阅读说明：本技术 用于车轮制动致动器的电动机、车轮制动致动器以及控制电动机的冷却系统的方法 (Electric motor for a wheel brake actuator, wheel brake actuator and method for controlling a cooling system of an electric motor ) 是由 M·布莱辛 A·布赫 M·克林格纳 C·科克雷尔 C·姆利纳克塞克 H·内梅特 W·帕勒 于 2019-09-09 设计创作，主要内容包括：本发明涉及一种用于致动车轮制动致动器的电动机,该电动机包括定子和转子,其中,该电动机还包括用于冷却剂的冷却系统,用于对电动机的一个或多个部分进行冷却。本发明还涉及一种包括电动机的车轮制动致动器以及一种控制用于致动车轮制动致动器的电动机的冷却系统的方法。(The invention relates to an electric motor for actuating a wheel brake actuator, comprising a stator and a rotor, wherein the electric motor further comprises a cooling system for a coolant for cooling one or more parts of the electric motor. The invention also relates to a wheel brake actuator comprising an electric motor and a method of controlling a cooling system for an electric motor for actuating a wheel brake actuator.)

1. An electric motor (l) for actuating a wheel brake actuator, the electric motor (l) comprising a stator (3) and a rotor (5), wherein the electric motor (1) further comprises a cooling system (11) for a cooling fluid to cool one or more parts of the electric motor (1).

2. The electric motor (1) according to claim 1, wherein the electric motor (1) further comprises a pump configured to supply a cooling fluid to the cooling system.

3. The electric motor (1) according to any of claims 1-2, wherein the cooling system (11) comprises a cooling layer arranged on one or more parts of the electric motor (1) to cool the electric motor (1) due to evaporation of a cooling fluid supplied to the cooling layer.

4. The electric motor (1) according to any one of claims 1-2, wherein the cooling system (11) comprises a cooling jacket (2) for a cooling fluid, the cooling jacket (2) comprising one or more portions arranged opposite one or more portions of the electric motor (1), wherein a cooling channel (6) for passage of the cooling fluid is defined between the one or more portions of the cooling jacket (2) and the one or more portions of the electric motor (1) opposite the one or more portions of the cooling jacket (2).

5. The electric motor (1) according to any of claims 1-2, wherein the cooling system (11) comprises a cooling jacket (2) for a cooling fluid, the cooling jacket (2) being arranged in contact with one or more parts of the electric motor (1), the cooling jacket (2) comprising cooling channels (6) for the passage of the cooling fluid.

6. The electric motor (1) according to claim 4 or 5, wherein the cooling jacket (2) is in the shape of a cylinder or a portion of a cylinder, which surrounds at least a portion of the electric motor (1) and comprises an inlet port (7) of the cooling channel (6) and an outlet port (8) of the cooling channel (6), the inlet port (7) being for the inlet of a cooling fluid into the cooling channel (6), the outlet port (8) being for the outlet of a cooling fluid from the cooling channel (6).

7. The electric motor (1) according to any one of claims 4 to 6, wherein the stator (3) comprises additional components, in particular electronic components, arranged adjacent to or above the outer surface of the stator (3), and wherein the cooling channels (6) extend in contact with or adjacent to at least some of the additional components or parts of the outer surface of the stator (3) where they are absent.

8. The electric motor (1) according to claim 7, wherein the flow direction of the cooling fluid through the cooling channel (6) is arranged such that the cooling fluid after entering the inlet port (7) first comes into contact with or flows over or near at least some of the additional components and subsequently comes into contact with or flows over or near one or more portions of the outer surface of the stator (3) without the additional components before exiting the outlet port (8).

9. The electric motor (1) according to any of claims 4 to 8, wherein the cooling system (11) comprises one or more secondary cooling channels separate from the cooling channels (6), the one or more secondary cooling channels being in contact with or above or near one or more parts of the electric motor (1) for cooling the one or more parts of the electric motor (1).

