Torque converter reactor assembly and method

A torque converter reactor includes a monolithic body of plastic resin having a hub and radially extending vanes terminating in an outer rim. A clutch with metal parts is partly encapsulated in the hub during a molding operation. The clutch is preheated to accommodate the resin shrink rate, and shut off plates keep the interior of the clutch free of plastic material.

FIELD OF THE INVENTION 
The present invention relates to a torque converter reactor or similar 
assembly having a monolithic plastic resin body including a hub and radial 
vanes with a rotary assembly such as a clutch with a plurality of metal 
parts captured within the hub, and to a method for making the asembly. 
DESCRIPTION OF THE PRIOR ART 
Torque converters have long been used in the transmission power trains of 
automotive vehicles and for other purposes. A typical fluid torque 
converter includes three functional elements: an impeller driven by a 
power input shaft, a turbine for driving a power output shaft and a 
reactor or stator that is fixed or stationary during normal torque 
multiplication operation. Fluid acting between these elements causes the 
output shaft to rotate in response to rotation of the input shaft with a 
varying torque-speed ratio. A typical reactor or stator includes a central 
portion or hub, an outer portion or rim, and fluid deflecting blades or 
vanes extending between the hub and rim. A central rotary assembly in the 
form of a clutch is provided so that at some shaft speeds the reactor can 
freewheel for increased efficiency when continued torque multiplication is 
not required. 
Plastic resin materials are becoming more widely used in automotive 
vehicles in place of metal because of factors such as lighter weight, ease 
of molding and improved performance. It would be desirable to use plastic 
resin in place of metal in the reactor element of a torque converter 
assembly. One known torque converter assembly includes a molded plastic 
hub with fluid vanes molded integrally around the outer hub. An outer rim 
of metal is fixed to the outer ends of the vanes. A clutch assembly is 
assembled into the hub, and is retained by a molded plastic retainer that 
also fits into the hub. This structure has been successful for its 
intended purpose, but is subject to disadvantages because it includes a 
number of parts that must be manufactured individually and then assembled 
together to make the reactor assembly. 
A torque converter reactor assembly of this type is one example of a 
structure in which a molded plastic body such as a hub portion is 
assembled together with a complex rotary assembly including several metal 
parts. Although it may be desirable to form the molded plastic body as a 
monolithic structure capturing or encapsulating the rotary assembly, there 
are problems that must be overcome. One problem is that during the molding 
step, the rotary assembly must be accurately and securely positioned 
relative to the mold and the plastic material. Another is that the plastic 
material must be kept from flowing into or interfering with the rotary 
assembly. Yet another problem is that the plastic material shrinks when it 
cures, and this can lead to an improper fit or undesirable forces between 
the plastic material and the rotary assembly. 
SUMMARY OF THE INVENTION 
Among the objects of the invention are to provide a method for making a 
torque converter reactor made partly of plastic that requires no assembly 
after molding of the plastic; to provide a method in which a rotary 
assembly, such as a clutch, can be molded into the hub of a monolithic 
body of plastic without plastic entering the clutch during molding; to 
provide a method in which the shrink rate of the plastic upon curing is 
compensated for; and to provide a torque converter reactor or the like in 
which a rotary assembly such as a clutch is captured in a hub portion by 
portions of a monolithic plastic boby. 
In brief, in accordance with the present invention, there is provided a 
method for making a torque converter reactor or similar structure of the 
type including a hub, a rotary assembly with a plurality of metal parts at 
the hub and radial vanes extending from the hub. In carrying out this 
method, the rotary assembly is preheated and then placed inside a mold 
having freely interconneted portions for forming the hub and vanes. The 
rotary assembly is located centrally within the hub forming portion of the 
mold. The freely interconnected mold portions are filled substantially 
simultaneously with a heated charge of plastic resin to form the hub vanes 
as one continuous plastic resin structure. The plastic resin structure is 
permitted to cure into a unitary, monolithic body having the rotary 
assembly captured within the hub. 
