Electromechanical brake actuator, drive module for an electromechanical brake actuator, and method for operating an electromechanical brake actuator

Abstract

A drive module for an electromechanical brake actuator includes an electric motor, a transmission kinematically coupled to the motor, having an operating member connectable to a pressure generating device that is linearly position adjustable against a restoring force in a first direction by the motor for operating the pressure generating device, a control device electrically connected to the motor for controlling the motor, a switch activatable by the transmission as a result of movement of the operating member in a second direction, and an electric braking circuit electrically connected to the motor and the switch and activatable by activation of the switch and by an electrical activation voltage. The activation voltage is generated by the motor acting as a generator when the motor receives the restoring force acting on the operating member upon deactivation of the control device, and the braking circuit is configured to brake the motor to generate a force acting in a direction opposite to the restoring force.

Description

Technical Field

[0001] The present invention relates to an electromechanical brake actuator, a drive module for an electromechanical brake actuator, and a method of operating an electromechanical brake actuator.

Background Art

[0002] Electromechanical brake boosters are typically used to enhance the operating force manually generated by a brake pedal, which is due to the master brake cylinder being operated by an electric motor. In a so-called "brake-by-wire" system, where a position adjustment signal is generated by operating the brake pedal or in some other way, and an electrohydraulic actuator is operated based on the position adjustment signal to generate a brake pressure, an actuator such as an electrohydraulic brake booster configured in a similar manner is also used.

[0003] Patent Document 1 discloses an electromechanical actuator for a brake system having a master brake cylinder, an electric motor, and a transmission device that connects the electric motor to the master brake cylinder to convert the movement of the motor into the movement of the master brake cylinder.

[0004] In an actuator configured as described above, for example, when the control of the electric motor is stopped while the electric motor is operating the master brake cylinder or generally a pressure generating device to increase the hydraulic pressure based on the stop of the current supply, the transmission is urged by the restoring force due to the increased hydraulic pressure. The transmission is operated by the restoring force to induce the rotation of the electric motor, whereby the electric motor operates as a generator. Since an uncontrolled pressure drop will cause an operation of the uncontrolled transmission, the electric motor is usually braked via an electronic braking circuit, particularly to avoid component damage in the transmission. However, it is also desirable to make the pressure drop as smooth as possible when the motor stops and to be able to quickly initiate effective compensation measures for generating the required braking pressure.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] Based on the above background, the present invention provides a drive module for an electromechanical brake actuator having the constituent elements of claim 1, an electromechanical brake actuator having the constituent elements of claim 8, and a method having the constituent elements of claim 10.

[0007] In a first aspect of the invention, a drive module for an electromechanical brake actuator includes an electric motor, a transmission kinematically coupled to the motor having an operating member connectable to a pressure generating device that is linearly position adjustable against a restoring force in a first direction by the motor to operate the pressure generating device, a control device electrically connected to the motor to control the motor, a switch activatable by the transmission as a result of movement of the operating member in a second direction, and an electric braking circuit electrically connected to the motor and the switch and activatable by activation of the switch and by an electrical activation voltage. The activation voltage is generated by the motor acting as a generator when the motor receives the restoring force acting on the operating member upon stopping of the control device, and the braking circuit is configured to brake the motor to generate a force acting in a direction opposite to the restoring force.

[0008] In a second aspect of the invention, an electromechanical brake actuator is contemplated having a drive module according to the first aspect of the invention and a pressure generating device coupled to the operating member of the transmission and having a hydraulic connection for providing hydraulic fluid to a wheel brake. The pressure generating device is configured to generate hydraulic pressure by expulsion of hydraulic fluid.

