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 for operating an electromechanical brake actuator. [Background technology]

[0002] Electromechanical brake boosters are typically used to boost the brake force manually generated by the brake pedal, by operating a master brake cylinder with an electric motor. Similar electrohydraulic brake booster and other actuators are also used in so-called "brake-by-wire" systems, where an electrohydraulic actuator is operated to generate brake pressure based on a brake pedal or other position adjustment signal.

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

[0004] In an actuator configured in this way, if control of the electric motor is discontinued, for example due to a cutoff in the current supply, while the electric motor is operating a master brake cylinder or generally a pressure generating device to increase hydraulic pressure, the increased hydraulic pressure acts as a restoring force on the transmission. The transmission is operated by the restoring force, causing the electric motor to rotate, which then operates as a generator. Because an uncontrolled pressure drop would cause uncontrolled operation of the transmission, the electric motor is usually braked via an electronic braking circuit to avoid component damage, particularly in the transmission. However, it is also desirable to ensure that the pressure drop occurs as smoothly as possible when the motor is stopped so that effective compensation measures to generate the required brake pressure can be initiated quickly. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] German Patent No. 102013213888 Summary of the Invention

[0006] Against this background, the present invention provides a drive module for an electromechanical brake actuator having the features of claim 1, an electromechanical brake actuator having the features of claim 8, and a method having the features of claim 10.

[0007] In a first aspect of the present 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, the operating member being linearly positionable by the motor against a return force in a first direction to operate the pressure-generating device; a control device electrically connected to the motor to control the motor; a switch actuable 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 actuable by activation of the switch and by an electric actuation voltage, the actuation voltage being generated by the motor when it acts as a generator by receiving a return force acting on the operating member when the control device is stopped, and the braking circuit is configured to brake the motor to generate a force by the motor acting in a direction opposite to the return force.

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

[0009] A third aspect of the present invention is directed to a method for operating an electromechanical brake actuator according to the second aspect of the present invention. The method includes controlling a motor by a control device to move an operating member in a first or second direction, thereby increasing or decreasing hydraulic pressure via a pressure-generating device. When the control device is stopped, for example, due to a supply voltage interruption or a malfunction of the control device itself, the operating member of the transmission moves in the second direction due to a return force acting as a result of the increased hydraulic pressure. The operating member moving in the second direction then drives the motor as a generator, causing the motor to generate an activation voltage, and a switch is activated by the transmission as a result of the movement of the operating member in the second direction. In a subsequent step, the brake circuit is activated when the activation voltage is supplied to the brake circuit and the switch is activated. The brake circuit then brakes the motor, causing the motor to generate a force acting in a direction opposite to the return force, slowing the movement of the operating member in the second direction.

[0010] The idea behind the present invention is that the passive electronic braking circuit that brakes the electric motor when the control device is stopped is not activated immediately when the control device is stopped, but only under the additional condition that the linearly returning part of the transmission releases the activation switch, which then activates the braking circuit. This creates the possibility that the transmission first travels freely or unbraked over a certain distance by hydraulic pressure acting as a restoring force from the pressure-generating device, and then is braked by the motor braked by the braking circuit. In particular, this has the advantage that the pressure-generating device reduces pressure without being braked at first, thereby reducing the time required for pressure reduction.

[0011] Preferred embodiments and developments emerge from the further dependent claims and from the description given with reference to the drawing figures.

[0012] In some embodiments, the motor has a control circuit, e.g., a bridge circuit, switchable 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, e.g., by switching the control circuit such that poles and / or individual phases of the motor are shorted through the control circuit, thereby causing at least a portion of the rotor windings and / or stator windings of the motor to form an eddy current brake.

[0013] In some embodiments, the braking circuit is configured to detect a 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 a stop of the control device is detected. For example, the control device may be configured to output a signal, e.g., in the form of a voltage, to the braking circuit under normal operation. If this signal is lost upon a stop of the control device, the braking circuit detects that a stop of the control device has occurred. To do this, the braking circuit may, for example, have a switch that closes when de-energized. If the control device signal is lost, the switch closes.

