RU2521059C1 - Helicopter transmission tail shaft - Google Patents

Abstract

FIELD: aircraft engineering.

SUBSTANCE: tail shaft comprises horizontal section connecting main and mid gears and inclined tail section connecting the mid and tail gears. Shaft horizontal section consists of several parts including tubular sections and bearing assemblies. Connection assemblies of the shaft horizontal part tubular sections are provided with splined adapters fitted in bearing assemblies. Tubular section splined connector at first bearing assembly on the main gear side incorporates a plate clutch with splined flange to interact with splined tip of adjacent tubular section. Last tubular section connection to mid gear and shaft inclined tail part connection to mid gear and tail gear are made with the help of splined connectors with plate clutches. First tubular section is connected to main gear with the help of flange joint with plate clutch.

EFFECT: fast preparation of helicopter to flight.

3 dwg

Description

The invention relates to the construction of helicopter transmissions. The tail shaft of the helicopter transmission is designed to transmit torque from the main gearbox, through the intermediate and tail gearboxes - to the tail rotor.

A known design of the tail shaft of a helicopter transmission (RU 2350515, 03/27/09), including tubular sections with connecting flanges and spline support couplings connecting the sections. One of the sections is made with an additional internal shaft, the free end of which is equipped with a gear rim of the first inductor, and the gear rim of the second inductor interacting with it is located on the connecting flange of the section for measuring torque.

The tail shaft of the transmission of the Mi-8 helicopter is closest to the claimed design (closest analogue: “Mi-8 helicopter”, Technical description, book II, “Mechanical engineering”, 1970, p.90, fig.105, p.98) and includes horizontal shaft portion and inclined shaft end portion. The main and intermediate gears are connected by the horizontal part of the tail shaft, and the intermediate and tail gears are connected by the inclined end part of the tail shaft. The tail shaft of the transmission consists of four articulated and two rigid parts (front and rear). The hinge parts are installed at the main gearbox, at the intermediate gearbox and in the end beam. Each hinged part is a steel pipe with two spline couplings (hinges) at the ends. The slot cavity is filled with grease. The middle hinged part of the tail shaft has a movable splined joint designed to compensate for deviations along the length of the fuselage, tail boom and tail shaft. A movable spline connection is also made on the end inclined hinge part of the tail shaft, which makes it possible to change the length of the tail shaft when the tail beam is bent in flight. All parts of the tail shaft (except for the middle hinge and rear rigid parts) are interconnected by flanges, and the ends of the shaft also have flange connections with the main and intermediate gears.

Rigid, integral parts of the tail shaft rest on seven supports that are attached to the frames of the fuselage and tail beam. The shaft rotates in ball bearings, which are seated in bearings through rubber clips.

The design flaws include, in particular, the presence of spline couplings at the ends of the tubular sections, which requires periodic replacement of lubricant and increases the preparation time of the helicopter for flight.

The design features of the tail components of the helicopter, in particular the power elements of the fuselage, as well as the design features of the new engines and other modern equipment required changes to the design of the tail shaft of the helicopter transmission.

The objective of the invention is to modernize the design of the tail shaft of the transmission of the helicopter in accordance with the features of the layout of the equipment of the tail of the helicopter, while maintaining the ability to compensate for deviations along the length of the fuselage or tail shaft, as well as simplifying and reducing the time of service due to the rejection of the use of spline couplings.

The problem is solved due to the fact that in the design of the tail shaft of the helicopter transmission, containing the horizontal part of the shaft connecting the main and intermediate gears, and the inclined end part of the shaft connecting the intermediate and tail gears, and the horizontal part of the shaft consists of several sections including tubular sections and bearings, in accordance with the invention - the connecting nodes of the tubular sections of the horizontal part of the shaft are made with splined tips, installed in the bearings, moreover, on the first bearing on the side of the main gearbox, the spline tubular section connecting unit is made with a plate coupling provided with a spline flange interacting with the spline tip of the adjacent tubular section, the connecting unit of the last tubular section to the intermediate gearbox and the inclined end part connecting unit shaft, respectively, to the intermediate gearbox and to the tail gearbox are made using splined connecting nodes with with clutch couplings, while the connecting unit of the first tubular section to the main gearbox is made using a flange connection with a plate clutch.