[0009] In a third aspect of the present invention, a method of operating an electromechanical brake actuator according to the second aspect of the present invention is contemplated. The method includes the motor being controlled by a control device such that the motor moves an operating member in a first or second direction, thereby causing a pressure generating device to increase or decrease hydraulic pressure. For example, when the supply voltage stops or when the control device itself malfunctions and stops, the operating member of the transmission moves in the second direction by a restoring force acting as a result of the increased hydraulic pressure. At this time, the operating member moving in the second direction drives the motor as a generator, thereby causing the motor to generate an activation voltage, and as a result of the movement of the operating member in the second direction, a switch is activated by the transmission. In the next step, when the activation voltage is supplied to the braking circuit and the switch is activated, the braking circuit is activated. Further, the braking circuit brakes the motor, thereby causing the motor to generate a force acting in the direction opposite to the restoring force, which decelerates the movement of the operating member in the second direction.

[0010] The idea underlying the present invention is not to activate a passive electronic braking circuit that brakes an electric motor when the control device stops immediately when the control device stops, but rather, under the additional condition that the linearly retracting part of the transmission releases an activation switch and further the activation switch activates the braking circuit, it is activated for the first time. Thereby, the possibility is created that the transmission first moves freely or without being braked over a specific section by the hydraulic pressure acting as a restoring force by the pressure generating device and then is braked by the motor braked by the braking circuit. In particular, thereby, the pressure generating device performs pressure reduction without being braked for the time being, which has the advantage of reducing the time for pressure reduction.

[0011] Preferred embodiments and developments will become apparent from the other dependent claims and from the description with reference to the figures of the drawings.

[0012] In some embodiments, the motor has a control circuit, such as a bridge circuit, that can be switched by a control device to operate the motor, and the braking circuit is intended to be set up to switch the control circuit to brake the motor. For example, the braking circuit switches the control circuit so that the poles of the motor and / or the individual phases are short-circuited through the control circuit, thereby causing at least a portion of the rotor winding and / or the stator winding of the motor to form an eddy current brake.

[0013] In some embodiments, the braking circuit is configured to detect the stop of the control device, particularly with reference to a stop signal output from the control device, and is intended to be activated only when the stop of the control device is detected. For example, the control device may be configured to output a signal, for example in the form of a voltage, to the braking circuit under normal operation. When this signal ceases during the stop of the control device, the braking circuit detects that the stop of the control device has occurred. To detect this, the braking circuit can have, for example, a switch that closes when de-energized. When the signal from the control device ceases, this switch closes.

[0014] In some embodiments, the operating member is intended to be movable between an initial position and a final operating position, a restoring force applies an initial stress to the operating member in the direction of the initial position, and the switch is arranged to be activated at the activation position of the operating member when the operating member is in the vicinity of the initial position rather than the final operating position. The operating member is slidable in a first direction, i.e., from its initial position towards the final operating position, for an increase in pressure by a pressure generating device. For a pressure reduction, the operating member is movable in a second direction, i.e., towards the initial position. The switch is positioned relative to the transmission such that it is released only during pressure reduction when the operating member is in the vicinity of the initial position rather than the final operating position. Thus, a free movement of the transmission is realized over at least 50% of the maximum stroke that the operating member can perform. In this way, the pressure reduction is further accelerated.

[0015] Generally, the initial position and the final operating position may be intended to define the maximum stroke of the operating member. In some embodiments, the activation position may be intended to be away from the initial position by an interval within a range between 5 percent and 40 percent of the maximum stroke. In this way, the activation switch is activated or operated for the first time only immediately before the operating member reaches the initial position. In this way, the pressure reduction is further accelerated.

[0016] In some embodiments, the switch may be intended to be configured as a proximity switch, in particular as a reed switch or a Hall switch. For example, the transmission may comprise a proximity member, such as a magnetic piece, and the proximity sensor is positioned relative to the transmission such that when the operating member moves in a second direction, the proximity member approaches the proximity sensor, thereby causing it to output a signal to the braking circuit.

[0017] In some embodiments, it may be intended to be manufactured as a mechanically releasable switch. In this case, the switch may be initially stressed to an open state by, for example, a spring, and is closed by a member of the transmission, thereby causing this switch to close an electrical switch in the braking circuit.

[0018] In some embodiments, the operating member may be constituted by a threaded spindle, the threaded spindle is linearly guided by a guide portion non-rotatably coupled thereto, and is linearly position-adjustable by a drive nut rotatable by a motor, and the switch is releasable by the guide portion. This brings the advantage that the guide portion originally already serves as a support structure for the sensor member, which in particular simplifies the integration of the proximity switch into the drive module.

