected to the rack.

The drawing shows the kinematic diagram of the stand.

The stand contains an electric motor 1 (EM). On the output shaft 2 of the electric motor 1, the driving pulley 3 of the belt drive 5 is rigidly fixed, and the driven pulley 4 of the belt drive 5 and the driving part of the clutch 7 are rigidly fixed on the shaft 6. The driven part of the clutch 7 and the inertial mass 9 are rigidly fixed on the shaft 8. The shaft 8 and the input shaft 11 of the crankcase 17 are connected by a splined clutch 10. The input shaft 11 of the crankcase 17 is in engagement with the shaft 15 by means of a toothed engagement (not shown in the drawing), the driving gear 12 of which is rigidly fixed on the shaft 11, and the driven gear 13 rotates freely on the shaft 15. The driving part 18 of the friction pack 14 rotates freely on the shaft 15 and is rigidly connected to the driven gear 13, and the driven part 19 of the friction pack 14 rigidly connected to shaft 15. Shaft 15 is rigidly connected to rack 16, sensors (not shown in the drawing), control unit (not shown in the drawing) and hydraulic system (not shown in the drawing).

The stand operates as follows.

Electric motor 1 spins clutch 7, inertial mass 9, splined clutch 10, input shaft 11 of crankcase 17 via belt drive 5, at which point friction pack 14 is disengaged (there is no friction in the clutches). After inertial mass 9 spins up to the specified speed (information on the rotation frequency is recorded by the sensor), the signal from the sensor is processed by the control unit and fed to the hydraulic system, disconnecting clutch 3 from the drive (turns on electric motor 1 and belt drive 5). Inertial mass 9 maintains rotation of leading part 18 of friction pack 14 of crankcase block 17. In this case, driven part 19 of friction pack 14 is locked by stand 16 (does not rotate). Then the cycles of alternate switching on and off of the friction pack 14 begin. During each switching on of the friction pack 14, the rotation speed of the inertial mass 9 decreases. When the minimum rotation speed of the inertial mass 9 is reached, the operation of the friction pack 14 stops for a while. The clutch 7 switches on, and the inertial mass 9 spins up to the specified rotation speed. And the friction pack test cycle is repeated.

As a result of using a friction test stand, it is possible to obtain characteristics of the reliability of friction operation under various loads and engagement cycles, and changes in clutch characteristics as the friction package wears out.

Claims (1)

A test rig for the clutches of an automatic transmission of a tractor, including an electric motor, on the output shaft of which the leading pulley of a belt drive is fixed, the driven pulley of which and the leading part of the clutch are fixed on the shaft, the driven part of the clutch and the inertial mass are fixed on the shaft, which is connected to the input shaft of the crankcase by a clutch, wherein the leading gear of the crankcase is fixed on the shaft, the driven gear rotates freely on the shaft, and the leading part of the friction pack rotates on the shaft and is rigidly connected to the driven gear, the driven part of the friction pack is connected to the shaft connected to the rack.