CN209410041U - A kind of motor-driven brake actuator - Google Patents

Abstract

A kind of motor-driven brake actuator, including motor (7), lubricating cup (20), driving mechanism (30), hydraulic pump (31), the driving mechanism (30) includes: gear-box rear cover (1), ball screw axis, ball screw axis (2) end is equipped with screw rod positioning pin (28), a part of the ball screw axis (2) and screw rod positioning pin (28) are set in screw rod positioning sleeve (27), the end of the screw rod positioning sleeve (27) is resisted against inside gear-box rear cover, the head end of the screw rod positioning sleeve also sets up ball screw nut (24), rolling bearing is set on the outside of the ball screw nut.Motor-driven brake actuator described in the utility model has following good effect: using motor driven, fast response time, the response time is 120 milliseconds to 150 milliseconds or so, 200 to 300 milliseconds shorter than the response time of ESP module.

Description

A kind of motor-driven brake actuator

Technical field

The present invention relates to field of automobile brake, especially a kind of motor-driven brake actuator.

Background technique

With the continuous progress of technology, electric drive is applied in large quantities in the car, for electronic driver or mixing The vehicle of power drive unit is verified, and the brake actuator of electric drive vehicle or hybrid vehicle makes conventional brake fluid Pressure system becomes extra, and vehicle driver, which does as usual, operates the brake pedal of vehicle, but it overcomes spring or the bullet by spring generation Power generates the feeling of similar conventional vehicular brake pedal.In the control unit of vehicle, the power of brake pedal is trampled by driver The brake force for each wheel of vehicle is calculated, generates the pressing force of brake unit by control unit at single wheel. However, currently, the development of the control unit about motor-driven brake actuator and immature.It is badly in need of a kind of stabilization, reliable And the strong brake actuator control unit of endurance fills up technological gap.

Summary of the invention

First aspect present invention provides a kind of motor-driven brake actuator comprising motor, lubricating cup, driving mechanism, Hydraulic pump, the driving mechanism include: gear-box rear cover, ball screw axis, rolling bearing, gear II, gear I, gearhousing Body, ball screw nut, inner shield ring I, housing seal circle I, screw rod positioning sleeve, screw rod positioning pin, the ball screw shaft end Equipped with screw rod positioning pin, for a part and screw rod set pin sleeve of the ball screw axis loaded in screw rod positioning sleeve, the screw rod is fixed The end of position set is resisted against inside gear-box rear cover, and the head end of the screw rod positioning sleeve also sets up ball screw nut, the rolling It is set with rolling bearing on the outside of ballscrew nut, is also equipped with gear II on the outside of the ball screw nut, gear II and motor Drive the gear I engagement of shaft end suit, the gear-box rear cover connection gear tank shell.

Gear II, ball screw nut, rolling bearing become a component by interference or other fixed forms. Screw rod positioning sleeve is cooperated by interference or other fixed forms with gear-box rear cover.

Motor, which is located at gear box casing left end, gear I and motor, becomes one by interference fit or other fit systems A component realizes transmission agency.

Hydraulic pump is located at the left end of driving mechanism, is staggered with motor, and the hydraulic pump includes the pump housing, the pump housing and driving machine Gear box casing connection in structure, hydraulic pump further includes limited screw, reset spring II, relay piston I, piston fixed pin, cup It is shape sealing element I, piston stopper pin, cup seal II, spring base I, relay piston II, reset spring I, spring base II, driven Piston I II.The pump housing is equipped with oil outlet I and oil outlet II, oil inlet I and oil inlet II；Cup-shaped is housed on the relay piston III It is solid that the left end sealing element I, relay piston III is sequentially arranged with spring base II, limited screw, reset spring II, relay piston I, piston Rationed marketing, cup seal I, piston stopper pin, cup seal II, spring base I, relay piston II, reset spring I；Driven work Plug I is linked together by limited screw and relay piston III, and relay piston I and relay piston II are solid by piston fixed pin It is scheduled on together, becomes a component, the starting force of the adjustable reset spring II of limited screw.

