Flexible gear arrangement with variable spring force

Abstract

Flexible gear arrangement (24), comprising: a hub assembly (30) comprising a first hub component (42) defining a first axis (A5) extending through opposite side surfaces (44, 46) of the first hub component (42), and a second hub component (52) movable relative to the first hub component (42) in a controlled direction perpendicular to the first axis (A5); a gear ring (28) rotatably attached to the hub assembly (30) and defining a gear ring rotation axis (A3), wherein the gear ring (28) is engaged to move with the second hub component (52) between a preloaded position in which the gear ring rotation axis (A3) is coaxial with the first axis (A5) and a displaced intermediate stop position in which the gear ring rotation axis (A3) is parallel to, but not coaxial with, the first axis (A5); a spring component (40) which is connected between the first hub component (42) and the second hub component (52) and which preloads the second hub component (52) into the preloaded position, wherein the spring component (40) provides a variable spring force (148) which increases when the second hub component (52) is moved towards the displaced intermediate stop position; and a fluid chamber (94, 96) containing a damping fluid surrounding the spring component (40), and a movable component (72, 74) for compressing the damping fluid to dampen the movement of the second hub component (52).

Description

Technical field

[0001] The present disclosure relates generally to a compliant gear arrangement, and in particular to a compliant gear arrangement that provides the displacement of a gear ring relative to a hub component using a spring component with a variable spring force. Damping of the displacement movement can also be provided. background

[0002] Gear trains can incorporate a variety of gears, such as a drive gear, intermediate gears, and driven gears, used to transmit torque and speed. Gear trains are used in engine applications and, depending on the specific engine application, may include a crankshaft gear driven by one or more intermediate gears to a camshaft gear. The torque and speed transmitted from the crankshaft gear to the camshaft gear can be used to open and close the valves and for fuel injection. Thus, a relatively rigid gear train may be required to maintain the correct timing of the events triggered by the camshaft gear with respect to the engine crankshaft angle.However, the dynamic activity of the crankshaft and camshaft gears can be considerable during engine operation, resulting in significant shock torques through the transmission linkage. These shock torques can cause the teeth of adjacent gears to disengage and then be rapidly forced back into mesh, or cause back-to-back tooth hammering, which can lead to audible noise and premature wear of the transmission linkage components.

[0003] Some engineers have attempted to counteract such problems by incorporating dampers, such as pendulum dampers or viscous dampers, into gear trains. Another approach is to introduce compliance into the gear train. In general terms, compliant gear trains provide reduced stiffness or slippage, allowing one or more gears to lessen their response to shock loads. Where a particular gear would otherwise be rapidly accelerated or decelerated due to a torque impulse, compliance allows it to gradually adjust its rotation to absorb the shock load. Thus, compliant gear trains can dampen shock loads, reducing excessive wear, mechanical stress, and audible noise.

[0004] U.S. Patent No. 2,992,532, granted to Miller, teaches a control system that uses hydraulic force to actively adjust the axis of rotation of an intermediate gear ring. Specifically, Miller proposes the use of a hydraulic system that undergoes pressure changes in response to torque fluctuations. As the control system pressure changes, the axis of rotation of the gear ring is actively shifted. For example, as a result of reduced torque fluctuations over time, the control system pressure decreases to force the teeth of the intermediate gear into a tighter mesh with the teeth of the drive gear, thereby reducing the occurrence of tooth separation. Thus, Miller teaches a control system for actively shifting the axis of rotation of a gear ring, rather than a compliant gear system that passively responds to torques exceeding a predetermined threshold.Although various alternatives exist to counteract the negative effects of dynamic gear train activity, there remains a constant need for solutions, especially when previously undetected problems are identified.

[0005] DE 11 2007 001 736 T5 describes a compliant gear arrangement, e.g. for use in a gear train of a motor, with a hub and a toothed ring which is displaceable from a coaxial alignment in response to a torque acting on the gear arrangement.