Further in accordance with the invention, there is provided a torque 
converter reactor or the like including a monolithic body of plastic resin 
material having a central hub, an outer rim and radial vanes extending 
from the hub to the rim. A rotary assembly has a plurality of metal parts. 
The hub includes a central recess and the rotary assembly is located in 
the central recess. The monolithic body includes portions surrounding the 
periphery of the assembly and overlying at least part of the opposite 
sides of the assembly for capturing the assembly within the hub.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings, a torque converter reactor or stator 
generally designated as 10 and constructed in accordance with the 
principles of the present invention is shown in FIGS. 1 and 2. The reactor 
includes a central hub portion 12 and a number of vanes 14 extending 
radially outward from the hub portion. The outer ends of the vanes 14 
intersect an outer rim portion 16 of the reactor 10. The hub portion 12, 
vanes 14 and rim portion 16 are parts of a single, monolithic body 17 of 
molded plastic resin material. Captured in a central location in the hub 
portion 12 is a rotary assembly 18 which, in the illustrated embodiments 
of the invention, is a clutch assembly. 
The term "monolithic" is used to describe a unitary and one-piece structure 
that is essentially made throughout of one homogeneous and uninterrupted 
material, as distinguished from structures that are made of distinct 
discrete components that may be attached together by fasteners or 
adhesives or the like. 
When the reactor or stator 10 is assembled with an impeller and turbine in 
a fluid torque converter (not shown), the vanes 14 defect fluid moving in 
the torque converter. Hub portion 12 includes oppositely directed integral 
lugs 20 and 22 forming castles acting as thrust washers for holding the 
reactor in a normally fixed position in an automotive vehicle power train 
between the engine and the transmission. The outer rim 16 includes a 
projecting flange 24 and serves to strengthen and locate the outer ends of 
the vanes 14. 
The rotary assembly 18 is a clutch that is also shown in FIG. 3. It 
includes a number of ferrous metal parts including an inner race 26 having 
internal splines 28 and an outer race 30 having keying slots 32. 
Projections 34 on the outer race 30 define tapered pockets in which are 
located clutch rollers 36 and springs 38. Normally the rollers 36 lock the 
inner and outer races 26 and 30 together and the reactor 10 is in a fixed 
or stationary position. Under certain operating conditions, the clutch 18 
permits the reactor 10 to freewheel and the outer race 30 can move 
relative to the inner race 26 for more efficient operation when torque 
multiplication is not needed. Principles of the present invention are 
applicable to rotary assemblies other than the specific clutch seen in the 
drawings. For example, bearing assemblies or other types of power 
transmission or rotation coupling assemblies can be mounted to a hub 
section of a structure like the reactor 10. 
In accordance with the invention, the monolithic body 17 is made with the 
rotary assembly 18 in place in the mold tooling generally designated as 40 
and seen in FIG. 4. This tooling includes upper and lower tooling 
assemblies 42 and 44 shown in the closed position ready to begin a molding 
cycle. The upper assembly 42 includes an upper plate 46 and upper backing 
plate 48 supporting an upper vane core 50 and top side castle core 52. A 
cone ejection pin 54 reciprocates in guide openings in the upper plate 50 
and core 52. Lower tooling assembly 44 includes a lower plate 56 
surrounding a transfer pot 58 and supporting a backing plate 60 carrying a 
sprue bushing 62. Another backing plate 64 mates with the upper backing 
plate 48 and supports a lower vane core 66 and bottom castle core 68. The 
upper and lower tooling assemblies separate when the mold tooling is open 
to provide access to the interior of the mold. 
A pair of material shut off plates 70 are located at the opposite sides of 
the rotary assembly 18 to prevent the flow of plastic resin material into 
the region between the races 26 and 30 during molding. As can be seen in 
FIG. 2, the plates 70 remain in place in the reactor 10 after molding. 
