Disconnect clutch piston cooling flow port

Abstract

The clutch assembly includes a shaft, a balance dam sealed to the shaft, a seal plate axially spaced from the balance dam and sealed to the shaft, and a piston. The piston is sealed to the shaft and axially disposed between the balance dam and the seal plate. The piston includes an orifice extending axially through the piston. A pressure chamber is bounded in part by the piston and the seal plate. The balance chamber is bounded in part by the piston and the balance dam. The pressure chamber is in fluid communication with the balance chamber via the orifice.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Non-provisional Application No. 18 / 139,408, filed April 26, 2023, the entire disclosure of which is incorporated herein by reference.

[0002] Technical Field The present disclosure relates generally to a disconnect clutch piston, and more particularly to a disconnect clutch piston with cooling flow ports. [Background technology]

[0003] Disconnect clutches are generally known. In some arrangements, a disconnect clutch assembly may include a shaft defining a portion of a pressure chamber and a portion of a balance chamber. In such arrangements, the shaft may include a first axial channel configured to provide oil flow to the pressure chamber and a second axial channel configured to apply oil cooling flow to the balance chamber. Further, the first axial channel and the second axial channel may be sealed from one another. It would be desirable to have alternative configurations and arrangements to reduce the complexity of the disconnect clutch assembly while still meeting durability and performance requirements. Summary of the Invention [Means for solving the problem]

[0004] Embodiments disclosed herein provide a clutch assembly including a shaft and a balance dam sealed to the shaft. The clutch assembly further includes a seal plate axially spaced from the balance dam and sealed to the shaft. The clutch assembly further includes a piston sealed to the shaft and axially disposed between the balance dam and the seal plate. The piston includes an orifice extending axially through the piston. A pressure chamber is bounded in part by the piston and the seal plate, and a balance chamber is bounded in part by the piston and the balance dam. The pressure chamber is in fluid communication with the balance chamber via the orifice.

[0005] In embodiments, the piston may be sealed against the balance dam and the seal plate. In embodiments, the balance dam may be fixed to the shaft and the piston may be axially slidable on the shaft. In embodiments, the pressure chamber may be sealed from the balance chamber except for the orifice. In embodiments, the balance dam may include a further orifice extending axially through the balance dam. The further orifice may be located radially inward of the orifice.

[0006] In embodiments, the clutch assembly may further include a resilient element disposed axially between the hydraulic piston and the balance dam to bias the hydraulic piston away from the balance dam. The orifice may be disposed radially outward of the resilient element. In embodiments, the piston may be sealed against the seal plate via a bonded seal. The orifice may be disposed radially closer to the bonded seal than the resilient element.

[0007] In embodiments, the shaft may include an axial channel in direct fluid communication with the pressure chamber. The axial channel may be in indirect fluid communication with the balance chamber via the pressure chamber. The clutch assembly may further include a flow path configured to provide fluid to the pressure chamber. The flow path may pass through the axial channel and may include a first portion bounded in part by the piston and the seal plate. The flow path may be further configured to provide fluid to the balance chamber. The flow path may pass through an orifice and may include a second portion bounded in part by the piston and the balance dam.

[0008] In embodiments, the clutch assembly may further include a backing plate fixed to the shaft. The balance dam may be axially disposed between the backing plate and the piston. The clutch assembly may further include a clutch plate carrier fixed to the backing plate and axially disposed between the backing plate and the balance dam. The clutch assembly may further include a plurality of clutch plates supported by the clutch plate carrier. The piston may be axially slidable on the shaft to clamp the plurality of clutch plates against the backing plate to close the clutch assembly. The balance dam may include an additional orifice extending axially through the balance dam, and the clutch plate carrier may include a cooling flow orifice extending radially through the clutch plate carrier. The additional orifice may be positioned radially inward of the orifice and the cooling flow orifice. The cooling flow orifice may be positioned to allow fluid to cool the plurality of clutch plates. The shaft may include an axial channel in direct fluid communication with the pressure chamber. The clutch assembly may further include a flow passage configured to provide fluid to the pressure chamber. The flow path may pass through the axial channel and may include a first portion bounded in part by the piston and the seal plate. The flow path may be further configured to provide fluid to a balance chamber. The flow path may pass through an orifice and may include a second portion bounded in part by the piston and the balance dam. The flow path may be further configured to provide fluid to cool the plurality of clutch plates. The flow path may pass through an additional orifice and a cooling flow orifice and may include a third portion bounded in part by the balance dam and the backing plate. The axial channel may be in indirect fluid communication with the balance chamber via a pressure chamber.