[0006] The present disclosure relates to one or more of the problems or questions set out above. Summary of Revelation

[0007] According to one aspect, a compliant gear arrangement comprises a hub assembly with a first hub component, which defines a first axis extending through opposing side faces of the first hub component, and a second hub component, which is movable relative to the first hub component in a controlled direction perpendicular to the first axis. A ring gear, rotatably mounted on the hub assembly and defining a ring gear axis of rotation, is engaged to move with the second hub component between a preloaded position, in which the ring gear axis of rotation is coaxial with the first axis, and a displaced intermediate stop position, in which the ring gear axis of rotation is parallel to, but not coaxial with, the first axis. A spring component is interposed between the first hub component and the second hub component and preloads the second hub component into the preloaded position.The spring component provides a variable spring force that increases as the second hub component moves towards the offset intermediate stop position. The compliant gear assembly features a fluid chamber containing a damping fluid surrounding the spring component, as well as a movable component for compressing the damping fluid to dampen the movement of the second hub component.

[0008] According to another aspect, an internal combustion engine comprises an engine block, a mounting bracket attached to one end of the engine block, and a transmission assembly attached to the mounting bracket or the engine block. The transmission assembly includes a drive gear, a driven gear, and a compliant gear assembly positioned between the drive gear and the driven gear. The compliant gear assembly includes a hub assembly, a ring gear, and a spring component.The hub assembly comprises a first hub component, which defines a first axis extending through opposite side faces of the first hub component, and a second hub component, which is movable relative to the first hub component in a controlled direction perpendicular to the first axis. The gear ring, which is rotatably mounted on the hub assembly and defines a gear ring rotation axis, is engaged to move with the second hub component between a preloaded position, in which the gear ring rotation axis is coaxial with the first axis, and a displaced intermediate stop position, in which the gear ring rotation axis is parallel to, but not coaxial with, the first axis.The spring component is positioned between the first and second hub components, pre-tensioning the second hub component and providing a variable spring force that increases as the second hub component moves towards the offset intermediate stop position. The compliant gear assembly includes a fluid chamber containing a damping fluid surrounding the spring component, and a movable component for compressing the damping fluid to dampen the movement of the second hub component.

[0009] According to yet another aspect, a method for transmitting torque using a gear train comprising a compliant gear assembly is provided. The compliant gear assembly includes a hub assembly, a gear ring, and a spring component. The hub assembly has a first hub component that defines a first axis extending through opposing side faces of the first hub component, and a second hub component that is movable relative to the first hub component in a controlled direction perpendicular to the first axis.The gear ring, which is rotatably mounted on the hub assembly and defines a gear ring axis of rotation, is engaged to move with the second hub component between a preloaded position, in which the gear ring axis of rotation is coaxial with the first axis, and a displaced intermediate stop position, in which the gear ring axis of rotation is parallel to, but not coaxial with, the first axis. The spring component is connected between the first and second hub components, preloads the second hub component into the preloaded position, and provides a variable spring force that increases as the second hub component moves towards the displaced intermediate stop position.The method comprises the following steps: maintaining the preloaded position of the second hub component using an initial preload force of the spring component, and transmitting a first torque from a drive gear to a driven gear using the compliant gear assembly while the second hub component is in the preloaded position. The method also comprises supplying a second torque, greater than the first torque, to the compliant gear assembly and moving the second hub component into the offset intermediate stop position by overcoming the initial preload force of the spring component using the second torque. The movement of the second hub component beyond the offset intermediate stop position is limited using an increased spring force of the spring component, greater than the initial preload force.Thus, the transmission of the second torque from the input gear to the output gear is limited by the use of the compliant gear arrangement while the second hub component is in the displaced intermediate stop position. The method also includes damping the movement of the second hub component using a damping fluid surrounding the spring component. Brief description of the drawings Fig. Figure 1 is a schematic illustration of a motor system comprising a gear train according to the present disclosure; Fig. Figure 2 is an exploded view of the compliant gear assembly of the gear train of Fig. 1 according to one embodiment of the present disclosure; Fig. Figure 3 is a sectional view of the compliant gear arrangement of Fig. 2, shown in a pre-tensioned position; Fig. Figure 4 is a sectional view of the compliant gear arrangement of Fig. 2, shown in a stop position; Fig. Figure 5 is a sectional view of the compliant gear arrangement of Fig. 2 and illustrates damping fluid supply channels according to one aspect of the present disclosure; Fig. Figure 6 is a sectional view of the compliant gear arrangement of Fig. 2 at a stage of the assembly process according to another aspect of the present disclosure; Fig. Figure 7 is a sectional view of the compliant gear arrangement of Fig. 2 at a further stage of the assembly process according to a further aspect of the present disclosure; and Fig. Figure 8 is a graph of the spring force versus the deflection and represents a variable spring force of the compliant gear arrangement of Fig. 2 according to another aspect of the present revelation. Detailed description