[0014] In some embodiments, the operating member is intended to be movable between an initial position and a final operating position, the return force initially stressing the operating member toward the initial position, and the switch is arranged to be activated when the operating member is in an activated position closer to the initial position than to the final operating position. The operating member is slidable in a first direction, i.e., from its initial position toward the final operating position, due to an increase in pressure by the pressure-generating device. To reduce pressure, the operating member is movable in a second direction, i.e., toward the initial position. The switch is positioned relative to the transmission so that it is released upon pressure reduction only when the operating member is closer to the initial position than to the final operating position. This allows the transmission to move freely over at least 50% of the maximum stroke that the operating member can perform. This allows for more rapid pressure reduction.

[0015] In general, 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 separated from the initial position by a distance ranging from 5 to 40 percent of the maximum stroke. In this way, the activation switch is activated or operated only shortly before the operating member reaches the initial position. In this way, pressure reduction is more rapid.

[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, e.g. a magnetic piece, and the proximity sensor is positioned relative to the transmission such that when the operating member is moved in the second direction, the proximity member approaches the proximity sensor, which thereby outputs a signal to the braking circuit.

[0017] In some embodiments, it may be intended to be made as a mechanically releasable switch, in which case the switch may be prestressed into an open state, for example by a spring, and closed by a gearing member, which in turn closes an electrical switch in the braking circuit.

[0018] In some embodiments, the operating member may be a threaded spindle, which is linearly guided by a guide part connected to the threaded spindle in a manner that prevents relative rotation therewith and which can be linearly adjusted by a drive nut that can be rotated by a motor, and the switch can be released by the guide part. This has the advantage that the guide part 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 intended to be configured as a brushless DC motor having a permanently excited rotor, a stator having at least three coil structures, and a commutation circuit coupled to the coil structures, controllable by a control device, the braking circuit being configured to short-circuit at least two of the coil structures so that they act as an eddy current brake. The commutation circuit thus constitutes a control circuit for the motor and may be embodied, for example, as a B6 bridge circuit.

[0020] In some embodiments, the pressure-generating device may include a cylinder and a piston accommodated in the cylinder, which is movable by hydraulic fluid so as to slide forward and backward by an operating member. The hydraulic connection is formed by a connecting bore in the cylinder, and the cylinder has an orifice bore that is released when the piston moves backward, connecting the cylinder to a reservoir. The pressure-generating device may be, for example, a master brake cylinder or a plunger. An activation switch for activating the braking circuit may be provided, allowing the piston to move backward over a relatively wide area to reduce pressure with minimal reaction force, substantially corresponding to the frictional forces in the transmission and motor. In this way, the orifice bore is released more quickly, which facilitates rapid compensation for the cessation of pressure generation, since alternative systems, such as ABS systems, may require hydraulic fluid from the reservoir in certain situations.

[0021] The invention will now be described with reference to the figures of the drawings, in which: [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a schematic cross-sectional view of an electromechanical brake actuator according to an embodiment of the present invention; [Figure 2] 1 is a schematic functional circuit diagram of a drive module according to an embodiment of the present invention, the transmission of which is not shown; [Figure 3] 2 is a flowchart of a method according to an embodiment of the present invention. [Figure 4] 1 is a graph plotting the velocity of movement of a piston of a brake actuator against the path of movement. DETAILED DESCRIPTION OF THE INVENTION

[0023] In the various figures, unless otherwise stated, the same reference numerals represent the same or functionally identical components.

[0024] Figure 1 shows, by way of example and in purely schematic form, an electromechanical brake actuator 300. As shown in Figure 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 can be operated by the drive module 100. As shown by way of example in FIG. 1 , the pressure-generating device 200 includes, for example, a cylinder 210, a piston 212, and, optionally, a reservoir 220. The cylinder 210 includes a connection 211, for example in the form of a hole, which may be formed, in particular in a first end region of the cylinder 210. Via this connection 211, the pressure-generating device 200 can be connected to one or more wheel brakes (not shown). Furthermore, the cylinder 200 includes, in particular in a second end region, an orifice hole 213, through which the cylinder 210 is connected to the reservoir 220 via piping. The piston 212 is axially movable in the cylinder 210 in a forward direction Y1 and a backward direction Y2 and may be prestressed by a return spring 214 in the backward direction Y2, as shown by way of example in FIG. 1 .

