The invention relates to an apparatus for connecting a transmission case to an engine, as well as a method of assembling transmissions.
Vehicle powertrains are complex assemblies including a multitude of components. One of the principal components of a vehicle powertrain is the transmission, which includes a rugged outer housing or case. Transmissions are often designed and built with the intention of being offered for use by various automotive manufacturers across different applications or vehicle models. Economies of scale and simplification of component handling during vehicle assembly dictate the use of at least some common transmission components across these various applications, and even in different types of transmissions, for example in different transmission families with disparate torque and gear ratio specifications. Engines of varying designs are likely used in the different applications, leading to a less than optimal number of different parts and their associated part numbers necessary to achieve the various combinations of transmissions and engines.
A transmission case adapter ring is provided that enables an outer transmission housing or case to be connected to an engine, thus enabling use of a common transmission case part number with different engine styles simply by changing the adapter ring. The adapter ring has engine mounting features configured to mount to a predetermined engine mounting face on a specific type or style of engine, and also has a case-side mounting face adapted to mount to a mounting face on the transmission case. The adapter ring is separate from, and mountable to, both the transmission case and the engine. Thus, the adapter ring enables an engine to be connected with any transmission that utilizes the particular type of transmission case.
The adapter rings are relatively small and easy to store, and may be pre-produced and stored until needed. The adapter rings are constructed of light weight, corrosion-resistant material such as aluminum to reduce overall vehicle weight while minimizing corrosion between the transmission case and a cast engine block. With the adapter ring, it is not necessary to produce a customized transmission case for each vehicle model.
Accordingly, in one aspect of the invention, an annular adapter ring has a case-side mounting face at one end adapted to mount to a mounting face of a transmission case. The adapter ring also has an engine-side mounting face at an opposite end that is adapted to mount to a predetermined engine mounting face of a particular type of engine. Preferably the case-side mounting face and the engine-side mounting face of the adapter ring are characterized by bolt patterns identical to bolt patterns of the transmission case and of the engine, respectively.
In another aspect of the invention, because the adapter ring is a separate component from the transmission casing and engine, both may be manufactured separately from the adapter ring, and the adapter ring may be selected from a suitable material independently of the material used for the transmission and engine. For example, the adapter ring may be aluminum, rather than steel, in order to reduce weight and improve fuel economy, while still providing a barrier having sufficient corrosion resistance between potentially incompatible materials, such as a magnesium transmission case and a cast iron engine block.
Within the scope of the invention, a powertrain is provided that includes a transmission having an outer case. The power train also includes an engine having an engine block with an engine mounting face formed on one side, such as with a specific engine bolt pattern. The powertrain includes an annular adapter ring that has a case-side mounting face adapted to mount to the transmission case and an engine-side mounting face adapted to mount to the engine mounting face, to thereby connect the transmission with the engine.
The adapter ring allows a novel method of assembling a powertrain that permits assembly of the transmission with a generic (i.e., common) type of outer case prior to a determination of the engine type or types to be used with the transmission. The method includes maintaining an inventory of transmissions of a first type, each contained within an outer transmission case of a first type. The method includes mounting an adapter ring to the outer case of one of the transmissions. The adapter ring has an engine-side mounting face configured with a predetermined engine bolt pattern adapted for connection with a first type of engine that has the predetermined engine bolt pattern.
Because only the adapter ring has an engine specific feature, i.e. the engine mounting bolt pattern, the method may include mounting a second adapter ring of a second type to the transmission case on a second transmission selected from the inventory, i.e., the second transmission being of identical types as those of the first transmission. The adapter ring of the second type has an engine-side mounting face configured with a second, different, predetermined engine bolt pattern so that the second adapter ring is configured for connection with a second type of engine having the second engine bolt pattern. Thus, the same generic type of transmission case may be used in different applications, such as when different types of engines are to be used with a given type of transmission, simply by utilizing different engine-specific adapter rings.
Furthermore, the entity that maintains the inventory of transmissions may or may not manufacture the adapter rings, and, in either case, may maintain an inventory of the different types of adapter rings and select the appropriate type of adapter ring for mounting to the transmissions, as described above, based on orders received for use of the transmissions with the specified type or types of engines. This permits flexibility in manufacturing output.