10. The electric motor (1) according to any of claims 4 to 9, wherein the cooling system (11) cools, heats or thermally controls one or more parts of the electric motor (1) comprising the additional components, in particular electronic components.

11. A wheel brake actuator comprising an electric motor (1) according to any one of claims 1-10.

12. Wheel brake actuator according to claim 11, wherein the cooling jacket (2) at least partially forms part of a housing (9) of the wheel brake actuator, and the inlet port (7) and the outlet port (8) of the cooling jacket (2) are formed in the housing (9) of the wheel brake actuator.

13. Wheel brake actuator according to claim 11, wherein the cooling system (11) is arranged between the housing (9) of the wheel brake actuator and an outer surface of the stator (3) of the electric motor (1).

14. A method (100) of controlling a cooling system for an electric motor for actuating a wheel brake actuator, the method comprising the steps of:

-receiving (101), by a controller, temperature signals at fixed time intervals from one or more temperature sensors coupled to the electric motor;

-comparing (102), at the controller, the temperature signal with a threshold value;

-providing (103), by the controller, a control signal to supply cooling fluid to the cooling system if the temperature signal is above the threshold.

15. The method (100) of claim 14, wherein the threshold is predetermined based on a temperature history of the motor or dynamically determined during operation of the motor.

Technical Field

The present invention relates to an electric motor for actuating a wheel brake actuator and a wheel brake actuator comprising such an electric motor. Further, the present invention provides a method of controlling a cooling system of an electric motor.

Background

Electromechanical (including electrical) wheel brake actuators are commonly used in commercial vehicles. Such wheel brake actuators, due to the inclusion of an electric motor, generate an increased amount of heat dissipation during operation compared to mechanical wheel brake actuators. High temperatures can reduce the wear resistance of the motor and other components of the electromechanical wheel brake actuator. Accordingly, an efficient cooling mechanism for an electromechanical wheel brake actuator is desired.

Currently, air cooling systems are used to cool wheel brake actuators, in particular the electric motors used to actuate these wheel brake actuators. However, the efficiency of air cooling systems for wheel brake actuators is limited by air convection which is directly dependent on air circulation and thus on vehicle speed. At low speeds, the convection coefficient is small due to the low wind speed and the high air temperature around the wheel brake actuators. Thus, at low speeds, cooling is insufficient because heat removal is significantly limited due to the low convection coefficient. Therefore, there is often an increased need for heat removal when the vehicle has slowed or has stopped to relieve stress on the wheel actuator components.

Disclosure of Invention

The object of the present invention is to overcome the drawbacks of the prior art and in particular to provide an alternative cooling system which increases the cooling efficiency of the electric motor of the wheel brake actuator, especially at low speed operation, and which improves the wear resistance of the wheel brake actuator.

This object is solved by the subject matter of independent claims 1, 11 and 14.

According to the present invention, an electric motor for actuating a wheel brake actuator includes a stator, a rotor, and a cooling system for cooling fluid to cool one or more portions of the electric motor. Since the cooling fluid has a higher heat capacity than air, the cooling efficiency of the motor, particularly the mechanical efficiency at low speed operation, is improved. The cooling fluid may include one or more of a liquid coolant, a gaseous coolant, a solid coolant, or a combination thereof.

According to one embodiment, the electric motor further comprises a liquid pump configured to supply cooling fluid to the cooling system. The electric motor may also be connected to a cooling device for cooling the cooling fluid. The cooling device may comprise a compressor-based refrigerator or an electric cooling device comprising, for example, Peltier elements.

According to another embodiment, the cooling system comprises a cooling layer arranged on one or more parts of the electric motor to cool the electric motor by evaporation of a cooling fluid supplied to the cooling layer.

According to an alternative embodiment, the cooling system comprises a cooling jacket for cooling fluid, the cooling jacket comprising one or more portions arranged opposite to the one or more portions of the electric motor, wherein a cooling channel for passage of the cooling fluid is defined between the one or more portions of the cooling jacket and the one or more portions of the electric motor opposite to the one or more portions of the cooling jacket.

