Unitized valve body having flow passages

A unitized valve body for use in an automatic transmission includes a plurality of valve bores and a plurality of hydraulic passages. Each valve bore is configured to receive a valve. The plurality of hydraulic passages are in fluid communication with the valve bores and arranged parallel to each other. The plurality of valve bores extend normal to the hydraulic passages and are arranged above and below the hydraulic passages.

FIELD

The present disclosure relates to a valve body having flow passages and a vehicle including a valve body having flow passage.

BACKGROUND

Transmission valve bodies typically consist of aluminum castings with worm trail routing of multiple connections between various working elements. These worm trail fluid paths typically must be two-dimensional, and cannot cross over a path of another trail. Due to this two-dimensional limitation of typical transmission valve bodies, providing a flow path from one element to another can often require a lengthy and convoluted path that adds to the complexity, cost, and size of the casting.

One method of overcoming this two-dimensional limitation includes manufacturing multiple valve bodies, each having its own two-dimensional worm trails, and connecting the valve bodies with one or more separator plates configured to permit fluid communication between the worm trails of the valve bodies in a third dimension at predetermined locations. Such separator plates require gasket seals and precise machining of the gasket surfaces. These separator plates also only allow binary cross-over of the hydraulic circuitry from one two-dimensional worm trail casting to another two-dimensional worm trail casting. Furthermore, the use of separator plates typically requires the use of additional fasteners to connect the assembly together, which can increase cost and assembly time. Additionally, the two-dimensional worm trails of each valve body must be routed around these fasteners, adding further size and complexity.

These sizing and complexity issues related to transmission valve bodies, among other issues related transmission valve bodies, are addressed by the present disclosure.

SUMMARY

In one form, the present disclosure provides a unitized valve body for use in an automatic transmission. The unitized valve body comprises a plurality of valve bores and a plurality of hydraulic passages. Each valve bore is configured to receive a valve. The plurality of hydraulic passages are in fluid communication with the valve bores and arranged parallel to each other. The plurality of valve bores extend normal to the hydraulic passages and are arranged above and below the hydraulic passages.

In variations of the unitized valve body of the above paragraph, which may be implemented individually or in any combination: the valve bores are arranged above and below the hydraulic passages in a staggered arrangement; a plurality of annuluses in fluid communication with a respective valve bore, the hydraulic passages being in fluid communication with the valve bores via the annuluses; a first set of hydraulic passages of the plurality of hydraulic passages are arranged in a row; a second set of hydraulic passages of the plurality of hydraulic passages are arranged in a row and a linking passage fluidly connects one hydraulic passage of the first set of hydraulic passages with one hydraulic passage of the second set of hydraulic passages; the linking passage extends normal to the hydraulic passages and the valve bores; the hydraulic passages are substantially linear; the valve body does not include mechanical fasteners; the valve body is formed by additive manufacturing; and the hydraulic passages have a circular cross-section.

In another form, the present disclosure provides a unitized valve body for use in an automatic transmission. The unitized valve body comprises a plurality of valve bores and a plurality of hydraulic passages. The plurality of hydraulic passages are in fluid communication with the valve bores and are arranged parallel to each other. The hydraulic passages being substantially linear. The plurality of valve bores extend normal to the hydraulic passages and are arranged above and below the hydraulic passages.

In yet another form, the present disclosure provides a unitized valve body manufactured by an additive manufacturing process.

DETAILED DESCRIPTION

With reference toFIG.1, a vehicle10is provided that includes a drivetrain system12and a powertrain system14. In the particular configuration shown inFIG.1, the drivetrain system12includes, inter alia, a propeller shaft16, a primary axle18, a secondary axle20, and a rear differential24. Rotary power (vehicle torque) generated by the powertrain system14is transmitted to the drivetrain system12. That is, rotatory power generated by the powertrain system14is transmitted to the primary axle18via the propeller shaft16to drive a set of rear wheels26. The primary axle18includes a first shaft18aand a second shaft18b. The first shaft18adrives a first wheel26aof the set of rear wheels26and the second shaft18bdrives a second wheel26bof the set of rear wheels26. The secondary axle20includes a first shaft20aand a second shaft20b. The first shaft20ais connected to a first wheel32aof a set of front wheels32and the second shaft20bis connected to a second wheel32bof the set of front wheels32. The powertrain system14includes an engine34and a transmission36such as an automatic transmission, for example. The engine34generates rotary power and may be an internal combustion engine, for example.

The transmission36transmits rotary power from the engine34to the drivetrain system12. The transmission36is generally controlled using hydraulic fluid. That is, the transmission36is cooled, lubricated, actuated, and modulates torque, for example, using hydraulic fluid. To these ends, the transmission36is in electrical communication with an electronic controller40used to direct, control, or otherwise regulate flow of fluid throughout the transmission36. In order to facilitate the flow of hydraulic fluid throughout the transmission36, the vehicle10includes at least one or more pumps to supply pressurized fluid to the transmission36. It should be appreciated that the pumps provide high flow high pressure hydraulic fluid to the transmission36.