Within the scope of the invention, particularly if it is expected that a given type of transmission will be used with two or more different types of engines, the method may include maintaining an inventory of adapter rings of the first and second types, receiving an order for the first type of transmission to be used with the first type of transmission, and, in response to the order, selecting the first type of adapter ring from the inventory for the step of mounting the first adapter ring described above. This allows the transmission to be preassembled, and only the adapter rings need be maintained in a separate, engine specific inventory. Similarly, the method may include receiving an order for the first type of transmission to be used with the second type of engine, and, in response to the order, selecting the second type of adapter ring from the inventory to be used for the step of mounting the second adapter ring described above.
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 modes for carrying out the invention when taken in connection with the accompanying drawings.
Referring to the drawings, wherein like reference numbers refer to like components,
Powertrain 10 includes an engine 26, which may be configured as an internal combustion engine, a fuel cell, or another type of engine sufficient for powering a vehicle (not shown) equipped with transmission 11, in particular by driving input member 12 of transmission 11 via an engine output member 28. Engine 26 is a first type of engine having certain characteristic design parameters, such as displacement volume, number and orientation of cylinders, etc., and/or other design parameters depending on the type or style of engine 26.
It is desirable to be able to utilize transmission 11 with many different engine applications and associated bolt patterns while maintaining as many generic or common components, such as a singular transmission case 46, throughout the various applications. Accordingly, powertrain 10 includes an adapter ring 32 adapted to bolt or otherwise connect transmission case 46 with a specific first type of engine 26. This connection is achieved more specifically between case 46 and an engine block portion 54 of engine 26, preferably a suitable grade of cast iron. Adapter ring 32 is preferably formed or cast from a high-strength, lightweight grade of aluminum to improve corrosion resistance and reduce the weight of transmission 11.
Adapter ring 32 is a first type of adapter ring having a case-side mounting face 34, i.e. an axial surface facing transmission case 46, and an engine-side mounting face 36 at an opposing axial surface. Case-side mounting face 34 includes features suitable for adapting the adapter ring 32 for connection to transmission case 46, such as adapter-to-case bolt openings 38. Case-side mounting face 34 and adapter-to-case bolt openings 38 correspond to mate up with or fit to a transmission case mounting face 40 on an outer surface of transmission case 46, and case bolt openings 42 formed, bored, or otherwise provided in transmission case 46. Adapter-to-case bolt openings 38 and case bolt openings 42 align, and case-side mounting face 34 fits with case mounting face 40 in this manner. Adapter ring 32 is then bolted and doweled (or piloted) to case 46.
As shown in
Engine-side mounting face 36 of adapter ring 32 includes adapter-to-engine bolt openings 50 arranged in a predetermined pattern to align with a particular engine mounting face 51 of engine 26. Engine 26 has a predetermined engine bolt pattern, as represented by engine bolt openings 52, that is formed, bored, or otherwise provided in engine block 54 of engine 26.
Because adapter ring 32 is the only component of powertrain 10 having engine-specific features, i.e., features specially adapted to connect to a particular mating feature of engine 26, such as an engine bolt pattern represented by engine bolt openings 52, identical types of the remaining components of powertrain 10 may be used without modification in powertrains having a different type of engine, and only a different type of adapter ring need be used. This is demonstrated by powertrain 100 of
Referring to
Because a second adapter ring 132 of a second type is used that is different than adapter ring 32 shown in
Referring to
Referring to
Referring to
Method 200 includes step 202, maintaining an inventory of transmissions of a first type, such as transmissions 11 of
Under method 200, the entity assembling transmissions 11 may receive an order under step 210 for the first type of transmission to be used with a first type of engine. Additionally or alternatively, the entity may receive an order under step 212 for the first type of transmission to be used with a second type of engine. In response to step 210, method 200 includes step 214, selecting the first type of adapter ring 32 from the inventory of adapter rings.
After step 214, method 200 includes step 216, mounting the first type of adapter ring 32 to the case 46 of transmission 11 of the first type from the inventory of assembled transmissions. Similarly, in response to step 212, method 200 includes step 218, selecting the second type of adapter ring 132 from the inventory of adapter rings. After step 218, method 200 includes step 220, mounting the second type of adapter ring 132 to the first type of transmission case 46 on a transmission 11 of the first type from the inventory of transmissions.
While the best modes for carrying out the invention have 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.