Multi-pump equipment and cooling system of work vehicles

Abstract

This invention relates to a multi-pump device for work vehicles and a cooling system for work vehicles. A multi-pump device for a work vehicle may include a main housing, a motor shaft, a water pump, and a refrigerant pump. The main housing has a first housing portion and a second housing portion coupled to the first housing portion. The motor shaft is positioned through the first housing portion. The water pump is coupled to the first housing portion and operable to pump coolant. The water pump is driven by the motor shaft. The refrigerant pump is coupled to the second housing portion and operable to pump refrigerant. The refrigerant pump is also driven by the motor shaft.

Description

Technical Field

[0001] This disclosure generally relates to a multi-pump device for a work vehicle. Background Technology

[0002] Internal combustion engine vehicles, electric vehicles, and hybrid vehicles may all require their own water pumps to circulate coolant through vehicle components (heat loads), even if the pump layouts may differ. The coolant can be water or antifreeze, a mixture of water and antifreeze chemicals such as ethylene glycol or propylene glycol. When the work vehicle is an internal combustion engine vehicle, the coolant can be used to cool the engine. When the work vehicle is an electric vehicle, the coolant can be used to cool electrical components. The coolant that absorbs heat from the vehicle components can then enter the radiator to dissipate heat. Airflow through the radiator will extract heat, allowing the coolant to absorb heat from the vehicle components again. Summary of the Invention

[0003] According to one aspect of this disclosure, a multi-pump device for a work vehicle may include a main housing, a motor shaft, a water pump, and a refrigerant pump. The main housing has a first housing portion and a second housing portion coupled to the first housing portion. The motor shaft is positioned through the first housing portion. The water pump is coupled to the first housing portion and operable to pump coolant. The water pump is driven by the motor shaft. The refrigerant pump is coupled to the second housing portion and operable to pump refrigerant. The refrigerant pump is also driven by the motor shaft.

[0004] According to one aspect of the invention, a cooling system for a work vehicle includes a multi-pump device, a pressure reducer, a main heat exchanger, a condenser, and at least one vehicle component. The multi-pump device may include a main housing, a motor shaft, a water pump, and a refrigerant pump. The main housing has a first housing portion and a second housing portion coupled to the first housing portion. The motor shaft is positioned through the first housing portion. The water pump is coupled to the first housing portion and operable to pump coolant. The water pump is driven by the motor shaft. The refrigerant pump is coupled to the second housing portion and operable to pump refrigerant. The refrigerant pump is also driven by the motor shaft. The pressure reducer receives refrigerant from the refrigerant pump and is operable to reduce the pressure of the refrigerant to lower its temperature. The main heat exchanger has a first unit and a second unit. The first unit is operable to receive refrigerant from the pressure reducer. The condenser is positioned downstream of the first unit of the main heat exchanger and is operable to cool the refrigerant into a liquid form. The vehicle component receives coolant from the water pump to dissipate heat. The second unit of the main heat exchanger is positioned downstream of the vehicle component. The second unit of the main heat exchanger is operable to absorb heat from vehicle components and discharge heat to the first unit of the main heat exchanger.

[0005] Other features and aspects will become apparent by considering the detailed description and accompanying drawings. Attached Figure Description

[0006] Please refer to the attached figures for a detailed description:

[0007] Figure 1 This is a schematic diagram showing a cooling system with a compressor.

[0008] Figure 2 This is a schematic diagram of a cooling system with a refrigerant circuit and a coolant circuit, which has heat load exchangers connected in series.

[0009] Figure 3 This is a schematic diagram of another cooling system with a refrigerant circuit and a coolant circuit, which has heat load exchangers connected in parallel.

[0010] Figure 4 This is a cross-sectional view showing a multi-pump device in one implementation.

[0011] Figure 5 This is a cross-sectional view of a multi-pump device in another implementation.

[0012] Specific implementation method

[0013] Reference Figure 1 The cooling system used in air conditioners includes an evaporator 004, a compressor 008, a condenser 002, and a thermal expansion valve (TXV). Refrigerant flows through these components in liquid and / or vapor form at different pressures. Air conditioners are typically mounted on the walls of a house, with some components located indoors and others outdoors. Generally, the compressor 008 and condenser 002 are located in the outdoor environment; the thermal expansion valve (TXV) and evaporator 004 are located in the indoor environment. The evaporator 004 is located on the low-pressure side (compressor suction side), and the condenser 002 is used on the high-pressure side. The thermal expansion valve (TXV) is used between the condenser 002 and the evaporator 004 to reduce pressure.