According to an alternative embodiment, the cooling system comprises a cooling jacket for cooling fluid, which cooling jacket is arranged in contact with one or more parts of the electric motor, which cooling jacket comprises cooling channels for the passage of the cooling fluid. The cooling channels provide improved control of the flow rate of the cooling fluid and may alter or define the order in which the cooling fluid is supplied to different parts of the motor. For example, it is effective to define cooling channels on the motor in such a manner that the electronic components arranged on the motor are first cooled by the cooling fluid and then a part of the motor is cooled again. The path of the cooling channels on the electric motor is thus arranged such that the components that need primary cooling are arranged upstream of the other components that need secondary cooling and downstream of the cooling channels.

According to another embodiment, the cooling jacket is in the shape of a cylinder or a part thereof, which surrounds at least a part of the electric motor and comprises an inlet port of the cooling channel for the inlet of the cooling fluid into the cooling channel and an outlet port of the cooling channel for the outlet of the cooling fluid out of the cooling channel. The cylindrical shape of the cooling jacket conforms to the shape of the motor and thus provides good contact with the motor and its outer surface and thus good cooling efficiency.

According to another embodiment, the stator comprises additional components, in particular electronic components, arranged adjacent to or above the outer surface of the stator, and wherein the cooling channels extend in contact with or adjacent to at least some of the additional components and a part of the outer surface of the stator where no additional components are present. This provides selective cooling of the various components and parts of the motor and increases the overall speed at which the motor is cooled. One or more additional housings may be provided for the electronic components.

According to a further embodiment, the flow direction of the cooling fluid flowing through the cooling channel is arranged such that the cooling fluid after entering the inlet port first comes into contact with or flows over or near at least some of the additional components and subsequently flows over or over one or more portions of the outer surface of the stator without additional components before exiting the outlet port. Thus, the more heat sensitive electronic components are cooled first and additional protection from damage is provided.

According to another embodiment, the cooling system includes one or more secondary cooling channels separate from the primary cooling channel, the one or more secondary cooling channels being in contact with, above, or near one or more portions of the electric motor for cooling the one or more portions.

According to another embodiment, the cooling system cools, heats or thermally controls one or more parts of the electric motor comprising additional components, in particular electronic components.

According to another aspect of the present invention, there is provided a wheel brake actuator including an electric motor, including the above-described embodiments.

According to one embodiment, the cooling jacket forms at least partially a part of the housing of the wheel brake actuator, and the inlet and outlet ports of the cooling jacket are formed in the housing of the wheel brake actuator. This configuration may simplify the structure and provide a higher degree of actuator integration.

According to another embodiment, the cooling system is arranged between the housing of the wheel brake actuator and the outer surface of the stator of the electric motor.

According to another aspect of the present invention, a method of controlling a cooling system for an electric motor for actuating a wheel brake actuator is provided.

The method comprises the following steps: receiving, by a controller, temperature signals at fixed time intervals from one or more temperature sensors coupled to a motor; comparing, at the controller, the temperature signal to a threshold; and providing, by the controller, a control signal to supply the cooling fluid to the cooling system if the temperature signal is above the threshold.

According to one embodiment, the threshold is predetermined based on a temperature history of the motor or dynamically determined during operation of the motor. The temperature history may be stored in a database in memory.

Preferred embodiments are given by the dependent claims.

It is noted that the method according to the invention may be found such that it implements an electric motor according to the described aspects of the invention, and vice versa.

Drawings

The following detailed description refers to the accompanying drawings. The same reference numbers may be used in different drawings to identify the same or similar elements. In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular structures, functions, etc. in order to provide a thorough understanding of the various aspects of the claimed invention.

