GEARBOX ASSEMBLY WITH DAMPING MATERIAL

Abstract

Motor vehicle transmission arrangement (10) for a motor vehicle, comprising: a first transmission component in the form of a ring gear (26) which has a first serrated toothing (34, 38) on its outer circumference; a second transmission component in the form of a clutch hub (30) arranged concentrically around the ring gear (26) and having on its inner circumference a second splined toothing (40, 42) which is complementary to and engages with the first splined toothing (34, 38) to transmit torque between them; and an annular damping component (28) arranged between the splined sections (34, 38, 40, 42) of the two gear components, the damping component having projecting sections on its outer circumference that engage with the second splined section (40, 42) and projecting sections on its inner circumference that engage with the first splined section (34, 38), wherein the damping component (28) is configured to reduce noise and / or vibration within the gear assembly (10), wherein the gear assembly (10) is configured to transmit torque between the first and the second gear component through the damping component (28), wherein the damping component (28) is adjacent to the second gear component and comprises a metallic section (46) and a non-metallic section (48),wherein the metallic section (46) of the damping component (28) comprises a pair of metal layers (46) and the non-metallic section comprises a polymer (48), wherein the polymer (48) is arranged between the pair of metal layers (46) and is completely encapsulated by the metal layers (46) so that none of the polymer (48) is exposed.

Description

TECHNICAL AREA

[0001] The present invention relates to transmission arrangements for motor vehicles and in particular to transmission arrangements that generate noise by engaging and / or disengaging torque transmission mechanisms and / or by means of transmission arrangements. BACKGROUND

[0002] Many automatic vehicle transmissions incorporate a variety of gear arrangements, connecting elements, shafts, torque transmission mechanisms, and other mechanical components. The various torque transmission mechanisms are used to selectively transfer torque from one rotating element to another or from a rotating element to a stationary element. Typical examples of torque transmission mechanisms include synchronizers, dog clutches, and multiple friction clutches and brakes. A multi-plate clutch or brake, for instance, can be used to connect one element of a planetary gear set, such as a ring gear, to the transmission housing, thereby changing the output of that particular planetary gear set.

[0003] Such torque transmission mechanisms can produce rattling or other noises because they are often used to engage or disengage gears, shafts, or other parts that rotate at different speeds, or to connect a rotating part to a stationary part. For example, the splines of a clutch plate can vibrate within the teeth of an internal hub or outer casing, creating corresponding noises. Such noises were typically masked by the sounds produced by an internal combustion engine. However, when an electric motor is used in a hybrid or electric vehicle, noises from the vehicle's powertrain, such as those from torque transmission mechanisms, gears, or clutch plates, are more readily audible. These noises are often considered undesirable from a customer's point of view.

[0004] One way to reduce noise from a vehicle's powertrain is to manufacture components from cast iron. Cast iron is known for its relatively high damping capacity; however, cast iron components are heavy, and the general trend in automotive technology is to make vehicle components lighter to achieve better fuel economy. Furthermore, cast iron can have other drawbacks, such as its susceptibility to cracking. Polymers are another material that exhibits high damping capacity; however, polymers are typically not strong enough to withstand the torque loads transmitted through a vehicle's powertrain, and they also cannot withstand the harsh fluids, heat, and other environmental factors within a vehicle's powertrain.Another way to reduce noise from the vehicle powertrain is to arrange elastic damping components between the individual torque-transmitting components of a transmission, as is known, for example, from the documents DE 102 03 307 A1, DE 38 43 272 A1 and US 5 653 321 A.

[0005] Accordingly, there is a need to dampen noise generated by a motor vehicle transmission, while work continues towards the design of lightweight and economical vehicles suitable for mass production.

[0006] The invention is therefore based on the objective of meeting this need. SUMMARY

[0007] This problem is solved by a gear arrangement having the features of claim 1.

[0008] The present invention provides a damping component within the transmission assembly, configured to dampen unwanted noise caused by the clutch plates or other transmission components. The damping component can utilize a variety of materials to ensure the robustness of the torque transmission while providing sound damping properties and maintaining a low weight. In some versions, the damping component comprises a polymer sandwiched between a pair of metal (e.g., aluminum or steel) layers.

