CA1230246A - Splined power transmission member - Google Patents

Abstract

ABSTRACT

In pressure forming splines or teeth in the sleeve of a clutch hub and the like, a rotatable toothed mandrel and a pair of sliding toothed racks are offset relative to one another such that when the sleeve of the clutch hub blank is placed on the mandrel, a ring-shaped lip portion of the sleeve adjacent the open sleeve end is not intermeshed between the mandrel teeth and rack teeth and thus is not splined and such that a transition region between the cylindrical oil seal surface and the sleeve is splined. The clutch hub thus includes splines on the sleeve terminating short of the open sleeve end in an unsplined ring-shaped lip portion and extending at the other end contiguous with splines formed in the transition region between the oil seal surface and sleeve. A clutch hub can thereby be manufactured having, in combination, a longitudinal tooth taper (bellmouth) within required close tolerances, e.g., within .010 inch, preferably within .005 inch, and an oil seal surface with roundness within required close tolerances, e.g., within .005 inch.

Description

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The present invention relates to a cup-shaped power transmission member having splinted elements formed thereon.

This is a division of cop ending Canadian Patent Application Serial No. 455,656, filed June 1, 1984.

The manufacture of power transmission members, to which this invention relates, has utilized a pair of slid able toothed racks and a rotatable toothed mandrel to develop the tooth form in the periphery of an annular or tubular workups.
A machine has been provided for rotatable supporting the mandrel between the pair of toothed racks which are mounted for sliding motion past opposite sides of the mandrel on slide members.

The McCardell US. Patent 3,214,751 issued Nov.

2, 1965 of common assignee herewith discloses a machine of this type having a rotatable cylindrical mandrel and a pair of tooth forming racks disposed on opposite diametrical sides of the mandrel and slid able in opposite directions against a tubular workups on the mandrel. A smooth (not toothed) mandrel is employed since tooth elements are to be formed on the outside of the tubular workups.

The Kelp US. Patent 3,982,415 issued Sept. 28, 1978 describes an apparatus for splinting a cup-shaped power transmission member wherein a pair of slid able tooth forming racks are employed in conjunction with a hollow, toothed mandrel supported rotatable at opposite open ends by first and second arbors with the annular end wall of the Jo j j.

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cup-shaped member engaged against the end of the mandrel.
The Kelp US. Patent 4,028,922 issued June 14, 1977 discloses a somewhat similar apparatus adapted for splinting a cup-shaped power transmission member wherein the hollow mandrel is affixed to the machine head stock spindle and the open sleeve of a cup-shaped work part is slid onto the free mandrel end. The sleeve of the work part is splinted along its length to the open end where axial depressions may be formed by the racks. The rack teeth forming the depressions are said to support the open end during splinting to reduce out of roundness thereof.
The Jungesjo US. Patent 4,155,237 issued May 22, 1979 also discloses a splinting machine including a pair of slid able tooth forming racks and a hollow, toothed mandrel.
The machine further includes a workups unloading member extending from the head stock spindle side of the machine through the hollow mandrel to engage a splinted work part, a slid able loading member on the tail stock side of the machine including a work part clamp to hold the work part on the end of the mandrel during splinting and rotatable with the mandrel for this purpose, a rotatable indexer mechanism with U-shaped work part retainers to feed individual parts between the loader and mandrel, and a guide tube between the loader and mandrel for guiding workups movement toward and away from the mandrel.
A splinting machine is also described in the Hooker US. Patent 1,510,889 issued Oct. 7, 1924. In this patent, a cup-shaped sheet metal blank is mounted on a rotatable toothed mandrel with the mandrel received in the open sleeve of the blank and the end wall of the blank engaged against the end of the mandrel by a threaded nut. A hub or rack with gear teeth thereon is mounted such that it can be reciprocated and rotated relative to the mandrel synchronously therewith to intermesh the teeth of the mandrel and hub with the sleeve of the blank there between.

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- 3 - ~3~6 And, the Lindell US. Patent 3,473,211 issued Oct. 21, 1969 illustrates a machine for rolling internal teeth in the sleeve of a cup-shaped sheet metal power transmission member while the sleeve is supported and clamped on a stationary toothed mandrel. A set of no-valving rollers engages the exterior surface of the sleeve to roll the sleeve into the mandrel teeth to form gear type teeth. Also see the McCardell US. Patent 3,062,077 issued Nov. 6, 1967 for the pressure forming of internal teeth on a work part.

