Coaxial helicopter reduction gearbox

FIELD: mechanical engineering; helicopter reduction gearboxes.

SUBSTANCE: proposed reduction gearbox for coaxial helicopter includes drive shaft, two coaxial driven shafts (inner and outer), gear train and planetary mechanisms which are kinematically interconnected; each mechanism includes sun gear wheel fitted on drive shaft and epicycle fitted on outer driven shaft. Gear train mechanism has idler units placed in carrier which is rigidly secured on inner driven shaft; number of satellites exceeds number of idler units by one; number of teeth of sun gear wheel and epicycle of gear train mechanism is multiple of number of idler units; total number of teeth of these members in planetary mechanism is multiple of number of satellites.

EFFECT: simplified construction of reduction gearbox; facilitated assembly; equality of opposite revolutions of coaxial shafts.

6 cl, 3 dwg

The proposal relates to mechanical engineering, in particular for helicopter gearboxes.

Known main gearbox R-26 helicopter coaxial circuit containing a drive shaft with a sprocket wheel, inner driven shaft with the small wheel, the outer driven shaft with a large wheel and the search stage of the parasite shafts, each of which contains a large parasitic wheel, coupled with a large outer wheel output shaft, and a small parasitic wheel, coupled with the small wheel inner shaft [1].

A disadvantage of the known device is its small resource because of the transfer of all power flow through one driving wheel.

Also known main gearbox of the helicopter coaxial configuration containing the input shaft with the sprocket wheel, two coaxial output shafts with the non-driven wheels, an intermediate coaxial shafts, each of which is fixed wheels, coupled with the non-driven wheels of the output shafts, and wheels linked with sprocket wheel input shaft [2].

The disadvantage of this device is that it is applicable for power plants helicopters low power (one engine 600 HP). It is impossible to perform with small dimensions due to the single-threaded transmit power to each slave shaft.

The closest in technical essence and the achieved result to the claimed solution is the main is eductor PB-3F helicopter Ka-25 coaxially with the shafts of the screws [3].

The gearbox contains the driving shaft, two driven shaft, inner and outer, kinematically interconnected search and planetary mechanisms. Each of the mechanisms includes a sun wheel on the control shaft and epicycle on the outer driven shaft. If this search mechanism contains a parasitic blocks arranged in a stationary housing, and a planetary mechanism has satellites, placed in a carrier rigidly mounted on the inner driven shaft.

The disadvantages of the known devices are manufacturing complexity and difficulty of Assembly and disassembly of the housing search mechanism and its parasitic blocks. Directly the case of spurious blocks consists of three trudnosgoraemyh nodes and does not have a rigid attachment.

When assembling the introduction engages wheels parasitic blocks with the respective wheels of the drive and driven shafts is possible only under strict orientation relative to each other. Wheel master and external slave shafts made with numbers of teeth 57 and 107 of the teeth), which nekretni the number of spurious blocks (6 pieces). This forces when assembling the gearbox to mark the teeth of the wheels parasitic blocks. It is beyond the teeth of wheels in this design need to combine still and numerous bore buildings, therefore, to assemble such a device is difficult.

Konsthistoria is to obtain the same angular orientation of the wheels of all parasitic blocks due to their straight teeth.

The technical result of the proposed solutions is to create a gearbox for powerful helicopters of simple construction and easy to assemble, allowing thus to obtain equal counter-revolutions of coaxial shafts.

To achieve the technical result in the gearbox of the helicopter coaxial circuit containing a drive shaft, two coaxially arranged driven shaft, inner and outer, kinematically interconnected search and planetary mechanisms, each of which includes a sun wheel on the control shaft and epicycle on the outer driven shaft, while the search mechanism includes a parasitic blocks arranged in a stationary housing, and a planetary mechanism has satellites, placed in a carrier rigidly mounted on the inner driven shaft, according to the number of satellites is greater per unit number of spurious blocks, with the number of teeth of the sun gear and epicycle search mechanism is a multiple of the number of spurious blocks, at the same time, the sum of the numbers of teeth of these elements in the planetary mechanism is a multiple of the number of satellites, and the gear ratio of the mechanisms associated with the expression:

i_pereb=2i_planets+1, where

i_pereb- gear ratio search mechanism;

i_planets- gear ratio planetang the mechanism.

Also under the proposal, each of the parasitic unit includes helical wheel rigidly connected with the spur wheel through the slot, which is designed as a continuation of the teeth of the spur wheel, cut height, and the number of teeth of the helical wheel is a multiple of the number of teeth of the spur wheel. Each phantom unit is made to lock the axial position and supported on the housing via bearings, ball thrust and roller, the inner race of which is made integral with the spur wheel of this block.

The presence of distinctive features, namely, the device with the number of satellites, exceeding by one the number of spurious blocks, the ratio of the number of teeth of the sun gear and epicycle search mechanism the number of spurious blocks, the ratio of the sum of the numbers of teeth of the sun gear and epicycle planetary gear number of satellites, number of ratios mechanisms in accordance with the expression:

i_pereb=2i_planets+1, where

i_pereb- gear ratio search mechanism

i_planets- gear ratio of the planetary mechanism,

demonstrates compliance with the proposed technical solution the patentability criteria of "novelty".

