Drive unit for a rotary-wing aircraft, and rotary-wing aircraft

Abstract

A drive unit for a rotary-wing aircraft has a first and second propeller, which rotates in the opposite direction to, and are axially spaced apart from, the first propeller. A first and second drive shaft are arranged coaxially with the first drive shaft, for the propellers, wherein the propellers are each rigid and mounted to be tiltable relative to the axis of rotation of their drive shafts. The tilt axis of each propeller extends in a plane perpendicular to the axis of rotation of the drive shafts and is oriented at an angle different from 90 relative to the longitudinal axis of the propeller. An electric drive module has at least two rotors which are coupled to one of the drive shafts, wherein the ratio of the diameter of the propellers to the axial distance between the propellers is between 4:1 and 12:1.

Claims

1. A drive unit for a rotary-wing aircraft, comprising: a first propeller and a second propeller, which rotates in the opposite direction to, and is axially spaced apart from, the first propeller, a first drive shaft and a second drive shaft, arranged coaxially with the first drive shaft, for the first and second propellers, wherein the first and second propellers are each rigid and are mounted so as to be tiltable relative to an axis of rotation of their drive shafts, wherein a tilt axis of each propeller extends in a plane perpendicular to the axis of rotation of the drive shafts and is oriented at an angle different from 90 degrees relative to a longitudinal axis of the propellers, an electric drive module having at least two rotors which are coupled to a respective one of the drive shafts, wherein the ratio of a diameter of the propellers to an axial distance between the propellers is between 4:1 and 12:1; wherein the drive unit comprises a bearing unit connecting the drive unit to a cabin of a rotary-wing aircraft so as to be pivotable relative to a pivot bearing point, wherein the unit formed of the electric drive module and the drive shafts is connected to the bearing unit using a universal joint, and wherein a bearing for an inner one of the drive shafts is arranged on a side of the universal joint facing away from the propellers.

2. The drive unit according to claim 1, wherein the tilt axis extends at an angle of +30 to +50 or 30 to 50 relative to the longitudinal axis of the propellers.

3. The drive unit according to claim 1, wherein at least one pin extends along the tilt axis and connects a hub of the propellers to the drive shaft in an articulated manner.

4. The drive unit according to claim 3, wherein an intermediate piece is arranged coaxially with the hub of the propellers and is detachably connected to the hub and on which the pin is mounted and which is adapted to be connected to the hub in various angular positions.

5. The drive unit according to claim 3, wherein the propellers have a connecting surface in which a multitude of holes is provided, and an intermediate piece on which the pin is mounted has a contact surface corresponding to the connecting surface, wherein the contact surface has a hole pattern provided therein which is configured such that the propellers can be connected to the intermediate piece in various angular positions.

6. The drive unit according to claim 1, wherein the electric drive module includes two electric motors which are accommodated coaxially with each other in a shared housing.

7. The drive unit according to claim 1, wherein an adjusting device acts between the bearing unit and a unit formed of the electric drive module and the drive shafts in order to be able to adjust an orientation of the drive shafts relative to the bearing unit.

8. The drive unit according to claim 7, wherein one end of the adjusting device engages the electric drive module.

9. A rotary-wing aircraft comprising a drive unit according to claim 1, wherein the rotary-wing aircraft includes a cabin which constitutes a passenger compartment and/or a payload compartment.

10. The rotary-wing aircraft according to claim 9, wherein the rotary-wing aircraft comprises a carrier for the drive unit, wherein an adjusting device is fixed to a bearing unit and is configured such that it can pivot a unit formed of the electric drive module and the drive shafts in relation to the carrier.

11. The rotary-wing aircraft according to claim 10, wherein the drive unit is arranged above the cabin, wherein the cabin constitutes the carrier.

12. A rotary-wing aircraft comprising a drive unit according to claim 2, the rotary-wing aircraft includes a cabin which constitutes a passenger compartment and/or a payload compartment.

13. The rotary-wing aircraft according to claim 12, wherein the rotary-wing aircraft comprises a carrier for the drive unit, wherein an adjusting device is fixed to a bearing unit and is configured such that it can pivot a unit formed of the electric drive module and the drive shafts in relation to the carrier.