The corrugation of tubular or cup-shaped blanks to simultaneously form internal and external tooth-like profiles by a rolling process employing a rotatable mounted toothed mandrel and a pair of rotating dies is known as shown, for example, in the Mason US. Patent 76,220 issued March 31, 1867, the Greece et at. US. Patent 3,407,638 issued Oct. 29, 1968, the Kiplinger US. Patent 3,630,058 issued Dec. 38, 1971 and the Anderson US. Patent 4,045,988 issued Sept. 6, 1977.

However, to-date prior art workers have had dip-faculty using the types of machines and methods described hereinabove in manufacturing a splinted cup-shaped power transmission member, such as a clutch hub, within the well known six or eight sigma tolerance which includes total part print tolerances. In particular, prior art workers have had difficulty with respect to the axially extending splints or teeth on the sleeve portion and especially in meeting the specific tolerance limiting taper of the splints along the longitudinal axis of the sleeve prescribed by users of the parts, such as automobile manufacturers. This problem has frequently been referred to as "bell mouthing" of the sleeve characterized by an outward tapering of the splinted sleeve in a longitudinal or axial direction from the annular end wall toward the open end of the sleeve. A typical tolerance for "bell mouthing" has been set as .016 inch for a particular clutch hub for power transmissions. Furthermore, it has been difficult to provide the desired longitudinal so/ .-2302~6 tooth tolerance (bell mouth tolerance) and at the same time maintain the proper roundness tolerance for the cylindrical oil seal surface or sleeve of the clutch hub. A typical tolerance for oil seal surface roundness has been set as .006 inch for the clutch hub just mentioned. The oil seal surface is typically connected to the sleeve portion of the power transmission member by a so-called transition region which heretofore has not been splinted or otherwise substantially deformed in the splinting process since past experience indicated that splinting of the transition region could increase out of roundness of the oil seal surface.

Clutch hubs of the type of interest are described in the aforementioned Kelp US. Patent 3,982,415.

It is an object of the invention to provide a power transmission member, such as a clutch hub, having a sleeve with pressure formed axially-extending splints or teeth inter-sooting with an unsplined annuls or ring-shaped lip portion adjacent -the open end of the sleeve such that the unsplined ring-shaped portion reduces the bell mouth to within close tolerance limits while also having the transition area provided with pressure formed spleens or teeth.

According to the present invention there is provided a power transition member including a radially extending end wall and a cylindrical axially extending sleeve connected to the end wall and terminating remote from the end wall in an open end. The sleeve has Allah extending splints formed thereon by inter meshing of teeth of the mandrel on which the sleeve is mounted and teeth of a pair of racks slid able therapist.
The splints terminate short of the open sleeve end in an unsplined ring-shaped lip portion which reduces bell mouth of the splints.

It is an object of a specific embodiment of the invention to provide a clutch hub and the like wherein the hub including the splinted sleeve and oil seal surface is within required sigma tolerance, especially wherein the bell mouth map 3L~31~Z~
of the splints or teeth on the sleeve is within about .010 inch, preferably within about .005 inch, and wherein the round-news of the cylindrical oil seal surface is within about .005 inch, despite having the transition region splinted.

The present invention contemplates inter meshing of a portion of the axial length of the sleeve between the mandrel teeth and rack teeth while leaving a ring-shaped lip portion of the sleeve adjacent the open end thereof positioned outside the region of the mandrel teeth and rack teeth such that the ring-shaped portion is not splinted and such that the unsplined portion reduces bell mouth of the splinted portion.

More specifically, the rotatable toothed mandrel and pair of toothed racks are offset from their normal positions such that when the open sleeve of a clutch hub blank is positioned on the mandrel, a ring or annulus-shaped lip portion of the sleeve adjacent its open end and of selected length is not mob/

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inter meshed between the mandrel teeth and rack teeth and thus is not pressure formed with splints during the actual splinting operation. Preferably, the ring-shaped lip portion is not deformed at all in the splinting operation.
Furthermore, the so-called transition area between the cylindrical oil seal surface and sleeve is preferably pressure foxed with splints or teeth in this offset arrangement. Applicant has found that this offset arrangement unexpectedly substantially reduces bell mouth and maintains oil seal surface roundness, producing a clutch hub having longitudinal splints or teeth on the sleeve with bell mouth within close tolerance, e.g. within about .010 inch, preferably within about .005 inch, and having an oil seal surface with roundness within close tolerance, e.g. about .005 inch, which tolerances are well within those specified by users of these parts.
BRIEF DESCRIPTION OF THE DRAWINGS
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Figure 1 is a side elevation Al view in schematic form showing a pair of slid able recooks with a mandrel located there between.

Figure 2 is a partial sectional view showing a clutch hub blank mounted on the mandrel between the racks with the mandrel and racks being offset axially relative to one another.