[0019] In some embodiments, the motor may be configured as a brushless DC motor having a permanent magnet rotor, a stator having at least three coil structures, and a rectifier circuit coupled to the coil structures that can be controlled by a control device. The braking circuit may be configured to short-circuit at least two coil structures so that they act as an eddy current brake. In this way, the rectifier circuit forms the control circuit of the motor and may be embodied, for example, as a B6 bridge circuit.

[0020] In some embodiments, the pressure generating device may be intended to have a cylinder and a piston accommodated in the cylinder that is movable by a working fluid so as to slide in the forward and backward directions by an operating member. The hydraulic connection portion is constituted by a connection hole of the cylinder, and the cylinder has an orifice hole that is released thereby when the piston moves in the backward direction and connects the cylinder to the reservoir. In this way, the pressure generating device may be, for example, a master brake cylinder or a plunger. By providing an activation switch for activating the braking circuit, the piston can move in the backward direction under a small reaction force substantially corresponding to the frictional force in the transmission and the motor over a relatively wide area for pressure reduction. In this way, it is realized that the orifice hole is released more quickly. This facilitates the rapid compensation of the stop of pressure generation. This is because alternative systems such as an ABS system may require working fluid from the reservoir depending on the situation.

[0021] Next, the present invention will be described with reference to the figures of the drawings. The drawings show the following.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0023] In each figure, unless otherwise noted, the same reference numerals represent the same components or components with the same functions.

[0024] FIG. 1 shows, by way of example and in a purely schematic form, an electromechanical brake actuator 300. As shown in FIG. 1, the brake actuator 300 includes a drive module 100 having an electric motor 1, a transmission 2, a control device 3, an activation switch 4, and an electric braking circuit 5, and includes a pressure generating device 200.

[0025] The pressure generating device 200 is generally configured to generate hydraulic pressure and is operable by the drive module 100. As shown by way of example in FIG. 1, the pressure generating device 200 has, for example, a cylinder 210, a piston 212, and optionally a reservoir 220. The cylinder 210 has a connection portion 211, for example in the form of a hole, which may be formed particularly in the first end region of the cylinder 210. Through this connection portion 211, the pressure generating device 200 can be connected to one or more wheel brakes (not shown). Further, the cylinder 200 has an orifice hole 213 particularly in the second end region, through which the cylinder 210 is connected to the reservoir 220 via a pipe. The piston 212 is axially movable in the cylinder 210 in the forward direction Y1 and the backward direction Y2, and may be initially stressed by a return spring 214 in the backward direction Y2 as shown by way of example in FIG. 1.

[0026] For an increase in hydraulic pressure, the piston 212 is movable in the forward direction Y1 by the drive module 100. Thereby, the internal volume of the cylinder 210 is reduced, and the hydraulic fluid is discharged through the connection portion 211. As schematically shown in FIG. 1, when the piston 212 moves far enough in the forward direction Y1, it immediately closes the orifice hole 213. For pressure reduction, the piston 212 is movable in the backward direction Y2 by the drive module 100. When the piston 212 is positioned behind the orifice hole 213 with respect to the backward direction Y2, it immediately releases it, whereby the hydraulic fluid enters the cylinder 210 from the reservoir 220.

[0027] As already described, the drive module 100 is configured to drive or operate the pressure generating device 200.

[0028] The electric motor 1 generally has a rotor 11 and a stator 12, and in particular, the rotor 11 is kinematically connected to the transmission 2. As a mere example in FIG. 2, the motor 1 embodied as a brushless DC motor is shown, which has a permanently excited rotor 11 and a stator 12 with three coil structures 121, 122, 123. Each of the coil structures 121, 122, 123 constitutes a connection portion. The motor 1 shown as an example in FIG. 2 further has a control circuit 13 which may be configured, for example, as a bridge circuit, which particularly serves as a rectifier circuit. In FIG. 2, as an example, the control circuit 13 is shown as being configured as a B6 bridge circuit having electronic switching members V1 to V6 such as transistors.