[0009] Embodiments according to the present disclosure provide various advantages, including cost reduction by creating a flow path that engages the disconnect clutch assembly and cools the clutch plates, which allows for the elimination of multiple channels in the shaft that are configured to engage the disconnect clutch assembly or cool the clutch plates. [Brief explanation of the drawings]

[0010] [Figure 1] 1 illustrates a detailed cross-sectional view of a disconnect clutch assembly according to an embodiment of the present disclosure. [Figure 2] 2 illustrates a cross-sectional view of an enlarged area of ​​the disconnect clutch assembly shown in FIG. 1; DETAILED DESCRIPTION OF THE INVENTION

[0011] Embodiments of the present disclosure are described herein. It should be understood that like drawing numbers appearing in different drawings identify identical or functionally similar structural elements. It should also be understood that the disclosed embodiments are merely examples, and that other embodiments may take various alternative forms. The figures are not necessarily to scale, and some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein should not be construed as limiting, but merely as representative references to teach those skilled in the art various uses of the embodiments. As one skilled in the art will understand, various features illustrated and described with reference to any one of the drawings can be combined with features illustrated in one or more other drawings to create embodiments not explicitly illustrated or described. The illustrated combinations of features provide representative embodiments for typical applications. However, various combinations and modifications of features consistent with the teachings of the present disclosure may be desired for particular applications or implementations.

[0012] The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the present disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods, devices, or materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure, the following exemplary methods, devices, and materials are described herein.

[0013] 1-2, a disconnect clutch assembly 100 according to one exemplary embodiment of the present disclosure is illustrated. The disconnect clutch assembly 100 is rotatable about a central axis A. As used herein, terms such as "axial," "radial," "circumferential," "outward," and the like are intended to be relative to the central axis A.

[0014] The disconnect clutch assembly 100 includes a shaft 102, a backing plate 104, a clutch plate 106, a piston 108, a balance dam 110, and a seal plate 112. The backing plate 104 is fixed to the shaft 102 by, for example, staking. The balance dam 110 is fixed to the shaft 102 by, for example, staking, and is axially disposed between the backing plate 104 and the piston 108. The balance dam 110 is sealed to the shaft 102 by, for example, staking. The balance dam 110 includes a first orifice 114 to allow cooling flow through the balance dam 110 to cool the clutch plate 106. The first orifice 114 may be located radially closer to the shaft 102 than the outer diameter of the balance dam 110. The first orifice 114 may include a countersink on at least one side of the balance dam 110.

[0015] The piston 108 is sealed to the shaft 102 by, for example, a seal 116 and is axially slidable on the shaft 102 to clamp the clutch plate 106 against the backing plate 104 and close the disconnect clutch assembly 100. The piston 108 and balance dam 110 are sealed together at a mating seal 118. The disconnect clutch assembly 100 includes a balance chamber 120 that is bounded in part by the piston 108 and balance dam 110. The balance chamber 120 is further defined by or bounded between the shaft 102, the balance dam 110, the mating seal 118, the piston 108, and the seal 116. "Bounded in part" means that a portion of the referenced chamber, flow passage, or other structure is bounded or formed by the referenced element.

[0016] The disconnect clutch assembly 100 also includes a clutch plate carrier 122 axially disposed between the backing plate 104 and the balance dam 110 and secured to the backing plate 104 by, for example, a riveted connection. The clutch plate carrier 122 includes cooling flow orifices 124 for permitting a radially flowing cooling oil flow to cool the plurality of clutch plates 106, as described further below.

[0017] The disconnect clutch assembly 100 also includes a resilient element 126 axially disposed between the piston 108 and the balance dam 110 to bias the piston 108 away from the balance dam 110. In the exemplary embodiment shown, the resilient element 126 includes a circumferentially disposed coil spring located radially inward of the clutch plate 106. While a coil spring is shown, other resilient elements are possible. For example, the resilient element 126 may include a Belleville washer or a rubber puck.

[0018] The seal plate 112 is sealed to the shaft 102 via a seal 128. The seal plate 112 is sealed to the piston 108 at a mating seal 130. The disconnect clutch assembly 100 includes a pressure chamber 132 that is bounded in part by the seal plate 112 and the piston 108. The pressure chamber 132 is further defined by or bounded between the shaft 102, the seal 116, the piston 108, the mating seal 130, the seal plate 112, and the seal 128. An increase in hydraulic pressure in the pressure chamber 132 causes the piston 108 to move toward the clutch plate 106, forcing the clutch plate 106 against the backing plate 104 and engaging (or closing) the disconnect clutch assembly 100.

