Generator connection system

Abstract

This invention relates to a generator input shaft assembly including a generator input shaft (160) and a disconnect input shaft (120). The generator input shaft is arranged to receive drive input from a generator, and the disconnect input shaft is arranged to deliver drive input from the generator input shaft to a disconnectable drive transmission device (116). The disconnectable drive transmission device is configured to transmit rotational drive from the generator input shaft assembly to the rotor (110) of the generator. The generator input shaft assembly is configured such that the generator input shaft can: float axially relative to the disconnect input shaft, and / or drive the disconnect input shaft when the axis of rotation of the generator input shaft is not parallel to the axis of rotation of the disconnect input shaft, thereby compensating for misaligned input to the generator input shaft. Other aspects of the invention relate to generators and systems including generator input shaft assemblies.

Description

Technical Field

[0001] The present invention relates to a disconnection device for disconnecting a rotary drive of an aircraft engine from a generator driven by the aircraft engine. Background Technology

[0002] Aircraft engines, such as jet engines or turbojet engines, can be used to drive generators that produce electricity for the aircraft during operation. Typically, the generator is driven by a drive shaft that is directly or indirectly (e.g., via a gearbox) connected to the main turbine of the aircraft engine.

[0003] Like any mechanical system, an aircraft engine's generator can experience mechanical failure. Therefore, a disconnect device is necessary to detach the generator from the engine's turbine. While the loss of power generation capacity due to disconnection can be severe, if the faulty generator is not disconnected from the turbine, the entire aircraft engine could be damaged or its performance impaired.

[0004] In this context, most existing disconnection devices provide a means by which an axial force is applied to a drive shaft, causing axial movement of the drive shaft, which in turn enables the disengagement mechanism to operate. Known methods exist in the prior art for providing this axial force, each with its own drawbacks. These three known methods are:

[0005] 1. Mechanical power is extracted from the rotating drive shaft to operate the disconnecting mechanism. While this enables very high actuation force and rapid disconnection, such known disconnecting mechanisms typically require very precise tolerances, thus necessitating a selective assembly process, and therefore often prove unreliable in cases of rotor bearing failure and loss of radial position. Consequently, this method has proven less reliable in practice than the preferred methods to date.

[0006] 2. Using large actuators and mechanical advantages such as lever arms to generate mechanisms, or using actuators to release large and powerful springs. These methods generally have a more robust assembly process and thus prove more reliable in service. However, the axial force they can generate is usually limited and not always sufficient to guarantee disconnection. Therefore, this method cannot guarantee successful disconnection in all possible failure scenarios;

[0007] 3. Using hydraulic pressure from the aircraft engine's oil cooling system to provide the axial force required for disconnection. While this solution can provide very high disconnection force, it is ineffective in the event of an oil cooling system failure. Therefore, this method cannot guarantee disconnection in all possible failure scenarios.

[0008] US 2017 / 0016489 A1 discloses a disconnecting mechanism including an input shaft defining a drive axis. The disconnecting shaft is selectively engaged with the input shaft and driven by the input shaft about the drive axis. When a ratchet actuator translates to engage a ramp, the disconnecting ramp shaft axially moves the disconnecting shaft from a first axial position to a second axial position.

[0009] An improved disconnection device is needed. Summary of the Invention

[0010] The inventors have confirmed that known disconnection devices can be improved. These improvements are best understood with reference to a known disconnection device in which the output from an aircraft engine drives a generator input shaft, which is selectively engageable with a disconnect shaft via a disconnectable drive transmission device to transmit drive to the generator rotor.

[0011] The inventors have identified several problems with the known system. One problem arises from misalignment between the generator input shaft and the engine output shaft. Such misalignment leads to accelerated wear of the drive transmission, which, in addition to reducing its service life, may also hinder the drive transmission from moving into its disconnection configuration, resulting in lower reliability of the disconnection device. Furthermore, the inventors have found that a lack of lubrication in the drive transmission further accelerates its wear. The present invention seeks to address these drawbacks.

[0012] According to the present invention, a generator arranged to be driven by a prime mover of an aircraft is provided, comprising: a rotor rotatable about a rotor axis; and a disconnectable drive transmission device.

[0013] The generator input shaft assembly includes:

[0014] A generator input shaft, arranged to receive the drive input to the generator; and

[0015] The input shaft is disconnected and arranged to deliver drive input from the generator input shaft to a disconnectable drive transmission device configured to transmit rotary drive from the generator input shaft assembly to the rotor.

[0016] The generator input shaft assembly is configured such that the generator input shaft can: float axially relative to the disconnect input shaft; and / or drive the disconnect input shaft when the rotation axis of the generator input shaft is not parallel to the rotation axis of the disconnect input shaft, thereby compensating for misaligned input to the generator input shaft.

[0017] This invention provides a solution to problems identified in known disconnectable devices. Specifically, if a misaligned input to the generator input shaft exists, the disconnectable drive transmission device will not suffer accelerated wear. Instead, the misalignment is compensated by a generator input shaft assembly that transmits drive even when the rotation axis of the generator input shaft is not parallel to the rotation axis of the disconnected input shaft. Furthermore, the generator input shaft is axially floatable relative to the disconnected input shaft, allowing it to transmit drive even when misalignment due to the position of the disconnected input shaft along the rotor axis exists.

[0018] The generator input shaft can be configured to drive a disconnected input shaft via an axially movable torque transmission interface. The axially movable torque transmission interface may include meshing input teeth. The meshing input teeth project radially relative to the disconnected input shaft. The meshing input teeth may include a first set of teeth extending from the inner circumferential surface of the disconnected input shaft. The first set of teeth may be arranged to mesh with a second set of teeth. The second set of teeth may extend from the outer circumferential surface of the generator input shaft. The axially movable torque transmission interface may include a spline arrangement.