[0026] Due to the increase in hydraulic pressure, the piston 212 is movable in the forward direction Y1 by the drive module 100. This reduces the internal volume of the cylinder 210, and hydraulic fluid is discharged through the connection 211. As shown schematically in Figure 1, the piston 212 closes the orifice hole 213 as soon as it moves far enough in the forward direction Y1. Due to the decrease in pressure, the piston 212 is movable in the backward direction Y2 by the drive module 100. As soon as the piston 212 is positioned rearward of the orifice hole 213 in the backward direction Y2, it releases it, thereby allowing hydraulic fluid to enter the cylinder 210 from the reservoir 220.

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

[0028] The electric motor 1 generally comprises a rotor 11 and a stator 12, with the rotor 11 being kinematically coupled to a transmission 2. Fig. 2 shows, purely by way of example, the motor 1 embodied as a brushless DC motor, which comprises a permanently excited rotor 11 and a stator 12 with three coil structures 121, 122, and 123. Each of the coil structures 121, 122, and 123 constitutes a phase connection. The motor 1 shown by way of example in Fig. 2 further comprises a control circuit 13, which may be configured, for example, as a bridge circuit and serves, in particular, as a rectifier circuit. Fig. 2 shows, by way of example, that the control circuit 13 is configured as a B6 bridge circuit with electronic switching elements 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 to control the motor 1, in particular to control 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 (an abbreviation for 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 to output control signals. For example, the control device 3 outputs control signals to the control circuit 13 for switching the switching members V1 to 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 FIGS. 1 and 2, the control device may also optionally be in signal conducting or electrical communication with a braking circuit 5, which will also be described below.

[0031] Referring again to FIG. 1 , 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 that is movable axially or linearly in the first and second directions X1 and X2 by the motor 2. The operating member 20 may be, for example, a threaded spindle. The transmission 2 may further have a guide portion 21 that is non-rotatably connected to the threaded spindle and that is guided, for example, along the housing 7 in which the transmission 2 is accommodated, so that it can slide in the first and second directions X1 and X2. The threaded spindle is thus linearly guided by the guide portion 21. To slide the threaded spindle axially, a drive nut 22 may be provided that has an internal thread that 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 connected to the drive shaft 10 of the motor 1, which engages with the external teeth 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 possible.

[0032] 1, the operating member 20 is coupled to the pressure generating device 200, in particular to the piston 212. Sliding the operating member 20 in a first direction X1 operates the pressure generating device 200 to increase pressure, for example by the operating member 20 sliding the piston 212 in a forward direction Y1. Sliding the operating member 20 in a second direction X2 operates the pressure generating device 200 to decrease pressure, for example by the operating member 20 sliding the piston 212 in a backward direction Y2.

[0033] Generally, the operating member is slidable between an initial position and an end position. Due to an increase in pressure, the operating member 20 slides from the initial position in a first direction X1 toward the end position.

[0034] 1, when the pressure-generating device 200 is operated to increase the pressure, a return force F in the backward direction Y is applied to the piston 212 by the spring 214, but in particular by the hydraulic fluid. When the motor 1 no longer generates torque, for example when the control device 3 is stopped, the return force F causes the operating member 20 to move in the second direction X2. The stroke section traveled by the operating member 20 between the initial position and the final operating position corresponds to the maximum stroke h20 of the operating member 20. As an example, FIG. 1 shows a position Z2 corresponding to the position of the guiding part 21 when the operating member 20 is in the final operating position, and a position Z1 corresponding to the position of the guiding part 21 when the operating member 20 is in the initial position.

[0035] The actuation switch 4 may be configured, for example, as a mechanically operable switch or as a proximity switch, as shown diagrammatically in FIG. 1 , such as a reed switch or a Hall switch. As shown diagrammatically in FIG. 1 , the switch 4 may be mounted, for example, on the housing 7. A proximity member 41, for example in the form of a magnet, may be arranged, for example, on the guide portion 21, so that the switch 4 is activated when the proximity member 41 moves below a predetermined distance relative to the switch 4, in particular when the guide portion 21 moves together with the operating member 20 in the second direction X2. Naturally, the switch 4 may be mounted on the guide portion 41, and the proximity member 41 may be mounted on the housing 7. Alternatively, the proximity member 41 or the switch 4 may be attached to the operating member 20. Thus, the switch 4 is preferably releasable by movement of the guide portion 21 in the second direction X1. This also applies to mechanical switches. In general, the switch 4 can be actuated by the gearing 2 as a result of movement of the operating member 20 in the second direction X2. When the switch 4 is actuated, or generally switched, by the transmission 2, the switch 4 releases the switching process in the brake circuit 5, for example by the switch 4 outputting a signal to the brake circuit 5.