[0014] In the path between evaporator 004 and compressor 008 (suction line), the refrigerant is at low pressure and low temperature. For compressor 008 to operate normally, the refrigerant is in vapor form (gas or superheated gas). When the refrigerant reaches compressor 008, compressor 008 compresses the vaporized refrigerant, resulting in high pressure (P00) of the refrigerant in the path between compressor 008 and condenser 002. HThe refrigerant is exposed to high temperatures (potentially overheating). When the refrigerant reaches condenser 002, condenser 002 cools the refrigerant and condenses it into a liquid form via a fan (not shown). The fan provides a first airflow AF1 that passes through the heat dissipation elements of condenser 002 to remove heat from condenser 002. The refrigerant at the outlet of condenser 002 must be a saturated or subcooled liquid to allow the thermal expansion valve (TXV) to operate smoothly. The refrigerant remains under high pressure in the path between condenser 002 and the thermal expansion valve (TXV).

[0015] The thermal expansion valve (TXV) then collects the refrigerant from the condenser 002. Within the thermal expansion valve (TXV), the refrigerant pressure drops sharply. The refrigerant temperature also decreases. Therefore, in the path between the thermal expansion valve (TXV) and the evaporator 004, the refrigerant is at a low pressure (P). L Low-pressure refrigerant flows into evaporator 004. Another fan (not shown) adjacent to evaporator 004 provides a second airflow AF2 (indoors) through the heat exchange elements of evaporator 004. The heat of the second airflow AF2 is absorbed by the refrigerant because the refrigerant in liquid form requires latent heat (energy potential energy) to turn into vapor. Again, the refrigerant is discharged from evaporator 004 and flows into compressor 008.

[0016] Figure 2 A cooling system 12 of the work vehicle 10 is shown. The cooling system 12 includes a refrigerant circuit 20, a coolant circuit 40, and a multi-pump device 60 operable to pump refrigerant in the refrigerant circuit 20 and coolant in the coolant circuit 40. The cooling system 12 may also include a main heat exchanger 14 operable to extract heat from the coolant circuit 40 and dissipate it to the refrigerant circuit 20. The cooling system 12 can be used to absorb heat from various vehicle components, including transmissions, shafts, electrical components, hydraulic pumps, and / or motors. When the work vehicle 10 is an electric vehicle, the electrical components may include, but are not limited to, motors, accessories, battery cells, inverters, and / or converters. The battery cells may include traction battery packs, DC converters, and auxiliary battery packs. As electricity flows, the temperature of the electrical components rises.

[0017] Regarding refrigerant circuit 20, unlike conventional cooling systems with compressor 008 that generates high system pressure, this refrigerant circuit uses pumps (refrigerant pumps 68, 88) to circulate the refrigerant. Refrigerant circuit 20 has a lower system pressure compared to conventional cooling systems.

[0018] The refrigerant circuit 20 may include: refrigerant pumps 68 and 88 of a multi-pump device 60, 80; a pressure reducer 22; a first unit (evaporator) 142 of the main heat exchanger 14; and a condenser 24. The refrigerant pumps 68 and 88 are operable to pump refrigerant from the condenser 24 to the first unit (evaporator) 142, such that the first unit 142 is downstream of the refrigerant pumps 68 and 88, and the condenser 24 is downstream of the first unit 142. The pressure reducer 22 reduces the pressure of the refrigerant and lowers its boiling point. Some of the refrigerant in liquid form becomes vapor, and the temperature of the refrigerant (both liquid and vapor forms) decreases. The refrigerant then enters the first unit 142 of the main heat exchanger 14 to absorb heat from the refrigerant circuit 40 through the second unit 144 of the main heat exchanger 14. During the heat exchange between the first unit 142 and the second unit 144, more of the liquid refrigerant becomes vapor. The refrigerant then enters the condenser 24. The airflow AF cools the refrigerant, and at least some of the refrigerant in vapor form becomes liquid.

[0019] Optionally, the refrigerant circuit 20 may also include a separator 26 positioned between the condenser 24 and the refrigerant pumps 68 and 88. The separator 26 separates the liquid form of the refrigerant from the vapor form, ensuring that only the liquid form of the refrigerant is pumped by the refrigerant pumps 68 and 88. When the refrigerant pumps 68 and 88 are rotary positive displacement pumps, such as gear pumps, the separator 26 helps prevent cavitation.