[0019] According to another aspect of the invention, a generator arranged to be driven by an aircraft engine is provided, comprising the generator input shaft assembly as described above. The generator may further include a fluid circuit configured to deliver fluid flow to an axially movable torque transmission interface. This has the advantage of providing a generator in which the axially movable torque transmission interface can be adequately lubricated to increase its wear resistance, thereby increasing its service life and improving the reliability of the disconnection device.

[0020] A fluid circuit can be configured to deliver fluid flow to a disconnectable drive transmission device. The disconnectable drive transmission device may include a first disconnecting member and a second disconnecting member, and a mating interface between them. The fluid circuit can be configured to deliver fluid flow to the mating interface. This has the advantage of providing a generator in which the disconnectable drive transmission device can be adequately lubricated to increase its wear resistance, thereby increasing its service life. Specifically, this has the advantage of improved reliability of the disconnecting device, especially during high-speed operation, and improved durability of the disconnecting device, allowing for more disconnections before the need for maintenance.

[0021] The first disconnecting component can be configured to transmit rotational drive to the rotor via intermeshing rotor interfaces. The fluid circuit can be configured to deliver fluid flow to the intermeshing rotor interfaces. This has the advantage of providing a generator in which the intermeshing rotor interfaces can be adequately lubricated to increase their wear resistance, thereby increasing their service life and improving the reliability of the disconnecting device.

[0022] The rotor can be mounted in the generator housing. The rotor can be connected to the rotor bearing journal. A fluid circuit can be configured to deliver fluid flow to the rotor bearing. This has the advantage of providing a generator in which the rotor bearing can be adequately lubricated to increase its wear resistance, thereby increasing its service life and improving the generator's reliability.

[0023] The fluid circuit may include a first branch configured to deliver fluid flow to an axially movable torque transmission interface between the generator input shaft and the disconnected input shaft. The first branch may also be configured to deliver fluid flow to a disconnectable drive transmission. The fluid circuit may include a second branch. The second branch may be configured to deliver fluid flow to the rotor bearing. This has the advantage of substantially separating the fluid circuit into two branches, thus reducing the negative impact of blockages or pressure losses in one branch on the other. Therefore, this provides the advantage of a more reliable disconnection device that continues to supply lubricating fluid to the axially movable torque transmission interface and the disconnectable drive transmission even in the event of rotor bearing failure. Furthermore, this provides the advantage that components will retain their wear resistance even under certain failure conditions.

[0024] According to another aspect of the invention, a system comprising the generator described above is provided. The system may further comprise an aircraft engine assembly including an engine assembly output shaft. The generator may be arranged to be driven by the engine assembly output shaft. The generator input shaft may be configured to float axially relative to the disconnect input shaft and / or to drive the disconnect input shaft when the axis of rotation of the generator input shaft is not parallel to the disconnect input shaft, so as to compensate for misalignment between the engine output shaft and the generator disconnect input shaft.

[0025] The generator input shaft may include a distal end facing the aircraft engine and a generator end facing the rotor. The generator input shaft can be configured such that the force exerted on the generator end by the pressure of the generator's fluid circuit is equal to the force exerted on the distal end by the pressure of the engine assembly fluid. This has the advantage that the pressure from the generator's fluid circuit is balanced by the fluid pressure impacting the distal end of the generator input shaft, so that the resultant force along its axis on the generator input shaft can be zero. This provides a system in which the generator input shaft is not subjected to high axial loads due to the hydrostatic pressure of the fluid. Therefore, premature wear and damage to the generator input shaft assembly are reduced. Attached Figure Description

[0026] Other features and advantages of the invention will become apparent from the following description of embodiments of the invention by way of example only and with reference to the accompanying drawings.

[0027] Figure 1 This is a schematic diagram illustrating a disconnection device according to an embodiment of the present invention.

[0028] Figure 2 It shows Figure 1 A schematic diagram of the disconnected device.

[0029] Figure 3 It shows Figure 1 A schematic diagram of the disconnected device.

[0030] Figure 4 It shows Figure 1 A schematic diagram of the disconnected device.

[0031] Figure 5 This is a schematic diagram showing an aircraft and an aircraft engine according to an embodiment of the present invention. Detailed Implementation

[0032] Turn Figure 1 and Figure 5 This document illustrates a generator input shaft assembly 129 according to one embodiment. The generator input shaft assembly 129 is shown and described herein within the context of a generator drive disconnect device 100. The generator drive disconnect device 100 may be included in a generator 3 of an aircraft 1, the generator 3 being arranged to be driven by an aircraft prime mover, such as an aircraft engine 2. The generator 3 includes a rotor 110 rotatable about a rotor axis A. The generator 3 also includes a disconnect input shaft 120 rotatable about the rotor axis A. The generator input shaft assembly 129 transmits drive from the aircraft engine 2 to the disconnect device 100. Drive from the engine may optionally be provided via the aircraft engine's output gearbox, preferably via the output shaft. Therefore, the system may include an aircraft engine assembly and a generator input shaft assembly 129, the aircraft engine assembly including a prime mover and an output shaft.