[0029] The control device 3 is electrically connected to the control circuit 13 or generally to the motor 1 and is configured for controlling the motor 1, in particular for controlling the operation of the motor 1. For example, the control device 3 may have a computing unit (not shown), in particular in the form of an ASIC (abbreviation of the English expression "application-specific integrated circuit"), and a storage unit, for example in the form of an SD memory. The control device 3 is configured in particular for outputting control signals. For example, the control device 3 outputs control signals to the control circuit 13 for switching the switching members V1-V6, so that the coil arrangements 121, 122, 123 of the stator 12 generate a rotating magnetic field that drives the rotor 11.

[0030] As further shown in Figures 1 and 2, the control device may also optionally be in signal conducting or electrical communication with a braking circuit 5, which is also described below.

[0031] Referring again to FIG. 1, it is clear that the transmission 2 kinematically couples the motor 1 to the piston 212, or generally to the pressure-generating device 200. The transmission 2 has in particular an operating member 20 which is movable axially or linearly in the first and second directions X1, X2 by the motor 2. The operating member 20 can be, for example, a threaded spindle. The transmission 2 can furthermore have a guide part 21 which is connected to the threaded spindle in a non-rotatable manner and which is guided, for example, slidably in the first and second directions X1, X2 along a housing 7 in which the transmission 2 is accommodated. The threaded spindle is thus guided linearly by the guide part 21. To slide the threaded spindle axially, a drive nut 22 can be provided which has an internal thread which engages with the external thread of the threaded spindle. The drive nut 22 can be rotated by the motor 1, for example via a spur gear 23 which is connected to the drive shaft 10 of the motor 1 and which engages with the external toothing of the drive nut 22, as shown purely by way of example in FIG. 1. Naturally, other torque transmission paths between the motor 1 and the operating member 20 are also conceivable.

[0032] As schematically shown in FIG. 1, the operating member 20 is connected to the pressure generating device 200, particularly to the piston 212. The sliding of the operating member 20 in the first direction X1 operates the pressure generating device 200 for increasing the pressure, for example, by the operating member 20 sliding the piston 212 in the forward direction Y1. The sliding of the operating member 20 in the second direction X2 operates the pressure generating device 200 for reducing the pressure, for example, by the operating member 20 sliding the piston 212 in the backward direction Y2.

[0033] Generally, the operating member is slidable between an initial position and a final operating position. For increasing the pressure, the operating member 20 slides from the initial position in the direction of the final operating position in the first direction X1. The maximum

[0034] As can be seen in FIG. 1, when the pressure generating device 200 is operated for increasing the pressure, a restoring force F in the backward direction Y is applied to the piston 212 by the spring 214, but particularly by the working fluid. For example, when the motor 1 stops generating torque when the control device 3 stops, the restoring force F causes the movement of the operating member 20 in the second direction X2. The stroke section in which the operating member 20 travels between the initial position and the final operating position corresponds to the maximum stroke h20 of the operating member 20. In FIG. 1, by way of example, a position Z2 corresponding to the position of the guide portion 21 when the operating member 20 is in the final operating position and a position Z1 corresponding to the position of the guide portion 21 when the operating member 20 is in the initial position are shown.

[0035] The activation switch 4 may be configured, for example, as a mechanically operable switch or as a proximity switch as schematically shown in FIG. 1, for example as a reed switch or a Hall switch. As schematically shown in FIG. 1, the switch 4 may be attached, for example, to the housing 7. For example, a proximity member 41 in the form of a magnet may be arranged, for example, on the guide portion 21, so that when the proximity member 41 falls below a pre-set distance relative to the switch 4, especially when the guide portion 21 moves in the second direction X2 together with the operating member 20, the switch 4 is activated. Of course, the switch 4 may be provided on the guide portion 41 and the proximity portion 41 may be provided on the housing 7. As an alternative, the proximity member 41 or the switch 4 may be attached to the operating member 20. Thus, the switch 4 is preferably releasable by the movement of the guide portion 21 in the second direction X1. This also applies to the case of a mechanical switch. Generally, the switch 4 can be activated by the transmission device 2 as a result of the movement of the operating member 20 in the second direction X2. When the switch 4 is activated by the transmission device 2 or generally switched, the switching process is released by the switch 4 in the braking circuit 5, which is, for example, by the switch 4 outputting a signal to the braking circuit 5.