[0019] The shaft 102 includes a first end 134 disposed adjacent to the engine (not shown) and a second end 136 disposed adjacent to the transmission (not shown). The shaft 102 may include an axial channel 138 in fluid communication with the pressure chamber 132 to regulate the pressure therein. For example, the shaft 102 may include a radial channel (not shown) that passes through an outer diameter of the axial channel 138 and extends radially through the outer diameter of the shaft 102. The radial channel may be axially disposed between the piston 108 and the seal plate 112 such that the axial channel 138 is in fluid communication with the pressure chamber 132 via the radial channel. The axial channel 138 may extend axially from the second end 136 toward the first end 134. For example, the axial channel 138 may extend axially through the second end 136. That is, the axial channel 138 may be open at the second end 136. In such an embodiment, the axial channel 138 must be sealed to direct the fluid, for example, by applying the piston 108, to prevent the fluid from exiting the second end 136 of the shaft 102.

[0020] Piston 108 includes a second orifice 140 for introducing fluid into balance chamber 120. That is, second orifice 140 extends axially through piston 108 from pressure chamber 132 to balance chamber 120. In other words, pressure chamber 132 and balance chamber 120 may be in fluid communication with each other via second orifice 140. Pressure chamber 132 and balance chamber 120 may be sealed from each other except for second orifice 140.

[0021] The second orifice 140 may be configured to introduce fluid into the balance chamber 120 to hydraulically balance the piston 108 and provide cooling flow to the clutch plates 106. Hydraulically balancing the piston 108 means that the balance chamber 120 and the pressure chambers 132 disposed on either side of the piston 108 are both filled with fluid, for example, oil, thereby compensating for any dynamic pressure effects from the rotation of the piston 108, balance dam 110, shaft 102, etc., and improving controllability of the piston 108 during a clutch engagement event.

[0022] The second orifice 140 is disposed radially between the seal portion 116 and the bonded seal portion 118. The second orifice 140 is disposed radially outward of the elastic element 126. Specifically, the second orifice 140 is disposed closer to the bonded seal portion 118 than the elastic element 126. The second orifice 140 may have a diameter of, for example, 1 millimeter (mm). The second orifice 140 may include a countersink in at least one side of the piston 108.

[0023] The disconnect clutch assembly 100 includes a flow passage 142. The flow passage 142 enters the pressure chamber 132 through an axial channel 138, e.g., via a radial channel. The flow passage 142 is bounded in part by the piston 108 and the seal plate 112. Pressurized fluid may be supplied from the shaft 102 to the flow passage 142, which extends into the pressure chamber 132. That is, the axial channel 138 is in direct fluid communication with the pressure chamber 132. The piston 108 engages or closes the disconnect clutch assembly 100 in response to pressurization of a medium (e.g., a fluid such as oil) in the pressure chamber 132, e.g., by axially displacing the piston 108 relative to the clutch plate 106.

[0024] Additionally, flow path 142 includes, i.e., passes through, second orifice 140 into balance chamber 120. Flow path 142 is bounded in part by piston 108 and balance dam 110. Pressurized fluid may be supplied from pressure chamber 132 to balance chamber 120 by passing through second orifice 140, for example, to hydraulically balance piston 108. That is, axial channel 138 is in indirect fluid communication with balance chamber 120 via pressure chamber 132.

[0025] Additionally, the flow passage 142 exits the balance chamber 120 through the first orifice 114. The flow passage 142 is further bounded in part by the balance dam 110 and the backing plate 104. The flow passage 142 passes through the cooling flow orifices 124 and is routed, for example, between the clutch plates 106 to cool them. That is, pressurized fluid can be provided from the balance chamber 120 to cool the clutch plates 106 by passing through the first orifice 114 and then through the cooling flow orifices 124. The fluid passes between the clutch plates 106 and is returned to the shaft 102.

[0026] The pressure chamber 132 is in fluid communication with the balance chamber 120 and the clutch plates 106 via a flow passage 142. That is, the flow passage 142 provides fluid to engage the disconnect clutch assembly 100, fill the balance chamber 120, and cool the clutch plates 106. Providing fluid communication between the pressure chamber 132, the balance chamber 120, and the clutch plates 106 may reduce the complexity of the disconnect clutch assembly 100 by eliminating the need for two channels located in the shaft 102 that are configured to either provide fluid to engage the disconnect clutch assembly 100 or to provide fluid to fill the balance chamber 120 and cool the clutch plates 106.

