Vehicle with Gear and Hydraulic Cooling System

Abstract

A vehicle includes a frame, at least one traction device, a tool, a gearbox, a hydraulic system having a hydraulic reservoir, and an oil cooling system. The at least one traction device is connected to the frame to facilitate the movement of the vehicle. The tool is connected to the frame and is configured to perform work operations. The oil cooling system is configured to cool the gearbox and the hydraulic system. The oil cooling system includes a first circuit and a second circuit for cooling oil, and a crossover circuit. The first circuit includes the gearbox and a first oil - air cooler configured to cool the cooling oil from the gearbox. The second circuit includes the hydraulic reservoir and a second oil - air cooler for cooling the cooling oil from the hydraulic reservoir. The crossover circuit includes the gearbox and the hydraulic reservoir and is configured to exchange cooling oil between the gearbox and the hydraulic reservoir to provide heat transfer between the first circuit and the second circuit.

Description

Background Art

[0001] The present disclosure relates to a cooling system for a vehicle, such as an agricultural harvester. More specifically, the present disclosure relates to a cooling system for cooling a transmission and a hydraulic system. Generally, two separate cooling systems are used for the transmission and the hydraulic system, each cooling system having its own cooler and piping. Summary of the Invention

[0002] In one aspect, the present disclosure provides a vehicle. The vehicle includes a frame, at least one traction device, a tool, a transmission, a hydraulic system having a hydraulic reservoir, and an oil cooling system. The at least one traction device is connected to the frame to facilitate movement of the vehicle. The tool is connected to the frame and is configured to perform an operation. The oil cooling system is configured to cool the transmission and the hydraulic system. The oil cooling system includes a first circuit for cooling oil, a second circuit for cooling oil, and a crossover circuit. The first circuit includes the transmission and a first oil-air cooler configured to cool the cooling oil from the transmission. The second circuit includes the hydraulic reservoir and a second oil-air cooler for cooling the cooling oil from the hydraulic reservoir. The crossover circuit includes the transmission and the hydraulic reservoir and is configured to exchange cooling oil between the transmission and the hydraulic reservoir to provide heat transfer between the first circuit and the second circuit.

[0003] In another aspect, the present invention provides a cooling system for a vehicle that includes a transmission and a hydraulic system. The cooling system includes a first circuit for a coolant, a second circuit for a coolant, and a crossover circuit. The first circuit is configured to cool the transmission. The second circuit is configured to cool the hydraulic system. The first circuit includes the transmission and a first cooler configured to cool the coolant from the transmission. The second circuit includes the hydraulic reservoir for the hydraulic system and a second cooler configured to cool the coolant from the hydraulic reservoir. The crossover circuit includes the transmission and the hydraulic reservoir and is configured to exchange coolant between the transmission and the hydraulic reservoir to provide heat transfer between the first circuit and the second circuit.

[0004] In another aspect, the present disclosure provides a vehicle system including a vehicle and a cooling system. The vehicle includes a first heat generating system and a second heat generating system. The cooling system is configured to cool the first heat generating system and the second heat generating system. The cooling system includes a first coolant circuit and a second coolant circuit. The first circuit is configured to transfer heat from the first heat generating system to a first cooler configured to cool the coolant. The second circuit is configured to transfer heat from the second heat generating system to a second cooler configured to cool the coolant. The first circuit and the second circuit are in fluid communication with each other such that the coolant cross-circulates between the first circuit and the second circuit.

[0005] In some embodiments, the oil cooling system further includes a first pump located in the first circuit, the first pump being configured to move the cooling oil between the transmission and the first oil-air cooler; and a second pump located in the second circuit, the second pump being configured to move the cooling oil between the hydraulic reservoir and the second oil-air cooler.

[0006] In some embodiments, the oil cooling system further includes a third pump configured to move the cooling oil in a bridging circuit.

[0007] In some embodiments, the third pump is configured to draw cooling oil from the transmission, and wherein the hydraulic reservoir is configured to direct the overflow cooling oil to the transmission.

[0008] In some embodiments, the oil cooling system further includes a pump located in the bridging circuit, the pump being configured to continuously move the cooling oil to effect continuous heat exchange between the first circuit and the second circuit.

[0009] In some embodiments, the oil cooling system further includes a rotor-driven transmission fluidly disposed between the first oil-air cooler and the transmission, wherein the rotor-driven transmission is configured to be cooled by the cooling oil in the first circuit.

[0010] In some embodiments, the first oil-air cooler and the second oil-air cooler are in communication with a common air source.

[0011] In some embodiments, the first cooler and the second cooler are air-cooled.

