Title:
Crankshaft oil deflector fastening apparatus
Kind Code:
A1


Abstract:
An oil deflector assembly includes an oil deflector plate for attachment between a crankshaft and an oil pan. The oil deflector plate assembly further includes a plurality of nuts and washers rotatably captured and retained by the plate for attaching the plate with respect to an engine block. The captured nuts and washers are preassembled to the plate, thereby improving engine assembly efficiency. In a preferred embodiment, the threaded hole of each nut is tapered to improve alignment with a corresponding threaded stud, and the washer includes a tapered hole to facilitate washer deformation thereby to lock the washer against the plate.



Inventors:
Rice, Alan E. (New Baltimore, MI, US)
Pannu, Manmeet S. (Sterling Heights, MI, US)
Application Number:
10/872122
Publication Date:
12/22/2005
Filing Date:
06/17/2004
Primary Class:
Other Classes:
123/196R
International Classes:
F01M11/00; (IPC1-7): F01M11/00
View Patent Images:
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Primary Examiner:
KAMEN, NOAH P
Attorney, Agent or Firm:
KARL F. BARR JR. (Detroit, MI, US)
Claims:
1. An oil deflector assembly for an engine crankcase to which a plurality of threaded fasteners is operatively connected, the oil deflector assembly comprising: a plate defining a plurality of apertures; and a plurality of nuts each being rotatably secured to the plate in a respective one of the plurality of apertures prior to engagement with a respective one of the threaded fasteners.

2. The oil deflector assembly of claim 1, wherein each of the plurality of nuts includes a portion that extends through the corresponding aperture, and wherein the oil deflector assembly further includes a plurality of washers each being operatively connected to one of the nuts.

3. The oil deflector assembly of claim 2, wherein each of the plurality of nuts defines a threaded hole for engagement with a respective one of the threaded fasteners, and wherein the hole is tapered.

4. The oil deflector assembly of claim 2, wherein each of the plurality of washers defines a tapered hole.

5. An engine comprising: an engine block; a crankshaft rotatably supported with respect to the engine block; a plurality of bearing caps mounted with respect to the engine block; a plurality of threaded studs mounted with respect to the bearing caps and arranged in a predetermined spatial relationship with respect to one another; an oil deflector plate defining a plurality of apertures in the same predetermined spatial relationship with respect to one another as the threaded studs; a plurality of nuts, each including a main body portion on a first side of the plate and a neck extending through a respective one of the plurality of apertures; a plurality of washers, each being positioned on a second side of the plate opposite from the first side; wherein each of the nuts defines a threaded nut hole that is tapered at one end for receiving a respective one of the threaded studs; and wherein each of the washers defines a tapered washer hole through which a portion of a respective nut extends to operatively connect the nut to the washer prior to attachment of said nuts to said threaded studs.

6. A method of assembling an oil deflector assembly, the method comprising: providing an oil deflector plate having a plurality of apertures; providing a plurality of nuts; providing a plurality of washers; inserting a portion of each nut into a respective one of said plurality of apertures; and attaching each washer to said portion of a respective nut to secure the respective nut and washer to the oil deflector plate while allowing each nut and washer to rotate with respect to the oil deflector plate.

7. The method of claim 6, wherein said attaching each washer to said portion of a respective nut includes crimping the respective nut to the corresponding washer.

8. The method of claim 6, wherein the nut defines a tapered nut hole having a wide end; wherein the washer includes a tapered washer hole having a wide end; and wherein the method further comprises attaching the oil deflector plate with respect to an engine block having a plurality of threaded studs mounted thereto, said attaching the oil deflector plate with respect to an engine block including (1) positioning the oil deflector plate with respect to the engine block such that each of said plurality of threaded studs enters the wide end of a respective nut hole and the wide end of a respective washer hole, and (2) turning each of the plurality of nuts to engage the respective threaded stud so that each nut exerts a first force on the corresponding washer and a reaction surface exerts a second, opposite, reaction force on the washer that is radially outward from the first force to create a bending moment that causes the periphery of the washer to engage a surface of the plate and thereby resist relative rotation of the washer with respect to the plate.

Description:

TECHNICAL FIELD

This invention relates to engine crankcase oil deflectors that have captured rotatable nuts and washers.

