The present disclosure generally relates to valve assemblies and, more particularly, to exhaust gas recirculation (EGR) valve assemblies.
In general, EGR valve assemblies are used to control the recirculation of exhaust gases through combustion chambers within internal combustion engines. Exhaust gas recirculation that is improperly controlled may result in air/fuel mixtures that are too rich or too lean for efficient combustion.
In one independent aspect, a valve assembly, such as an EGR valve assembly, may generally include a valve housing including a body with a wall defining a flow passage along a flow path between an inlet and an outlet, the valve housing further defining a bore communicating with the flow passage and extending transverse to the flow path; a shaft supported in the bore and extending into the flow passage; a flap supported on the shaft in the flow passage, the flap being movable relative to the flow passage between a closed position and an open position; and a sealing member projecting from the wall into the flow path, the sealing member having a sealing surface configured to interact with the flap in the closed position to inhibit gas flow through the flow passage, an opposite surface facing away from the sealing surface and tapering toward the wall, and a circumferential end surface proximate the bore, the end surface being tapered away from the bore.
In another independent aspect, a method of manufacturing a valve assembly, such as an EGR valve assembly, may be provided. The valve assembly may include a valve housing with a body having a wall defining a flow passage along a flow path between an inlet and an outlet, a flap supported in the flow passage for movement between a closed position and an open position, a first sealing member projecting from the wall into the flow path, the first sealing member having a first sealing surface configured to interact with a first portion of the flap in the closed position to inhibit gas flow through the flow passage, and a second sealing member projecting from the wall into the flow path, the second sealing member having a second sealing surface configured to interact with a second portion of the flap in the closed position to inhibit gas flow through the flow passage. The method may generally include supporting the flap in the flow passage with the first portion of the flap engaging the first sealing surface and the second portion of the flap engaging the second sealing surface; engaging, through the inlet, a first ram against a side of the first portion of the flap opposite the first sealing surface; engaging, through the outlet, a second ram against a side of the second portion of the flap opposite the second sealing surface; and simultaneously applying, with the first ram and the second ram, force to the flap to coin the first portion of the flap against the first sealing surface and to coin the second portion of the flap against the second sealing surface.
In yet another independent aspect, a valve assembly, such as an EGR valve assembly, may generally include a valve housing including a body with a wall defining a flow passage along a flow path between an inlet and an outlet; a shaft supported by the valve housing and extending into the flow passage, the shaft extending along and being pivotable about a shaft axis; a flap supported on the shaft in the flow passage, the flap being movable relative to the flow passage between a closed position, in which flow of gas through the flow passage is inhibited, and an open position; an actuator assembly including a drive shaft extending along and pivotable about a drive axis; and a spider assembly configured to drivingly connect the drive shaft and the shaft. The spider assembly may include a spider member defining a first slot facing toward the drive shaft and extending along a first slot axis and a second slot facing toward the shaft and extending along second slot axis, the second slot axis being transverse to the first slot axis, a first sliding member connectable to the drive shaft and positionable in the first slot, the first sliding member being configured to slide in the first slot and along the first slot axis, and a second sliding member connectable to the shaft and positionable in the second slot, the second sliding member being configured to slide in the second slot and along the second slot axis.
Other independent aspects of the disclosure may become apparent by consideration of the detailed description, claims and accompanying drawings.
Before any independent embodiments are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other independent embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
Use of “including” and “comprising” and variations thereof as used herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Use of “consisting of” and variations thereof as used herein is meant to encompass only the items listed thereafter and equivalents thereof. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings.
Relative terminology, such as, for example, “about”, “approximately”, “substantially”, etc., used in connection with a quantity or condition would be understood by those of ordinary skill to be inclusive of the stated value and has the meaning dictated by the context (for example, the term includes at least the degree of error associated with the measurement of, tolerances (e.g., manufacturing, assembly, use, etc.) associated with the particular value, etc.). Such terminology should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression “from about 2 to about 4” also discloses the range “from 2 to 4”. The relative terminology may refer to plus or minus a percentage (e.g., 1%, 5%, 10%or more) of an indicated value.
Also, the functionality described herein as being performed by one component may be performed by multiple components in a distributed manner. Likewise, functionality performed by multiple components may be consolidated and performed by a single component. Similarly, a component described as performing particular functionality may also perform additional functionality not described herein. For example, a device or structure that is “configured” in a certain way is configured in at least that way but may also be configured in ways that are not listed.
The embodiment(s) described below and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present disclosure. As such, it will be appreciated that variations and modifications to the elements and their configuration and/or arrangement exist within the spirit and scope of one or more independent aspects as described.
The valve assembly 10 includes a valve housing portion 14 defining a flow passage 18 through which gas flows along a flow path. A butterfly flap 22 is supported on a driven shaft 26 (at a flap end 27) for pivoting movement therewith between an open position, a closed position, in which gas flow is inhibited, and a plurality of intermediate flow positions. An opposite transmission end 28 of the driven shaft 26 (see
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Additionally, the inner surface 66 provides a surface against which the flap 22 is able to seal. With continued reference to
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In operation, exhaust gases flow through the inlet 70, along the flow passage 18, and through the outlet 74. When the flap 22 is in the open position and, more particularly, in a fully open position, the flow is at a maximum. The exhaust gases flow over the sealing ridges 86, 90, and flow around the flap 22 and around the driven shaft 26. When the flap 22 is in the closed position, the flap 22 engages the sealing surfaces 94, 106 to at least substantially block and prevent the flow of exhaust gases through the flow passage 18.