[0012] In some embodiments, the coolant is oil, and wherein the oil is further configured to lubricate the transmission.

[0013] Other aspects of the present disclosure will become apparent by considering the detailed description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a perspective view of a harvester.

[0015] Figure 2 is Figure 1 a schematic cooling system diagram of a harvester.

[0016] Figure 3 is Figure 2 a schematic diagram of a combined cooler of the cooling system.

[0017] Figure 4 is Figure 2 a schematic heat transfer diagram of the cooling system during harvesting.

[0018] Figure 5 is Figure 2 a schematic heat transfer diagram of the cooling system during travel. Detailed Implementation Modes

[0019] Before explaining any embodiments of the present disclosure in detail, it should be understood that the present disclosure is not limited in its application to the details of the construction and arrangement of components set forth in the following description or shown in the drawings. The present disclosure is capable of supporting other embodiments and can be practiced or carried out in various ways. The term "about" as used herein is intended to give its ordinary meaning, such as "approximate".

[0020] Figure 1 A vehicle system 10 including a vehicle 12 is shown according to one embodiment. Although the vehicle 12 shown is shown as a combine harvester, in other embodiments, the vehicle 12 can be any suitable machine or device, such as other agricultural vehicles, construction vehicles, or other vehicles with tools, etc. The vehicle 12 includes at least one tool 14 for performing work operations. In the embodiment shown, the vehicle 12 includes tools such as a header 16 and a separator 18 for harvesting and separating crops, respectively. In other embodiments, the at least one tool 14 may include other devices for agricultural applications, construction applications, and other applications requiring work operations, such as buckets, scrapers, cutters, etc.

[0021] The shown vehicle 12 includes a header 16, a separator 18, a prime mover 20 (such as an engine), a cab 22, a feed chamber 24, and at least one traction device 26. The prime mover 20 is configured to move the vehicle 12 in the travel direction 28 through the at least one traction device 26. The shown at least one traction device 26 includes wheels, but one or more continuous tracks or other suitable traction devices can be used to facilitate movement along the support surface.

[0022] The header 16 includes a cutter 30 and a reel 32. The cutter is configured to cut the crop being harvested, and the reel is configured to press the crop against the cutter 30 to cut the crop.

[0023] Vehicle system 10 also includes a transmission 34, such as a main engine transmission, a hydraulic system 36, and a cooling system 38 for cooling the main engine transmission 34 and the hydraulic system 36. In other embodiments, the transmission 34 being cooled can be other types of transmissions other than the main engine transmission, such as any engine transmission or other drive transmission. In other embodiments, the main engine transmission 34 and the hydraulic system 36 can each be any type of heat generating system configured to be cooled by the cooling system 38. In the illustrated embodiment, the cooling system 38 is an oil cooling system that uses oil as the coolant. The oil also serves as a lubricant for the main engine transmission 34 and a fluid for the hydraulic system 36. In other embodiments, other types of cooling systems with other types of coolants can be employed.

[0024] Figure 2 The cooling system 38 is shown, which includes a transmission cooling circuit 40, a hydraulic cooling circuit 42, and a crossover circuit 44.

[0025] The transmission cooling circuit 40 includes the main engine transmission 34, a transmission cooling pump 46, and a transmission cooler 48, all of which are fluidly connected in a continuous circuit by a series of pipes 50. The transmission cooling pump 46 is disposed downstream of the main engine transmission 34 and upstream of the transmission cooler 48, and is configured to draw coolant from the main engine transmission 34. The transmission cooling pump 46 can have a flow rate of up to about 16 gallons per minute (59 liters per minute), but in other embodiments the flow rate can be higher or lower. The transmission cooling pump 46 in the illustrated configuration is a fixed displacement single rotation pump, but can have another configuration in other embodiments. For example, the displacement can be about 1.52 cubic inches (24.84 cubic centimeters), but can be higher or lower in other embodiments.

[0026] The transmission cooler 48 is disposed downstream of the transmission cooling pump 46 and upstream of the main engine transmission 34. The transmission cooler 48 is an oil - air cooler in the illustrated embodiment, but can be another type of cooler in other embodiments. Specifically, the transmission cooler 48 is a heat exchanger containing oil, and the oil is cooled by an external air flow from a fan 52 ( Figure 3 ) such as an engine cooling fan or other fans in other embodiments. The transmission cooler 48 is configured to supply cooled coolant to the main engine transmission 34. Thus, the transmission cooling circuit 40 is configured to cool the main engine transmission 34.