[0010] With reference to Fig. Figure 1 shows a schematic view of an engine system 10 according to the present disclosure. The engine system 10 may include an internal combustion engine 12, which, for illustrative purposes only and without limitation, may be a four-stroke compression-ignition engine, and may include an engine block 14 defining a plurality of combustion chambers or cylinders (not shown). The internal combustion engine 12 may be any type of engine (e.g., internal combustion, gasoline, diesel, gas fuel, natural gas, propane), may be of any size, with any number of cylinders, any type of combustion chamber (e.g., cylindrical, rotary with spark ignition, compression ignition, four-stroke and two-stroke, etc.), and in any configuration (e.g., V-, in-line, radial, etc.).

[0011] The internal combustion engine 12 can have an engine housing 16 and a transmission train 18 attached to the engine housing 16 or the engine block 14. The transmission train 18 can have a drive gear 20, which defines a drive gear axis of rotation A1 and has a direction of rotation indicated by arrow R1. An intermediate gear 22, which can also be referred to as a compliant gear assembly 24, can be coupled to and meshed with the drive gear 20. A driven gear 26 can be meshed with the compliant gear assembly 24 and can have a driven gear axis of rotation A2. The compliant gear assembly 24 can have a ring gear 28 that is rotatable about a hub assembly 30 and can have a ring gear axis of rotation A3 that is movable in a controlled displacement direction indicated by arrow T1, which responds to certain torque applications, as described in more detail herein.In particular, the gear ring rotation axis A3 can be moved in a direction perpendicular to the gear ring rotation axis A3 over a displacement distance D1 to a position shown at A4. As shown, the controlled displacement direction T1 can be essentially parallel to a line P1 that is tangent to the pitch circles of both the compliant gear arrangement 24 and the driven gear 26.

[0012] Now, referring to Fig. Section 2 discusses an exemplary embodiment of the compliant gear assembly 24. The compliant gear assembly 24 can generally comprise the hub assembly 30, the gear ring 28, and a spring component 40. The hub assembly 30 can comprise a first hub component 42, which defines a first axis A5 extending through opposing side surfaces 44, 46 of the first hub component 42. In particular, the first hub component 42 can have a stub shaft 48 suitable for directly or indirectly attaching the compliant gear assembly 24 to the motor housing 16, which can also generally be referred to as the support housing. For example, the stub shaft 48 can have a mounting projection 50, such as a cylindrical mounting projection, to secure a fixed position of the stub shaft 48 relative to the support housing 16.Alternatively, the shaft stub 48 can be mounted on an independent mounting structure which can be secured to the motor housing 16 or the motor block 14.

[0013] The hub assembly 30 can also have a second hub component 52 which, as described in more detail below, is movable relative to the first hub component 42, or the shaft stub 48, in a controlled direction perpendicular to the first axis A5. Referring again to Fig. 1. The second hub component 52 can be moved in the direction indicated by arrow T1. Back to Fig. 2. The second hub component 52 can have a circular gear body 54, wherein the gear ring 28 is rotatable relative to the circular gear body 54 and thus movable with the second hub component 52. For example, the gear ring 28 can be attached to the hub assembly 30 using a bushing or a similar component.

