Trucks equipped with a wet brake cooling system
By integrating the traction gear cooling circuit with the wet brake system and using external cooling fins and an integrated cooling channel, the complexity, weight, and space of conventional wet brake cooling systems are minimized, achieving efficient heat dissipation and reduced cross-contamination.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- リープヘルマイニングイクイップメントニューポートニューズカンパニー
- Filing Date
- 2025-09-19
- Publication Date
- 2026-06-18
AI Technical Summary
Conventional wet brake cooling systems for trucks are heavy, costly, and require significant space due to their complex cooling circuits, which often involve cross-contamination risks.
The system integrates a traction gear cooling circuit with the wet brake cooling system, utilizing the traction gear's mass and oil to dissipate heat, and incorporates external cooling fins and an integrated cooling channel within the wet brake housing, allowing for separate hydraulic fluids and reduced complexity.
This configuration reduces the weight, cost, and space requirements of the brake cooling system while maintaining performance, avoiding cross-contamination and utilizing existing truck systems for heat dissipation.
Smart Images
Figure 2026099736000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a truck equipped with a wet brake cooling system.
Background Art
[0002] The service brakes of a truck can be configured as dry friction brakes or wet friction brakes. The wet brakes can be configured particularly as wet disc brakes.
Summary of the Invention
[0003] In a wet disc brake, there is usually a stack of brake discs, which are interleaved with brake plates attached to the stator of the brake and are immersed in a hydraulic working fluid. As the distance between the brake discs and the brake plates decreases, due to an increase in the shear force in the hydraulic working fluid, the brake torque is transmitted through the hydraulic working fluid without the discs and plates actually contacting each other.
[0004] In a conventional wet brake, at least when used in a truck, the hydraulic working fluid in the wet brake is cooled in a cooling circuit. That is, the hydraulic working fluid flows from the brake to the cooling circuit and is cooled by a radiator or heat exchanger included in the cooling circuit before returning to the brake. Since braking can potentially contaminate the oil, such a cooling circuit for the brake is usually fluidly separated from other cooling circuits of the truck. A wet disc brake cooling system is cooled, for example, by transferring heat to an engine coolant circuit. This includes a heat exchanger, a pump, and a complex cooling circuit.
[0005] Therefore, the cooling associated with known wet brakes is heavy and requires many components.
[0006] Therefore, an object of the present disclosure is to reduce the weight, cost, and space requirements of a wet brake cooling system while meeting minimum performance criteria.
[0007] To address at least some of these objectives, in one general aspect, the present disclosure provides a track that uses the mass of the traction gear set and the oil of the traction gear set to dissipate heat. The traction gear set in many OHT (off-highway tire) tracks already includes a cooling circuit.
[0008] In a more general context, the disclosure provides a track and wet brake that utilizes an integrated cooling channel within a wet disc brake housing.
[0009] In a more general context, the disclosure provides a track and wet brake that uses external cooling fins on a wet disc brake housing.
[0010] These general aspects may be used in combination or individually.
[0011] In a first independent aspect, the present disclosure provides a track comprising a plurality of wheels, at least one traction motor, at least one traction gear, at least one wet brake, and at least one traction gear cooling circuit. The at least one traction motor is configured to drive at least one of the plurality of wheels via the at least one traction gear, and the at least one traction gear cooling circuit is configured to cool the at least one traction gear. Furthermore, the at least one traction gear cooling circuit is further configured to cool the wet brake.
[0012] As a result, the traction gear cooling circuit is also used to cool the wet brakes. The hydraulic fluid used to cool the gears, and the gears themselves, have a high heat capacity that can be used to absorb the heat generated by the wet brakes. This configuration utilizes existing systems on the track for heat dissipation.
[0013] According to one aspect of the present disclosure, the brake chamber of at least one wet brake is filled with a first hydraulic fluid, the track is equipped with a heat exchanger for cooling the first hydraulic fluid, the heat exchanger is connected to the at least one traction gear cooling circuit, thereby thermally connecting the hydraulic fluid of the wet brake to the hydraulic fluid flowing through the traction gear cooling circuit via the heat exchanger. This avoids cross-contamination between the cooling circuits and makes it possible to use different hydraulic fluids for the wet brake and the traction gear.