[0033] Figure 1An embodiment of the disconnect device 100 is shown. A disconnect input shaft 120 is rotatably mounted in a generator housing 150 and journal-connected by a bearing 127 to rotate about a rotor axis A. A generator input shaft 160 is mounted within the disconnect input shaft 120 via a set of intermeshing splines 123, 163. The disconnect input shaft 120 and the generator input shaft 160 are collectively included in an input shaft assembly 129. In operation, the aircraft engine can be connected to the input shaft assembly via a spline 164 disposed on the generator input shaft 160. In this way, the input shaft assembly 129 transmits rotational drive from the aircraft engine to drive the disconnect device 100 to rotate about a rotor axis A. The generator rotor 110 is rotatably mounted in the housing 150 and journal-connected by a rotor bearing 117. The rotor includes a spline 114 arranged to engage with a spline 104 of the first disconnect member 101. Therefore, the first disconnecting member 101 can rotate together with the rotor 110 via engaging splines 104, 114, and can move relative to the rotor 110 along the rotor axis A. The disconnecting device 100 includes a disconnectable drive transmission device 116 arranged to transmit rotational drive between the first disconnecting member 101 and the second disconnecting member 121. The second disconnecting member 121 is arranged to rotate together with the disconnecting input shaft 120. Although Figure 1 The second disconnecting member 121 shown is an integral part of the disconnecting input shaft 120, but it should be understood that this component may be different from the disconnecting input shaft 120 and still rotate with it. The first disconnecting member 101 and the second disconnecting member 121 each include a first clutch member 105 and a second clutch member 125 that are axially separable from each other. When engaged, the clutch members 105, 125 facilitate the transmission of rotary drive in the drive transmission device 116, such that the drive transmission device 116 is in a connected configuration. In the connected configuration, the drive transmission device 116 transmits rotary drive from the disconnecting input shaft 120 to the rotor 110 via the first disconnecting member 101 and the second disconnecting member 121. The drive transmission device is in a disconnected configuration when the clutch members 105, 125 are axially separated by the relative axial separation of the first disconnecting member 101 and the second disconnecting member 121. Such separation can be achieved by any suitable disconnecting mechanism. For example, a ramp member 130, which is rotatable with the drive transmission device 116, and includes a ramp 131, can be provided. The disconnecting actuation member 140 can be mounted to the housing 150 and can be actuated toward the rotor axis A, i.e. toward the ramp member 130. After actuating the disconnecting actuation member 140, its engagement ramp 131 causes the first disconnecting member 101 to move axially away from the second disconnecting member 121, thereby moving the drive transmission device 116 to its disconnected configuration.

[0034] Clutch components 105 and 125 are collectively constructed as a claw clutch and are axially separable along the rotor axis A. However, it should be understood that other suitable forms of drive transmission devices, such as friction clutches, can be used. The first disengagement member 101 is movable along the rotor axis A between a first axial position and a second axial position. In the first axial position of the first disengagement member 101, the first clutch component 105 is engaged with the second clutch component 125, such that the drive transmission device 116 is in its engaged configuration. In the second axial position of the first disengagement member 101, the first clutch component 105 is disengaged from the second clutch component 125, such that the drive transmission device 116 is in its disengaged configuration. Figure 1 In the diagram, the first disconnecting member 101 is shown in its first axial position, such that the drive transmission device 116 is in its connected configuration. In the connected configuration of the drive transmission device 116, clutch members 105, 125 cause the first disconnecting member 101 and the second disconnecting member 121 to rotate together at the same speed. In the disconnected configuration of the drive transmission device 116, clutch members 105, 125 separate along the rotor axis A, such that the first disconnecting member 101 and the second disconnecting member 121 rotate independently of each other.

[0035] exist Figure 1 In the arrangement shown, the second disconnecting member 121 cannot move along the rotor axis A relative to the disconnecting input shaft 120. In another arrangement, the second disconnecting member 121 may be a separate component of the disconnecting input shaft 120 and may be configured to rotate with the disconnecting input shaft by, for example, a set of meshing teeth. In yet another arrangement, the second disconnecting member 121 is a separate component of the disconnecting input shaft 120 and may move along the rotor axis A relative to the disconnecting input shaft 120, for example, by providing a meshing spline. Therefore, although the accompanying drawings illustrated herein show an embodiment in which only the first disconnecting member 101 is movable along the rotor axis A, it should be understood that this arrangement may be modified such that the second disconnecting member 121 may also be movable along the rotor axis A, or only the second disconnecting member 121 may be movable along the rotor axis A, in order to move the drive transmission device 116 into and out of the disconnect configuration.

[0036] Rotor 110 is rotatable within housing 150 and journal-connected by bearing 117. Rotor 110 includes a plurality of splines 114 on its inner circumferential surface. These may be disposed on flange 111. First disconnect member 101 includes a plurality of splines 104 arranged around the outer circumferential surface of a second end 107 of first disconnect member 101. Splines 104 engage splines 114 to allow rotational drive to be transmitted between first disconnect member 101 and rotor 110. Splines 104, 114 allow first disconnect member 101 to translate along rotor axis A between a first axial position and a second axial position. Thus, first disconnect member 101 can rotate relative to housing 150 together with rotor 110 while being axially movable relative to rotor 101. In the connection configuration, rotational drive is transmitted from disconnect input shaft 104 to rotor 110 via drive transmission device 116 and splines 104, 114. Rotor 110 also includes a rotor shaft 112 fixedly mounted to rotor 110. The rotor shaft 112 extends axially from the rotor 110 along the rotor axis A toward the drive transmission device 116.

[0037] The disconnect device 100 may also include a biasing device 119. The biasing device 119 may be arranged to bias the drive transmission device 116 to its connection configuration. Figure 1 In the diagram, the biasing device is shown as a helical spring disposed around the rotor shaft 112 in an annular space 118 surrounding the rotor axis A. However, it should be understood that other suitable biasing devices can be used instead of the spring, or as an addition to the spring. The biasing device 119 is arranged in a compressed state such that it applies a force to bias the first disconnecting member 101 away from the rotor 110. Thus, the biasing device 119 biases the first disconnecting member 101 toward the second disconnecting member 121, thereby biasing the first clutch member 105 toward engagement with the second clutch member 125, thereby biasing the drive transmission device 116 to its connection configuration. Therefore, the biasing device 119 is a connection biasing device.

[0038] The disconnecting device 100 also includes a disconnecting mechanism. The disconnecting mechanism includes any suitable mechanism capable of moving the drive transmission device 116 to the disconnecting configuration. This separation can be achieved by axially moving the first disconnecting member 101 relative to the second disconnecting member 121.