[0014] Also with reference to Fig. 3. The spring component 40 can be connected between the first hub component 42 and the second hub component 52. In particular, the spring component 40, which cannot be a coil spring component, can have a first stack of disc springs 56, such as Belleville springs or spring washers, which are received in a first spring bore 58 of the shaft stub 48. According to the exemplary embodiment, the shaft stub 48 can also define a second spring bore 60 which receives a second stack of disc springs 62, wherein the first and second spring bores 58, 60 are oriented along an axis A6 perpendicular to the first axis A5. Respective spacers 64, 66 can be positioned between end walls 68, 70 of the spring bores 58, 60 and the first and second stacks of disc springs 56, 62.Pistons 72, 74 can also be movable within their respective spring bores 58, 60 and can have first ends 76, 78 in contact with a sliding piece 80, and second ends 82, 84, each in contact with one of the stacks of disc springs 56, 62. As described in more detail below, the sliding piece 80 can be positioned between the first hub component 42 and the second hub component 52 and configured to transmit a preload force from the spring component 40, which may have stacks of disc springs 56, 62, to the second hub component 52.

[0015] The pistons 72, 74, together with the end walls 68, 70 and side walls 86, 88, which define the spring bores 58, 60, and the plugs 90, 92, can define fluid chambers 94, 96, which can contain a damping fluid for damping movements of the second hub component 52. With reference to Fig. For example, the motor block 14 can define a plurality of fluid channels (not shown) that supply a damping fluid along fluid supply lines 98a, 100a provided in the support housing 16, or another mounting structure, which are in fluid communication with fluid supply lines 98b, 100b provided in the shaft stub 48. The fluid supply lines 98b, 100b can ultimately open into respective fluid chambers 94, 96. While shut-off valves (not shown) arranged along the fluid supply lines 98a, 100a or the fluid supply lines 98b, 100b can provide a controlled supply of damping fluid into the fluid chambers 94, 96, a diameter clearance between the pistons 72, 74 and the respective spring bores 58, 60 can provide the only exit path for the damping fluid from the fluid chambers 94, 96. In particular, the diameter clearance can ensure a controlled exit of the damping fluid from the fluid chambers 94, 96.As should be clear, the diameter clearance can be selected to provide a desired damping effect. According to one particular embodiment, a diameter clearance of approximately 60 micrometers can be provided. However, it should be clear that the amount of controlled discharge, which can alternatively be provided using orifices or other known means, can be selected to provide the desired damping for the specific application.

[0016] Back to Fig. 2. A cover plate 102 can be provided, which can be arranged on a first axial side of the gear ring 28 and the hub assembly 30, and a base plate 104, which can be arranged on a second axial side of the gear ring 28 and the hub assembly 30, can also be provided. According to the exemplary embodiment, a set of screws 106 can be provided, which pass through openings 108 formed in the cover plate 102, openings 110 formed in the shaft stub 48, and openings 112 formed in the base plate 104. A central screw 114 can be received through a central opening 116 through the cover plate 102 and a central opening 118 of the shaft stub 48.The central screw 114 can extend through the mounting projection 50 of the shaft stub 48 and can be secured in a mounting bore (not shown) formed in the support housing 16 to fasten the flexible gear assembly 24 to the internal combustion engine 12. When properly assembled and fastened, the openings 120 through the base plate 104 connect the fluid supply lines 98a, 100a to the fluid supply lines 98b, 100b. Although not discussed in detail herein, lubrication supply lines can also be provided to supply lubricating oil to certain components of the flexible gear assembly 24.

[0017] As explained above, the sliding piece 80 can transmit a combined preload force of the first and second stack of disc springs 56, 62 to the second hub component 52. In particular, as shown in Fig. Figure 3 shows that the stacks of disc springs 56, 62, by contact with the pistons 72, 74 and the sliding piece 80, preload the circular gear body 54 and thus the gear rim 28 into a preloaded position in which the gear rim's axis of rotation A3 is coaxial with the first axis A5. In the preloaded position, the pistons 72, 74, the sliding piece 80, the circular gear body 54, and the gear rim 28 are forced in a direction indicated by arrow T2, and a clearance or gap may be provided between the sliding piece 80 and the shaft stub 48, generally shown at 122. The clearance or gap 122 may correspond to the displacement distance D1 described above and may be selected based on a desired rigidity of the gear train 18. For example, according to some embodiments, a deflection of less than one millimeter may be desirable.