[0036] In the embodiment of FIG. 1 , the switch 4 may be positioned, for example, in the first direction X1 by a distance s20 from the position Z1, which distance s20 optionally lies within a range of 5 to 40 percent of the maximum stroke h20. Thus, the guide portion advances from the final operating position in the second direction X2 by 60 to 95 percent of the maximum stroke h20 before activating the switch 4. The position of the operating member 20 at which the switch 4 is activated may be referred to as the activation position. That is, the activation position may be away from the initial position by a distance s20 within a range of 5 to 40 percent of the maximum stroke h20. In general, the switch 4 may be positioned such that the operating member 20 is in an activation position closer to the initial position than the final operating position.

[0037] The braking circuit 5 is shown only 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 implemented as a passive electrical circuit and is configured to brake the motor 1 when the control device 3 stalls. For example, the braking circuit 5 may be configured to short-circuit at least two of the three coil structures 121, 122, and 123 shown in FIG. 2, which thereby form an eddy current brake that brakes the rotating rotor 11. To this end, the braking circuit 5 may close at least two of the three switches V2, V4, and V6, for example.

[0038] The braking circuit 5 is configured to be activated when an activation voltage is received and the switch 4 is additionally activated. In addition, the braking circuit 5 is optionally configured to detect a stop of the control device 3, in particular with reference to a stop signal output from the control device 3, and to be activated only when a stop of the control device 3 is detected. The activation voltage is generated by the motor 1, since its rotor 11 rotates when the operating member 20 moves in the second direction X2 due to the return force F when the control device 3 is stopped, and thus the motor 1 constitutes a generator.

[0039] The electromechanical actuator 300 described above can be operated according to method M, the procedure of which is shown diagrammatically in FIG.

[0040] In step M1, the control device 3 controls the motor 1 so that the motor 1 moves the operating member 20 in the first or second direction X1, X2 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 a breakdown of the control device 3 has occurred. If a breakdown is not detected, this is indicated by the symbol "-" in Figure 3, and further step M1 is executed. If a breakdown of the control device 3 is detected, this is indicated by the symbol "+" in Figure 3, and the method proceeds to execute steps M2 to M5.

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

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

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

[0045] In step M6, which may be considered a substep of step M5, the braking circuit 6 brakes the motor 1, for example by shorting at least two of the three coil structures 121, 122, 123, as exemplarily shown in Figure 2. This brakes the motor 1 and generates a force acting in the opposite direction to the return force, which slows down the movement of the operating member 20 in the second direction X2.

[0046] The effect of the present invention is particularly clear in FIG. 4, which shows a graph in which the horizontal axis A1 represents the stroke traveled by the piston 212 or operating member 20, and the vertical axis represents the speed at which the piston 212 or operating member 20 moves.

[0047] In FIG. 4, the operating member 20 is in its final operating position at position Pm, at which position Pm the control device 3 stops. Consequently, the piston 212 or the operating member 20 accelerates substantially linearly as a result of the hydraulic return force F. Once the operating member 20 exceeds speed Vg (position Pg in FIG. 4), the motor 1 begins to act as a generator, generating an activation voltage that supplies the braking circuit 5. If the braking circuit 5 were already activated at this point, a different speed profile would result, as shown by the dashed-dot line L1 in FIG. 4. As can be seen from the profile of line L1, the motor 1 is immediately braked in this case by the braking circuit 5, and the speed of the operating member 20 or the piston 212 decreases substantially linearly until the operating member 20 reaches its initial position and reaches its final speed ve.

[0048] The method according to the invention, or the configuration of the actuator 300 with the switch 4 according to the invention, results in the speed profile shown by the dash-dot line L2 in Fig. 4. Accordingly, the motor 1 also 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 essentially linearly until the operating member 20 reaches the activation position Pa. At the activation position Pa, the switch 4 is activated, which activates the braking circuit 5 and subsequently brakes the motor 1. From the activation position Pa, the speed therefore decreases again to the final speed Ve until the initial position is reached.

[0049] The time required by the operating member 20, and thus the piston 212, to perform the maximum stroke h20 is inversely proportional to the area under the respective transitions L1, L2 in the example of Fig. 4. It can therefore be seen that the speed transition L2 obtained according to the invention leads to a clear reduction in the time required to perform the maximum pressure reduction stroke h20.