Task kinematic selection the scheme, and low gear (gearbox) for counter-rotation of the propellers of the helicopter with an equal number of turns is quite complex, since it is necessary to consider many requirements for this design mathematical, design and production requirements. In connection with these stringent requirements step-down transmission, such as gearing, presented in the prototype, perform with the same number of satellites and parasitic blocks (prototype - 6).

It is known that the total weight of the multistage transmission is inversely proportional to the transmission ratio trailing planetary stage. Its final drive ratio offered gear is higher than that of the prototype (6,273 against 5,632). Due to certain rational combination of the number of teeth, number of satellites and parasitic blocks not only managed to reduce the weight of the gearbox, but also greatly simplify the design. Optimally-chosen combination of gear ratios of the search and planetary mechanisms allowed to remove one of the parasite blocks, as a consequence, the opportunity arose for making the body of the two hard knots tied powerful tight-fitting bolts located on the circumference of the centers parasitic blocks. Thus, significantly decreased the complexity of Assembly and disassembly of the gearbox.

When building search and planetary gears, the ratio of numbers of teeth of the sun gear and epicycle number of spurious units and the ratio of the amount of h in the villages of the teeth of the solar ear and epicycle number of satellites can be installed in any position without prior marking.

One of the wheels of the parasitic unit is made helical, therefore there is the possibility in the Assembly by moving each of the parasitic unit along the direct engagement of one of its wheels, to obtain simultaneous contact of all five parasitic helical wheels with helical wheel drive shaft. The presence of the adjusting elements between the housing and the bearings allowed firmly fix selected axial position of the parasitic unit.

The ratio of numbers of teeth of the wheels of the parasitic unit provided the same angular position of these wheels relative to each other. These symptoms can significantly reduce the requirements to the accuracy of the orientation of one wheel of the parasitic unit relative to another and to reduce the complexity of manufacturing gear.

It should be noted that the known device, for example the above reducer R-26, which achieved full multiplicity of teeth in mesh [1]. This causes increased vibroactivity transmission and, as a consequence, the rapid malfunction. Therefore, in the inventive device the selection of the numbers of teeth of the search and planetary mechanisms was performed in strict accordance gear ratios: i_pereb=2i_planets+1.

In the search mechanism: solar wheel is 55 (fifty five) teeth, apical - 115 (one hundred fifteen) teeth, 5 (five) parasitic BL the Cove with 17 (seventeen) teeth on one wheel, cut the continuation of which for the formation of the spline is rigidly mounted a second wheel 51 (fifty one) tooth. Consequently, the gear ratio of the search mechanism:

From the expression it is evident: the number of teeth of the sun gear and epicycle search mechanism is a multiple of the number of spurious blocks, and the number of teeth of one wheel parasitic block is a multiple of the number of teeth of the second of its wheels.

In the planetary mechanism: solar wheel has 33 (thirty-three) of the tooth, apical - 87 (eighty seven) teeth, 6 (six) satellites 28 (twenty-eight teeth on each. Consequently, the gear ratio of the planetary mechanism:

From the expression it is evident: the sum of the numbers of teeth of the sun gear and epicycle planetary mechanism is a multiple of the number of satellites. Comparable ratio of both mechanisms and get:

that is, 2i_planets+1=i_pereb.

Optimally found correlations allowed us to create a structurally simple gearbox, easy for assembling and providing the above benefits equal to counter the momentum of coaxial shafts.

From the above it follows that the technical result of the invention is achieved by the OIC of the set of essential features, as the newly introduced and known, therefore, the claimed technical solution meets the patentability criterion of "inventive step".

The essence of the proposal is illustrated by drawings, where figure 1 schematically shows a longitudinal section of the gear; figure 2 presents a cross-section of the gearbox And with views of the planetary gear with the plan of the angular velocity of rotating elements; figure 3 presents a cross-section reducer b-B with a view search mechanism with the plan of the angular velocity of rotating elements.

Note that in the drawings for clarity shown only those parts that are necessary for understanding technical solutions, and related elements, well known to experts in this field, the drawings are not presented.

In the above specific example, the gearbox is a separate unit mounted on the helicopter collaboration with two engines, and together with them is a single power plant of the helicopter.

The gearbox consists of connected buildings, within which it is placed: the main mechanism of gears, aggregates and oil system.

The inventive device relates to only part of the units and systems of the gearbox, this part includes the upper body shaft bore the existing screws the case of the search mechanism itself of the search mechanism, the planetary gear mechanism.

The gearbox of the helicopter coaxial configuration contains the driving shaft 1, is placed along the longitudinal axis of the device on the bearings 2 and 3, respectively installed in a stationary housing search mechanism 4 and the cover 5, tied between a tight-fitting bolts 6.

Drive shaft 1 has two cylindrical solar wheels 7 and 8. Top sun wheel 7 is made as a spur wheel external gearing with 33 two straight corrected teeth. The lower the sun wheel 8 is made as a helical wheel external gearing with the 55th corrected oblique teeth.