[0039] The accompanying drawings described herein relate to a possible example of a known disconnecting mechanism that may be employed in disconnecting device 100. In this example, a ramp member 130 is disposed around the outer peripheral surface of a first end 106 of a first disconnecting member 101. The ramp member includes a ramp 131 extending around at least a portion of an angular range of the ramp member 130. The ramp member 130 includes an inner flat section 133 comprising an annular surface disposed around a rotor axis A, the annular surface extending around the entire angular range of the first disconnecting member 101. The ramp member 130 also includes an outer flat section 132 disposed at least partially around the rotor axis A, i.e., around at least a portion of the angular range of the first disconnecting member 101. The ramp 131 and the outer flat section 132 are disposed radially outside the inner flat section 133. The outer flat section 132 is axially offset from the inner flat section 133 along the rotor axis A. In this embodiment, the outer flat section 132 is offset from the inner flat section 133 toward the flange 111, but those skilled in the art will understand that different arrangements may be used in different embodiments, such as embodiments in which the ramp member is alternatively arranged around the second disconnect member 121. The ramp 131 of the ramp member 130 begins at an axial position of the outer flat section 132 and slopes helically toward the axial position of the inner flat section 133, i.e., toward the disconnect input shaft 120 in this embodiment. Thus, the ramp 131 provides a slope with a generally axial orientation extending from the axial position of the outer flat section 132 toward the axial position of the inner flat section 133.

[0040] The disconnection mechanism in this example also includes a disconnection actuation member 140 located within an actuation chamber 145 of the housing 150. Figure 1 In the diagram, the disconnecting actuation member 140 is shown as a cylindrical portion that can be slidably received by the extension 142 of the housing 150; however, it should be understood that other suitable means may be used to mount the disconnecting actuation member 140 to the housing. Furthermore, although... Figure 1 The disconnect actuation member shown has a motion axis perpendicular to rotor axis A, but it should be understood that the disconnect actuation member 140 may also be tilted relative to rotor axis A. The disconnect actuation member 140 is movable between a deactivated position and an activated position. A spring 144 is disposed between the disconnect actuation member 140 and the housing 150, but it should be understood that other suitable biasing devices may be used. The spring 144 biases the disconnect actuation member 140 toward its activated position, i.e., toward rotor axis A in a direction perpendicular to rotor axis A. Figure 1In the deactivated position, the disconnecting actuation member 140 is in its inactive position. A retaining device (not shown) holds the disconnecting actuation member 140 in its inactive position against the force of the spring 144. Those skilled in the art will understand that any such retaining device capable of spring-loaded disconnecting actuation member 140 is suitable. The retaining device may include a mechanical latching mechanism or any suitable pneumatic, hydraulic, or magnetic mechanism capable of holding the disconnecting actuation member 140 in its inactive position against the force of the spring 144. Those skilled in the art will understand that once the retaining mechanism is released, the spring 144 will force the disconnecting actuation member 140 toward the rotor axis A into an activated position, in which the disconnecting actuation member 140 can actuate the disconnecting mechanism. Alternatively, the biasing and retaining device may be replaced or supplemented by an active actuation device (not shown) capable of moving the actuation member 140 between its inactive and activated positions. Such active actuation device may include a solenoid, hydraulic or pneumatic arrangement, or any other arrangement capable of actuating the disconnection actuation member 140 toward the ramp member 131 and further toward the rotor axis A.

[0041] In the deactivated position, the disconnecting actuation member 140 of the disconnecting mechanism in this example is positioned close to and radially outward of the ramp member 130, but not in contact with it. The movement of the disconnecting actuation member 140 into the activated position, i.e., toward the rotor axis A, allows it to engage the ramp member 130. When the disconnecting actuation member 140 engages the ramp 131 on the ramp member 130, the interaction between the disconnecting actuation member 140 and the ramp 131 forces the ramp member 130 to move the first disconnecting member 101 from its first axial position to its second axial position along the rotor axis A, thereby moving the drive transmission device 116 to its disconnected configuration.

[0042] like Figure 1 As shown, the disconnecting actuation member 140 is in its deactivated position. The biasing device 119 holds the first disconnecting member 101 in its first axial position. Therefore, the drive transmission device 116 is in its connected configuration such that rotational drive is transmitted from the disconnecting input shaft 120 via the drive transmission device 116 to the first disconnecting member 101 and the rotor 110. Thus, the disconnecting input shaft 120, the first disconnecting member 101, the ramp member 130, and the rotor 110 rotate together relative to the disconnecting actuation member 140.

[0043] Once the retaining mechanism of the disconnecting actuation member 140 is released, the disconnecting actuation member 140 is biased by the spring 144 toward its actuated position, i.e., toward the ramp member 130. Depending on the rotational position of the ramp member 130 when the disconnecting actuation member 140 moves to its actuated position, the disconnecting actuation member 140 will contact the outer peripheral surface of the ramp 131 or engage the outer flat section 132. In the former case, the ramp member 130 will rotate relative to the disconnecting actuation member 140 until the outer flat section 132 is rotated to align with the disconnecting actuation member 140, at which point the spring 144 continues to bias the disconnecting actuation member 140 toward the rotor axis A and engage it with the outer flat section 140. In either case, the disconnecting actuation member 140 will engage the outer flat section 132 during one rotation of the ramp member 130 about the rotor axis A.