[0027] The rotor drive transmission 54 (e.g., a rotor drive three-speed transmission) is disposed in parallel between the transmission cooler 48 and the main engine transmission 34. The rotor drive transmission 54 is configured to receive coolant from the transmission cooler 48 in parallel with the main engine transmission 34. The rotor drive transmission 54 is configured to supply coolant downstream of the main engine transmission 34, specifically to the transmission reservoir 56 containing the hot coolant. Accordingly, the rotor drive transmission 54 is also cooled. In other configurations, the rotor drive transmission 54 can be another type of transmission or another heat generating system.

[0028] The hydraulic cooling circuit 42 includes a hydraulic cooling pump 60, a hydraulic cooler 62, and a hydraulic reservoir 58 for the hydraulic system 36, all of which are fluidly connected in a continuous loop by a series of pipes 64. The hydraulic reservoir 58 is an open reservoir (e.g., vented and unpressurized). The hydraulic cooling pump 60 is disposed downstream of the hydraulic reservoir 58 and upstream of the hydraulic cooler 62, and the hydraulic cooling pump 60 is configured to draw coolant from the hydraulic reservoir 58. The hydraulic cooling pump 60 can have a flow rate of about 29 gallons per minute (110 liters per minute), but the flow rate can be higher or lower in other embodiments. In the illustrated configuration, the hydraulic cooling pump 60 is a fixed displacement single rotation pump, but can have other configurations in other embodiments. For example, the displacement can be about 3.16 cubic inches (51.83 cubic centimeters), but can be higher or lower in other embodiments.

[0029] The hydraulic cooler 62 is disposed downstream of the hydraulic cooling pump 60 and upstream of the hydraulic reservoir 58. The hydraulic cooler 62 is an oil-air cooler in the illustrated embodiment, but can be another type of cooler in other embodiments. Specifically, the hydraulic cooler 62 is a heat exchanger containing oil that is cooled by an external air flow from the fan 52 ( Figure 5 ). In other embodiments, the hydraulic cooler 62 can be cooled by a different air flow from a different fan. In still other embodiments, the hydraulic cooler 62 can be a different type of heat exchanger. The hydraulic cooler 62 is configured to return the cooled coolant to the hydraulic reservoir 58. Accordingly, the hydraulic cooling circuit 42 is configured to cool the coolant in the hydraulic reservoir 58 and thus cool the hydraulic system 36.

[0030] The hydraulic system 36 can include a transmission 66, such as a multi-motor transmission (MMT), which is arranged to be in fluid communication with the hydraulic cooling circuit 42. The transmission 66 can respectively have a first motor 68a, a second motor 68b, and a third motor 68c, as in the illustrated embodiment. However, in other embodiments, the transmission can have one motor, two motors, four or more motors, or any suitable number of motors. The motors 68a, 68b, 68c can be variable displacement dual-rotation direction motors (as shown) or can be other types of motors in other embodiments. One of the motors (e.g., the first motor 68A) can be part of the hydraulic cooling circuit 42, as shown, which is arranged downstream of the hydraulic cooling pump 60 and before the hydraulic cooler 62. The hydraulic system 36 further includes a hydraulic pump device 70 and a closed reservoir 72. The closed reservoir 72 is in fluid communication with the motors 68a, 68b, 68c. The hydraulic pump device 70 also supplies coolant to the hydraulic reservoir 58.

[0031] The crossover circuit 44 includes a hydraulic reservoir 58, a main engine transmission 34, and a crossover pump 74 (which can also be referred to as a proportioner), all of which are fluidly connected in a continuous circuit by a series of pipes 76. The crossover circuit 44 can also include a hydraulic pump device 70, where the closed reservoir 72 is arranged downstream of the crossover pump 74 and before the hydraulic reservoir 58 for supplying coolant to the hydraulic reservoir 58. The crossover pump 74 is arranged downstream of the main engine transmission 34 and is configured to draw coolant from the main engine transmission 34 in parallel with the transmission cooling pump 46. The crossover pump 74 can have a flow rate of up to about 9 gallons per minute (32 liters per minute), but in other embodiments, this flow rate can be higher or lower. The crossover pump 74 in the illustrated configuration is a fixed displacement single-rotation pump, but can have other configurations in other embodiments. For example, the displacement can be about 0.83 cubic inches (13.52 cubic centimeters), but can be higher or lower in other embodiments. The crossover pump 74 supplies the coolant from the main engine transmission 34 to the hydraulic pump device 70 and ultimately to the hydraulic reservoir 58. The hydraulic reservoir 58 is configured to mix the coolant from the main engine transmission 34 and the hydraulic pump device 70 with the coolant from the hydraulic cooler 62. The hydraulic reservoir 58 is also configured to supply the overflow coolant to the main engine transmission 34 in a cascading manner, for example, at a flow rate of about 9 gallons per minute (32 liters per minute) or other suitable flow rates.