[0018] In response to torque loads that overcome the preload force of the first and second stack of disc springs 56, 62, the second hub component 52 can be disengaged from the preloaded position of Fig. 3 be moved into a fixed stop position, as in Fig. Figure 4 illustrates this. In particular, a torque load greater than the preload force of the stacks of disc springs 56, 62 can force the gear ring 28, the circular gear body 54, the sliding block 80, and the pistons 72, 74 in the direction of displacement indicated by arrow T1. If sufficient to overcome the preload force, this movement will compress or deflect the stacks of disc springs 56, 62 and move the gear ring rotation axis A3 in the direction indicated by arrow T1. As a result, the gear ring rotation axis A3 can be displaced through a variety of offset stop positions so that it is parallel to, but not coaxial with, the first axis A5, and a clearance or gap 124 can be provided between the shaft stub 48 and the circular gear body 54 on the side of the shaft stub 48 opposite the sliding block 80.

[0019] Furthermore, the damping fluid can absorb the torque peak (i.e., the shock torque exceeding the preload force) by absorbing the energy and releasing it as heat. As should be clear, the second hub component 52 can be movable through an infinite range of offset intermediate stop positions between the preloaded position and the fixed stop position. In the fixed stop position, the clearance or gap 124 and the distance between the gear ring rotation axis A3 and the first axis A5 can correspond to the displacement distance D1. In some embodiments, contact between the sliding piece 80 and the shaft stub 48 can prevent complete compression of the spring component 40.

[0020] With reference to Fig. Figure 6 illustrates a stage of an exemplary assembly process. In particular, fasteners 130, 132 can be used during the assembly of the compliant gear assembly 24 to hold the first and second stacks of disc springs 56, 62 in a desired compressed state. As shown, the fasteners 130, 132 can be received in threaded bores 134, 136 of the respective pistons 72, 74, so that the fasteners 130, 132 can be rotated in one direction to increase the compression of the stacks of springs 56, 62 with the pistons 72, 74, and rotated in another direction to decrease the compression of the stacks of springs 56, 62. After the shaft stub 48 has been assembled with the circular gear body 54 and the sliding piece 80, the fastening elements 130, 132 can be removed and the plugs 90, 92 can be inserted, as shown in Fig. Figure 7 shows. However, the fastening elements 130, 132 can be omitted if the pistons 72, 74 are compressed during assembly using alternative means.

[0021] The first and second stacks of disc springs 56, 62 can be selected and arranged to provide a desired variable spring force. As shown, each stack can contain twelve individual disc springs 56, 62, such as Belleville springs or spring washers, depicted in a row-parallel configuration. However, it should be clear that alternative arrangements of disc springs, or alternative components providing a variable spring force, including rubber components, can be used. Furthermore, although two stacks of disc springs are shown, any number of components or stacks can be used.

[0022] Now, referring to graph 140 of Fig. Figure 8 shows an exemplary variable spring force provided by the stacks of disc springs 56, 62. In particular, graph 140 plots the displacement (hereafter also referred to as compression or deflection) 142 in millimeters against the spring force 144 in newtons. While a helical spring provides a linear or constant spring rate (i.e., only a small or insignificant increase in spring force is provided, especially over a relatively short displacement), as shown in Figure 146, the spring component 40 of the compliant gear arrangement 24 disclosed herein, which may be something other than a helical spring or nested helical springs, can provide a variable spring force 148. The variable spring force 148, as provided by the stacks of disc springs 56, 62 described herein, provides a substantial increase in force over the relatively short displacement distance.In particular, the variable spring force 148 can be set to an initial preload force, such as approximately 2000 Newtons, which is increased to 6500 Newtons when the spring component 40, which may comprise the stacks of disc springs 56, 62, is compressed to a deflection distance of one millimeter, which may correspond to the displacement distance D1. Thus, in some embodiments, the force required to deflect the spring component 40 can more than double when the second hub component 52 is moved from the preloaded position of . Fig. 3 to the fixed stop position of Fig. 4 is moved. Industrial applicability

[0023] The present disclosure has potential application in any machine and / or motor that uses a gear train to transmit torque and speed. Furthermore, the present disclosure applies to gear trains comprising intermediate gears that experience shock torque loads from the drive gears or the driven gears with which the intermediate gears are meshed. Even further, the present disclosure is applicable to a compliant gear arrangement that can be interposed between drive and driven gears to dampen shock torque loads over a relatively wide range of speeds and loads.