It will be apparent to those skilled in the art having the benefit of the present disclosure that the various aspects of the invention claimed may be practiced in other examples that depart from these specific details. In certain instances, descriptions of well-known devices and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

Fig. 1 shows a schematic cross-sectional view of an electric motor according to one of the embodiments of the invention;

fig. 2 shows an overall view of the electric motor according to fig. 1;

FIG. 3 shows a flow chart of a method according to the invention; and

fig. 4 shows a schematic arrangement of the interaction between the motor and the cooling system.

Detailed Description

In the embodiment shown in fig. 1, the electric motor 1 is included in a cooling jacket 2 of a cooling system 11 (not shown in fig. 1), wherein the cooling jacket 2 forms part of a housing 9 of the wheel brake actuator. The force, in particular the linear force, of the wheel brake actuator is generated by an electric motor 1, which electric motor 1 comprises a stator 3 and a rotor 5. The stator 3 contains the coils 4 of the motor 1. The stator 3 is fixed to a housing 9 of the wheel brake actuator, in particular to the part of the housing forming the cooling jacket 2 and adjacent to the wall of the cooling jacket 2. The cooling jacket 2 is arranged in contact with one or more parts of the electric motor 1. The cooling jacket 2 comprises a cooling channel 6 for the passage of a cooling fluid.

Referring to fig. 2, the cooling jacket 2 has a cylindrical shape surrounding at least a portion of the motor 1. The cooling jacket 2 comprises an inlet port 7 of the cooling channel 6, the inlet port 7 for the inlet of the cooling fluid into the cooling channel 6, and an outlet port 8 of the cooling channel 6, the outlet port 8 for the outlet of the cooling fluid from the cooling channel 6. A pump for supplying cooling fluid may be connected to the inlet port 7. Furthermore, the inlet port 7 and the outlet port 8 may be connected to a cooling device to provide a closed cooling cycle.

Referring to fig. 3, a method 100 of controlling a cooling system for an electric motor that actuates wheel brake actuators is shown. The controller of the cooling system receives a temperature signal S from one or more temperature sensors coupled to the electric motor at step 101_t. Receiving the temperature signal S periodically at fixed time intervals_t. Upon receiving the temperature signal S_tThereafter, the controller will receive the temperature signal S in step 102_tIs compared with a threshold TH. The threshold TH may be predetermined based on the temperature history of the motor under different operating conditions and stored in a database connected to the controller. Alternatively, the threshold TH may be dynamically determined during motor operation based on a temperature defined by temperature signals received at fixed time intervals. If the controller determines the temperature signal S at step 102_tAbove the threshold TH, the controller provides a control signal S to the cooling device and/or the pump at step 103_cTo supply cooling fluid to the cooling system. In supplying cooling fluid toAfter cooling the system, the cooling system begins to cool the motor. If the controller determines the temperature signal S_tFalling below or at least equal to the threshold TH, the controller may provide an interrupt signal to interrupt the supply of cooling fluid to the cooling system. Therefore, the consumed power for supplying the cooling fluid is reduced, and the cooling system is operated only when needed due to the operating conditions of the motor.

Referring to fig. 4, a controller 12 is shown in conjunction with the motor 1 and the cooling system 11. Receiving a temperature signal S at a controller 12 from one or more temperature sensors 10 coupled to the electric motor 1_t. After controller 12 performs comparison step 102 shown in FIG. 3, controller 12 sends control signal S_cTo supply cooling fluid to the cooling system 11 or to interrupt the supply of cooling fluid to the cooling system. The control signal S can be adjusted_cTo a liquid pump configured to provide cooling fluid to the cooling system 11. Then, the cooling system 11 starts or interrupts cooling of the motor l.

The features disclosed in the above description, in the drawings and in the claims may be essential for the implementation of the invention in its different embodiments, individually or in any combination.

List of reference numerals

1 electric motor

2 Cooling jacket

3 stator

4 stator coil

5 rotor

6 Cooling channel

7 inlet port

8 outlet port

9 housing of wheel brake actuator

10 sensor

11 cooling system

12 controller