The exhaust gases may contain water vapor, particles, and other impurities. As exhaust gases flow through the flow passage 18, deposits, such as condensate, “coke”, “gunk”, soot, and other matter may form on the inner surface 66. If deposits form on the sealing ridges 86, 90, the flap 22, the driven shaft 26, the bore 62, etc., sealing efficiency and movement of the flap 22 and the shaft 26 may be inhibited. Sloped surfaces within the flow passage 18 (e.g., the opposite surfaces 102, 114, the tapered ends 115, 116, etc.) cause deposits to flow away from locations (e.g., the sealing surfaces 94, 106, the bore 62) where deposits may inhibit sealing efficiency.
In the manufacturing process, the flap 22 is supported on the shaft 26 in the flow passage 18 and engaged with the sealing surfaces 94, 106. A first ram 147 is inserted into the inlet 70 and pressed against a first side 150 of the flap 22 opposite the sealing surface 94, while a second ram 148 is inserted into the outlet 74 and pressed against a second side 154 of the flap 22 opposite the sealing surface 106. The rams 147, 148 apply force 155, 156 to the opposite sides 150, 154 of the flap 22 (e.g., on opposite sides of a driven shaft 26) to coin or cold forge the flap 22 against the first sealing surface 94 and against the second sealing surface 106. As a result, the flap 22 conforms to contours of the sealing surfaces 94, 106, and vice versa.
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Each force 155, 156 is greater than about 4,000 pound-force (lbf) and up to about 12,000 lbf. More particularly, each force is greater than about 7,000 lbf and up to about 9,000 lbf (e.g., about 8,000 lbf). In the illustrated process, the forces 155, 156 are substantially equal and are applied simultaneously. The forces 155, 156 are applied for at least one second (s) and up to about 20 s (e.g., in the illustrated embodiment, about 5 s).
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The electric motor 162 includes a pivoting drive shaft 170 defining a drive shaft axis A3. In some embodiments, the drive shaft axis A3 not be collinear with the driven shaft axis A2. A spider assembly 174 (see
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A spring bearing surface 246 is defined on an interior side of the second recess 242 (e.g., on a clockwise side of the second recess 242 when viewed in
The spring 194 interfaces between the spider member 190 and the valve housing portion 14 in order to pivotably bias the spider assembly 174 and, more specifically, the spider member 190, the driven bowtie 182, and the driven shaft 26, in a direction corresponding to the closed position of the flap 22. As shown in
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The spring holder 196 includes (see
A spring positioning projection 274 protrudes from the flange 266 in a direction opposite to the centering projections 270a, 270b, 270c. The spring positioning projection 274 is oriented at approximately 90° relative to the flange 266 and engages an inner surface of the spring 194 when the spring holder 196 is in position in the spider assembly 174 to position the spring 194 relative to the spring holder 196 and relative to the valve housing portion 14. An orienting projection 278 extends radially from the flange 266 and, as illustrated, is configured (e.g., sized, shaped, etc.) to fit within the second recess 242 of the valve housing portion 14 to orient the spring holder 196 relative to the valve housing portion 14.
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In operation of the valve assembly 10, control signals are provided (e.g., to the controller) to control the actuator assembly 34 to position the flap 22 in a desired position in the flow passage 18 for a desired flow of gas through the flow passage 18. The motor 162 pivots the drive shaft 170, causing pivoting movement of the drive bowtie 178 and the spider member 190 against the biasing force of the spring 194. Pivoting movement of the spider member 190 causes pivoting movement of the driven bowtie 182, the driven shaft 26, and the flap 22. The range of motion of the flap 22 is limited by the extent of the angle α1 and a width of the first protrusion 222.
As mentioned above, the driven shaft axis A2 and the drive shaft axis A3 may be misaligned. The spider assembly 174 is configured to transmit torque from the drive shaft 170 to the flap 22 despite a misalignment between the axes A2, A3. If the axes, A2, A3 are misaligned, as the drive bowtie 178 pivots, the drive bowtie 178 may simultaneously slide along the first slot 206. Similarly, as the spider member 190 pivots with the drive bowtie 178, the driven bowtie 182 pivots and may also simultaneously slide along the second slot 210. The sliding movement of the bowties 178, 182 may accommodate axial misalignment of the shafts 170, 26.
Manufacturing tolerances may exist between the drive and driven components. As a result, a certain amount of lash could exist within the spider assembly 174, which could inhibit shafts 170, 26 from rotating on a one-to-one basis at all times and at all rotational angles. In the illustrated construction, the spring 194 biases the components (e.g., to a position corresponding to the closed position of the flap 22) to compensate for the lash. In other constructions (not shown), the spider assembly 174 may be used in other shaft arrangements (e.g., between a different type of drive shaft and driven shaft) to, for example, accommodate misalignment of the shafts, take up lash, etc.
Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the invention as described above. The embodiment(s) described above and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present disclosure. As such, it will be appreciated that variations and modifications to the elements and their configuration and/or arrangement exist within the spirit and scope of one or more independent aspects as described.
One or more independent features and/or independent advantages of the invention may be set forth in the claims.
This application claims priority to pending U.S. Provisional Patent Application No. 63/485,725 filed on Feb. 17, 2023, the entire contents of which is incorporated herein by reference.
Number | Date | Country | |
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63485725 | Feb 2023 | US |