[0027] While exemplary embodiments have been described above, these embodiments are not intended to describe all possible forms encompassed by the claims. The terms used herein are terms of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the present disclosure. As previously described, features of various embodiments can be combined to form further embodiments of the present disclosure that may not be explicitly described or illustrated. While various embodiments have been described as offering advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those skilled in the art will recognize that one or more features or characteristics may be compromised to achieve desired overall system attributes depending on the specific application and implementation. These attributes may include, but are not limited to, cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, maintainability, weight, manufacturability, ease of assembly, etc. Thus, to the extent that any embodiments are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics, these embodiments are not outside the scope of the present disclosure and may be desirable for particular applications. [Explanation of symbols]

[0028] 100 Disconnecting clutch assembly 102 Shaft 104 Backing Plate 106 Clutch plate 108 Piston 110 Balance Dam 112 Seal plate 114 Orifice 116 Seal part 118 Joint seal part 120 Balance Chamber 122 Clutch plate carrier 124 Cooling flow orifice 126 Elastic Elements 128 Seal part 130 Joint seal part 132 Pressure Chamber 134 End 136 End 138 Axial Channel 140 Orifice 142 Channel A center axis

Claims

1. 1. A clutch assembly comprising: A shaft, a balance dam sealed against the shaft; a seal plate axially spaced from the balance dam and sealed to the shaft; a piston sealed against the shaft and axially disposed between the balance dam and the seal plate, the piston including an orifice extending axially through the piston; a pressure chamber bounded in part by the piston and the seal plate, and a balance chamber bounded in part by the piston and the balance dam; The pressure chamber is in fluid communication with the balance chamber through the orifice.

2. 2. The clutch assembly of claim 1, wherein said piston is sealed against said balance dam and said seal plate.

3. 2. The clutch assembly of claim 1, wherein said balance dam is fixed to said shaft and said piston is axially slidable on said shaft.

4. 2. The clutch assembly of claim 1, wherein said pressure chamber is sealed from said balance chamber except for said orifice.

5. 2. The clutch assembly of claim 1, further comprising an elastic element disposed axially between the piston and the balance dam to bias the piston away from the balance dam, the orifice being disposed radially outward of the elastic element.

6. 6. The clutch assembly of claim 5, wherein the piston is sealed against the seal plate via a bonded seal, and the orifice is located radially closer to the bonded seal than to the resilient element.

7. 2. The clutch assembly of claim 1, wherein the balance dam includes a further orifice extending axially through the balance dam, the further orifice being disposed radially inward of the orifice.

8. The clutch assembly of claim 1 , wherein said shaft includes an axial channel in direct fluid communication with said pressure chamber.

9. The clutch assembly of claim 8 , wherein the axial channel is in indirect fluid communication with the balance chamber through the pressure chamber.

10. 9. The clutch assembly of claim 8, further comprising a flow passage configured to provide fluid to said pressure chamber, said flow passage passing through said axial channel and including a first portion bounded in part by a piston and said seal plate.

11. 11. The clutch assembly of claim 10, wherein the flow passage is further configured to provide fluid to the balance chamber, the flow passage including a second portion passing through the orifice and bounded in part by the piston and the balance dam.

12. a backing plate fixed to the shaft, the balance dam being axially disposed between the backing plate and the piston; a clutch plate carrier fixed to the backing plate and axially disposed between the backing plate and the balance dam; 2. The clutch assembly of claim 1, further comprising: a plurality of clutch plates supported by the clutch plate carrier, the piston being axially slidable on the shaft to clamp the plurality of clutch plates against the backing plate to close the clutch assembly.

13. 13. The clutch assembly of claim 12, wherein the balance dam includes an additional orifice extending axially through the balance dam and the clutch plate carrier includes a cooling flow orifice extending radially through the clutch plate carrier.

14. 14. The clutch assembly of claim 13, wherein the additional orifice is disposed radially inward of the orifice and the cooling flow orifice.

15. The clutch assembly of claim 13, wherein the cooling flow orifices are positioned to allow fluid to cool the plurality of clutch plates.

16. The clutch assembly of claim 13 , wherein the shaft includes an axial channel in direct fluid communication with the pressure chamber.

17. 17. The clutch assembly of claim 16, further comprising a flow passage configured to provide fluid to the pressure chamber, the flow passage passing through the axial channel and including a first portion bounded in part by the piston and the seal plate.

18. 18. The clutch assembly of claim 17, wherein the flow passage is further configured to provide fluid to the balance chamber, the flow passage including a second portion passing through the orifice and bounded in part by the piston and the balance dam.

19. 19. The clutch assembly of claim 18, wherein the flow passage is further configured to provide fluid for cooling the plurality of clutch plates, the flow passage including a third portion passing through the additional orifice and the cooling flow orifice and bounded in part by the balance dam and the backing plate.

20. The clutch assembly of claim 16, wherein the axial channel is in indirect fluid communication with the balance chamber through the pressure chamber.

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