14. A drive unit for a rotary-wing aircraft, comprising: a first propeller and a second propeller, which rotates in the opposite direction to, and is axially spaced apart from, the first propeller, a first drive shaft and a second drive shaft, arranged coaxially with the first drive shaft, for the first and second propellers, wherein the first and second propellers are each rigid and are mounted so as to be tiltable relative to an axis of rotation of their drive shafts, wherein a tilt axis of each propeller extends in a plane perpendicular to the axis of rotation of the drive shafts and is oriented at an angle different from 90 degrees relative to a longitudinal axis of the propellers, an electric drive module having at least two rotors which are coupled to a respective one of the drive shafts, wherein the ratio of a diameter of the propellers to an axial distance between the propellers is between 4:1 and 12:1, wherein at least one pin extends along the tilt axis and connects a hub of the propellers to the drive shaft in an articulated manner, and wherein the propellers have a connecting surface in which a multitude of holes is provided, and an intermediate piece on which the pin is mounted has a contact surface corresponding to the connecting surface, wherein the contact surface has a hole pattern provided therein which is configured such that the propellers can be connected to the intermediate piece in various angular positions.

Description

(1) Further advantages and features will be apparent from the description below and from the accompanying drawings, to which reference is made and in which:

(2) FIG. 1 shows a rotary-wing aircraft according to the invention with a drive unit according to the invention;

(3) FIG. 2 shows a sectional representation of the rotary-wing aircraft from FIG. 1 in the area of the drive unit;

(4) FIG. 3 shows a detail view of the rotary-wing aircraft in the area of a bearing unit of the drive unit;

(5) FIG. 4 shows a cross-section taken through the bearing unit;

(6) FIG. 5 shows a detail view in the area of an adjusting device of the drive unit;

(7) FIG. 6 shows a top view of a propeller;

(8) FIG. 7 shows a detail view of a propeller suspension;

(9) FIG. 8 shows a further detail view of a propeller suspension;

(10) FIG. 9 shows a detail view of an alternative propeller suspension; and

(11) FIG. 10 shows the propeller suspension from FIG. 9.

(12) FIG. 1 shows a rotary-wing aircraft/helicopter 10 having a drive unit 12.

(13) The rotary-wing aircraft 10 has a cabin 14 in which a passenger compartment 16 and a payload compartment 18 are formed. Alternatively, the rotary-wing aircraft 10 may be designed exclusively for the transport of goods, so that the passenger compartment 16 may be dispensed with or is used as a second payload compartment.

(14) The maximum take-off weight of the rotary-wing aircraft 10 is, for example, between 150 kg and 600 kg.

(15) The rotary-wing aircraft 10 comprises a carrier 20 for the drive unit 12, the carrier being attached to the cabin 14. The drive unit 12 is arranged above the cabin 14 here.

(16) Alternatively, the carrier 20 may be formed by the cabin 14.

(17) The drive unit 12, which is also illustrated in FIG. 2, comprises a first propeller 22 and a second propeller 24.

(18) The two propellers 22, 24 are arranged to be coaxial with each other and axially spaced apart from each other. In particular, the propellers 22, 24 form a double propeller.

(19) The two propellers 22, 24 rotate in opposite directions to each other. They have a fixed angle of attack, since the propeller blades are rigidly connected to the hub thereof. Exactly two propeller blades are provided here.

(20) The ratio of the diameter of the propellers 22, 24 to the axial distance between the propellers 22, 24 is, for example, between 4:1 and 12:1. In the case of different diameters of the propellers, this ratio refers to the smaller diameter.

(21) Furthermore, the drive unit 12 comprises a first drive shaft 26 and a second drive shaft 28 arranged coaxially with the first drive shaft 26. The drive shaft 26 is associated with the lower propeller 22, and the drive shaft 28 is associated with the upper propeller 24.

(22) The drive shaft 26 is formed as a hollow shaft, and the drive shaft 28 is guided in the hollow shaft.