The transmission36includes, inter alia, a casing (not shown) and a valve body assembly38. With reference toFIGS.2-7, the valve body assembly38is secured to the casing and includes a plurality of solenoid actuators48and a valve body50. Each solenoid actuator48includes a spool valve (not shown; i.e., hydraulic control valve). The spool valve is slidably disposed within a corresponding valve bore53of the valve body50and is configured to be axially positioned by an armature (not shown) of the solenoid actuator48depending on an activation state of the solenoid actuator48. The spool valve includes a plurality of cylindrical sealing segments (not shown) axially spaced apart from each other and having an outer diameter greater than adjacent lengths of the spool valve. A cylindrical surface (not shown) of the sealing segments is allowed to engage an inner cylindrical surface of the valve bore53, while fluid communication is permitted in the areas between adjacent ones of the sealing segments. A spring (not shown) may bias the spool valve in an axial direction within the valve bore53. The solenoid actuators48can be on/off actuators, variable pressure actuators, or variable flow actuators and can receive electrical power from an electrical source and can receive control signals from a control module.

The valve body50is in the form of a single unitized, monolithic body that can be manufactured by an additive manufacturing process. In this way, the valve body50does not include fasteners such as bolts, for example, securing two or more shells or housings to each other and/or to one or more separator plates. In one example, the manufacturing process can include aluminum binder jetting. In another example, the manufacturing process can include laser sintering, for example, that can generally include a laser, a means for applying subsequent layers of powdered sintering material (e.g., metal powder), and a controller that controls operation of the laser and the amount and timing of the deposition of the metal powder. It should be understood that other 3D printing/additive manufacturing methods may be employed to achieve the unitized, monolithic body, along with a variety of different materials, while remaining within the scope of the present disclosure.

The valve body50includes a plurality of sides62. In the example illustrated, side62a(FIGS.2,4, and7) of the valve body50defines the plurality of valve bores53formed therein. The valve body50also defines a plurality of annuluses or rings63(FIGS.5and7) and a plurality of trunk hydraulic passages64(FIGS.4-7). The plurality of annuluses63are axially spaced apart from each other along a corresponding valve bore53. The annuluses63are also in fluid communication with the corresponding valve bore53. Each annulus63is also in fluid communication with a corresponding passage64via an inlet/outlet port. One example of such annulus63is disclosed in Applicant's co-pending application titled “UNITIZED VALVE BODY HAVING ANNULUS” which is commonly owned with the present application and the contents of which are incorporated herein by reference in its entirety.

A plurality of connecting passages66are in fluid communication with different devices through the transmission36. For example, the connecting passages66can be coupled to a corresponding one of a return line of a pump (not shown), an outlet of a cooling fluid circuit (not shown), a supply line of the pump (not shown), a clutch lubrication circuit (not shown), a clutch actuator (not shown) corresponding to the odd numbered gears (not shown) of the transmission36, a filtered fluid inlet (not shown), or a clutch actuator (not shown) corresponding to the even numbered gears (not shown) of the transmission36, though other devices can be used.

The plurality of connecting passages66are also in fluid communication with respective valve bores53and/or one or more hydraulic passages64. As shown inFIG.8, in one example, passage66afluidly connects one annulus63associated with a respective valve bore53to another annulus63associated with the respective valve bore53. In another example, connecting passages66b,66cfluidly connect a respective annulus63associated with one valve bore53to a respective annulus63associated with another valve bore53. The first and second connecting passages66b,66cmay be fluidly connected via a respective hydraulic passage64.

With reference toFIGS.4-8, the hydraulic passages64may be connected to a pressurized fluid source such as a pump located external to the valve body50. The hydraulic passages64are also in fluid communication with the valve bores53and are arranged parallel to each other. The valve bores53extend normal to the hydraulic passages64and are arranged above and below the hydraulic passages64in a staggered arrangement (FIG.5). In the example illustrated, each hydraulic passage64is substantially linear and has a generally circular cross-section. In some forms, the hydraulic passages64may have a semi-circular or other suitable cross-section, for example, allowing hydraulic fluid to easily flow through. One or more of the hydraulic passages64extend substantially a length of the valve body50. A set of hydraulic passages64are arranged in a row and are fluidly isolated from each other (FIGS.4and6). One hydraulic passage64of the set of hydraulic passages64arranged in one row is in fluid communication with a corresponding hydraulic passage64of another set of hydraulic passages64arranged in another row via a linking passage70. The linking passage70extends normal to the hydraulic passages64and the valve bores53. The annuluses63are 2.1 times greater than the diameter of the hydraulic passages64. The valve bores53are 2 times greater than the diameter of the hydraulic passages64. The linking passages70are 1.5 times greater than the diameter of the hydraulic passages64.

The valve body50of the present disclosure being additively manufactured provides the benefit of allowing multiple hydraulic passages64of the plurality of hydraulic passages64to be connected to the valve bores53. In this way, the hydraulic passages64are positioned parallel to each other and the valve bores53may be arranged above and below the hydraulic passages64in a staggered arrangement, which reduces the overall footprint of the valve body50. The valve body50of the present disclosure being additively manufactured also provides the benefit of reduced passage lengths allowed by connecting passages in multiple dimensions.