Figure 3 is a cross-sectional view of a clutch hub blank.

Figure 4 is a partial cross-sectional view of the splinted clutch hub of the present invention.

Figure 5 is an elevation Al view of the splinted clutch hub showing the splinted sleeve, oil seal surface and transition region there between.

sir 2~6 Figure 6 is similar to Fig. 2 showing a machine with certain tail stock components deleted.

Figure 7 issue elevat-onal-view of another splinted clutch hub shrug the splinted sleeve and annular end wall.

DESCRIPTION OF PREFERRED E~30DIMENTS
. _ Fig. 1 illustrates in a schematic form a machine having a pair of rectilinearly-shaped splint or tooth-forming racks lo 12 and a toothed mandrel I supported there between. As is well known, the elongated racks 10, 12 are mounted in the machine for sliding potion in opposite directions past opposite sides of the mandrel 14. The racks include transversely-e~tending teeth loan aye usually shaped in a pro-selected pattern proceeding from the leading end lob 12b to the trailing end lock 12c of each rack. A preferred rack configuration is described in US. Patent No. 4,485,657, November 8, 1984 in the names of Paul Fitzpatrick and Robert R. Ripley and of common assignee herewith. Fig.
2 shows the racks 10, 12 mounted on upper and lower L-shaped tool holder plates 20, 22 which, in turn, are carried on upper and lower slide members 21, 23 as is well known in the art. The tooth-forming racks 10, 12 are driven in sliding motion by a suitable drive mechanism, e.g., a hydraulic piston and cylinder system as is also known in the art, e.g. as shown in the McCardell US. Patents 3,015,2-43 and 3,214,951 of common assignee herewith.
The piston and cylinder assemblies are substantially identical in size and are interconnected to a common source of fluid pressure (not shown) .. . . . .
Wyeth control valve interposed-between the hydraulic assemblies and the common fluid pressure source to simultaneously control both assemblies.
The hydraulic assemblies bias the racks 10, 12 concurrently at the same velocity in opposite directions due to the interlocking effect of the hydraulic pressure on the assemblies.

The machine also includes a head stock spindle 24 rotatable supported in the rigid machine frame 26 by anti-friction bearings 28 as is well known, only one set of which is shown in Fig. 2. The spindle 24 extends in cantilever fashion past the machine frame 26 to between the vertically opposed racks 10, 12.

Keyed on the cantilevered end of the spindle 24 is a mandrel 30 having a large diameter, externally-toothed portion aye and a smaller diameter portion 30b. The mandrel portion aye includes external, radially-extending teeth 30c adapted to mesh with the teeth loan aye of the racks. The mandrel teeth 30c typically are fully conjugate to the splint or tooth form to be formed in the clutch hub blank W while the teeth of the racks typically include one section of fully conjugate teeth and also other sections of teeth which vary from the conjugate shape in preselected manner to facilitate deformation of the blank W, as is described in the aforementioned ITS Patent No. 4,485,657.

Fastened by suitable means, such as screws and the like, ` to the mandrel is an annular adapter plate 32 for purposes to be described.
Also keyed on the spindle 24 is a timing gear 34 having teeth aye adapted to mesh with timing racks 36, 38 bolted or otherwise - attached to the tool holder plates 20, 22, respectively. The functionof the timing gear 34 and timing racks 36, 38 is to insure that rotation of mandrel 24 is coordinated and synchronized with the sliding movement of the racks 10, 12 which must mesh therewith. In particular, the timing gear 34 and racks 36, 38 insure proper meshing-between the mandrel and rack teeth.

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As is apparent in Fig. 2, spacer members 40, 42 are located between the timing racks 36, 38 and the adjacent tooth racks lo 12 on the tooling holder plates 20, 22. These spacer members 40, 42 are attached or otherwise held on the plates and may be of different size to vary the axial position of the toothed racks 10, 12 relative to the axial position of the toothed mandrel 24 for purposes to be explained below.

The clutch hub blank W is shown in Figs. 2 and 3.
lo The clutch hub blank includes an annular end wall 50 con-netted by annular shoulders 52 and 54 to a cylindrical oil sealing surface or sleeve 56 defining a piston or 0-ring receiving bore 57 which must be maintained within a pro-selected roundness tolerance after splinting of sleeve 60.
The roundness of the oil sealing surface or sleeve 56 on the clutch hub blank typically is less than .004 inch, usually less than .002 inch prior to splinting. The oil sealing surface 56 is in turn connected by a transition region 58 of curvilinear profile, particularly generally truncated conical in shape, to a cylindrical sleeve 60 having an open end 62. The sleeve 60 of the clutch hub will be pressure formed between the mandrel teeth 30c and rack teeth loan aye to form axially-extending splints or teeth 70, Fig. 4. For one clutch hub application, the splinted hub must satisfy the six or eight sigma tolerance and in particular the splints or teeth 70 must not taper outwardly along the length of the sleeve 60 toward the open end 62, i.e., bell mouth, more than .016 inch, Fig. 4. At the same time the oil seal surface or sleeve 56 must be maintained within a roundness tolerance of .006 inch.