[0014] According to one aspect of the present disclosure, the at least one traction gear cooling circuit comprises a pump and a refrigerant heat exchanger, the pump configured to circulate a second hydraulic fluid through the heat exchanger, the refrigerant heat exchanger, and the at least one traction gear. Thus, a single cooling circuit is used to cool the traction gear and the wet brake. In embodiments, the at least one traction gear comprises a housing including a gear chamber containing the gear, and the second hydraulic fluid flows through the gear chamber. In particular, the refrigerant heat exchanger may be a refrigerant / air heat exchanger such as an oil / air heat exchanger.
[0015] According to aspects of this disclosure, the wet brake comprises a housing, and the heat exchanger is located within the housing or is configured to be integrated with the housing. This reduces the complexity and dimensions of the cooling system.
[0016] In particular, the first hydraulic fluid of a wet brake is drawn from the wet brake and cooled without being cooled by a separate heat exchanger.
[0017] In a second independent aspect, the present disclosure relates to a track comprising a plurality of wheels, at least one traction motor, and at least one wet brake, wherein the at least one traction motor is configured to drive at least one of the plurality of wheels, the brake chamber of the at least one wet brake is filled with a first hydraulic fluid, the wet brake comprises a housing and a heat exchanger for cooling the first hydraulic fluid, the heat exchanger being located within the housing or being integrated with the housing, thereby reducing the complexity and size of the cooling system.
[0018] In aspects of this disclosure, the first hydraulic fluid is sealed within the housing of the wet brake and cooled within the housing. Thereafter, the first hydraulic fluid of the wet brake is cooled without drawing the fluid from the wet brake and cooling it in a separate heat exchanger.
[0019] The heat exchanger with the second independent phase can be connected to any type of cooling circuit. In particular, a separate cooling circuit for wet brakes may be used, or any existing cooling circuit of the truck may be used.
[0020] In embodiments, the first and second independent aspects of this disclosure are combined, thereby connecting a heat exchanger, which is located within or integrated into the housing of a wet brake, to a cooling circuit for the traction gear.
[0021] In a third independent aspect, the present disclosure provides a wet brake comprising a housing, a brake chamber, and a plurality of brake discs disposed in the brake chamber, wherein the brake chamber is filled with a first hydraulic fluid, and a heat exchanger for cooling the first hydraulic fluid is disposed within the housing or is configured to be integrated with the housing. The wet brake according to the third aspect has the same advantages as those already described above for the second independent aspect and can be configured as described above for the second independent aspect.
[0022] The feasible features of a track with a first and / or second independent phase and a wet brake with a third independent phase are described below.
[0023] In this embodiment, the first hydraulic fluid is sealed within the housing of the wet brake and cooled within the housing.
[0024] In aspects of this disclosure, the first hydraulic fluid is moved within the housing by the rotation of a brake disc located inside the housing, without the use of a pump.
[0025] In this embodiment, the cooling channels of the heat exchanger are integrated into the housing and connected to at least one traction gear cooling circuit. Thus, the housing functions as a heat exchanger between the first cooling fluid of the wet brake and the second hydraulic fluid of the traction gear cooling circuit.
[0026] In this embodiment, the heat exchanger is located in the sump of a wet brake, which is situated inside the housing, and the sump is configured to support at least a portion of the first hydraulic fluid. This also makes it possible to cool the first hydraulic fluid.
[0027] In one aspect, a cooling fan is provided on the outer surface of the housing of the wet brake. Thereby, heat is released from the wet brake to the outside air, alleviating the cooling requirements that would otherwise have to be provided by a heat exchanger.
[0028] In one aspect, the truck is a dump truck having a dump body pivotally attached to the frame of the dump truck.
[0029] In one aspect, the truck is a battery electric truck equipped with a battery pack for supplying power to at least one traction motor.
[0030] In one aspect, the truck is a diesel electric truck equipped with an internal combustion engine that drives a generator for supplying power to the at least one traction motor.
[0031] The wet brake of the present disclosure may be a wet disk brake.
[0032] In an embodiment, the wet brake of the present disclosure is disposed on the rear wheels of the truck.
[0033] The truck may be an open-pit mining truck.
[0034] The truck may have a payload exceeding 50 metric tons, and optionally exceeding 100 metric tons.
[0035] The present disclosure is described herein with reference to the drawings and embodiments.