[0036] In the embodiment of FIG. 1, the switch 4 may be arranged, for example, at a distance from the position Z1 by an interval s20 in the first direction X1, and this interval s20 is, optionally, within the range between 5% and 40% of the maximum stroke h20. Thus, the guide portion moves in the second direction X2 from the operation final position between 60% and 95% of the maximum stroke h20 before activating the switch 4. The position of the operating member 20 at which the switch 4 is activated can be called the activation position. That is, the activation position may be away from the initial position by an interval s20 within the range between 5% and 40% of the maximum stroke h20. Generally, the switch 4 may be arranged such that the operating member 20 is at an activation position closer to the initial position than the operation final position.

[0037] The braking circuit 5 is only shown symbolically as a block in FIGS. 1 and 2 and is electrically connected to the motor 1 and the switch 4. Optionally, the braking circuit 5 may additionally be electrically connected to the control device 3. The braking circuit 5 is fabricated as a passive electrical circuit and is configured to brake the motor 1 when the control device 3 stops. For example, the braking circuit 5 may be configured to short-circuit at least two of the three coil structures 121, 122, 123 shown in FIG. 2, thereby forming an eddy current brake that brakes the rotor 11 as it rotates. To that end, the braking circuit 5 can close at least two of, for example, the three switches V2, V4, V6.

[0038] The braking circuit 5 is configured to be actuated when it receives an actuation voltage and the switch 4 is additionally actuated. In addition to this, optionally, the braking circuit 5 is configured to detect the stop of the control device 3, particularly with reference to a stop signal output from the control device 3, and to be actuated only when the stop of the control device 3 is detected. The actuation voltage is generated by the motor 1. This is because when the rotor 11 rotates when the operating member 20 moves in the second direction X2 by the restoring force F when the control device 3 stops, the motor 1 thus constitutes a generator.

[0039] The electromechanical actuator 300 described above can be operated based on the method M, the procedure of which is schematically shown in FIG. 3.

[0040] In step M1, the control device 3 controls the motor 1, whereby the motor 1 moves the operating member 20 in the first or second direction X1, X2 so as to increase or decrease the hydraulic pressure by the pressure generating device 200. For example, the control device 3 outputs a control signal to the control circuit 13 of the motor 1 to switch the switching member 13.

[0041] In step M11, the braking circuit 5 detects whether the control device 3 has stopped. When no stop is detected, this is indicated by the symbol "-" in FIG. 3, and further step M1 is executed. When the stop of the control device 3 is detected, this is indicated by the symbol "+" in FIG. 3, and the method proceeds to the execution of steps M2 to M5.

[0042] In step M2, through the piston 212 or generally through the pressure generating device 200, the operating member 20 moves in the second direction X2 by the restoring force F acting on the operating member 20 based on the hydraulic pressure. When the operating member 20 moves in the second direction X2, in step M3, the motor 1 is driven as a generator by the transmission device 2, thereby generating an activation voltage, which is applied to the braking circuit 5.

[0043] In step M4, as a result of the movement of the operating member 20 in the second direction X2, the switch 4 is activated by the transmission device 2. In particular, when the operating member 20 reaches the activation position, that is, when for example the guide portion 21 reaches the switch 4 during the movement in the second direction X2 in FIG. 1, the switch 4 is operated.