According to the invention, a clutch hub can be produced within six and preferably eight sigma tolerance.
In particular, splint bell mouth within about .010 inch, preferably within about .005 inch, and oil seal surface roundness within about .005 inch, are obtainable, these Ss/j~J

Sue values being within the required specific tolerances. pro achieve these tolerances in the final splinted clutch hub P, the clutch hub blank W is mounted on the mandrel 24 which is offset axially relative to the toothed racks 10, 12 by a distance X as viewed in Fig. 2. The axial offset is measured from the centerline of racks 10, 12 to the centerline of the large diameter portion aye of the mandrel as viewed in Fig. 2. It is apparent that the annular shoulder 54 is engaged against the adapter plate 32 by a member 70 mounted on a freely rotating tail stock spindle 72. The spindle 72 is rotatable supported in the machine frame extension 73 by anti-friction bearings 74 (only one set shown) as is well known and illustrated in the aforementioned McCardell US. patents.

In Fig. 2, the cylindrical oil seal surface or sleeve 56 fits over the cylindrical surface 32b of the adapter plate with a slight internal clearance of .001-.002 inch there between while the sleeve 60 fits over the mandrel 30 as shown with a slight internal clearance of .001-.002 inch there between. As a result of the relative axial offset between the racks 10, 12 and mandrel 30, the sleeve 60 extends past the racks 10, 12 toward the head stock side of the machine and is unsupported by the racks. This arrangement provides an annular or ring-shaped lip portion aye of the sleeve adjacent the open sleeve end 62 which is not positioned between the mandrel 24 and racks 10, 12 and thus is not pressure formed or splinted with the remaining portion of the sleeve 60. Also with this arrangement, the transition region 58 between the sleeve 60 and oil seal surface 56 is pressure-formed between the mandrel teeth 30c and rack teeth loan aye in a tooth or spline-like shape, see Fig. 5.

It is apparent that the relative axial offset between the mandrel 30 and racks 10, 12 can be provided by moving either the mandrel or racks or both relative to one another. The use of spacer members 40, 42 provides a convenient s sly, If ~;23C~
means for varying the axial offset. It may be possible with the present invention to dispense with the member 70 and tail stock spindle 72, Fig. 6. In particular, the ring-shaped lip portion aye of sleeve 60 has been found to impart a self-locating effect to the blank W
as it is splinted to maintain the blank in substantially fixed position on the mandrel without the need for ox-vernal clamping means.
During the actual rolling operations, the toothed racks 10, 12 are activated to slide in opposite directions past the mandrel 30 with the rack teeth loan aye contacting the sleeve 60, except for annuls or lip aye, and the transition region 58 and inter-meshing the mandrel teeth 30c to pressure form the splint or tooth profile or shape therein. During deformation, the annuls on ring-shaped portion aye is not pressure formed and the splints on the remainder of the sleeve terminate short of the open sleeve end 62 at the ring-shaped portion aye as shown.
The annuls or ring-shaped portion aye has been found to unexpectedly and substantially reduce bell mouth and to allow formation of the tooth or splint shape in the sleeve 60 within a close bell mouth tolerance of .010 inch, preferably within a bell mouth tolerance of .005 inch. It appears that the ring-shaped lip portion aye functions to restrain ox-pension of the open sleeve end 62 during splinting to sub-staunchly reduce bell mouth within the required tolerance, although Applicant does not intend to be bound by this theory.
The length, L, of the ring-shaped lip portion aye in the axial direction is selected to be sufficient to exert the necessary restraining force against expansion of the open sleeve and during splinting and to that end preferably is a least about 15~ of the total length of the sleeve 60. Pressure-forming of tooth or spline-like shapes in the transition region 58 allows theunderfo~med annuls or ring-shaped lip portion aye to be provided at the sleeve open end 62 and yet provide a tooth or splint axial length which is sufficient for the intended purpose as a clutch hub. Furthermore, pressure-s so - I - ~3~6 forming in this manner can be effected and yet provide the cylindrical oil seal surface 56 within its close roundness tolerance of .005 inch, despite the splinting of the trays-it ion region 58 situated closely thereto. This was us-expected since prior experience indicated that oil seal roundness would be increased by splinting the transition region 58. Annular end wall 50 and shoulders 52 and 54 likewise are maintained within required tolerances.
The pressure formed clutch hub P shown in Fig. 5 thus is characterized as having a splinted sleeve and cylindrical oil sealing sleeve and being within six sigma tolerance, preferably within eight sigma tolerance wherein bell mouth of the longitudinal splints or teeth 80 is within a close tolerance of about .010 inch, preferably about .005 inch, and wherein roundness of the oil seal surface or sleeve 56 is within a close tolerance of about .005 inch. It is further characterized as having the us-splinted ring-shaped lip portion aye adjacent the open sleeve end 62 of sufficient axial length to substantially reduce bell mouth to within these aforementioned tolerances and having the transition region splinted contiguously and concurrently with the splints on the sleeve 60.
Those skilled in the art will appreciate that a splinted clutch hub P' of the type shown in Fig. 7 can be made by the invention. In Fig. 7, like numerals primed represent like features. For example, clutch hub P' in-eludes an annular end wall 50' connected by shoulders 52', 54' to splinted sleeve 60' having an unsplined lip portion aye' adjacent the open end 62' to substantially reduce bell mouth of the splinted sleeve. As is apparent in Fig. 7, clutch hub P' does not include an oil sealing sleeve.
As used herein and in the appended claims, the term splint is intended to include splints, tooth elements or tooth forms as well as similar features provided on power transmission members.