[0032] As Figure 3As shown, the transmission cooler 48 and the hydraulic cooler 62 can be configured as a single unit, such as a combined cooler 78. The combined cooler 78 is a single heat exchanger having separate flow paths for the transmission cooler 48 and the hydraulic cooler 62. For example, the transmission cooler 48 can have approximately 7 tubes, while the hydraulic cooler 62 can have approximately 15 tubes, but other suitable numbers and ratios of tubes can be employed for a given system. The combined cooler 78 is in a heat exchange relationship with a shared cooling fluid (such as the airflow from the fan 52) to provide cooling for the transmission cooler 48 and the hydraulic cooler 62. The combined cooler 78, together with the crossflow (jumper loop 44) described above, forms a more stable cooling system with the ability to self-regulate temperature. The size of the combined cooler 78 is generally designed to meet the average heat rejection requirements of the overall cooling system (with some acceptable margin to achieve acceptable cooling of all components), but then allows the crossflow to regulate the temperatures on both sides (e.g., the transmission cooling loop 40 side and the hydraulic cooling loop 42 side) to inhibit component overheating and better utilize the heat rejection capacity of the cooling system. In other embodiments, the transmission cooler 48 and the hydraulic cooler 62 do not need to be formed as a single unit. The transmission cooler 48 and the hydraulic cooler 62 can be separate heat exchangers and still share the same cooling fluid, and separate cooling fluids can be employed in other embodiments. In any case, the transmission cooler 48 and the hydraulic cooler 62 are arranged in parallel to reject heat from the main engine transmission 34 and the hydraulic reservoir 58.

[0033] In operation, the main engine transmission 34 and the hydraulic system 36 generate heat, and the cooling system 38 moves the heat. Figure 4Shows heat transfer within the cooling system 38 during a harvesting operation or other operation (e.g., in tool mode when a tool 14 such as a separator 18 is actuated). As shown, heat (Qgear) is absorbed by the coolant in the main engine transmission 34, which accumulates in the transmission reservoir 56. When the temperature (Tmeg) of the main engine transmission coolant is greater than the temperature (Thyd) of the hydraulic reservoir coolant, a portion (Qx) of the main engine transmission heat is transferred to the hydraulic reservoir 58, and another portion (Qgoc) of the main engine transmission heat is transferred to the cooling air through the transmission cooler 48. During harvesting, the transmission cooling (Qgoc) will be relatively high, while the propulsion / hydraulic cooling (Qhoc) is relatively low. In this case, the temperature (Tmeg) of the main engine transmission reservoir coolant increases, while the temperature of the hydraulic reservoir (Thyd) is generally relatively low in temperature. Thus, the cross-coolant flow between the transmission reservoir 56 and the hydraulic reservoir 58 (as described above) transfers heat from the higher temperature to the lower temperature reservoir. This is beneficial for balancing the reservoir temperatures. In tool mode, this means that even if the transmission cooler 48 cannot completely discharge all of the heat load on the cooling system 38 side, however, the main engine transmission temperature (Tmeg) will be moderated (preventing overheating in the transmission cooling circuit 40). Conversely, since heat is being transferred into the hydraulic reservoir 58, the temperature there will increase, allowing the hydraulic cooler 62 to discharge more heat to the cooling air. Thus, both the transmission cooler 48 and the hydraulic cooler 62 are configured to cool the main engine transmission 34 when the temperature (Tmeg) of the main engine transmission coolant is higher than the temperature (Thyd) of the hydraulic reservoir coolant.

[0034] Figure 5Illustrated is the heat transfer within the cooling system 38 during travel when the tool 14 is not actuated (e.g., during transportation of the vehicle 12 in a transportation mode). As shown, heat (Qhyd) is absorbed by the coolant in the hydraulic reservoir 58. When the temperature (Tmg) of the main engine transmission coolant is less than the temperature (Thyd) of the hydraulic reservoir coolant, at this time a portion (Qx) of the heat in the hydraulic reservoir is transferred to the main engine transmission 34 through the jumper circuit 44, and another portion (Qhoc) of the heat in the hydraulic reservoir is transferred to the cooling air through the hydraulic cooler 62. During transportation (tool off), the transmission cooling (Qgoc) may significantly decrease. However, the propulsion load (e.g., at 25 mph (40 kph)) may be very high, thus requiring higher hydraulic / propulsion cooling. In this case, the hydraulic reservoir temperature (Thyd) is typically higher than the main engine transmission reservoir temperature (Tmeg). Therefore, the cross-coolant flow carries heat from the hydraulic reservoir 58 to the main engine transmission reservoir 56. This enables the transmission cooler 48 to discharge more heat (Qgoc) to the cooling air. Thus, both the transmission cooler 48 and the hydraulic cooler 62 are configured to cool the hydraulic system 36 when the temperature (Thyd) of the hydraulic reservoir coolant is higher than the temperature (Tmg) of the main engine transmission coolant.