[0044] In step M41, the braking control unit 5 detects whether the activation voltage has been generated and whether the switch 4 has been activated. Since the braking control unit 5 is fabricated as a passive electrical circuit, the detection step M41 can include, for example, the operation of the first switching member of the braking control unit by the activation voltage and the operation of the second switching member by the switching signal generated by the switch 4. In step M41, when one of these two preconditions is not satisfied (symbol "-" in FIG. 3), the method M can return to step M2, as illustrated in FIG. 3 as an example. When the activation voltage and the activation of the switch are detected, as indicated by the symbol "+" in FIG. 3, the braking circuit 5 is activated in step M5.

[0045] In step M6, which can also be regarded as a sub-step of step M5, the braking circuit 6 brakes the motor 1, for example, by short-circuiting at least two of the three coil structures 121, 122, and 123, as exemplified in FIG. 2. Thereby, the motor 1 is braked to generate a force acting in the direction opposite to the restoring force, and this force decelerates the movement of the operating member 20 in the second direction X2.

[0046] The effect of the present invention becomes clear, in particular, in FIG. 4 showing a graph in which the stroke by which the piston 212 or the operating member 20 advances on the horizontal axis A1 and the speed at which the piston 212 or the operating member 20 moves on the vertical axis are plotted.

[0047] In FIG. 4, the operating member 20 is at the position Pm at the final position of its operation, and the control device 3 stops at this position Pm. As a result, the piston 212 or the operating member 20 accelerates substantially linearly as a result of the hydraulic restoring force F. When the speed Vg of the operating member 20 is exceeded (position Pg in FIG. 4), the motor 1 starts to act as a generator, generates an activation voltage, and the braking circuit 5 receives its supply. If the braking circuit 5 is already activated at this point, as illustrated by the two-dot chain line L1 in FIG. 4, another speed transition will occur. As seen in the transition of the line L1, the motor 1 is immediately braked by the braking circuit 5 in this case, and the speed of the operating member 20 or the piston 212 decreases substantially linearly to the final speed ve at a low speed until the operating member 20 reaches the initial position.

[0048] In the method according to the present invention, or based on the configuration of the actuator 300 provided with the switch 4 according to the present invention, the speed transition shown by the dashed line L2 in FIG. 4 is brought about. Accordingly, the motor 1 starts to act as a generator from the position Pg of the operating member 20 and generates an activation voltage, which is supplied to the braking circuit 5. However, the braking circuit 5 is not yet activated, and the speed of the piston 212 or the operating member 20 continues to increase substantially linearly until the operating member 20 reaches the activation position Pa. At the activation position Pa, the switch 4 is activated, thereby activating the braking circuit 5 and continuously braking the motor 1. Therefore, from the activation position Pa, the speed decreases again to the final speed Ve until it reaches the initial position.

[0049] The time required for the operating member 20 and accordingly the piston 212 to perform the maximum stroke h20 is inversely proportional to the area below the respective transitions L1, L2 in the example of FIG. 4. Therefore, it can be seen that the speed transition L2 obtained based on the present invention leads to a significant shortening of the time required to execute the maximum stroke h20 for pressure reduction.

[0050] Although the present invention has been described by way of example with reference to the embodiments above, the present invention is not limited to these and can be modified in various forms. In particular, combinations of the above embodiments are also conceivable.

Explanation of Reference Numerals

[0051] 1 Electric motor 2 Transmission device 3 Control device 4 Switch 5 Braking circuit 11 Rotor 12 Stator 13 Rectifier circuit, control circuit 20 Operating member 21 Guide portion 22 Driving nut 100 Driving module 121, 122, 123 Coil structure 200 Pressure generating device 202 Hydraulic connection part 210 Cylinder 211 Connection part, connection hole 212 Piston 213 Orifice hole 220 Reservoir 300 Electro-mechanical brake actuator X1 First direction X2 Second direction Y1 Forward direction Y2 Reverse direction

Claims

1. In a drive module (100) for an electromechanical brake actuator (300), an electric motor (1), a transmission (2) kinematically connected to the motor (1), having an operating member (20) connectable to the pressure generating device (200), the operating member (20) being linearly positionally adjustable against a restoring force in a first direction (X1) by the motor (1) for operating the pressure generating device (200), a control device (3) electrically connected to the motor (1) for controlling the motor (1), a switch (4) activatable by the transmission (2) as a result of movement of the operating member (20) in a second direction (X2), and an electric brake circuit (5) electrically connected to the motor (1) and the switch (4), activatable by activation of the switch (4) and by an electrical activation voltage, wherein the activation voltage is generated by the motor (1) when acting as a generator by the motor receiving the restoring force acting on the operating member (20) when the control device (3) is stopped, and the brake circuit (5) is configured to brake the motor (1) to generate a force acting in a direction opposite to the restoring force by the motor (1). A drive module.