Reset spring I is set gradually in the pump housing from left to right, one end of reset spring I is set in relay piston II Left end, the right end of relay piston II connects relay piston I；

Chamber V is constituted between the left end relay piston II and the pump housing, is constituted between the pump housing in the middle part of the relay piston II Chamber IV, relay piston I include hydraulic port, the relay piston II Inner Constitution chamber III, outside the relay piston II with it is described Chamber II is constituted between the pump housing.It is also equipped with relay piston III in the pump housing of the relay piston I right end, relay piston III and institute Setting reset spring II between relay piston I is stated, chamber I is constituted between relay piston III and the pump housing.

Cylinder body is divided into chamber I, chamber II, chamber III, chamber IV, chamber V by above-mentioned cup seal I and cup seal II everywhere Totally five chambers, the flow direction of brake fluid is all unidirectional between adjacent chamber.

The relay piston III right end includes groove, and the optical axis portion of ball screw axis left end is accommodated in the groove.

It further include at least one oil inlet and at least one oil outlet on the pump housing, the oil inlet is connected to the lubricating cup.

Lubricating cup is located at the top of hydraulic pump.

The working principle of motor-driven brake actuator of the present invention:

Brake pedal is stepped on, and control system is according to the letter of the Hall sensor aperture of driver's pedal (sensor according to) Number, motor is rotated, the gear I rotation being mounted on motor output shaft is driven.Gear I rotation drives the gear II being engaged with Rotation, ball screw nut are interference fitted into gear II and rotate together, and realize that ball screw axis horizontally slips and (do not rotate), When braking, ball screw axially left sliding.

Limited screw is together by a threaded connection with relay piston III and slides left and right.

Brake fluid respectively enters chamber I, chamber IV through oil inlet I, oil inlet II from lubricating cup.Through cup seal I, Cup-shaped seal Part II reaches chamber II.Ball screw axially left sliding drives relay piston III to slide together to the left with limited screw, limits spiral shell Silk slide to the left, the space compression chamber III leads to the hydraulic increase of chamber III, and brake fluid is orally pressed into chamber II, at the same time, due to from Piston III moves downward compression chamber II, leads to hydraulic increase, and chamber II brake fluid is exported from oil outlet II.

Relay piston I, relay piston II are attached by piston fixed pin, relay piston I, relay piston II, piston Fixed pin three slides left and right together, referred to as piston component.

In addition, relay piston II is equipped with piston stopper pin, which limits the sliding scale of relay piston II, resistance Only relay piston II is excessively slided to the right.As a result, especially when intelligent hydraulic force aid system fails, using fluid pressure type system When dynamic, when a thrashing, another system is prevented to fail, starting protection effect.Using piston component as object, do not start When braking, piston component is in the leftmost side, and the power that reset spring I acts on piston component is more than or equal to reset spring II and acts on The power of piston component.When braking, relay piston III compression chamber II and reset spring II to the left is pressurized on the right side of piston component When power is greater than left side pressure, piston component slides to the left, compression chamber V, leads to hydraulic increase, and V brake fluid of chamber is from fuel-displaced Mouth I output.

Brake pedal release, releases braking, (sensor is according to driver's pedal according to Hall sensor for control system Aperture) signal, rotate backward motor, drive be mounted on motor output shaft gear I rotation.Gear I rotation drive with Meshed gears II rotation, ball screw nut presses to gear II interference and rotates together, and realizes the axial right side of ball screw Sliding.At this point, relay piston III left pressure is greater than right side, relay piston III also slides to the right together, reset spring II by Step resets, and spring force gradually reduces, at this point, piston component left pressure is greater than right atrial pressure, piston component Slideslip to the right, and chamber V, chamber II, the hydraulic reduction of chamber III, brake fluid are back to chamber V, chamber II, chamber III from oil outlet I, II mouthfuls of oil outlet respectively, oil The release of cup edge arrow direction supplements brake fluid to chamber IV, chamber I, and chamber IV, chamber I will be made by cup seal I, cup seal II Hydrodynamic is supplemented to chamber V, chamber II, chamber III, is finally reached original state.