[0024] Generally referring to Fig. 1-8, an internal combustion engine 12 can have an engine housing 16 and a transmission assembly 18 attached to the engine housing 16 or the engine block 14. The transmission assembly 18 can have a compliant gear arrangement 24 meshed with a drive gear 20 and a driven gear 26 to transmit torque from the drive gear 20 to the driven gear 26. The compliant gear arrangement 24 can generally have a hub assembly 30 comprising a first hub component 42, which defines a first axis A5 extending through opposing side surfaces 44, 46 of the first hub component 42, and a second hub component 52, which is movable relative to the first hub component 42 in a controlled displacement direction T1 perpendicular to the first axis A5. A gear ring 28 is rotatable around the hub assembly 30 and movable together with the second hub component 52.A spring component 40, which may have first and second stacks of disc springs 56, 62, is connected between the first and second hub components 42, 52 and pre-tensions the second hub component 52 into a pre-tensioned position. In the pre-tensioned position, as in . Fig. 3 shows a gear ring rotation axis A3 coaxial with the first axis A5.

[0025] The preloaded position of the second hub component 52 can be maintained using an initial preload force of the spring component 40. A first torque, which may be a medium torque and insufficient to overcome the preload force of the spring component 40, can be transmitted from the drive gear 20 to the driven gear 26 using the compliant gear arrangement 24 while the second hub component 52 is in the preloaded position. However, the second hub component 52 can be preloaded in response to a second torque, which may be a shock torque load greater than the first torque, and which is supplied to the compliant gear arrangement 24, as shown in Fig.The second hub component 52, shown in Figure 4, can be moved into a fixed stop position by overcoming the initial preload force of the spring component 40 with the aid of the second torque. Damping of this movement of the second hub component 52 can be provided by using the pistons 72, 74, the damping fluid provided in the fluid chambers 94, 96, and a controlled discharge, which can be provided by a diameter clearance between the pistons 72, 74 and the respective spring bores 58, 60.

[0026] Depending on the fixed stop position and the range of offset intermediate stop positions between the preloaded position and the fixed stop position, the gear ring rotation axis A3 can be shifted so that it is parallel to, but not coaxial with, the first axis A5. The movement of the second hub component 52 beyond one of the offset intermediate stop positions can be limited by using an increased spring force of the spring component 40 that is greater than the initial preload force. For example, the second torque may be sufficient to overcome the initial preload force, but insufficient to overcome the increasing spring force at a greater displacement.Thus, the transmission of the second torque from the drive gear 20 to the driven gear 26 can be limited by using the compliant gear arrangement 24 while the second hub component 52 is in the displaced intermediate stop position.

[0027] The compliant transmission arrangement disclosed herein provides a means of reducing shock torques or torque peaks transmitted through a transmission train. In particular, the compliant transmission arrangement can be displaced to dampen its response to shock torque loads, thereby reducing excessive noise and wear that might otherwise occur. In some embodiments, the compliant transmission arrangement can provide a sound power reduction of the motor by 1 to 6 dB. These benefits are provided over a wider range of torques and speeds than with conventional compliant transmissions.In particular, the compliant gear arrangement of the present disclosure includes a spring component with a reduced preload compared to conventional designs, which increases considerably when the spring component is compressed to respond to a wide range of torques and speeds. Furthermore, torque peaks can be absorbed and converted into heat using the damping fluid provided in the spring chambers. In contrast, conventional designs using coil springs absorb torque peaks and ultimately release the energy back into the gear train.

[0028] It should be clear that the preceding description is for illustrative purposes only and is in no way intended to limit the scope of the present disclosure. It will therefore be clear to the person skilled in the art that further aspects of the disclosure can be derived from the study of the drawings, the disclosure itself, and the following claims.

