Drive hub for torque converter clutch

A drive hub for a torque converter lock-up clutch and damper assembly wherein a one-piece hub provides radial location for the driving and driven members and a pressure seal to provide the requisite pressure differential across the clutch pressure plate for application of the clutch during torque converter use.

BACKGROUND OF THE INVENTION 
The present invention relates to a novel drive hub used in a lock-up clutch 
assembly for a torque converter. In some presently known torque 
converters, the torque converter clutch assembly is located radially in 
the torque converter by the turbine hub and turbine shaft operatively 
connected to the transmission input shaft for the vehicle. The driven 
portion of the clutch is located on the turbine hub while the larger mass, 
including the pressure plate, etc., is located by a spacer which is, in 
turn, located on the turbine shaft. Manufacturing clearances and 
tolerances on these parts result in generally poor location of the clutch 
assembly, including any damper structure, in the radial direction, 
contributing to unacceptable vibration characteristics and poor 
durablility. The present invention overcomes these problems in the use of 
a novel one-piece hub for the clutch assembly. 
SUMMARY OF THE INVENTION 
The present invention relates to a one-piece clutch hub which replaces the 
hub member and separate spacer arrangement presently utilized in some 
designs of torque converter lock-up clutch assemblies. This unitary hub 
provides for radial location of all clutch and damper components relative 
to a single component within the clutch assembly. This component is, in 
turn, radially located by a single component of the torque converter, thus 
reducing the number of components whose manufacturing tolerances and 
operating clearances contribute to mis-location in the assembly. Also, the 
ability to maintain static and dynamic balance is substantially improved 
since the location of components is more controlled. 
The present invention further relates to a one-piece drive hub component 
for a torque converter lock-up clutch assembly wherein the minimization of 
the number of components in the clutch assembly improves the "stack" of 
component tolerances, reducing overall variation and allowing the use of 
smaller nominal clearances. This hub also improves component balance 
characteristics and allows a performance improvement by making space 
previously required for clearances available for functioning components. 
Further objects are to provide a construction of maximum simplicity, 
efficiency, economy and ease of assembly and operation, and such further 
objects, advantages and capabilities as will later more fully appear and 
are inherently possessed thereby.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring more particularly to the disclosure in the drawings wherein is 
shown an illustrative embodiment of the present invention, FIG. 1 
discloses a conventional hub and spacer assembly utilized for some designs 
of a torque converter lock-up clutch 10 wherein the torque converter 
housing 11 is operatively connected to the output shaft of a vehicle 
engine (not shown) and directly connected to an impeller therefor, and a 
turbine 13 mounted on a turbine hub 14 has internal splines 15 receiving 
the splined end of a transmission input shaft (not shown). 
External splines 16 on the turbine hub mesh with internal splines of a 
clutch hub 18 carrying a hub plate 19 for a clutch damper assembly. 
Housing plates 21,22 encompass the hub plate 19 and compression springs 
23; the plates 21,22 being operatively connected to a piston plate 24 
having a friction face operatively engaging a friction surface on the 
torque converter housing as seen in FIG. 2. A generally annular spacer 27 
is located between the housing 11 and the clutch hub 18 and has an inner 
extension 29 received in a recess 28 of the housing 11. Also, the spacer 
has an annular groove 31 for a suitable seal ring 32 engaged by an inner 
guide flange 33 on the piston plate 24 to guide the axial movement of the 
piston plate and provide the requisite pressure differential on the 
opposite sides of the pressure plate during lock-up of the clutch. 
Considering FIG. 2, a torque converter and damper assembly 35 is shown with 
like parts having the same numerals with the addition of a script a. The 
torque converter housing 11a is connected to the impeller 12a and has an 
annular friction surface 26a facing the friction ring 25a on the piston 
plate 24a. The turbine 13a is mounted on a turbine hub 14a having internal 
splines 15a for the transmission input shaft and external splines 16a. A 
one-piece drive hub 36 has a central passage 37 provided with an 
internally splined counterbore 38 receiving the splines 16a on the turbine 
hub 14a; the counterbore defining a shoulder 39 abutting the end of the 
turbine hub. The hub includes a forward reduced annular extension 41 
defining a shoulder 42 and received in a recess 28a of the torque 
converter housing 11a. 
In the external surface 43 of the hub is formed an annular groove 44 
receiving a resilient sealing ring 45 for engagement with the inner guide 
flange 33a of the piston plate 24a, and a reduced portion 46 of surface 43 
has external splines 47 to mesh with the inner splined periphery of a 
clutch plate 19a for the damper assembly 51. An annular bearing assembly 
49 is located between the shoulder 42 of the hub 36 and the torque 
converter housing 11a. 
The damper assembly 51 shown in FIG. 2 is a two-stage extended travel 
damper such as described in U.S. Pat. No. 4,347,717 and includes a pair of 
outer housing plates 52,53 secured to the piston plate 24a and having 
inwardly offset drive straps 54,54, a hub plate 55 having arms 56 
separating damper springs 57, the inner extension of the hub plate forming 
one housing plate 21a of an inner housing portion for damper springs 23a; 
the plates 21a,22a encompassing the springs and inner hub plate 19a. 
Reference is made to the above cited patent for the remainder of the 
damper structure and its function. Although shown in conjunction with a 
two-stage damper, this hub may be used with a single stage damper such as 
shown in U.S. Pat. No. 4,188,806. 
As seen in FIG. 2, the one-piece drive hub 36 provides a single component 
to reduce the "stack" of component tolerances and allow the use of smaller 
nominal clearances. This hub provides for improved radial location of the 
piston plate 24a, clutch hub plate 19a and housing plates 21a and 22a. 
Also, this clutch hub 36 is radially located on the turbine hub 14a. A 
further advantage of this hub is that it can be easily formed from 
powdered metal without complicated coring or molds in view of the 
configuration of the hub, the splines and passages.