Dual seal for supercharger

Abstract

A sealing arrangement (116) within a bearing plate (110) of a supercharger (104) is configured to withstand pressurized air flow. The sealing arrangement includes an air seal (120) and a separate oil seal (122). The oil seal may be pressed into the air seal using an axial retainer (124). The axial retainer may bias the oil seal against the air seal. The air seal may include multiple sealing lips. The oil seal also may include multiple sealing lips. At least one of the sealing lips of the oil seal may extend away from the air seal while another sealing lip of the oil seal extends towards the air seal.

Description

Attorney Docket No. 15720.1221WOU1DUAL SEAL FOR SUPERCHARGERCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is being filed as a PCT application and claims the benefit of U.S. provisional application No. 63 / 779,560, filed March 28, 2025, titled DUAL SEAL FOR SUPERCHARGER, the disclosure of which is hereby incorporated herein by reference in its entirety.BACKGROUND

[0002] Dual compression engine boosting systems utilizing both a turbocharger and a supercharger are known. Superchargers and turbochargers are forced induction systems that increase engine power by compressing air before it enters the combustion chamber, thereby allowing more air and fuel to be burned during each cycle. Superchargers are mechanically driven by the engine's crankshaft through a belt or chain system. Turbochargers, in contrast, are powered by the engine's exhaust gases. Air compressed by the turbocharger may enter the supercharger for further compression before passing to the engine.SUMMARY

[0003] A supercharger includes a rotary chamber through which air flows. A sealing arrangement is disposed at a bearing plate bounding the rotary chamber. A sealing arrangement inhibits leaks of air from the rotary chamber past the bearing plate (e.g., into a gear chamber of the supercharger). In certain examples, the air passing through the rotary chamber is pressurized by a turbocharger upstream of the supercharger. Accordingly, the sealing arrangement is configured to combat leaks of pressurized air through the bearing plate.

[0004] In certain implementations, the sealing arrangement includes both an air seal and a separate oil seal disposed about a drive shaft extending through the bearing plate. In certain examples, the air seal includes one or more sealing lips extending in a first direction along the drive shaft and the oil seal includes a sealing lip extending in a second direction along the drive shaft. In certain examples, the second direction is opposite the first direction.

[0005] In certain examples, the oil seal also includes a sealing lip extending in the first direction along the drive shaft.

[0006] In certain implementations, the sealing arrangement includes an axial retainer to secure the air seal and the oil seal in position along the drive shaft. In certain examples, the oilAttorney Docket No. 15720.1221WOU1seal is disposed between the air seal and the axial retainer. In certain examples, the axial retainer abuts the oil seal, which abuts the air seal.

[0007] In certain examples, the axial retainer includes flanges extending radially outwardly from a ring-shaped body. In certain examples, the ring-shaped body has a frusto-conical shape. In certain examples, the flanges extend radially outwardly from a wider end of the ring-shaped body and are angled towards the narrower end.

[0008] A variety of additional inventive aspects will be set forth in the description that follows. The inventive aspects can relate to individual features and to combinations of features. It is to be understood that both the forgoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the embodiments disclosed herein are based.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The accompanying drawings, which are incorporated in and constitute a part of the description, illustrate several aspects of the present disclosure. A brief description of the drawings is as follows:

[0010] FIG. l is a schematic diagram of an air intake system for an engine.

[0011] FIG. 2 illustrates an example rotary group disposed within a body of an example supercharger, the rotary group being configured in accordance with the principles of the present disclosure.

[0012] FIG. 3 is a longitudinal cross-section of the rotary group of FIG. 2 showing sealing arrangements disposed within bearing plate passages.

[0013] FIG. 4 is an enlarged view of a portion of FIG. 3.

[0014] FIG. 5 shows an example bearing plate passage of FIG. 4 with the drive shaft and sealing arrangement omitted for ease in viewing the passage body.

[0015] FIG. 6 shows an example sealing arrangement suitable for use with the rotary group of FIG. 2, the sealing arrangement including an air seal, an oil seal, and an axial retainer shown exploded from each other for ease in viewing.