Claims

[1] Flexible gear arrangement (24), comprising: a hub assembly (30) comprising a first hub component (42) defining a first axis (A5) extending through opposite side surfaces (44, 46) of the first hub component (42), and a second hub component (52) movable relative to the first hub component (42) in a controlled direction perpendicular to the first axis (A5); a gear ring (28) rotatably attached to the hub assembly (30) and defining a gear ring rotation axis (A3), wherein the gear ring (28) is engaged to move with the second hub component (52) between a preloaded position in which the gear ring rotation axis (A3) is coaxial with the first axis (A5) and a displaced intermediate stop position in which the gear ring rotation axis (A3) is parallel to, but not coaxial with, the first axis (A5); a spring component (40) which is connected between the first hub component (42) and the second hub component (52) and which preloads the second hub component (52) into the preloaded position, wherein the spring component (40) provides a variable spring force (148) which increases when the second hub component (52) is moved towards the displaced intermediate stop position; and a fluid chamber (94, 96) containing a damping fluid surrounding the spring component (40), and a movable component (72, 74) for compressing the damping fluid to dampen the movement of the second hub component (52). [2] Flexible gear arrangement (24) according to claim 1, wherein the variable spring force (148) doubles when the second hub component (52) is moved from the preloaded position to a fixed stop position. [3] Flexible gear arrangement (24) according to claim 1, wherein the first hub component (42) has a shaft stub (48) suitable for attaching the flexible gear arrangement (24) to a support housing (16), and the second hub component (52) has a circular gear body (54), wherein the gear ring (28) is rotatable relative to the circular gear body (54). [4] Flexible gear arrangement (24) according to claim 3, wherein the spring component (40) has a first stack of disc springs (56) arranged to provide the variable spring force (148). [5] Internal combustion engine (12), comprising: an engine block (14); a support housing (16) which is attached to one end of the engine block (14); and a gear train (18) which is attached to the support housing (16) or the motor block (14) and comprises a drive gear (20), a driven gear (26), and a compliant gear arrangement (24) interposed between the drive gear (20) and the driven gear (26) according to claim 1. [6] Internal combustion engine (12) according to claim 5, wherein the controlled direction is substantially parallel to a line (P1) that is tangent to the pitch circles of both the compliant gear arrangement (24) and the driven gear (26). [7] Method for transmitting a torque using a gear train (18) comprising a compliant gear assembly (24), wherein the compliant gear assembly (24) comprises a hub assembly (30) having a first hub component (42) defining a first axis (A5) extending through opposing side faces (44, 46) of the first hub component (42), and a second hub component (52) movable relative to the first hub component (42) in a controlled direction perpendicular to the first axis (A5), wherein the compliant gear assembly (24) further comprises a gear ring (28) rotatably attached to the hub assembly (30) and defining a gear ring rotation axis (A3), wherein the gear ring (28) is engaged to align with the second hub component (52) between a preloaded position in which the gear ring rotation axis (A3) is coaxial with the first axis (A5) is,and a displaced intermediate stop position in which the gear ring rotation axis (A3) is parallel to, but not coaxial with, the first axis (A5), wherein the compliant gear arrangement (24) also has a spring component (40) which is connected between the first hub component (42) and the second hub component (52) and provides a variable spring force (148), wherein the method comprises the following steps: Maintaining the preloaded position of the second hub component (52) using an initial preload force of the spring component (40); Transmitting a first torque from a drive gear (20) to a driven gear (26) using the compliant gear arrangement (24) while the second hub component (52) is in the preloaded position; Supplying a second torque, greater than the first torque, to the compliant gear arrangement (24); Moving the second hub component (52) into the displaced intermediate stop position by overcoming the initial preload force of the spring component (40) with the help of the second torque; Limiting the movement of the second hub component (52) beyond the displaced intermediate stop position by using an increased spring force of the spring component (40) that is greater than the initial preload force, and Limiting the transmission of the second torque from the drive gear (20) to the driven gear (26) using the compliant gear arrangement (24) while the second hub component (52) is in the offset intermediate stop position; and Damping the movement of the second hub component (52) using a damping fluid surrounding the spring component (40).

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