Brief Description of the Drawings
[0036] [Figure 1] FIG. 1 shows an embodiment of a truck of the present disclosure. [Figure 2] FIG. 2 shows an embodiment of the cooling system of a truck and an embodiment of a wet brake of the present disclosure. [Figure 3A]Figure 3A shows the configuration of the power supply unit that provides energy to the truck's traction motor. [Figure 3B] Figure 3B shows the configuration of the power supply unit that provides energy to the truck's traction motor. [Modes for carrying out the invention]
[0037] This disclosure provides a novel configuration for transferring heat from a truck's rear wet disc brake system to the traction gear set, traction gear set oil, and / or the outside air, designed to be minimally compliant. This configuration minimizes the complexity, cost, weight, and space occupied by the brake cooling system. This configuration utilizes the truck's existing system for heat dissipation.
[0038] Figure 1 shows an embodiment of the track 10 of the present disclosure. The track 10 comprises wheels 20, at least some of which are driven by traction motors.
[0039] The traction motor 25 can drive a wheel or wheel group via a traction gear 35 schematically shown in Figure 2, and the traction gear 35 drives the wheel or wheel group by reducing the rotational speed of the traction motor.
[0040] In this embodiment, at least two rear wheels may each be driven by a traction motor via a traction gear.
[0041] Furthermore, at least one of the wheels 20 is operably coupled to a wet brake 100 to apply the brakes to the wheel 20. In one embodiment, each of the rear wheels 20 may be provided with a wet brake 100.
[0042] The wheels are positioned on the frame 40, and the dump body 50 is positioned on the frame 40 so that it can rotate around a horizontal pivot axis 70 by actuators for moving the dump body, such as hydraulic cylinders 60.
[0043] Furthermore, the power supply unit 30 is positioned on the frame and supplies electrical energy to drive the traction motor.
[0044] As schematically shown in Figure 3A, the power supply unit 30 may include an internal combustion engine 31 that drives a generator 32 that generates electricity to drive the traction motor 25.
[0045] As schematically shown in Figure 3B, the power supply unit 30 may include a battery unit 33 that supplies electricity to drive the traction motor 25. The battery unit 33 may be provided instead of, or in addition to, the internal combustion engine and generator 32.
[0046] The brake 100 may include a housing that surrounds a brake chamber 110 in which the brake elements of the brake are located. The brake chamber is filled at least partially with hydraulic fluid.
[0047] The wet brake 100 may be configured in particular as a wet disc brake. In a wet disc brake, there is a stack of rotating brake discs 120, which alternate with brake plates mounted on the brake stator and are immersed in hydraulic fluid within a brake chamber 110. By increasing the clamping force between the brake discs 120 and the brake plates, brake torque is transmitted through the oil without the discs and plates actually making contact, due to an increase in the shear force in the hydraulic fluid.
[0048] Furthermore, the traction gear 35 is provided with a cooling circuit 200. This cooling circuit 200 circulates the hydraulic fluid through the gear 35 to the sump 240, and then via the pump 230 to a refrigerant / air heat exchanger 210 that cools the hydraulic fluid.
[0049] This disclosure offers two new perspectives.
[0050] The first aspect is to cool the wet brake 100 by using the cooling circuit 200 of the traction gear 35. The hydraulic fluid used to cool the gear 35 and the gear itself have a high heat capacity that can be used to absorb the heat generated by the wet brake.
[0051] To avoid cross-contamination between cooling circuits and to allow the use of different hydraulic fluids, the hydraulic fluid of the wet brake 100 is thermally connected to the hydraulic fluid flowing through the cooling circuit of the traction gear 35 by a heat exchanger 140. Specifically, the fluid duct 150 of the heat exchanger 140 is connected to the fluid line 220 of the cooling circuit 200 of the traction gear 35, so that the hydraulic fluid flowing through the cooling circuit 200 of the traction gear 35 also flows through the heat exchanger, and the heat exchanger fluidly separates the hydraulic fluid of the wet brake 100 from the hydraulic fluid of the traction gear 35.
[0052] The second aspect is to cool the hydraulic fluid of the wet brake 100 without guiding the hydraulic fluid from the wet brake and cooling it in a separate radiator or heat exchanger. In particular, the present disclosure provides a cooling duct 150 integrated within the housing 130 of the wet brake, through which the cooling fluid of the cooling circuit 200 is guided to cool the hydraulic fluid in the wet brake 100. Thus, the housing 130 functions as a heat exchanger between the cooling fluid and the hydraulic fluid of the wet brake. Alternatively, a heat exchanger 140 for cooling the hydraulic fluid of the wet brake may be provided within the oil sump 160 of the wet brake 100.