[0016] FIG. 7 shows a cross-section of each of the components of the sealing arrangement of FIG. 6.Attorney Docket No. 15720.1221WOU1DETAILED DESCRIPTION

[0017] Reference will now be made in detail to exemplary aspects of the present disclosure that are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

[0018] A prime mover (e.g., engine) 102 of a vehicle often includes an air intake system 100 for supplying air to an intake of the prime mover 102. In certain implementations, the air intake system 100 includes a supercharger 104 to supply compressed air to the engine 102 (a diesel combustion engine, a hydrogen engine, etc.). The supercharger 104 receives air at an air intake 103, compresses the air using a rotating group 108, and directs the compressed air to an outlet 105 leading to the engine 102. In certain examples, a turbocharger 106 may be provided upstream of the supercharger 104 to further compress the air. In such examples, the air entering the intake 103 of the supercharger 104 is already compressed (i.e., pressurized).

[0019] As shown in FIG. 2, an example supercharger 104 includes a rotating group 108 mounted within a supercharger body 109. The rotating group 108 includes one or more drive shafts 112 extending through a bearing plate 110. In certain examples, the bearing plate 110 divides the housing 109 of the supercharger 104 into a rotary chamber 111 and a gear chamber 115. In the example shown, two drive shafts 112a, 112b are mounted in parallel within the rotary chamber 111 and extend through the bearing plate 110. Each drive shaft 112 carries a respective rotor 114 (e.g., rotor 114a and rotor 114b) that turn along rotary axes R towards each other to drive air through the rotary chamber 111 from the air intake 103 to the outlet 105. Gears of the drive shafts 112 may be lubricated within the gear chamber 115.

[0020] A sealing arrangement 116 is disposed at the bearing plate 110. The sealing arrangement 116 inhibits leaks of air from the rotary chamber 111 past the bearing plate 110 (e.g., into the gear chamber 115). In certain examples, the air passing through the rotary chamber 111 is pressurized by the turbocharger 106 upstream of the supercharger 104. Accordingly, the sealing arrangement 116 is configured to combat leaks of pressurized air through the bearing plate 110.

[0021] In certain implementations, the bearing plate 110 defines a passage 118 in which the sealing arrangement 116 is disposed. The passage 118 extends from a first open end 130 to a second open end 132 at the rotary chamber 111. In certain examples, the first open end 130 is larger (e.g., has a larger cross-dimension) than the second open end 132. In an example, the second open end 132 is sized to fit around the drive shaft 112 with just enough clearance to allow rotation of the drive shaft 112 within the second open end 132. In some examples, theAttorney Docket No. 15720.1221WOU1passage 118 tapers radially inwardly between the first and second open ends 130, 132. In other examples, the passage 118 steps radially inwardly from the first open end 130 to the second open end 132 (e.g., see FIG. 5). For example, the passage 118 may step inwardly to provide a stop surface for various components of the sealing arrangement 116.

[0022] In certain implementations, a respective sealing arrangement 116 is disposed about each drive shaft 112. For example, in FIG. 3, a first sealing arrangement 116a is disposed about the first drive shaft 112a and a second sealing arrangement 116b is disposed about the second drive shaft 112b. In certain examples, the bearing plate 110 defines a respective passage 118 for each drive shaft 112 and a respective sealing arrangement 116 is disposed within each passage 118. For example, in FIG. 3, the first sealing arrangement 116a is disposed in a first passage 118a of the bearing plate 110 and the second sealing arrangement 116b is disposed in a second passage 118b of the bearing plate 110. In certain examples, the first and second sealing arrangements 116a, 116b are substantially identical to each other. In certain examples, the first sealing arrangement 116a is a different size from the second sealing arrangement 116b.

[0023] As shown in FIGS. 4, 6, and 7, an example sealing arrangement 116 includes both an air seal 120 and a separate oil seal 122. In certain implementations, an axial retainer 124 holds the oil seal 122 and / or the air seal 120 in position as will be described in more detail herein. The air seal 120 is disposed within the passage 118 between the second open end 132 and the oil seal 122. In certain examples, the air seal 120 abuts against a first step surface 134 at the second open end 132 (e.g., see FIG. 4). The oil seal 122 is disposed within the passage 118 between the air seal 120 and the axial retainer 124. In certain examples, the oil seal 122 abuts against the air seal 120 (e.g., see FIG. 4). In certain examples, the oil seal 122 may contact a second step surface 136 at an intermediate location along the passage 118. In certain examples, the axial retainer 124 abuts against the oil seal 122. In certain examples, a ball bearing 139 for the drive shaft 112 seats within the passage 118 at the first open end 130 to define a sealing chamber 140 within the passage 118. In certain examples, the ball bearing 139 abuts against a third step surface 138 at an intermediate location along the passage 118. In certain examples, the ball bearing 139 is spaced from the axial retainer 124.