BACKGROUND OF THE INVENTION

A typical oil pan is disposed beneath a cylinder block and a crankshaft, and is configured to receive oil that drains or is otherwise exhausted from the cylinder block, crankshaft, and/or main bearings that support the crankshaft. The oil collects in a sump of the oil pan, and is then pumped from a sump pick-up location into a lubrication system associated with the engine.

Rotation of the crankshaft causes air to rotate with the crankshaft. This rotating air may be referred to as “crankshaft windage.” During operation of the engine, some oil that would otherwise drain into the oil pan may instead become entrained in the crankshaft windage. Accordingly, some vehicle engines include an oil deflector, also sometimes referred to as a “windage tray” and an “oil scraper,” to separate the crankshaft from the oil pan in order to reduce or eliminate the effects of crankshaft rotation on oil stored or collected in the oil pan.

Traditional oil deflectors consist of a louvered tray mounted to the main crankshaft bearing cap bolts. The oil deflector removes oil from the crankshaft windage, which allows the oil to drain back to the sump and be recirculated through the engine's lubrication system.

SUMMARY OF THE INVENTION

An oil deflector assembly for an engine is provided that facilitates rapid and efficient attachment of the oil deflector assembly with respect to an engine block. The oil deflector assembly includes a formed plate that defines a plurality of apertures. The oil deflector assembly also comprises a plurality of fastening apparatuses, each having a washer and a nut that is engageable with a corresponding threaded fastener mounted with respect to the engine block. A portion of each fastening apparatus extends through a respective aperture, and the plate structure defining the respective aperture rotatably captures and retains the fastening apparatus.

The captured fastening apparatuses are preassembled to the oil deflector plate, preferably by placing the nut and washer feeder and press tools, programmed to feed and crimp a specified pattern of nuts, inline with the deflector plate's progressive die. Accordingly, the oil deflector of the invention reduces engine assembly time by eliminating the need for an engine assembler to hand start loose nuts on each of the threaded fasteners. Correspondingly, the oil deflector of the invention also eliminates guards and other devices used to prevent loose nuts and washers from dropping into the engine during hand starting loose nuts.

In a preferred embodiment, the inner diameter of each nut includes a tapered portion to act as an alignment feature that facilitates alignment of the nut with a corresponding threaded fastener when the plate is positioned for attachment with respect to the engine block. The taper thus further simplifies attachment of the oil deflector to the engine block by reducing or eliminating the need to individually align each of the plurality of nuts for engagement with a corresponding threaded fastener.

In the preferred embodiment, each washer includes a geometric feature that allows the fastening apparatuses to lock when tightened and to return to a free-spinning state when loosened. More specifically, each washer defines a hole through which a respective threaded fastener extends to engage the corresponding nut. The hole is tapered so that the diameter of the hole is greatest at the edge that receives the threaded fastener. When the nut is tightened on the threaded fastener, the taper of the hole facilitates deformation of the washer such that the washer engages a surface of the oil deflector plate to resist relative rotation between the fastening apparatus and the plate. This allows for error-proofing in a multiple-spindle tightening tool in that a nut that achieves an unusually high torque in the first revolutions of tightening by the tool will trigger all of the tool spindles to stop.

The above features and advantages, and other features and advantages, of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic, partially exploded perspective view of an engine including an engine block rotatably supporting a crankshaft and an oil deflector assembly; and

FIG. 2 is a schematic, partial cutaway side view of a fastening apparatus on the oil deflector assembly of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, an engine 10 includes an engine block 14 that rotatably supports a crankshaft 18. The engine block 14 defines the upper portion of a crankcase 22. The block 14 has a lower mounting surface 26 that is adapted to connect with a lower crankcase member (not shown) carrying an oil pan (not shown). The engine block 14 includes transverse webs 28 with attached bearing caps 30. The bearing caps 30 include aligned openings that receive bearings (not shown) supporting the journals (not shown) of the crankshaft 18. Threaded fasteners such as mounting studs 32 are affixed on the bottoms of the bearing caps 30 so as to be operatively connected to the engine block 14. The mounting studs 32 are arranged in a predetermined spatial relationship with one another.