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The above-described apparatus and method for making the transmission member of the present invention are also disclosed and claimed in above-identified Canadian parent application 455,656, filed June 1, 19~4.

While certain embodiments of the method and Papa-fetus have been described in detail herein, those familiar with this art will recognize that various modifications and changes can be made therein for making the transmission member of the present invention as defined in the following claims.

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Claims (14)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A power transmission member comprising a radially-extending end wall and a cylindrical axially-extending sleeve connected to the end wall and terminating remote from the end wall in an open end, said sleeve having axially-extending splines formed therein by intermeshing of teeth of a mandrel on which the sleeve is mounted and teeth of a pair of racks slidable therepast, said splines terminating short of the open sleeve end in an unsplined ring-shaped lip portion which reduces bellmouth of the splines.

2. The power transmission member of claim 1 wherein the ring-shaped portion is not deformed during formation of the splines on the remainder of the sleeve by intermeshing of the mandrel teeth and rack teeth.

3. The power transmission member of claim 1 wherein the bellmouth of the splines on the sleeve is within about .010 inch.

4. The power transmission member of claim 1 wherein the bellmouth of the splines on the sleeve is within about .005 inch.

5. The power transmission member of claim 1 wherein the axial length of the ring-shaped portion is at least 15% of the total length of the sleeve.

6. The power transmission member of claim 1 which is a clutch hub for use in a transmission.

7. The power transmission member of claim 1 which includes a curvilinear transition region between the splined sleeve and annular end wall and said transition region includes splines contiguous with the splines of the splined sleeve and formed at the same time therewith by intermeshing of the madrel teeth and rack teeth.

8. A power transmission member comprising a radially-extending end wall, a first cylindrical axially-extending sealing sleeve connected to the end wall and a second cylindrical axially-extending sleeve connected to the sealing sleeve and terminating remote from the sealing sleeve in an open end, said second sleeve having axially-extending splines formed therein by intermeshing of teeth of a mandrel on which the second sleeve is mounted and teeth of a pair of racks slidable therepast, said splines terminating short of the open sleeve end in an unsplined ring-shaped lip portion which maintains bellmouth of the splines within close tolerance.

9. The power transmission member of claim 8 wherein the ring-shaped portion is not deformed during formation of the splines on the remainder of the second sleeve by inter-meshing of the mandrel teeth and rack teeth.

10. The power transmission member of claim 8 wherein the power transmission member includes a curvilinear transition region between the splined sleeve and sealing sleeve and said transition region includes splines contiguous with the splines of the splined sleeve and formed at the same time therewith by intermeshing of the mandrel teeth and rack teeth.

11. The power transmission member of claim 8 wherein the bellmouth of the splines on the second sleeve is within about .010 inch and the roundness of the sealing sleeve is within about .005 inch.

12. The power transmission member of claim 8 wherein the bellmouth of the splines on the second sleeve is within about .005 inch and the roundness of the sealing sleeve is within about .005 inch.

13. The power transmission member of claim 8 wherein the axial length of the ring-shaped portion is at least 15% of the total length of the second sleeve.

14. The power transmission member of claim 8 which is a clutch hub for use in a transmission.