(23) An electric drive module 30 is provided for driving the drive shafts 26, 28. The drive module 30 comprises two electric motors 32, 34, which are in the form of internal rotor motors. The rotors 36 of the electric motors 32, 34 are each coupled to a respective one of the drive shafts 26, 28.

(24) The two electric motors 32, 34 are accommodated in a common housing 38, the electric motors 32, 34 being arranged coaxially with each other in the housing 38.

(25) The housing 38 comprises a heat sink 40 and upper and lower housing covers 42, 44. The heat sink 40, which is provided with cooling fins on the outside, allows the heat produced in the electric motors 32, 34 to be dissipated particularly quickly.

(26) Formed in the lower housing cover 44 is an extension 45, in which a bearing 47 is provided for the drive shaft 26.

(27) The rotor 36 of the upper electric motor 32 is firmly connected to the drive shaft 26, which is formed as a hollow shaft and drives the lower propeller 22, and the rotor of the lower electric motor 34 is firmly connected to the drive shaft 28 of the upper propeller 24 and drives the latter by means of the drive shaft 28 guided through the hollow shaft.

(28) The drive unit 12 further comprises a bearing unit 46, by means of which the drive unit 12 is connected to the cabin 14 so as to be pivotable relative to a pivot bearing point D.

(29) The bearing unit 46 can be seen particularly clearly in FIGS. 3 and 4.

(30) The bearing unit 46 comprises a cone-shaped connecting element 48, which is bolted to the carrier 20 of the rotary-wing aircraft 10. In particular, the connecting element 48 is bolted to the carrier 20 through a total of four connecting points.

(31) In addition, an adjusting device 50 is provided to allow the alignment of the drive shafts 26, 28 to be adjusted relative to the bearing unit 46 or to the carrier 20.

(32) The adjusting device 50 acts between the bearing unit 46 and a unit formed by the drive module 30 and the drive shafts 26, 28.

(33) In the exemplary embodiment, one end of the adjusting device 50 engages the drive module 30.

(34) The adjusting device 50 comprises two length-adjustable actuators 52, which are more particularly arranged at an angle to one another.

(35) In particular, the actuators 52 are attached by one end to the housing 38, more specifically to the underside of the housing 38.

(36) As can be seen in FIG. 5, the actuators 52 are attached in an articulated manner to the housing 38, in particular to the lower housing cover 44.

(37) The actuators 52 are fastened by their respective other end to the connecting element 48 of the bearing unit 46.

(38) Consequently, a change in the length of the actuators 52 causes the housing 38 to be pivoted, as a result of which the drive shafts 26, 28, which are guided in the housing 38, are also pivoted.

(39) Owing to a certain minimum distance between the connecting points of the actuators 52 in the radial direction in relation to the center axis of the drive shafts, the forces required to pivot the unit formed by the drive module 30 and the drive shafts 26, 28 can be kept low.

(40) To allow the drive shafts 26, 28 to pivot, the unit formed by the drive module and the drive shafts 26, 28 is connected to the bearing unit 46 by means of a universal joint 51. The universal joint is used to transmit the lifting force to the carrier 20 in flight.

(41) The universal joint 51 includes a cross piece 53, which is pivotably mounted on the bearing unit 46 on the outside by means of two studs 55 and is pivotably mounted on the lower housing cover 44 on the inside by means of two studs 55.

(42) In this context, the universal joint 51 is located above the bearing 47 for the drive shaft 28. In other words, the bearing 47 for the inner one of the two drive shafts 26, 28 is arranged on the side of the universal joint 51 facing away from the propellers 22, 24. This can be seen particularly clearly in the sectional representation in FIG. 2 as well as in FIG. 4.

(43) FIG. 6 shows a top view of the rotary-wing aircraft 10, in particular of the upper propeller 24 in the area of a support 54 of the propeller 24 at the drive shaft 28. FIG. 7 shows a cross-section taken through the support 54.

(44) The propeller 24 is mounted so as to be tiltable about a tilt axis K relative to the axis of rotation R of the drive shaft 28.

(45) Two pins 56 extend along the tilt axis K and connect a hub 58 of the propeller 24 to the drive shaft 28 in an articulated manner.

(46) The lower propeller 22 is mounted in the same way.