Second aspect of the present invention provides a kind of braking method of motor-driven brake actuator comprising:

Step S1: brake pedal is stepped on, and control system rotates motor according to the signal of sensor；Drive is mounted on electricity Gear I rotation on machine output shaft.

Step S2: gear I rotation drives the gear II rotation being engaged with, and ball screw nut and gear II are interference fitted To rotating together, realize that ball screw axis horizontally slips, when braking, ball screw axially left sliding；Limited screw and driven work Plug III, which is together by a threaded connection, to be slid left and right.

Step S3: brake fluid respectively enters chamber I, chamber IV through oil inlet from lubricating cup, and through cup seal I, Cup-shaped seal Part II reaches chamber II.

Step S4: ball screw axially left sliding drives relay piston III to slide together to the left with limited screw, limits Screw slides to the left, and the space compression chamber III leads to the hydraulic increase of chamber III, and brake fluid is orally pressed into chamber II, at the same time, due to Relay piston III moves downward compression chamber II, leads to hydraulic increase, and chamber II brake fluid is exported from oil outlet II.

Step S5: relay piston I, relay piston II is attached by piston fixed pin, relay piston I, relay piston II, piston fixed pin three slide left and right together.The sliding of the piston stopper pin limitation relay piston II of relay piston II Range prevents relay piston II from excessively sliding to the right.As a result, especially when intelligent hydraulic force aid system fails, use is hydraulic When formula is braked, when a thrashing, another system is prevented to fail, starting protection effect.

Step S6: brake pedal release releases braking, and control system keeps motor reversed according to the signal of Hall sensor Rotation drives the gear I rotation being mounted on motor output shaft；Gear I rotation drives the gear II rotation being engaged with, ball Feed screw nut presses to gear II interference and rotates together, and realizes ball screw axially right sliding.At this point, relay piston III is left Lateral pressure is greater than right side, and relay piston III is also slided to the right together, and reset spring II gradually resets, and spring force gradually reduces, this When, piston component left pressure is greater than right atrial pressure, and piston component to the right make by Slideslip, chamber V, chamber II, the hydraulic reduction of chamber III Hydrodynamic is back to chamber V, chamber II, chamber III from oil outlet, and for lubricating cup release supplement brake fluid to chamber IV, chamber I, chamber IV, chamber I pass through cup Brake fluid is supplemented to chamber V, chamber II, chamber III by shape sealing element I, cup seal II, is finally reached original state.

Using piston component as object, when not starting braking, piston component is in the rightmost side, and reset spring I acts on work The power of plug assembly is more than or equal to the power that reset spring II acts on piston component.When braking, relay piston III compression chamber II to the left And reset spring II, when pressure is greater than left side pressure on the right side of piston component, piston component slides to the left, compression chamber V, lead to hydraulic increase, V brake fluid of chamber is exported from oil outlet I.

Successively execute step S1- step S6.

Motor-driven brake actuator of the present invention has following good effect:

1. using motor driven, fast response time, the response time is 120 milliseconds to 150 milliseconds or so, than ESP module Response time want 200 to 300 milliseconds short.

2. motor driven, ECU control, may be mounted on the vehicle of automatic Pilot, are a kind of future developing trends.

3. it is compact-sized, components cost is reduced, also has certain reduction in size and weight, meets present development of automobile Trend.

4. DC brushless motor used in the present apparatus designs a kind of fuzzy PID control strategy of parameter adaptive, gram The parameter of the parameter and dragging load that take traditional motor itself can change in the process of running, so that preset parameter The shortcomings that PID controller cannot make system all keep performance indicator when designing under various operating conditions.