[0024] In certain implementations, the air seal 120 includes a body 142 configured to fit around the drive shaft 112. For example, the body 142 may be ring shaped and define a central passage 144 through which the drive shaft 112 extends. One or more sealing lips 146 extend from the body 142 into the central passage 144. The sealing lips 146 are configured to contact the drive shaft 112 to inhibit air flow through the passage 118. In certain examples, the sealingAttorney Docket No. 15720.1221WOU1lips 146 extend in a first direction along the drive shaft 112 towards the rotary chamber 111. In certain examples, the first step surface 134 of the passage 118 defines a chamfer 135 that defines a space into which one of the sealing lips 146 extends (e.g., see FIG. 4). In certain examples, the air seal 120 also includes a sealing surface 148 configured to contact an inner surface of the passage 118. In certain examples, the body 142 is formed of a different material from the sealing lips 146. For example, the body 142 may be formed of a stiffer or more rigid material than sealing lips 146. In an example, the body 142 is formed of metal while the sealing lips 146 are formed of rubber or plastic (e.g., polytetrafluoroethylene). In certain examples, the sealing surface 148 includes a sealant coated over a metal case.

[0025] In certain implementations, the oil seal 122 includes a body 150 configured to fit around the drive shaft 112. For example, the body 150 may be ring shaped and define a central passage 152 through which the drive shaft 112 extends. One or more sealing lips 154, 156 extend from the body 150 into the central passage 152. In certain examples, the central passages 144, 152 of the air seal 120 and the oil seal 124 align with each other along the respective rotation axis R. In certain examples, the oil seal 122 also includes a sealing surface 158 configured to contact an inner surface of the passage 118. In certain examples, the body 150 is formed of a different material from the sealing lips 154, 156 and sealing surface 158. For example, the body 150 may be formed of a stiffer or more rigid material than the sealing lips 154, 156. In an example, the body 150 is formed of metal, the sealing lip 154 is formed of rubber, and the sealing lip 156 is formed of plastic (e.g., polytetrafluoroethylene). In an example, the sealing surface 158 is formed of rubber.

[0026] In certain examples, a first sealing lip 154 of the oil seal 122 extends in the first direction along the drive shaft 112 towards the rotary chamber 111. In certain examples, a second sealing lip 156 of the oil seal 122 extends in a second direction away from the rotary chamber 111. In an example, the second direction is opposite the first direction. In some examples, the first sealing lip 154 is substantially the same as the sealing lips 146 of the air seal 120. In other examples, however, the first sealing lip 154 is formed of a different material from the sealing lips 146 of the air seal 120. In certain implementations, the first sealing lip 154 of the oil seal 122 inhibits the passage of debris (e.g., dust) through the sealing chamber 140. In certain examples, the first sealing lip 154 contacts the drive shaft 112 with less pressure than the sealing lips 146. In certain examples, the first sealing lip 154 does not contact the drive shaft 112. In certain examples, the second sealing lip 156 includes a textured surface thatAttorney Docket No. 15720.1221WOU1contacts the drive shaft 112. In certain examples, the second sealing lip 156 is longer than the first sealing lip 154.

[0027] In certain implementations, the oil seal 122 is larger than the air seal 120. In certain implementations, the air seal 120 defines a first abutment surface 145 and the oil seal 122 defines a second abutment surface 155. The second abutment surface 155 of the oil seal 122 contacts the first abutment surface 145 of the air seal 120 when the sealing arrangement 116 is disposed within the passage 118. In certain examples, the oil seal 122 is pressed against the air seal 120 by the axial retainer 124. In certain examples, the oil seal 122 is biased (e.g., spring-biased) against the air seal 120 by the axial retainer 124.

[0028] In certain implementations, the axial retainer 124 includes a body 160 defining a central passage 162. In certain examples, one or more flanges 164 extend radially outwardly from the body 160. The flanges 164 are circumferentially spaced along an exterior of the body 160. In certain examples, the body 160 has a depth D that extends along the respective rotation axis R from a first end 161 to a second end 163. The body 160 tapers radially outwardly as the body 160 extends from the first end 161 to the second end 163. In certain examples, the body 160 has a frusto-conical shape. In certain examples, the flanges 164 extend radially outwardly from a second end 163 of the body 160. In certain examples, the flanges 164 are angled towards the first end 161 as the flanges 164 extend radially outwardly from the body 160. In certain examples, the tips of the flanges 164 contact the inner surface of the passage 118 defined in the bearing plate 110. In certain examples, the second end 163 of the body 160 abuts the oil seal 122 when the axial retainer 124 is mounted within the passage 118.