[0020] The coolant circuit 40 may include: water pumps 64 and 84; at least one heat load exchanger; and a second unit 144 of the main heat exchanger 14. The water pumps 64 and 84 are operable to circulate coolant. The coolant pumped by the water pumps 64 and 84 enters the at least one heat load exchanger and absorbs heat from the heat load (vehicle components). The coolant then enters the second unit 144 of the main heat exchanger 14 for heat dissipation. The heat load exchanger may be used to cool vehicle components such as transmissions, shafts, battery cells, hydraulic pumps, and motors. In this implementation, at least one heat load exchanger includes a first heat load exchanger 41, a second heat load exchanger 42, and a third heat load exchanger 43. If the operating vehicle 10 is an electric or hybrid vehicle, the first heat load exchanger 41 may, for example, be used to dissipate heat from the battery cell, and the first heat load exchanger 41 is located upstream of the second heat load exchanger 42 and the third heat load exchanger 43. Figure 2 A first heat load exchanger 41, a second heat load exchanger 42, and a third heat load exchanger 43 connected in series are shown; however, in other implementations, the heat load exchangers may be connected in different ways. For example, Figure 3A first heat load exchanger 41, a second heat load exchanger 42, and a third heat load exchanger 43 connected in parallel are shown. Flow control valves (not shown) may be present to control the volume of coolant entering the first heat load exchanger 41, the second heat load exchanger 42, and the third heat load exchanger 43. A buffer tank (not shown) may also be required for the coolant circuit 40, operable to store excess coolant and discharge coolant when the coolant circuit 40 requires more coolant. Note that the coolant pumped by the water pump is not limited to water, antifreeze fluid (ethylene glycol), or other types of fluids.

[0021] Reference Figure 4 In one implementation, the multi-pump device 60 of the work vehicle 10 may include a motor shaft 61, a main housing 62, a water pump 64, and a refrigerant pump 68. The multi-pump device 60 has an in-line configuration that allows for optimized inlet conditions for the water pump 64. The multi-pump device 60 may be coupled to or include a motor 63 that rotates the motor shaft 61. In this implementation, the motor 63 is an electric motor. The main housing 62 has a first housing portion 622 and a second housing portion 624 coupled to the first housing portion 622. In this implementation, the first housing portion 622 and the second housing portion 624 are arranged in a vertical orientation, and the motor shaft 61 rotates about an axis parallel to the vertical orientation.

[0022] The first housing portion 622 includes an upper compartment 6222 and a lower compartment 6226 located below the upper compartment 6222. The upper compartment 6222 and the lower compartment 6226 of the first housing portion 622 cooperate to receive coolant. A baffle 6224 is positioned between the upper compartment 6222 and the lower compartment 6226 to control the flow of coolant between the upper compartment 6222 and the lower compartment 6226.

[0023] The upper compartment 6222 is operable to receive coolant from the water pump inlet 6225 to increase fluid pressure. The upper compartment 6222 and the surface of the coolant fluid define a space 6221 within the upper compartment 6222. A pressure cap 6223 is attached to the upper compartment 6222 and can be used to change the volume of coolant, fluid pressure, and / or air pressure within the space 6221.

[0024] A motor shaft 61 is positioned through a first housing portion 622. A water pump 64 is coupled to or has the first housing portion 622. The water pump 64 includes a water pump impeller 642 driven by the motor shaft 61. The water pump impeller 642 is positioned within a lower compartment 6226 and is therefore immersed in coolant. The lower compartment 6226 includes a water pump outlet 6227 for coolant to flow out from the water pump 64. The coolant then enters a first heat load exchanger 41, a second heat load exchanger 42, and / or a third heat load exchanger 43, such as... Figure 2 or Figure 3 As shown. The lower compartment 6226 has a volute structure / volute housing (not shown), the area of ​​which gradually increases as the volute structure approaches the pump outlet 6227. The pump impeller 642, housed within the volute structure, rotates together with the motor shaft 61 to discharge coolant.

[0025] The water pump 64, together with the first housing portion 622, provides multiple functions for the coolant circuit 40 beyond pumping coolant. In this implementation, the coolant circuit 40 may not require a separate buffer tank or overflow bottle. The combination of the upper compartment 6222 and the lower compartment 6226 stores coolant, prevents coolant surging, and provides pressurized coolant as the coolant level (volume) increases. Submerging the water pump impeller 642 within the pressurized lower compartment 6226, which contains antifreeze (ethylene glycol), improves pump condition and prevents pump cavitation. During operation of the water pump 64, coolant bubbles will be generated. Due to buoyancy, coolant bubbles in the upper compartment 6222 will float to the surface of the upper compartment 6222. The bubbles will be collected only in the upper compartment 6222. In this respect, the pump impeller 642 located in the lower compartment 6226 will not pump air bubbles, and the lifespan of the pump 64 and other components of the coolant circuit 40 will increase. As the motor shaft 61 rotates, the temperature of the first housing portion 622 rises, and the air pressure in space 6221 increases. Due to the level of the coolant and the air pressure in space 6221, the boiling point of the coolant will rise to prevent coolant evaporation. Fluid pressure and air pressure also inhibit the formation of air bubbles that cause pump cavitation.