[0009] Additional features may be provided, including but not limited to the following: a damping component comprising a pair of metal layers; a polymer arranged between the pair of metal layers; each metal layer comprising aluminum and / or steel; first and second gear components formed substantially from aluminum and / or steel; wherein the gear assembly further comprises a plurality of nested coupling plates configured to selectively transmit torque within the gear assembly; the damping component is configured to reduce noise generated by the plurality of nested coupling plates; wherein the damping component is a stamped insert sandwiched between the first and second gear components; the first gear component comprising a plurality of first splined teeth;the second transmission component comprising a plurality of second splined teeth; the plurality of first and second splined teeth that are complementary and configured to mesh and transmit torque through them; wherein the damping component is arranged between the plurality of first and second splined teeth; wherein the first transmission component is a ring gear and the second transmission component is a clutch hub; a section of the toothed clutch plates that mesh with the clutch hub; wherein the first transmission component is a clutch plate having a plurality of teeth extending therefrom; the second transmission component forming a plurality of torque teeth configured to accommodate the plurality of teeth of the clutch plate; wherein the damping component is an insert arranged in one torque tooth of the plurality of torque teeth;wherein the damping component is a first damping component, wherein the arrangement further comprises a plurality of additional damping components, each additional damping component being arranged in a torque tooth of the plurality of torque teeth; the damping component is a clutch hub or clutch housing; the second component is a transmission housing; the damping component is coupled to the transmission housing; the damping component comprises a polymer; wherein the pair of outer layers is formed of metal; wherein the damping component is configured to transmit torque; wherein the torque transmission arrangement further comprises a first transmission component and a second transmission component; wherein the damping component is configured to transmit torque between the first and the second transmission component;and wherein the torque transmission arrangement further comprises an element defining a plurality of torque teeth configured to accommodate the plurality of teeth of the coupling plate.

[0010] Further aspects, advantages, and areas of application will become apparent from the description provided herein. It is understood that the description and specific examples serve only as illustrations. DRAWINGS

[0011] The drawings described herein serve only as illustrations. Fig. Figure 1A is a cutaway cross-sectional view of a part of a motor vehicle transmission assembly, including a damping component according to the principles of the present invention; Fig. 1B is a cutaway perspective of part of the gear assembly of Fig. 1A, including the damping component, according to the principles of the present invention; Fig. 1C is a cutaway exploded view of part of the gear assembly of Fig. 1A-1B, including the damping component, according to the principles of the present invention; Fig. 1D is a cross-sectional view of the [structure / area] in the Fig. Damping component shown in 1A-1C, taken along lines 1D-1D in Fig. 1C according to the principles of the present invention; and Fig. 1E is a schematic, perspective, withdrawn view of a part of the [unclear] in the Fig. Damping component shown in 1A-1D according to the principles of the present invention. DETAILED DESCRIPTION

[0012] Referring to Fig. Figure 1 shows a section of a motor vehicle automatic transmission, generally designated by the number 10. The automatic transmission 10 includes a metal housing 12 that accommodates, positions, and protects various components, such as an input or output shaft 16, a variety of planetary gear assemblies 18A, 18B, and various other components.

[0013] In this example, such a planetary gear assembly 18A includes a sun gear 20, a planet carrier 22 with a plurality of typically three or four planet gears 24, and a ring gear 26. The sun gear 20 meshes with the planet gears 24, which are arranged concentrically around the sun gear 20, and the planet gears 24 mesh with the ring gear 26, which is arranged concentrically around the planet gears 24 and the sun gear 20. The sun gear 20, the planet carrier 22, and the ring gear 26 can all be selectively or permanently connected to other gears, carriers, or stationary components within the gear assembly 10 to transmit torque. A damping component 28 and a coupling hub 30 are arranged concentrically around the ring gear 26.

[0014] The Fig. 1B and Fig. Figure 1C illustrates assembly and exploded views of the planetary gear assembly 18A with the coupling hub 30, the damping component 28, the ring gear 26, and a retaining ring 32. The planet carrier 22, the planet gears 24, and the sun gear 20 have been omitted for clarity when showing the remaining components. When the planetary gear assembly 18A is mounted, the retaining ring 32 holds the ring gear 26 axially in position relative to the coupling hub 30.

[0015] In the example shown, as in Fig. As can be seen in Figure 1C, the ring gear 26 has a plurality of splined teeth 34 extending from an outer surface 36 of the ring gear 26, and the splined teeth 34 are separated by a plurality of recesses 38. The coupling hub 30 has several corresponding splined teeth 40 and recesses 42 configured to mesh with the splined teeth 34 and recesses 38 of the ring gear 26 to rotatably lock the ring gear 26 and the coupling hub 30. The splined teeth 40 and recesses 42 of the coupling hub 30 are formed on an inner surface 44 of the coupling hub 30. Each recess 42 of the clutch hub 30 is configured to receive a splined tooth 34 of the ring gear 26, and each recess 38 of the ring gear 26 is configured to receive a splined tooth 40 of the clutch hub 30.

[0016] The damping component 28 is arranged between the clutch hub 30 and the ring gear 26. In this example, the damping component is a stamped insert positioned between the splines 34, 40 of the clutch hub 30 and the ring gear 26, such that the damping component bears against both the outer surface 36 of the ring gear 26 and the inner surface 44 of the clutch hub 30. Thus, the damping component 28 has opposing projecting sections 45, 47 that are located in the recesses 38, 42 of the ring gear 26 and the clutch hub 30. Therefore, in this example, the damping component 28 meshes with the splines of both the ring gear 26 and the clutch hub 30.

[0017] When the clutch hub 30 and the ring gear 26 are rotationally fixed to each other, a torque is transmitted between them. The damping component 28 is therefore also able to transmit torque between the ring gear 26 and the clutch hub 30. In other words, the transmission assembly 10 is configured to transmit torque between the ring gear 26 and the clutch hub 30 via the damping component 28.