[0035] Accordingly, the main engine transmission 34 and the rotor drive transmission 54 are directly cooled by the transmission cooler 48 and are in parallel with the hydraulic cooler 62. Additionally, the hydraulic system 36 is directly cooled by the hydraulic cooler 62 and is in parallel with the transmission cooler 48. If one side of the cooling system 38 receives more heat than its corresponding cooler can dissipate, the excess heat from that side will flow to the other side through the mixing of the overflowing coolant. In this way, the cooling system 38 can automatically balance heat rejection and inhibit overheating of individual components. The combined cooler 78 provides the advantages of a large oil cooler concept, which has the ability to provide excellent temperature control for the transmission and the hydraulic device.

[0036] Accordingly, the present disclosure particularly provides a cooling system 38 having a continuous cross-coolant flow to automatically balance heat rejection between separate cooling circuits and inhibit overheating of separate components. The various features and advantages of the present invention are set forth in the appended claims.

Claims

1. A vehicle system (10) comprising: A vehicle (12) including a first heating system (34) and a second heating system (36); And A cooling system (38) configured to cool the first heating system (34) and the second heating system (36), the cooling system (38) comprising: A first circuit (40) for a coolant, the first circuit (40) configured to transfer heat from the first heating system (34) to a first cooler (48), the first cooler (48) configured to cool the coolant; A second circuit (42) for the coolant, the second circuit (42) configured to transfer heat from the second heating system (36) to a second cooler (62), the second cooler (62) configured to cool the coolant; and A fluid conduit (76), Wherein the first circuit (40) and the second circuit (42) are in fluid communication with each other via the fluid conduit (76) so that the coolant cross - circulates between the first circuit (40) and the second circuit (42), and Wherein the fluid conduit (76) provides fluid communication between the first circuit (40) and the second circuit (42), wherein the fluid conduit (76) conveys coolant between the first heating system (34) and the second heating system (36), and wherein the fluid conduit is configured to move coolant from a hydraulic reservoir (58) in the second heating system (36) to the first heating system (34).

2. The vehicle system (10) according to claim 1, wherein, The fluid conduit (76) is configured to direct coolant between the first heating system (34) and the second heating system (36).

3. The vehicle system (10) according to claim 2, wherein, The hydraulic reservoir (58) of the second heating system (36) is configured to receive cooled coolant from the second cooler (62) and receive coolant from the first heating system (34).

4. The vehicle system (10) according to claim 3, wherein, The cooling system (38) further comprises: A pump (46) configured to move un - cooled coolant from the first heating system (34) to the hydraulic reservoir (58).

5. The vehicle system (10) according to claim 1, wherein, The vehicle (12) includes: At least one traction device (26) for facilitating movement of the vehicle (12); and A tool (14) configured to perform work operations.

6. The vehicle system (10) according to claim 1, wherein, The first heating system (34) includes a transmission (34), and the second heating system (36) includes a hydraulic system (36) having a hydraulic reservoir (58), wherein the second circuit (42) is configured to cool the coolant contained in the hydraulic reservoir (58).

7. The vehicle system (10) according to claim 1, wherein, The first cooler (48) and the second cooler (62) are air - cooled.

8. The vehicle system (10) according to claim 1, wherein, The coolant is oil, and wherein the oil is further configured to lubricate components of the first heating system (34).

9. The vehicle system (10) according to claim 1, wherein, The cooling system (38) further comprises: A first pump (46) located in a first circuit (40), the first pump (46) being configured to move the coolant between the first heat generating system (34) and the first cooler (48); and A second pump (60) located in a second circuit (42), the second pump (60) being configured to move the coolant between the second heat generating system (36) and the second cooler (62).

10. The vehicle system (10) according to claim 9 further includes a jumper circuit (44) defining the cross-circulation, wherein, The bridging circuit (44) includes the fluid conduit (76), wherein the cooling system (38) further includes a third pump (74), the third pump being configured to move the coolant in the bridging circuit (44), wherein the third pump (74) is configured to draw the coolant from the first heat generating system (34), and wherein the second heat generating system (36) is configured to direct the overflow coolant to the first heat generating system (34).

Images