(47) The tilt axis K of each propeller 22, 24 extends in a plane perpendicular to the axis of rotation R of the drive shafts 26, 28 and is oriented at an angle different from 90 in relation to the longitudinal axis L of the propeller 22, 24. Preferably, the tilt axis K extends at an angle of +30 to +50 or 30 to 50 relative to the longitudinal axis L of the propeller 22, 24.

(48) FIG. 8 shows a cross-section taken through the support 54.

(49) It is apparent from FIG. 8 that an intermediate piece 60 is provided which is arranged coaxially with the hub 58 of the propeller 24. The pin 56 is mounted on the intermediate piece 60.

(50) The intermediate piece 60 is detachably connected to the hub 58, in particular by means of a toothing 62. In this way, the hub 58 can be connected to the intermediate piece 60 in various angular positions.

(51) FIGS. 8 and 9 illustrate an alternative possibility for realizing an angular offset of the propellers 22, 24 relative to the tilt axis K.

(52) In this case, the support 54 is realized by a component 64, which is connected to the propeller 24, and an intermediate piece 66. In FIG. 10, the intermediate piece 66 is hidden for better illustration.

(53) The component 64 has a connecting surface 68 provided thereon (see FIG. 10), in which two hole circles 70, 72 are formed, so that the connecting surface 68 has a multitude of holes 74, 76.

(54) The hole circles 70, 72 have different diameters.

(55) The holes 74 of the first hole circle 70 are arranged so as to be angularly offset from the holes 76 of the second hole circle 72. For example, the holes 74, 76 of one hole circle 70, 72 have an offset of 6 from each other and the holes 74 of the first hole circle 70 are also offset by 3 from the holes 76 of the second hole circle 72. In the exemplary embodiment, each hole circle 70, 72 therefore has 60 holes 74, 76.

(56) The pin 56, which is concealed in FIGS. 9 and 10, is mounted at the intermediate piece 66.

(57) The intermediate piece 66 has a contact surface 78 which corresponds to the connecting surface 68 and which is concealed in FIG. 9 because the contact surface 78 rests against the connecting surface 68.

(58) A hole pattern 80 is provided in the contact surface 78.

(59) The holes 74, 76 in the connecting surface 68 and the holes 82, 84 of the hole pattern 80 serve as bolt holes to attach the propeller 24 to the intermediate piece 66. For this purpose, the hole pattern 80 of the contact surface 78 may be oriented such that at least some holes 82 are in alignment with holes 74, 76 of the connecting surface 68 so that a bolt 86 can be fitted through the connecting surface 68 and the contact surface 78.

(60) The hole pattern 80 is formed such that the propeller 24 can be connected to the intermediate piece 66 in various angular positions.

(61) In FIG. 9, it can be seen that the hole pattern 80 has a first group of holes 82 in alignment with the holes 74 of the first hole circle 70 of the connecting surface 68 and a second group of holes 84 in alignment with the holes 76 of the second hole circle 72 of the connecting surface 68. The holes of one group thus each have the same radial distance from an axis of rotation of the propeller 24 or, put differently, they are located on a circle whose diameter corresponds to the diameter of one of the hole circles 70, 72. In other words, the holes 82 of the first group are associated with the first hole circle 70 and the holes 84 of the second group are associated with the second hole circle 72.

(62) As can be further seen in FIG. 9, the holes 82, 84 of the hole pattern 80 are arranged such that not all of the holes 82, 84 are aligned with the holes 74, 76 at the same time.

(63) In this way, an improved angular adjustment can be made possible in cooperation with the mutually offset holes 74, 76 of the hole circles 70, 72, in which an angular offset between the possible angular positions is as small as possible. In the exemplary embodiment, the angular offset between the feasible positions is 3 in each case.

(64) More specifically, the hole pattern 80 has different pairs of holes, each having one hole 82 of the first group and one hole 84 of the second group, the pairs of holes being alternately aligned with the holes 74, 76 of the hole circles 70, 72.

(65) The mounting of the propeller 22 may be implemented in the same way.

(66) In an alternative embodiment, which is not shown for simplicity, the component 64 may be integrally formed with the propeller 22, 24.