A crankshaft oil deflector assembly 34 includes an oil deflector plate 36. The plate 36 is stamped, and includes elongated slots 38 for the drainage of oil into the oil pan (not shown). The plate 36 also defines a plurality of apertures 40 having the same predetermined spatial relationship with one another as the mounting studs 32. Accordingly, when the oil deflector assembly 34 is sufficiently positioned with respect to the engine block 14, each of the plurality of apertures 40 aligns with a corresponding mounting stud 32. The oil deflector assembly 34 includes a plurality of fastening apparatuses 44. Each fastening apparatus 44 includes a nut 48 and a washer 52 to hold the oil deflector plate 36 against mounting nuts 56 on the mounting studs 32. Each fastening apparatus 44 partially extends through a respective aperture 40 and is rotatably retained and captured by the structure of the plate forming the respective aperture 40. The engine block 14 is depicted in a position wherein the open crankcase cavity formed by the engine block 14 faces upward for attachment of the oil deflector assembly 34 with respect to the block 14.

Referring to FIG. 2, wherein like reference numbers refer to like components from FIG. 1, one of the fastening apparatuses 44 is schematically depicted in a captured state within one of the apertures 40 of plate 36. Each aperture 40 and fastening element 44 in the oil deflector assembly 34 is substantially identical. The nut 48 defines a threaded hole 60 for receiving and engaging one of the mounting studs shown at 32 in FIG. 1. More specifically, the hole is defined by a main body portion 64 and a neck 68. The neck 68 is generally cylindrical, and extends from the main body portion 64 through the aperture 40. The nut 48 includes an extension 70 from the neck 68 that defines a tapered portion 72 of the hole 60. The tapered portion 72 is configured so that the diameter of the hole 60 at the lead end of the nut 48 at which a mounting stud is received is larger than the diameter of the hole 60 at the main body portion 64. Accordingly, the tapered portion 72 functions as an alignment feature for facilitating the alignment of a corresponding stud with the nut during attachment of the oil deflector plate 36 to the engine.

The washer 52 includes a hole 74 at least partially defined by frustoconical surface 75 so that hole 74 has a first diameter 76 and a second diameter 80. The first diameter 76 is smaller than the second diameter 80, and is closer to the plate 36 and the main body portion 64 of the nut 48 than is the second diameter 80. During assembly of the oil deflector assembly 34, the extension 70 is inserted into the hole 74 and is crimped so that outer surface 82 of the extension (shown crimped in phantom at 70′) abuts surface 75 and extends radially outward from the first diameter 76, thereby connecting the nut 48 and the washer 52 by physical part interference.

The fastening apparatus 44, i.e., nut 48 and washer 52, is rotatably captured by the plate 36. That is, the plate 36 retains the nut and washer while allowing their rotation about axis A. More specifically, the plate 36 includes a first surface 84 forming one side of the plate, a second surface 88 forming an opposite side of the plate, and an annular surface 90 defining the aperture 40. The annular surface 90 restricts lateral, i.e., radial, movement of the fastening apparatus 44 by physical part interference with the neck 68. The first surface 84 restricts axial movement of the fastening apparatus in a first direction by physical part interference with nut surface 94 defined by the main body portion 64. The second surface 88 restricts axial movement of the fastening apparatus in a second direction opposite the first direction by physical part interference with the washer surface 98. There is adequate clearance between the surfaces 84, 88, 90 of the plate 36 and the fastening apparatus 44 to permit the nut 48 to spin freely about axis A.

As nut 48 is rotated and engages a mounting stud, a force F1 is exerted by a lip 100 of neck 68 on surface 98 of the washer 52. An opposite reaction force F2 radially outward from force F1 is exerted on surface 102 of the washer by a reaction surface (shown at 101 in FIG. 1) formed by a corresponding mounting nut (shown at 56 in FIG. 1). Forces F1 and F2 generate a bending moment that causes the washer to deform into a concave shape. The taper of hole 74 facilitates deformation of the washer (partially shown in a deformed state in phantom at 52′) as a result of the bending moment so that surface 98 at the periphery 106 of washer 52 contacts surface 88 of the plate, thereby resisting rotation of the nut relative to the plate and, accordingly, locking the fastening element. The fastening apparatus 44 thus clamps the plate 36 to the engine assembly at, for example, a tightening specification of 25 Nm, and returns to a free-spinning state when loosened.

While the best mode for carrying out the invention has been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.