The tail shaft consists of six horizontal and one inclined tubular sections, five bearing bearings and four plate couplings. The fifth plate clutch is used in the connecting unit of the first tubular section to the tail drive shaft from the main gearbox. The combination of spline joints and plate couplings in the four connecting nodes of the tubular sections makes the structure rigid (without intermediate spline couplings). The use of plate couplings made it possible to reduce the time of preparation of the helicopter for flight, since Compared to the Mi-8 helicopter, there is no need to change the grease in the spline couplings. The execution of the spline tip on the first support and the execution of the corresponding plate coupling with the spline flange make it possible to compensate for the long error by moving the plate coupling along the splines of the support tip, i.e. deviations along the length of the fuselage or tail shaft. The inclined part of the tail shaft is unsupported, consists of one tubular section and includes two plate couplings. The horizontal part of the tail shaft is made of steel pipes, and the inclined part of the tail shaft is made of duralumin pipe, the diameter of which is increased in comparison with the diameter of steel pipes. Non-standard technical solutions used in the design made it possible to modernize the tail transmission of the helicopter.

The design of the tail shaft of the transmission of the helicopter is illustrated by drawings, which depict:

figure 1 - diagram of the tail shaft of the transmission of the helicopter;

figure 2 - the horizontal part of the tail shaft;

figure 3 - the inclined end of the tail shaft.

The tail shaft of the helicopter transmission (Fig. 1) is a tubular structure, divided along the length into several compartments, and contains (Figs. 1, 2) horizontal part 1 (connecting the main and intermediate gearbox) and (Figs. 1, 3) an inclined end Part 2 (connecting the intermediate and tail gears of the tail gear drive). The tail shaft includes only seven compartments from the tubular sections. Six of them make up the horizontal part 1 of the shaft. This is the first tubular section 3, four intermediate sections 4 and the last tubular section 5, which are interconnected by splined tips 6, and the connecting units are installed in five bearing bearings 7. The inclined part 2 of the tail shaft is installed without supports and consists of one tubular section 8.

To ensure the rigidity of the structure and reduce the time of preparation of the machine for flight (compared to Mi-8, where spline couplings that require lubricant replacement) are used, plate couplings are used in several connecting nodes of the tail shaft. In the connecting node on the first bearing support 7 from the main gearbox side 7 (FIG. 2), the tubular section 3 is provided with a plate coupling 9 made with a mating spline flange cooperating with a spline tip 6 of the adjacent intermediate tubular section 4. Connecting the last tubular section 5 to the intermediate gear made using a spline connection and a plate coupling 10.

The connection of the tubular section 8 (FIG. 3) of the inclined shaft end portion 2 to the intermediate gear and to the tail gear is made using splined joints and plate couplings 11. In addition, the flange end of the first tubular section 3 (FIG. 2) is connected to the main gear using the flange of the fifth plate coupling 12.

The transmission tail shaft transmits torque from the main gearbox to the intermediate gearbox and further from the intermediate gearbox to the tail gearbox and tail rotor. In this case, possible deviations along the length of the fuselage of the helicopter and / or the tail shaft of the transmission are compensated by moving the plate coupling 9 along the splines of the support 7.

Claims (1)

The tail shaft of the helicopter transmission, containing the horizontal part of the shaft connecting the main and intermediate gears, and the inclined end part of the shaft connecting the intermediate and tail gears, the horizontal part of the shaft consisting of several compartments along the length, including tubular sections and bearing bearings, characterized in that the connecting nodes of the tubular sections of the horizontal part of the shaft are made with splined tips installed in the bearing supports, and on the first bearing support from the sides of the main gearbox, the spline connecting unit of the tubular section is made with a plate coupling provided with a spline flange interacting with the spline tip of the adjacent tubular section, the connecting unit of the last tubular section to the intermediate gearbox and the connecting unit of the inclined shaft end portion, respectively, to the intermediate gearbox and to the tail gearbox using splined connecting nodes with plate couplings, while the connecting node of the first tubular section to the main editor The vector is carried out using a flange connection with a plate coupling.

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