2. The drive module (100) according to claim 1, wherein the brake circuit (5) is further configured to detect the stop of the control device (3), in particular with reference to a stop signal output from the control device (3), and is activated only when the stop of the control device (3) is detected.

3. The drive module (100) according to claim 1 or 2, wherein the operating member (20) is movable between an initial position and a final operating position, the restoring force applies an initial stress to the operating member (20) in the direction of the initial position, and the switch (4) is arranged to be activated at the activation position of the operating member (20) when the operating member (20) is in the vicinity of the initial position rather than the final operating position.

4. The drive module (100) according to claim 3, wherein the initial position and the final operating position define a maximum stroke (h20) of the operating member (20), and the activation position is offset from the initial position by an interval (s20) within a range between 5 percent and 40 percent of the maximum stroke (h20).

5. The drive module (100) according to any one of claims 1 to 4, wherein the switch (4) is configured as a proximity switch, in particular as a reed switch or a Hall switch, or is manufactured as a mechanically releasable switch.

6. The drive module (100) according to any one of claims 1 to 5, wherein the operating member (20) is constituted by a threaded spindle, the threaded spindle is linearly guided by a guide portion (21) non-rotatably coupled thereto, and is linearly positionable by a drive nut (22) rotatable by the motor (1), and the switch (4) is releasable by the guide portion (21).

7. The drive module (100) according to any one of claims 1 to 6, wherein the motor (1) is configured as a brushless DC motor having a permanent magnet rotor (11), a stator (12) having at least three coil structures (121, 122, 123), and a rectifier circuit (13) coupled to the coil structures (121, 122, 123) controllable by the control device (3), and the braking circuit (5) is configured to short-circuit at least two of the coil structures (121, 122, 123) so that they act as an eddy current brake.

8. In an electromechanical brake actuator (300), a drive module (100) according to any one of claims 1 to 7, and a pressure generating device (200) coupled to the operating member (20) of the transmission device (2) and having a hydraulic connection portion (202) for providing hydraulic fluid to a wheel brake.

9. The brake actuator (300) according to claim 8, wherein the pressure generating device (200) has a cylinder (210) and a piston (212) accommodated in the cylinder (210) movable by hydraulic fluid so as to slide in a forward direction (Y1) and a backward direction (Y2) by the operating member (20), the hydraulic connection portion (202) is constituted by a connection hole (211) of the cylinder (210), and the cylinder (210) has an orifice hole (213) which is released when the piston (212) moves in the backward direction (Y2) and connects the cylinder (210) to a reservoir (220).

10. A method (M) for operating an electromechanical brake actuator (300) according to claim 8 or 9, wherein the motor (1) is controlled by the control device (3) (M1) such that the motor (1) moves the operating member (20) in a first or second direction (X1, X2), thereby increasing or decreasing the hydraulic pressure by the pressure generating device (20), when the control device (3) stops, a restoring force acting as a result of the increased hydraulic pressure moves the operating member (20) in the second direction (X2) (M2), the operating member (20) moving in the second direction (X2) drives the motor (1) as a generator, thereby generating an activation voltage by the motor (5) (M3), as a result of the movement of the operating member (20) in the second direction (X2), the switch (4) is activated by the transmission device (2) (M4), when the activation voltage is supplied to the brake circuit (5) and the switch (4) is activated, the brake circuit (5) is activated (M5), the brake circuit (6) brakes the motor (1), thereby generating a force acting in a direction opposite to the restoring force that decelerates the movement of the operating member (20) in the second direction (X2), method.

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