[0018] The damping component 28 could have any configuration and arrangement sufficient to reduce at least one noise and one vibration with the gear arrangement 10. Reference is now made to the Fig. 1D, Fig. Figure 1E, in which an example of a cross-section of the damping component 28 is shown. In this example, the damping component 28 includes a metallic section and a non-metallic section. The damping component 28 comprises, for example, a pair of metal layers 46 and a polymer 48 arranged between the pair of metal layers 46. For example, the polymer 48 can be a viscoelastic polymer core with a pair of metal skins 46 attached to it, such that the polymer 48 is enclosed within the metal skins 46. In some examples, the polymer 48 is completely encapsulated within the metal skins 46, so that none of the polymer 48 is exposed. The metal skins 46 can, for example, be formed from sheet metal.

[0019] The metal skins 46 can comprise any desired metal, such as aluminum or steel. Thus, the damping component 28 comprises a damping layer 48, which in this example is positioned between a pair of outer layers 46. Examples of damping materials that can be used in the damping component 28 are layered metal and polymer materials marketed by Material Sciences Corporation under the registered trademarks Quiet Steel® and Quiet Aluminum®.

[0020] Referring back to Fig.In Figure 1A, the motor vehicle transmission assembly 10 further comprises a plurality of nested clutch plates 50, 52 configured to selectively transmit torque within the transmission assembly 10. In this example, a set of first clutch plates 50 of the plurality of nested clutch plates 50, 52 meshes via splines 56 with an outer surface 54 of the clutch hub 30. A set of second clutch plates 52 of the plurality of nested clutch plates 50, 52 meshes with an inner surface 58 of the transmission housing 12 or with any other desirable component. The clutch plates 50, 52 are nested such that each clutch plate 50 of the first set is adjacent to a clutch plate 52 of the second set.

[0021] The coupling plates 50, 52 can be friction coupling plates that can be selectively engaged by a piston 62 or other actuator configured to press the first and second sets 50, 52 of the coupling plates together through one or more application plates 64 against a retaining plate 63. For example, friction lining material can be arranged on opposing surfaces of the coupling plates 50, 52. When compressed, the coupling plates 50, 52 transmit, for example, a torque between the coupling hub 30 and the housing 12. The coupling assembly can be held together, for example, by a retaining ring 65. Alternatively, other types of couplings and / or brakes, such as drum or jaw couplings, could be used. Thus, the plurality of nested coupling plates 50, 52 is configured to selectively transmit torque within the transmission assembly 10.

[0022] The damping component 28 is configured to reduce noise and / or vibration generated by any of the gears 20, 24, 26 in the planetary gear assemblies 18A, 18B, the plurality of toothed clutch plates 50, 52, or any other component within the transmission assembly 10. Thus, transmission components can be made of materials not traditionally considered sound-dampening materials, such as aluminum or steel. For example, the ring gear 26 and the clutch hub 30 could be made of steel or aluminum, which could generate noise, but the damping component 28 could dampen such noise. Cast iron, therefore, need not be used for its sound-dampening qualities; however, in some examples, some transmission components are still made of cast iron, even with the addition of the damping component 28.

[0023] Furthermore, splined gears in hubs, housings and shafts can be produced by stamping instead of casting if steel or aluminium is used for the manufacture of hubs, housings or shafts, which may mean that the splined gears can be produced more easily.

Claims

[1] Motor vehicle transmission arrangement (10) for a motor vehicle, comprising: a first transmission component in the form of a ring gear (26) which has a first serrated toothing (34, 38) on its outer circumference; a second transmission component in the form of a clutch hub (30) arranged concentrically around the ring gear (26) and having on its inner circumference a second splined toothing (40, 42) which is complementary to and engages with the first splined toothing (34, 38) to transmit torque between them; and an annular damping component (28) arranged between the splined sections (34, 38, 40, 42) of the two gear components, the damping component having projecting sections on its outer circumference that engage with the second splined section (40, 42) and projecting sections on its inner circumference that engage with the first splined section (34, 38), wherein the damping component (28) is configured to reduce noise and / or vibration within the gear assembly (10), wherein the gear assembly (10) is configured to transmit torque between the first and the second gear component through the damping component (28), wherein the damping component (28) is adjacent to the second gear component and comprises a metallic section (46) and a non-metallic section (48),wherein the metallic section (46) of the damping component (28) comprises a pair of metal layers (46) and the non-metallic section comprises a polymer (48), wherein the polymer (48) is arranged between the pair of metal layers (46) and is completely encapsulated by the metal layers (46) so that none of the polymer (48) is exposed. [2] Motor vehicle transmission arrangement according to claim 1, wherein each of the metal layers (46) of the pair of metal layers (46) comprises aluminium and / or steel. [3] Motor vehicle transmission assembly according to one of the preceding claims, wherein the first and second transmission components consist substantially of at least aluminium and steel, wherein the motor vehicle transmission assembly (10) further comprises a plurality of nested clutch plates (50, 52) configured to selectively transmit the torque within the transmission assembly (10), wherein the damping component (28) is configured to reduce the noise generated by the plurality of nested clutch plates (50, 52).

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