[0044] As the ramp member 130 continues to rotate relative to the disconnecting actuation member 140, the outer flat section 132 also continues to rotate until the disconnecting actuation member 140 finally engages the ramp 131. At this point, the continued rotation of the ramp member 130 relative to the disconnecting actuation member 140 forces the ramp member 130 into an axial position, thereby moving the first disconnecting member 101 from its first axial position to its second axial position, thus disengaging the drive transmission device 116. Once the ramp member 130 has been forced a sufficient distance along the rotor axis A, the continued bias of the disconnecting actuation member 140 toward the rotor axis A allows the disconnecting actuation member 140 to move radially inward toward the rotor axis A, thereby engaging the disconnecting actuation member 140 with the inner flat section 133. The engagement of the disconnecting actuation member 140 with the inner flat section 133 holds the ramp member 130 in the axial position, which, against the action of the biasing device 119, holds the first disconnecting mechanism 101 in its second axial position.

[0045] The generator input shaft assembly 129 includes a disconnect input shaft 120 and a generator input shaft 160. The generator input shaft 160 is at least partially mounted within the disconnect input shaft 120 and has a rotational axis about the input axis C. Figure 1In this configuration, the generator input shaft 160 is arranged around the rotor axis A; therefore, the input axis C and the rotor axis A are collinear. The generator input shaft 160 includes a spline 163 extending from the outer peripheral surface of a first end 160a of the generator input shaft 160. The disconnect input shaft 120 includes a spline 123 extending from its inner peripheral surface, arranged to engage with the spline 163. This spline connection 123, 163 allows the generator input shaft 160 to transmit rotary drive to the disconnect input shaft 120. Furthermore, the spline connection 123, 163 allows the generator input shaft 160 to move axially relative to the disconnect input shaft 120 along the rotor axis A. Although the accompanying drawings and description specify that the disconnect input shaft 120 and the generator input shaft 160 are connected by a spline engagement, it should be understood that any suitable means can be used to transmit rotary drive while allowing relative axial movement, such as an axially movable torque transmission interface. Furthermore, spline engagements 123 and 163 are arranged such that the generator input shaft 160 can oscillate about the rotor axis A, allowing the input axis C and the rotor axis A to become non-parallel. In one embodiment, this is achieved by an arrangement in which the inner diameter of the disconnected input shaft 120 is sufficiently larger than the maximum outer diameter of the spline 163, thereby allowing the spline 163 to oscillate relative to the spline 123. Spline engagements 123 and 163 may include crown splines to further facilitate this degree of freedom of movement of the generator input shaft 160 relative to the disconnected input shaft 120. Thus, spline engagements 123 and 163 facilitate the transmission of rotary drive between the generator input shaft 160 and the disconnected input shaft 120, even when the generator input shaft 160 is axially moved relative to the disconnected input shaft 120 and / or the generator input shaft 110 is not parallel to the rotor axis A.

[0046] Optionally, the generator input shaft 160 also includes a shear neck 168. As is known in the art, the shear neck 168 comprises a portion of the shaft with reduced thickness. Therefore, if the generator input shaft 160 experiences high shear stress caused by, for example, a delayed generator rotor and a faulty disconnect device, the generator input shaft 160 will fail at the shear neck 168 to reduce adverse effects on the gearbox. The generator input shaft 160 also includes a plurality of splines 164 disposed at a second end 160b of the generator input shaft 160. The splines 164 are shown as being disposed around the outer peripheral surface of the second end 160b of the generator input shaft 160. The splines 164 serve as means for connecting the generator input shaft 160 to the aircraft engine, as will be described in reference. Figure 2 As described.

[0047] Figure 2 The above reference is shown. Figure 1An embodiment of the disconnect device 100. The disconnect device 100 is configured to selectively transmit drive from the aircraft engine of the aircraft to the rotor 110 of the generator. Rotary drive can be transmitted to the disconnect device 100 via an aircraft gearbox (not shown). The aircraft gearbox transmits rotary drive via an aircraft gearbox output shaft 170. Figure 2 As shown, the gearbox output shaft 170 is rotatably mounted in the aircraft gearbox housing 180 and connected by bearings 181a and 181b, allowing the gearbox output shaft 170 to rotate about the gearbox axis B. The gearbox output shaft 170 includes a spline 174 on its inner circumferential surface. The generator input shaft 160 and the gearbox output shaft 170 are arranged such that spline 164 can mesh with spline 174. This spline connection 164, 174 allows the gearbox output shaft 170 to transmit rotary drive to the generator input shaft 160. Furthermore, the spline connection 164, 174 allows the generator input shaft 160 to move axially relative to the gearbox output shaft 170 along the rotor axis B. Although the accompanying drawings and description specify that the gearbox output shaft 170 and the generator input shaft 160 are connected by a spline engagement, it should be understood that any suitable means can be used to transmit rotary drive while allowing relative axial movement, such as an axially movable torque transmission interface. The spline joints 164 and 174 between the gearbox output shaft 170 and the generator input shaft 160 can be arranged in a similar manner to the spline joints 123 and 163 between the generator input shaft 170 and the disconnect input shaft 170, so that the spline joints 164 and 174 facilitate the transmission of rotary drive between the generator input shaft 160 and the gearbox output shaft 170, even if the generator input shaft 150 moves axially relative to the gearbox output shaft 170 and / or the generator input shaft 160 is not parallel to the gearbox axis B.

[0048] exist Figure 2 In the diagram, gearbox axis B is shown as an offset distance x from rotor axis A. Although gearbox axis B is shown as parallel to rotor axis A, it should be understood that the disclosure presented herein is not limited to this arrangement and can be equally applied to cases where gearbox axis B is not parallel to rotor axis A, and / or deviates from rotor axis A. Figure 2 This illustrates a possible scenario in an aircraft engine assembly where the axis of rotation of the gearbox output shaft 170, or any other input supplying rotational drive to the generator, is not parallel to and / or deviates from the axis of rotation of the generator rotor. Therefore, the generator input is misaligned. This could be due to manufacturing tolerances. In other words, rotor axis A may not be parallel to and / or deviate from gearbox axis B.