To the housing search mechanism 4 is attached to the upper case 9, in which the bearings 10 and 11 has an outer driven shaft 12. On the outer driven shaft 12 fixed two epicycle 13 and 14. Top epicycle 13 is made as a spur wheel with internal engagement with the 87th straight corrected teeth. The lower apical 14 is made as a spur wheel with internal engagement with 115 direct corrected teeth.

Inside the external shaft 12 in bearings 15 and 16 has an inner driven shaft 17. To the internal slave shaft 17 is rigidly fixed carrier 18, in which at equal distances around the circumference there are six satellites 19, namely ramatoulie gear external gear with 28 straight corrected teeth. Satellites 19 is set based on carrier 18 through bearings 20. Each satellite 19 is in mesh with a sun wheel 7 and epicycles 13, forming a planetary mechanism.

In the case of the search mechanism 4 and the cover 5 made five equidistant sockets that have roller bearings 21 and angular contact ball bearings 22, which supports the parasitic unit 23. Parasitic unit 23 includes a spur wheel 24 external gearing with 17 straight corrected teeth, cut height for education 17 and the outer slot. The continuation of these teeth with tension mounted helical wheel 25 external gear 51 a slanting outer tooth and 17 internal splines are the same for all five parasite blocks the angular position of the outer teeth and the inner slot. Each wheel 24 is coupled with epicycles 14, and each wheel 25 is in mesh with a sun wheel 8, forming, thus, the search mechanism.

Under the ends of the ball angular contact bearing 22 are elements 26, for example an adjusting ring for axial fixation of the parasitic unit.

The inner race of the roller bearing 21 made integral with the spur wheel 24 of the parasitic unit 23 to increase the rigidity of the block and reduce the vibratory activity of the gearbox.

The device operates as about the time.

The gearbox is designed to transfer the torque from the motors to the shafts bearing screws and other units of consumption at the helicopter.

During the rotation of the driving shaft 1 sun wheel 8, coupled with five gear 25 causes the rotation of the wheel 24, apicil 14 and connected with it the outer driven shaft 12, which receives rotation with reduced speed and in the direction opposite to the rotation of the driving shaft 1 gear ratio:

Simultaneously with the rotation of the driving shaft 1 sun wheel 7 causes the rotation of the satellites 19, which objetivas on a rotating epicycle 13 and in doing so, planetary motion, according cage 18 and connected with it the internal slave shaft 17 rotate in the direction of the driving shaft 1 with reduced speed.

The internal gear ratio of the planetary number is:

and gear ratio to the internal slave shaft 17 is:

or

Thus, the reducer sums the power of both engines and transmits it to the shaft bearing screws in accordance with the set mode of the motors and drives helicopter units.

The device was designed and manufactured for the ode name Vyalkova and successfully used on the client.

From the above it follows that the manufacture of this device industrially straightforward, involves the use of the developed materials and standard equipment that demonstrates compliance with the proposed technical solution to the patentability criterion of "industrial applicability".

Sources of information

1. Mechanical transmission of helicopters. / Edited Vincedelmonte. M: mechanical engineering, 1983 press, p.104, RIS, 3.35.

2. Patent RU NO. 2059535, B64C 27/00, 1996.

3. Mechanical transmission of helicopters. / Edited Vincedelmonte. M: mechanical engineering, 1983, p.106-109, RIS, 3.40.

1. The gearbox of the helicopter coaxial circuit containing a drive shaft, two coaxially arranged driven shaft, inner and outer, kinematically interconnected search and planetary mechanisms, each of which includes a sun wheel on the control shaft and epicycle on the outer driven shaft, while the search mechanism includes a parasitic blocks arranged in a stationary housing, and a planetary mechanism has satellites, placed in a carrier rigidly mounted on the inner driven shaft, characterized in that the number of satellites is greater per unit number of spurious blocks, with the number of teeth of the sun gear and epicycle search mechanism is a multiple of the number of spurious the locks, the sum of the numbers of teeth of these elements in the planetary mechanism is a multiple of the number of satellites, and the gear ratio of the mechanisms associated with the expression

i_pereb=2i_planets+1,

where i_pereb- gear ratio search mechanism;

i_planets- gear ratio of the planetary mechanism.

2. The gearbox of the helicopter coaxial configuration according to claim 1, characterized in that each of the parasitic unit includes helical wheel rigidly connected with the spur wheel through the slot.

3. The gearbox of the helicopter coaxial configuration according to claim 1 or 2, characterized in that the slots of the parasitic unit is made as a continuation of the teeth of the spur wheel, cut height.

4. The gearbox of the helicopter coaxial configuration according to claim 1 or 2, characterized in that the number of teeth of the helical wheel parasitic block is a multiple of the number of teeth of the spur wheel.

5. The gearbox of the helicopter coaxial configuration according to claim 1 or 2, characterized in that each parasite block is made can be locked in axial position.

6. The gearbox of the helicopter coaxial configuration according to claim 1 or 2, characterized in that each parasite block is made based on the housing by means of bearings, ball thrust and roller, the inner race of which is made integral with the spur wheel of this block.