[0053] As a result, the heat exchanger 140 is integrated into the wet brake. Furthermore, the hydraulic fluid of the wet brake is moved within the wet brake by the rotation of the brake disc 120, and is thereby cooled by the heat exchanger.
[0054] The second scenario may also be used when installing a separate cooling circuit for wet brakes, or when using other cooling circuits on the truck. This includes using water cooling to cool the wet brakes.
[0055] However, in this embodiment, the traction gear 35 is cooled by a traction gear cooling circuit 200.
[0056] Furthermore, according to the third aspect, the cooling fins 135 are positioned on the outer surface of the housing 130 of the wet brake 100 to release heat to the outside air.
Claims
1. Multiple wheels, At least one traction motor, At least one traction gear, At least one wet brake, At least one traction gear cooling circuit, A truck equipped with, The at least one traction motor is configured to drive at least one of the plurality of wheels via the at least one traction gear, The at least one traction gear cooling circuit is configured to cool the at least one traction gear, The at least one traction gear cooling circuit is further configured to cool the wet brake. track.
2. The brake chamber of the at least one wet brake is filled with first hydraulic fluid. The truck is equipped with a heat exchanger for cooling the first hydraulic fluid, The heat exchanger is connected to the at least one traction gear cooling circuit. The truck according to claim 1.
3. The aforementioned at least one traction gear cooling circuit comprises a pump and a refrigerant heat exchanger, The pump is configured to circulate the second hydraulic fluid through the heat exchanger, the refrigerant heat exchanger, and the at least one traction gear. The truck according to claim 2.
4. The aforementioned wet brake includes a housing, The heat exchanger is located within the housing or is configured to be integrated with the housing. The truck according to claim 2.
5. The cooling channel is integrated within the housing. The cooling channel is connected to the at least one traction gear cooling circuit. The truck according to claim 4.
6. The heat exchanger is located in the sump of the wet brake, which is located inside the housing. The sump is configured to contain at least a portion of the first hydraulic fluid. The truck according to claim 4.
7. Multiple wheels, At least one traction motor, At least one wet brake, A truck equipped with, The at least one traction motor is configured to drive at least one of the plurality of wheels, The brake chamber of the at least one wet brake is filled with first hydraulic fluid. The wet brake comprises a housing and a heat exchanger for cooling the first hydraulic fluid. The heat exchanger is located within the housing or is configured to be integrated with the housing. track.
8. The first hydraulic fluid is sealed within the housing of the wet brake and cooled within the housing. The truck according to claim 7.
9. The first hydraulic fluid is moved within the housing without the use of a pump by the rotation of a brake disc located inside the housing. The truck according to claim 7.
10. The cooling channels of the heat exchanger are integrated within the housing. The truck according to claim 7.
11. The heat exchanger is located in the sump of the wet brake, which is located inside the housing. The sump is configured to contain at least a portion of the first hydraulic fluid. The truck according to claim 7.
12. The aforementioned truck is a dump truck equipped with a dump body that is rotatably mounted on the frame of the dump truck. The truck according to claim 1.
13. The truck is a battery-electric truck equipped with a battery pack for supplying power to the at least one traction motor. The truck according to claim 1.
14. The truck is a diesel-electric truck equipped with an internal combustion engine that drives a generator for supplying power to at least one traction motor. The truck according to claim 1.
15. Cooling fins are provided on the outer surface of the housing of the wet brake. The truck according to claim 7.
16. Housing and Brake chamber and Multiple brake discs arranged in the aforementioned brake chamber, A wet brake equipped with, The brake chamber is filled with first hydraulic fluid. The heat exchanger for cooling the first hydraulic fluid is located within the housing or is integrated with the housing. Wet brakes.
17. Cooling fins are provided on the outer surface of the housing. The wet brake according to claim 16.
18. The first hydraulic fluid is sealed within the housing of the wet brake and cooled within the housing. The first hydraulic fluid is moved within the housing without the use of a pump by the rotation of a brake disc located inside the housing. The wet brake according to claim 16.
19. The cooling channels of the heat exchanger are integrated within the housing. The wet brake according to claim 16.
20. The heat exchanger is located in the sump of the wet brake, which is located inside the housing. The sump is configured to contain at least a portion of the first hydraulic fluid. The wet brake according to claim 16.