[0049] In some existing disconnect devices, the gearbox output shaft is connected to the generator input shaft via a splined engagement, with the input shaft directly connected to the disconnect device, for example, allowing rotary drive to be transmitted directly from the gearbox output shaft to the disconnect device. In these existing disconnect devices, any misalignment between the gearbox output shaft and the generator input shaft will cause the input side of the disconnect device to be non-parallel to the rotational axis of the generator rotor. Therefore, a drive transmission mechanism is needed to transmit the rotary drive from the disconnect input shaft to the rotor, transmitting drive between two misaligned shafts. This misalignment leads to accelerated wear of the drive transmission mechanism. For example, in drive transmission mechanisms comprising a group of meshing clutch components, misalignment between them will lead to accelerated wear of the clutch components, resulting in increased maintenance requirements and lower reliability of the disconnect device. Furthermore, misalignment in the drive transmission mechanism makes rapid disconnection more difficult.

[0050] The embodiments described herein seek to address the problem of accelerated wear of the drive transmission 116 by employing a generator input shaft assembly 129, which includes a separate generator input shaft 160 and a disconnect input shaft 120 as described above. Figure 2 In the illustrated case, the gearbox axis B is misaligned with the rotor axis A, meaning the gearbox output shaft 170 is misaligned with the rotor 110. This misalignment causes the input axis C to be non-parallel to the rotor axis A, meaning the generator input shaft 160 rotates about an axis not parallel to the rotor 110. In this illustration, the input axis C forms an angle δ with the rotor axis A. Figure 2 In this diagram, portions of the generator input shaft 160 may impact the surrounding portions of the gearbox output shaft 170 and the disconnected input shaft 120; the angle δ is exaggerated for illustrative purposes. The arrangement shown allows the generator input shaft 160 to accommodate misalignment by its ability to rotate, thereby transmitting rotary drive even when its input axis C is not parallel to the rotor axis A. Specifically, this is achieved through spline joints 164, 174 between the gearbox output shaft and the generator input shaft 160, and spline joints 123, 163 between the generator input shaft 160 and the disconnected input shaft 120, thereby allowing the generator input shaft 120 to accommodate misalignment between the gearbox output shaft 170 and the rotor axis 11, thus reducing misalignment between the first disconnect member 101 and the second disconnect member 121 of the drive transmission device 116.

[0051] In addition to being able to oscillate about rotor axis A, the generator input shaft 160 is also configured to float axially relative to the disconnect input shaft 120 and relative to the gearbox output shaft 120. The generator input shaft 160 may further be provided with a first flange 165 extending from the outer peripheral surface of the generator input shaft near the open end of the disconnect input shaft 120. The flange 165 provides a means of limiting movement of the generator input shaft 160 along rotor axis A toward the drive transmission device 116. The generator input shaft 160 may further be provided with a second flange 166 extending from the outer peripheral surface of the generator input shaft near the open end of the gearbox output shaft 170. The flange 166 provides a means of limiting movement of the generator input shaft 160 along rotor axis A toward the gearbox.

[0052] Figure 3 The above reference is shown. Figure 1 and Figure 2 An embodiment of the disconnection device 100. Specifically, Figure 3 The flow of a lubricating fluid, such as oil, throughout the disconnect device is illustrated, providing lubrication and heat exchange for certain components in use for cooling purposes. In some existing disconnect devices lacking the generator input shaft assembly 129 described herein, a fluid circuit for such an assembly is not required. Therefore, an oil circuit that can be employed in embodiments of the disconnect device 100 is provided herein, and the flow of a suitable cooling / lubricating fluid in use is depicted using dashed areas. Although oil is mentioned herein, those skilled in the art will understand that any other suitable fluid, particularly a liquid, capable of providing the required lubrication and / or heat transfer may be suitable. The oil circuit includes an orifice 115 disposed in the rotor shaft 112. The orifice 115 is in fluid communication with an inlet port (not shown) disposed upstream of the disconnect device and facing the rotor 110. The orifice 115 is pressure-regulated upstream using a pressure relief valve (not shown) and facilitates the flow of oil from the rotor 110 through the rotor shaft 112 to the disconnect device 100. The rotor shaft 112 includes a first fluid port 112a and a second fluid port 112b, which can be considered as appropriately sized attenuators to control the oil flow rate. In this way, the flow of oil is maintained and controlled even when the rotor is stationary or disconnected from the input shaft 160.

[0053] A first fluid port 112a is provided by an axial bore through the end wall of the rotor shaft 112. The first fluid port 112a is in fluid communication with both the orifice 115 and the disconnect spline chamber 167, where spline engagements 123, 163 are located between the generator input shaft 160 and the disconnect input shaft 120. Therefore, the first fluid port 112a provides a flow path to allow oil to flow from the orifice 115 to the disconnect spline chamber 167. Centrifugal force acting on the oil in the disconnect spline chamber 167, provided by the rotating input shaft assembly 129 in use, causes the oil to submerge the splines 123, 163. In this way, the first fluid port 112a provides oil to lubricate the splines 123, 163. An O-ring 122 is provided at the interface between the disconnect input shaft 120 and the generator input shaft 160 to seal the interface and prevent oil leakage from the disconnect spline chamber 167. The drive transmission device 116 is in fluid communication with the disconnect spline chamber 167. Therefore, oil from the disconnect spline chamber 167 can be supplied to the drive transmission 116, thereby flooding the clutch components 105 and 125 with oil. This lubricates the clutch components 105 and 125 of the drive transmission 116. An O-ring 135 is disposed at the interface between the ramp member 130 and the disconnect input shaft 120 to seal the interface and prevent oil leakage from the drive transmission. The first disconnect member 101 includes a first fluid port 101a. The ramp member 130 includes a fluid port 130a. The fluid ports 101a and 130a together provide a flow path between the drive transmission 116 and the actuation chamber 145. Centrifugal force acting on the oil flooding the drive transmission 116 forces the oil from the drive transmission through the fluid ports 101a and 130a into the actuation chamber 145. In this way, oil is supplied to disconnect any other components in the actuation member 140 and the actuation chamber 145 that may require lubrication and / or cooling, such as the ramp member 130.