[0026] The multi-pump device 60 may also include a magnetic coupling 66 operable to transmit a portion of the power from the motor shaft 61 to the refrigerant pump 68. For example... Figure 4 As shown, the magnetic coupling 66 includes a drive element 662 and a driven element 664. The drive element 662 is located within a first housing portion 622, while the driven element 664 is located within a second housing portion 624. The first housing portion 622 may include a magnet compartment 6228 located below the pump impeller 642 or below the lower compartment 6226. The drive element 662 of the magnetic coupling 66 is located at least within the magnet compartment 6228. The drive element 662 is also coupled to a motor shaft 61 and rotates at the same speed as the pump impeller 642. The driven element 664 is coupled to a refrigerant pump 68 via shaft 666.

[0027] Refrigerant pump 68 is coupled to the second housing portion 624 and is operable to pump refrigerant. Refrigerant pump 68 is driven by motor shaft 61, which rotates magnetic coupling 66. Due to the magnetic field between driving element 662 and driven element 664, driven element 664 can rotate at the same speed as driving element 662. Water pump 64 and refrigerant pump 68 can be driven at the same speed as motor 63.

[0028] Note that in this implementation, the magnetic coupling 66 provides a non-contact torque / power transmission from the water pump impeller 642 to the refrigerant pump 68, thereby eliminating the need for shaft seals. Pressurized coolant will not leak from the first housing portion 622. In other implementations (not shown), the motor shaft 61 may be positioned through the first housing portion 622 and the second housing portion 624 and directly drive the refrigerant pump 68.

[0029] The multi-pump device 60 integrates a water pump 64 and a refrigerant pump 68 to simplify the structure of the cooling system 12, prevent the refrigerant from surging in the refrigerant circuit 40, and provide improved pumping conditions.

[0030] Reference Figure 5 The document also introduces a multi-pump device 80 integrating a water pump 84 and a refrigerant pump 88. The multi-pump device 80 may include a motor shaft 81, a main housing 82, a water pump 84, a gear set 85, and a refrigerant pump 88. The main housing 82 includes a first housing portion 822 and a second housing portion 824 coupled to the first housing portion 822. The water pump 84 is coupled to the first housing portion 822 and is operable to pump refrigerant. The refrigerant pump 88 is coupled to the second housing portion 824 and is operable to pump refrigerant, and is driven by the motor shaft 81. The multi-pump device 80 may be coupled to or include a motor 83 that rotates the motor shaft 81. In this implementation, the motor 83 is an electric motor.

[0031] Motor shaft 81 is positioned to pass through first housing portion 822 and directly drive water pump 84. Gear set 85 is coupled to motor shaft 81 and refrigerant pump 88. In some cases, water pump 84 and refrigerant pump 88 may need to rotate at different speeds, and gear set 85 can be used to meet this need. For example, water pump 84 may need to run faster than refrigerant pump 88. In this implementation, gear set 85 includes a first gear 852 coupled to or fixed to motor shaft 81. Gear set 85 also includes a second gear 854 meshing with the first gear 852 and coupled to refrigerant pump 88 via shafts 863, 866. The first gear 852 has a first diameter, and the second gear 854 has a second diameter larger than the first diameter of the first gear 852, such that the speed of refrigerant pump 88 is slower than the speed of water pump 84.

[0032] For example, if the speed range of the refrigerant pump 88 is 800-1600 rpm and the speed range of the water pump 84 is 2000-4000 rpm, then the second diameter of the second gear 854 is 2.5 times larger than the first diameter of the first gear 852. Due to the 2.5:1 reduction ratio, the motor shaft 81 can directly drive the water pump 84 and indirectly drive the refrigerant pump 88 at a lower speed. The number of gears and the gear ratio described herein are for illustrative purposes only. The number of gears and their diameters can vary depending on the required speed ratio or direction of rotation. For example, the gear set 85 may have another gear (not shown) meshing between the first gear 852 and the second gear 854 to make them rotate in opposite directions.