[0050] Although the invention has been described above by way of example with reference to the examples, the invention is not limited thereto and can be modified in many different ways, and in particular combinations of the above-described examples are also conceivable. [Explanation of symbols]

[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 Information section 22 Drive nut 100 Drive Module 121,122,123 Coil structure 200 Pressure-Generating Device 202 Hydraulic Connection 210 cylinders 211 Connection part, connection hole 212 Piston 213 Orifice hole 220 Reservoir 300 Electromechanical Brake Actuator X1 First direction X2 Second direction Y1 Forward direction Y2 Reverse direction

Claims

1. A drive module (100) for an electromechanical brake actuator (300), comprising: an electric motor (1); a transmission (2) kinematically coupled to the motor (1), the transmission (2) having an operating member (20) connectable to the pressure-generating device (200), the position of which is linearly adjustable by the motor (1) in a first direction (X1) against a return force in order to operate the pressure-generating device (200); a control device (3) electrically connected to the motor (1) for controlling the motor (1); a switch (4) that is actuatable by the transmission (2) as a result of movement of the operating member (20) in a second direction (X2); an electric braking circuit (5) electrically connected to the motor (1) and the switch (4) and operable by activation of the switch (4) and by an electric activation voltage; The actuation voltage is generated by the motor (1) when the motor acts as a generator by receiving a return force acting on the operating member (20) when the control device (3) is stopped, and the braking circuit (5) is configured to brake the motor (1) so as to generate a force by the motor (1) acting in a direction opposite to the return force.

2. 2. The drive module (100) of claim 1, wherein the braking circuit (5) is further configured to detect a 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 a stop of the control device (3) is detected.

3. 3. The drive module (100) of claim 1 or 2, wherein the operating member (20) is movable between an initial position and a final operating position, a 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 when the operating member (20) is in an activated position closer to the initial position than to the final operating position.

4. 4. The drive module (100) of 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 separated from the initial position by a section (s20) that is within a range between 5 percent and 40 percent of the maximum stroke (h20).

5. 3. The drive module (100) according to claim 1 or 2, wherein the switch (4) is configured as a proximity switch, in particular as a reed switch or a Hall switch, or is made as a mechanically releasable switch.

6. 3. The drive module (100) according to claim 1 or 2, wherein the operating member (20) is constituted by a threaded spindle, which is linearly guided by a guide portion (21) connected to the threaded spindle so as not to rotate relative to the threaded spindle, and whose position can be adjusted linearly by a drive nut (22) rotatable by the motor (1), and the switch (4) can be released by the guide portion (21).

7. 3. The drive module (100) according to claim 1 or 2, wherein the motor (1) is configured as a brushless DC motor having a permanently excited 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) that is controllable by the control device (3), and the braking circuit (5) is configured to short-circuit at least two coil structures (121, 122, 123) so that they act as eddy current brakes.

8. An electromechanical brake actuator (300) comprising a drive module (100) according to claim 1 or 2, a pressure generating device (200) connected to the operating member (20) of the transmission (2) and having a hydraulic connection (202) for providing hydraulic fluid to the wheel brakes.

9. 9. The brake actuator (300) according to claim 8, wherein the pressure generating device (200) comprises a cylinder (210) and a piston (212) housed 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) being constituted by a connection hole (211) of the cylinder (210), and the cylinder (210) has an orifice hole (213) which is released by the piston (212) when the piston (212) moves in the backward direction (Y2) to connect the cylinder (210) with a reservoir (220).

10. 9. The method (M) of operating an electromechanical brake actuator (300) according to claim 8, further comprising: The motor (1) is controlled (M1) by the control device (3) so 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 (200); When the control device (3) is stopped, A restoring force acting as a result of the increased hydraulic pressure moves the operating member (20) in a second direction (X2) (M2); The operating member (20) moving in a second direction (X2) drives the motor (1) as a generator, thereby causing the motor (1) to generate an actuation voltage (M3); The switch (4) is activated (M4) by the transmission (2) as a result of the movement of the operating member (20) in a second direction (X2), When the activation voltage is supplied to the braking circuit (5) and the switch (4) is activated, the braking circuit (5) is activated (M5); The braking circuit (5) brakes the motor (1), causing the motor (1) to generate a force acting in a direction opposite to the return force, which slows down the movement of the operating member (20) in the second direction (X2).

Images