[0054] A second fluid port 112b is provided by a radial bore through the circumferential wall of the rotor shaft 112. The rotor shaft 112 may also include a notch 112c, which is diametrically opposed to the second fluid port 112b to substantially mechanically counterbalance the material removal effect of the second fluid port 112b. The second fluid port 112b is in fluid communication with both the orifice 115 and the annular space 118, thereby providing an oil flow path between them. Thus, in use, the pressure acting on the oil forces the oil out of the orifice 115, through the second fluid port 112b, and into the annular space 118. In this way, the annular space 118 can be flooded with oil. An O-ring 109 is disposed at the interface between the first disconnecting member 101 and the rotor 110, at the outer peripheral surface of the annular space 118, to seal the interface and prevent oil leakage. In addition to the biasing device 119, the annular space 118 also includes a spacer 190. Spacer 190 is an annular band disposed around rotor shaft 112 between first disconnect member 101 and biasing device 119 to hold biasing device 119 in a desired axial position. Spacer 190 includes a plurality of radial holes 190a. Spacer 190 maintains the positioning of biasing device 119 around rotor shaft 112 while allowing oil to flow within annular space 118. First disconnect member 101 also includes a second fluid port 101b. Second fluid port 101b provides a flow path between annular space 118 and rotor spline chamber 102, wherein spline engagements 104, 114 are disposed between first disconnect member 101 and rotor 110. Centrifugal force acting on the oil in annular space 118 forces oil through second fluid port 101b out of annular space 118 and into rotor spline chamber 102. Thus, second fluid port 101b supplies oil to rotor spline chamber 102, thereby flooding splines 104, 114 with oil. In this manner, the second fluid port 101b provides oil to lubricate the splines 104 and 114. Furthermore, the second fluid port 101b provides a weir to allow the annular space 118 to be submerged in oil; this ensures that the contact surfaces of the biasing device 119 are lubricated. The rotor 110 includes a fluid port 110a. The fluid port 110a provides a flow path between the rotor spline chamber 102 and the rotor bearing 117. Centrifugal force acting on the oil in the rotor spline chamber 102 forces the oil through the fluid port 110a out of the rotor spline chamber 102 and towards the rotor bearing 117. In this manner, the fluid port 110a provides oil to lubricate the bearing 117.

[0055] Therefore, from a single feed of oil from orifice 115 of rotor shaft 112, oil is correspondingly supplied to multiple components of the disconnect device 100 requiring lubrication, including disconnect actuation member 140, rotor bearing 117, splines 104, 114, 123, 163, and clutch members 105, 125. Furthermore, oil is supplied to these components using two separate fluid ports 112a, 112b from orifice 115. As shown, dividing the oil circuit into a first branch and a second branch may be advantageous because, in the event of an interruption or pressure loss in the oil flow in the first branch, the negative impact on the second branch will be reduced compared to using a single-path circuit. Similarly, in the event of an interruption or pressure loss in the oil flow in the second branch, the negative impact on the first branch will be reduced. One example where this may be advantageous is in the event of an oil pressure loss from the branch defined by the first fluid port 112a due to, for example, rotor disconnection or failure of rotor bearing 117; despite this, the splines at drive transmission device 116 and / or interface 123 will continue to be submerged in oil and thus continue to be lubricated. Therefore, the fluid circuit provided herein complements the generator input shaft assembly 129 by providing further wear and failure mode resistance to the drive transmission, thereby extending its service life. Complementing the shear neck 168 described above, the generator input shaft 160 may optionally include an oil plug 169. As... Figure 3 As shown, the oil plug 169 is located inside the generator input shaft 160, at an axial position between the shear neck 168 and the disconnect spline chamber 167. Thus, in the event of failure of the generator input shaft 160 at the shear neck 168, the oil plug 169 will prevent oil from escaping from the disconnect spline chamber 167.

[0056] Figure 4 The above reference is shown. Figures 1 to 3 An embodiment of the disconnection device 100. Specifically, Figure 4 The presence of oil around the generator input shaft 160 is shown. As described above, the first fluid port 112a provides an oil jet from orifice 115 to the disconnect spline chamber 167, and the significant centrifugal force acting on the oil in the disconnect spline chamber 167, provided by the rotating input shaft assembly 129 in use, causes the oil to submerge the splines 123, 163. Those skilled in the art will understand that the oil in the disconnect spline chamber 167 will have a certain pressure P1. Furthermore, the oil in the disconnect spline chamber 167 will be directed along the input axis C toward the gearbox output shaft 170, i.e., to... Figure 4The oil in the disconnected spline chamber 167 impacts the generator input shaft 160 in a specific area A1. Therefore, the oil in the disconnected spline chamber 167 will exert a force F1 on the generator input shaft 160 in the direction of the arrow. Force F1 will be equal to the product of pressure P1 and area A1. As will be understood, the hydrostatic pressure of the oil used to lubricate splines 123, 163 can generate a resultant force and associated axial load on the generator input shaft 160. Assuming the generator input shaft 160 is configured to float axially relative to the disconnected input shaft 120 and gearbox output shaft 170, such a resultant force will cause the generator input shaft 160 to accelerate toward the gearbox output shaft 170 until flange 166 contacts the gearbox output shaft 170, thus limiting any further axial movement of the generator input shaft 160. In this position, the generator input shaft 160 will continue to experience a compressive axial load due to the resultant force from the oil pressure.