[0033] The multi-pump device 80 may include a magnetic coupling 86 operable to transmit a portion of power from a second gear 854 via shafts 863, 866 to a refrigerant pump 88. The magnetic coupling 86 includes a drive element 862 coupled to the second gear and positioned within a first housing portion 822. The magnetic coupling 86 also includes a driven element 864 coupled to the refrigerant pump 88 and positioned within a second housing portion 824. The driven element 864 rotates together with the drive element 862.

[0034] Note that in this implementation, the magnetic coupling 86 provides a non-contact transmission of torque / power from the second gear 854 to the refrigerant pump 68, thereby eliminating the need for shaft seals. In other implementations (not shown), shafts 863, 866 are connected as a single shaft and positioned to pass through the first housing portion 822 and the second housing portion 824, directly driving the refrigerant pump 88.

[0035] Without limiting the scope, interpretation, or application of the claims herein, one or more of the technical effects of the exemplary embodiments disclosed herein are the combination of a water (antifreeze) pump and a refrigerant pump such that both pumps are driven by a motor shaft. Another technical effect of one or more exemplary embodiments disclosed herein is that the water pump is submerged within a first housing portion (pressurized buffer tank) containing coolant, thereby creating favorable operating conditions. Another technical effect of one or more exemplary embodiments disclosed herein is that it provides a multi-pump device in which the water pump and refrigerant pump can rotate at different speeds. Another technical effect of one or more exemplary embodiments disclosed herein is that it provides a multi-pump device applicable to cooling systems with multiple heat exchange loops, thereby simplifying the cooling system.

[0036] As used herein, unless otherwise limited or modified, a list of elements separated by connective terms (e.g., “and”) and preceded by the phrase “at least one of…” or “one or more of…” indicates a construction or arrangement that may include the individual elements of the list or any combination thereof. For example, “at least one of A, B, and C” or “one or more of A, B, and C” means only A, only B, only C, or any combination of two or more of A, B, and C (e.g., A and B; B and C; A and C; or A, B, and C).

[0037] While exemplary embodiments of the present disclosure have been described above, these descriptions should not be considered limiting. Rather, other changes and modifications may be made without departing from the scope and spirit of the present disclosure as defined in the appended claims.

Claims

1. A multi-pump device for a work vehicle, the multi-pump device comprising: A main housing having a first housing portion and a second housing portion connected to the first housing portion; A motor shaft, which is positioned to pass through the first housing portion; A water pump, which is connected to the first housing portion and is operable to pump coolant and is driven by the motor shaft; as well as A refrigerant pump, which is coupled to the second housing portion and is operable to pump refrigerant and is driven by the motor shaft, The water pump includes a water pump impeller driven by the motor shaft, the first housing portion includes an upper compartment and a lower compartment below the upper compartment, the coolant is in communication between the upper compartment and the lower compartment, and the upper compartment is operable to receive coolant from the water pump inlet to increase the fluid pressure.

2. The multi-pump device for the work vehicle according to claim 1, wherein, The first housing portion and the second housing portion are arranged in a vertical orientation, and the motor shaft rotates about an axis parallel to the vertical orientation.

3. The multi-pump device for the work vehicle according to claim 1, wherein, The water pump impeller is positioned in the lower compartment and rotates together with the motor shaft to discharge the coolant.

4. The multi-pump device for the work vehicle according to claim 1, the multi-pump device further comprising a magnetic coupling operable to transmit a portion of the power from the motor shaft to the refrigerant pump.

5. The multi-pump device for the operating vehicle according to claim 1, wherein the multi-pump device further comprises a gear set connected to the motor shaft and the refrigerant pump.

6. The multi-pump device for the work vehicle according to claim 5, wherein, The gear set includes a first gear connected to the motor shaft and a second gear meshing with the first gear and connected to the refrigerant pump.

7. The multi-pump device for the work vehicle according to claim 6, wherein, The first gear has a first diameter and the second gear has a second diameter that is larger than the first diameter, such that the speed of the refrigerant pump is slower than the speed of the water pump.

8. A cooling system for a work vehicle, the cooling system comprising: The multi-pump device for the work vehicle according to claim 1; A pressure reducer that receives refrigerant from the refrigerant pump and is operable to reduce the pressure of the refrigerant in order to lower the temperature of the refrigerant; A main heat exchanger having a first unit and a second unit, wherein the first unit is operable to receive the refrigerant from the pressure reducer; A condenser, positioned downstream of the first unit of the main heat exchanger, and operable to cool the refrigerant into a liquid form; and A vehicle component that receives coolant from the water pump to dissipate heat; The second unit of the main heat exchanger is located downstream of the vehicle component and is operable to absorb heat from the vehicle component and discharge heat to the first unit of the main heat exchanger.

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