DRIVE HUB FOR TORQUE CONVERTER CLUTCH

Abstract: A drive hub for a torque converter lock-up clutch and damper assembly (35) wherein a one-piece hub (36) provides radial location for the driving (lla) and driven members (l4a) and a pressure seal (45) to provide the requisite pressure differential across the clutch pressure plate (24a) for application of the clutch during torque converter use.

Description: The present invention relates to a novel drive hub used in a lock-up clutch assembly for torque converter. In some presently known torque converters, the torque con­ verter 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 the generally poor location of the clutch assembly, including any damper structure, in the radial direction, contributing to unacceptable vibration characteristics and poor durability. The present invention overcomes these problems in the use of a novel one-piece hub for the clutch assembly. 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 pro­ vides for radial location of all clutch and damper compo­ nents relative to a single component within the clutch assembly. This component is, in turn, radially located by a single 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 torque converter lock-up clutch assembly wherein the minimization of the number of com­ ponents in the clutch assembly improves the "stack" of component tolerances, reducing overall variation and allow­ ing the use of smaller nominal clearances. This hub also improves component balance characteristics and allows a performance improvement by making space previously required for clearance available for functioning components. Further objects are to provide a construction of maximum simplicity, efficiency, economy and ease of assem­ bly and operation, and such further objects, advantages and capabilities as will later more fully appear and are in­ herently possessed thereby. Figure l is a partial cross sectional view through the hub portion of a lock-up clutch and damper assembly for a present torque converter. Figure 2 is a partial cross sectional view of the novel drive hub of the present invention in a torque converter lock-up clutch. Figure 3 is an enlarged view of a portion of the drive hub, part in elevation and part in cross section. Figure 4 is an enlarged end elevational view of the hub taken from the right-hand end of Figure 3. Figure 5 is an enlarged cross sectional view of the hub shown in perspective. Referring more particularly to the disclosure in the drawings wherein is shown an illustrative embodiment of the present invention, Figure l discloses a conventional hub and spacer assembly utilized for some designs of a torque converter lock-up clutch l0 wherein the torque converter housing ll is operatively connected to the output shaft of a vehicle engine (not shown) and directly connected to an impeller therefor, and a turbine l3 mounted on a turbine hub l4 has internal splines l5 receiving the splined end of a transmission input shaft (not shown). External splines l6 on the turbine hub mesh with internal splines of a clutch hub l8 carrying a hub plate l9 for a clutch damper assembly. Housing plates 2l,22 encom­ pass the hub plate l9 and compression springs 23; the plates 2l,22 being operative connected to a piston plate 24 having a friction face operatively engaging a friction surface on the torque converter housing as seen in Figure 2. A generally annular spacer 27 is located between the housing ll and the clutch hub l8 and has an inner ex­ tension 29 received in a recess 28 of the housing ll. Also, the spacer has an annular groove 3l 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 Figure 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 lla is connected to the impeller l2a and has an annular friction surface 26a facing the friction ring 25a on the piston plate 24a. The turbine l3a is mounted on a turbine hub l4a having internal splines l5a for the transmission input shaft and external splines l6a. A one-piece drive hub 36 has a central passage 37 provided with an internally splined counterbore 38 receiving the splines l6a on the turbine l4a; the counterbore de­ fining a shoulder 39 abutting the end of the turbine hub. The hub includes a forward reduced annular extension 4l defining a shoulder 42 and received in a recess 28a of the torque converter housing lla. 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 peri­ phery of clutch plate l9a for the damper assembly 5l. An annular bearing assembly 49 is located between the shoulder 42 of the hub 36 and the torque converter housing lla. The damper assembly 5l shown in Figure 2 is a two-stage extended travel damper such as described in U. S. Patent No. 4,347,7l7 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 extensions of the hub plate forming one housing plate 2la of an inner housing portion for damper springs 23a; the plates 2la,22a encompassing the springs and inner hub plate l9a. Refer­ ence 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. Patent No. 4,l88,806. As seen in Figure 2, the one-piece drive hub 36 provides a single component to reduce the "stack" of compo­ nent tolerances and allow the use of smaller nominal clearances. This hub provides for improved radial location of the piston plate 24a, clutch hub plate l9a and housing plates 2la and 22a. Also, this clutch hub 36 is radially located on the turbine hub l4a. A further advantage of this hub is that is can be easily formed from powdered metal without complicated coring or molds in view of the configuration of the hub, the splines and passages.

Claims: 1. A one-piece drive hub and spacer (36) for a lock-up clutch in a torque converter, comprising an elongated hub barrel having a counterbored internal passage (37), a plurality of internal splines (38) in the counter­ bored portion adapted to receive the externally splined turbine hub (l4a) of the torque converter, a cylindrical external surface (43) receiving the inner periphery (33a) of a clutch piston plate (24a), sealing means (45) in said surface engaging the plate periphery, and external splines (47) formed adjacent one end of the said surface adapted to receive a hub plate (l9a) for said lock-up clutch. 2. A one-piece hub and spacer as set forth in Claim l, wherein said counterbored passage (37) defines a shoulder (39) acting to engage the end of said turbine hub (l4a). 3. A one-piece drive hub and spacer as set forth in Claim l, wherein said barrel has a shoulder (42) at one end of said cylindrical surface adapted to engage bearing means in the torque converter housing. 4. A one-piece drive hub and spacer as set forth in Claim l, in which said sealing means includes a resilient O-ring (45) received in an annular groove (44) in said cylindrical surface (43).

Inventors: HALL, DAVID ALAN, YUERGENS, KENNETH CHRISTOPHER
Applicants: BORG-WARNER AUTOMOTIVE, INC.
Application year: 1987
Main classification: F16H45
IPC codes: F16H45, F16D1