[0057] To reduce such axial loads, the embodiments described herein advantageously provide a second force F2 capable of balancing the first force F1. The gearbox output shaft 170, to which the disconnect device 100 can be connected in use, may be provided with an oil circuit (not shown). The oil circuit may include an inlet port (not shown) in fluid communication with an orifice 172 of the gearbox output shaft 170. The inlet port supplies oil to the gearbox spline chamber 171 via the orifice 172. The centrifugal force acting on the oil in the gearbox spline chamber 171 provided by the rotating gearbox output shaft 170 in use causes the oil to submerge the splines 164, 174. In this way, the fluid port 172 supplies oil to lubricate the splines 164, 174. An O-ring 173 is provided at the interface between the gearbox output shaft 170 and the generator input shaft 160 to seal the interface and prevent oil leakage from the gearbox spline chamber 171. Similar to the disconnect spline chamber 167, the oil in the gearbox spline chamber 171 will have a certain pressure P2, and will move along the input axis C toward the disconnect input shaft 120, i.e. Figure 4 The oil in the generator spline chamber 171 will exert a force F2 on the generator input shaft 160 in the direction of the arrow, within a specific area A2. The force F2 will be equal to the product of the pressure P2 and the area A2.

[0058] The disconnect device 100 is configured such that F1 = F2, so that there is no resultant force along the input axis C due to the oil pressure on the generator input shaft 160. Therefore, the disconnect device 100 is configured such that A1P1 = A2P2. In fact, even in the case of, for example, P1 ≠ P2, this condition can be satisfied by selecting appropriate values ​​for A1 and / or A2 accordingly. Similarly, even in the case of A1 ≠ A2, the condition of resultant force can be satisfied by selecting appropriate values ​​for P1 and / or P2 accordingly. Therefore, this embodiment of the disconnect device 100 advantageously provides design flexibility while maintaining compatibility with the aircraft engines that may be installed.

[0059] Figure 5 The aircraft 1, comprising an aircraft engine 2 and a generator 3, is schematically shown. The aircraft engine 2 is capable of transmitting drive to the generator 3 via the generator input shaft 160. The generator input shaft 160 is capable of transmitting drive to the rotor 110 via the disconnect device 100 as described above.

[0060] Various modifications can be made to all the above embodiments by adding, deleting and / or replacing them to provide further embodiments, wherein any and / or all embodiments are covered by the appended claims.

Claims

1. A generator arranged to be driven by the prime mover of an aircraft, comprising: A rotor, which is capable of rotating about a rotor axis; Disconnectable drive transmission device; The generator input shaft assembly includes: A generator input shaft is arranged to receive a drive input to the generator; and A disconnectable input shaft is arranged to deliver drive input from the generator input shaft to the disconnectable drive transmission device, the disconnectable drive transmission device being configured to transmit rotary drive from the generator input shaft assembly to the rotor, wherein the disconnectable input shaft is rotatably mounted within the generator housing and is connected by bearing journals to rotate about the rotor axis; The generator input shaft assembly is configured such that the generator input shaft can: float axially relative to the disconnect input shaft; and / or drive the disconnect input shaft when the axis of rotation of the generator input shaft is not parallel to the axis of rotation of the disconnect input shaft, thereby compensating for misaligned input to the generator input shaft.

2. The generator according to claim 1, characterized in that, The generator input shaft is configured to drive the disconnect input shaft via an axially movable torque transmission interface.

3. The generator according to claim 2, characterized in that, The axially movable torque transmission interface includes intermeshing input teeth.

4. The generator according to claim 3, characterized in that, The meshing input teeth protrude radially relative to the disconnected input shaft.

5. The generator according to claim 4, characterized in that, The meshing input teeth include a first set of teeth extending from the inner circumferential surface of the disconnected input shaft, the first set of teeth being arranged to mesh with a second set of teeth extending from the outer circumferential surface of the generator input shaft.

6. The generator according to claim 5, characterized in that, The axially movable torque transmission interface includes a spline arrangement.

7. The generator according to any one of claims 2 to 6, characterized in that, The generator also includes a fluid circuit configured to deliver a fluid flow to the axially movable torque transmission interface.

8. The generator according to claim 7, characterized in that, The fluid circuit is configured to deliver fluid flow to a disconnectable drive transmission device.

9. The generator according to claim 8, characterized in that, The disconnectable drive transmission device includes a first disconnecting member and a second disconnecting member and a joint interface between them, wherein the fluid circuit is configured to deliver fluid flow to the joint interface.

10. The generator according to claim 9, characterized in that, The first disconnecting member is configured to transmit rotational drive to the rotor via an intermeshing rotor interface, and the fluid circuit is configured to deliver fluid flow to the intermeshing rotor interface.

11. The generator according to claim 7, characterized in that, The rotor is mounted in the generator housing and connected by a rotor bearing journal, and the fluid circuit is configured to deliver fluid flow to the rotor bearing.

12. The generator according to claim 11, characterized in that, The fluid circuit includes a first branch configured to deliver fluid flow to the axially movable torque transmission interface and / or the disconnectable drive transmission device between the generator input shaft and the disconnected input shaft. Furthermore, the fluid circuit further includes a second branch configured to deliver fluid flow to the rotor bearing.

13. A system comprising a generator according to any one of claims 1 to 12 and an aircraft engine assembly including an engine assembly output shaft, the generator being arranged to be driven by the engine assembly output shaft; in, The generator input shaft is configured to float axially relative to the disconnect input shaft and / or to drive the disconnect input shaft when the axis of rotation of the generator input shaft is not parallel to the disconnect input shaft, so as to compensate for misalignment between the engine assembly output shaft and the disconnect input shaft of the generator.

14. The system according to claim 13, characterized in that, The generator input shaft includes: Facing the far end of the aircraft engine, and The generator end facing the rotor; The generator is configured such that the force generated by the pressure of the fluid circuit of the generator and impacting the generator end is equal to the force generated by the pressure of the fluid of the engine assembly and impacting the distal end.

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