Each plate 70 is a thin, annular disk with an inner periphery overlying 
the inner race 26 without blocking the splines 28 and an outer periphery 
overlying the outer race 30. 
A transfer cone 72 is held in a precisely determined position in the mold 
tooling 40 between the castle cores 52 and 68. A recess 74 in the top of 
the cone 72 registers with a projection 76 on the core 52 surrounding a 
passage 78 for the ejection pin 54. The bottom of cone 72 is generally 
conical and includes standoffs 79 that fit into a conical opening 
extending through the lower core 68 from the sprue bushing inlet 80. A 
conical flow passage is defined between the cone 72 and the bottom castle 
core 68 arround the standoffs 79 leading from the transfer pot 58 and 
sprue bushing 62 to the interior of the mold tooling 40. 
Transfer cone 72 acts together with a number of positioning pins 82 to 
accurately position the rotary assembly 18 in the mold. Cone 72 includes a 
step 84 upon which the assembly and the plates 70 rest when the assembly 
18 is placed over the cone 72. With the cone in place in the mold, the 
rotary assembly 18 is radially positioned at the center of the reactor 10. 
Pins 82 are held by the bottom castle core and support the lower shut off 
palte 70 for positioning the rotary assembly in the axial direction. 
The mold tooling 40 defines a region 86 between the top side and bottom 
castle cores 52 and 68 for forming the hub portion 12. A region 88 between 
the upper and lower vane cores 50 and 66 forms the vanes 14. A region 90 
between the backing plates 48 and 64 forms the rim portion 16. Each of 
these regions is unobstructed and freely communicates with the others for 
simultaneous formation of the monolithic body 17 in the tooling 40. 
In the manufacture of the reactor 10 in accordance with the present 
invention, the rotary assembly 18 is preheated to an elevated temperature 
related to the shrink rate of the material of body 17 when it cures. A 
heat resistant, thermosetting plastic resin, specifically a phenolic resin 
such a s thirty five percent fiberglass filled Grade RX865 phenolic resin 
available from Rogers Corporation, is presently preferred. This material 
has a shrink rate of about two and one-half thousandths of an inch per 
inch during curing. To accommodate this shrinkage, the rotary assembly is 
preheated to about three hundred thirty degrees F so that it will contract 
an equivalent amount when it cools to the ambient temperature. Preferably 
the rotary assembly together with the shut off plates 70 is preheated in 
place on the transfer cone 72. 
A charge of plastic resin is heated to a molding temperature of about two 
hundred thirty degrees F and loaded into the transfer pot 58. After 
preheating, the cone 72, plates 70 and assembly 18 are located into the 
mold tooling 40 and the tooling is closed. The rotary assembly 18 is 
accurately positioned by the cone 72 and pins 82. A transfer pressure of 
about five thousand pounds per square inch is applied to the resin in the 
transfer pot 58 and the material flows through the sprue bushing 62 and 
into the mold cavity regions 86, 88 and 90. 
The plastic resin is permitted to cure in the mold for about sixty seconds. 
Then the mold is opened and the reactor 10 is removed from the mold by a 
knock out system including the ejection pin 54. At this point, the reactor 
10 is complete, but the transfer cone 72 is attached to the reactor by 
cured plastic resin. The cone is separated from the reactor by removing 
plastic material in the region shown by broken line 92 in FIGS. 2 and 4. 
The cone 72 may be reused in making subsequent reactors 10. 
The dimensional change in the plastic resin as it cures is similar to the 
dimensional change in the preheated metal parts of the rotary assembly 18 
as it cools. Thus the assembly 18 fits properly in the hub portion 12 of 
the monolithic body 17. The plastic material surrounds the outer periphery 
of the assembly 18, and portions 94 and 96 of the body 17 overlie opposed 
sides of the assembly 18 so that the assembly is partly encapsulated in 
the desired position. No further assembly operations are required, and 
following the molding operations, the reactor 10 is handled and installed 
as a single component.