[0029] Having described the preferred aspects and implementations of the present disclosure, modifications and equivalents of the disclosed concepts may readily occur to one skilled in the art. However, it is intended that such modifications and equivalents be included within the scope of the claims which are appended hereto.

Claims

Attorney Docket No. 15720.1221WOU1What is claimed is:

1. A rotating group for a supercharger comprising:a bearing plate defining first and second passages;first and second drive shafts extending through the first and second passages of the bearing plate; anda sealing arrangement disposed within the first passage, the sealing arrangement including an oil seal, an air seal that is a separate part from the oil seal, and an axial retainer mounted over the first drive shaft, the oil seal being disposed between the air seal and the axial retainer.

2. The rotating group of claim 1, wherein the axial retainer including a ring with radially outwardly extending flanges, the flanges being angled away from the oil seal.

3. The rotating group of claim 1, wherein the first passage radially expands outwardly as the first passage extends from a first open end to a second open end, wherein the air seal is disposed at the first open end, wherein the oil seals abuts the air seal, and wherein the axial retainer abuts the oil seal.

4. The rotating group of claim 3, wherein the oil seal has a greater radial diameter than the air seal.

5. The rotating group of any of claims 1-4, wherein the air seal includes a plurality of sealing lips extending away from the oil seal.

6. The rotating group of any of claims 1-5, wherein the oil seal includes a first sealing lip extending towards the axial retainer.

7. The rotating group of claim 6, wherein the oil seal includes a second sealing lip extending towards the air seal.

8. The rotating group of claim 7, wherein the second sealing lip of the oil seal is formed of a different material from the sealing lips of the air seal.Attorney Docket No. 15720.1221WOU19. The rotating group of claim 3, wherein a ball bearing closes the first passage at the second open end, the ball bearing being spaced from the axial retainer.

10. The rotating group of claim 3, wherein the air seal abuts against a first step surface at the first end of the first passage; and wherein the oil seal contacts a second step surface at an intermediate location along the first passage.

11. A sealing arrangement to seal between an air side and a gear side of a supercharger, the sealing arrangement comprising:an air seal including a first main body defining a first center passage, the air seal also including a plurality of sealing lips extending radially into the first center passage from the first main body;an oil seal that is a separate part from the air seal, the oil seal including a second main body defining a second center passage, the oil seal also including a first sealing lip extending into the second center passage in a first direction and a second sealing lip extending into the second center passage in a second direction that is different from the first direction; and an axial retainer including a ring-shaped body and a plurality of flanges extending radially outwardly from the ring-shaped body, the flanges extending away from the oil seal.

12. The sealing arrangement of claim 11, wherein the plurality of sealing lips of the air seal includes two sealing lips extending in a common direction.

13. The sealing arrangement of claim 12, wherein the common direction is away from the oil seal.

14. The sealing arrangement of claim 11, wherein the first direction is towards the axial retainer and the second direction is towards the air seal.

15. The sealing arrangement of claim 11, wherein the ring-shaped body of the axial retainer has a depth that extends from a first end to a second end, the ring-shaped body tapering radially outwardly as the body extends from the first end to the second end.Attorney Docket No. 15720.1221WOU116. The sealing arrangement of claim 15, wherein the second end of the ring-shaped body abuts the oil seal.

17. The sealing arrangement of claim 15, wherein the ring-shaped body has a frusto-conical shape.

18. A method of sealing a rotary cavity of a supercharger at a bearing plate, the method comprising:inserting an air seal into a passage defined in the bearing plate until the air seal abuts a recessed wall within the passage;inserting an oil seal into the passage until the oil seal abuts the air seal; and inserting an axial retainer into the passage until the axial retainer abuts the oil seal to retain the air seal and the oil seal within the passage.

19. The method of claim 18, wherein inserting the axial retainer into the passage until the axial retainer abuts the oil seal comprises inserting the axial retainer into the passage until a ring-shaped body of the axial retainer abuts the oil seal and outward flanges of the axial retainer abut an inner surface of the passage.

20. The method of claim 18, further comprising inserting a ball bearing into the passage, wherein the ball bearing remains spaced from the axial retainer.

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