Detailed description of the invention

Fig. 1 is the structural schematic diagram of a preferred embodiment of motor-driven brake actuator of the present invention；

Fig. 2 is the internal cross section structural schematic diagram of embodiment illustrated in fig. 1；

Specific embodiment

Embodiment 1.1: a kind of motor-driven brake actuator, it includes motor 7, lubricating cup 20, driving machine as shown in Figure 1 Structure 30, hydraulic pump 31, driving mechanism 30 as described in Figure 2 include: gear-box rear cover 1, ball screw axis 2, rolling bearing 3, gear II 4, gear I 5, gear box casing 6, ball screw nut 24, inner shield ring I 25, housing seal circle I 26, screw rod positioning sleeve 27, screw rod positioning pin 28,2 end of ball screw axis be equipped with screw rod positioning pin 28, a part of the ball screw axis 2 with Screw rod positioning pin 28 is set in screw rod positioning sleeve 27, and the end of the screw rod positioning sleeve 27 is resisted against inside gear-box rear cover 1, The head end of the screw rod positioning sleeve 27 also sets up ball screw nut 24, sets between screw rod positioning sleeve 27 and ball screw nut 24 Inner shield ring I 25 is set, two rolling bearings 3 are pressed on the outside of the ball screw nut 24, are gone back on the outside of the ball screw nut 24 Equipped with gear II 4, gear II 4 is engaged with the gear I 5 that the driving shaft end of motor 7 is set with, and the gear-box rear cover 1 connects Gear box casing 6 is connect, which is also set on the outside of the output shaft of the motor 7, and gear box casing 6 is by gear II 4 and gear I 5 is coated wherein.Gear box casing 6 and gear-box rear cover 1 are attached by bolt, and with housing seal circle I26 is sealed.Gear box casing 6 is equipped with gear I 5, gear II 4, rolling bearing 3, ball screw nut 24.Gear II 4 and ball screw axis 2 connected by ball screw nut 24, and with the support of rolling bearing 3.Gear II 4, ball screw nut 24, rolling bearing 3 becomes a component by interference or other fixed forms.Screw rod positioning sleeve 27 by interference or Other fixed forms are cooperated with gear-box rear cover 1, and screw rod positioning pin 28 and ball screw axis 2 are interference fitted, in its right end, Slot of the ball screw axis 2 on screw rod positioning sleeve 27 is slid left and right, is not rotated.

Motor 7 is located at 6 left end of gear box casing.Motor 7 is bolted on the gear box casing 6 in driving mechanism On, gear I 5 and machine shaft become a component, realize transmission agency by interference fit.

Hydraulic pump 31 is located at the left end of driving mechanism 30, is staggered with motor 7, and the hydraulic pump 31 includes the pump housing 18, the pump Body 18 is connect with the gear box casing 6 in driving mechanism by flange face, and hydraulic pump 31 further includes limited screw 8, reset spring II 9, relay piston I 10, piston fixed pin 11, cup seal I 12, piston stopper pin 13, cup seal II 14, bullet Spring abutment I 15, relay piston II 16, reset spring I 17, spring base II 21, relay piston III 22.The pump housing 18 is equipped with Hydraulic fluid port I 29a and oil outlet II 29b, oil inlet I 32a and oil inlet II 32b；Cup is housed on the relay piston III 22 Shape sealing element I 12 and cup seal II 14, two sealing elements play the role of one-way sealing, 22 left end relay piston III It is sequentially arranged with spring base II 21, reset spring II 9, relay piston I 10, piston fixed pin 11, piston stopper pin 13, driven Piston I I 16, reset spring I 17；Relay piston I 10 is linked together by limited screw 8 and relay piston III 22, Relay piston I 10 and relay piston II 16 is fixed together by piston fixed pin 11, becomes a component, limited screw The starting force of 8 adjustable reset spring II 9.

Set gradually reset spring I 17 from left to right in the pump housing 18, one end of reset spring I 17 be set in from The right end of the left end of piston II 16, relay piston II 16 connects relay piston I 10.

Piston fixed pin 11,16 left end relay piston II is arranged in the junction of relay piston II 16 and relay piston I 10 Cup seal II 14 is also set up, is also equipped with spring between 16 left end relay piston II and the reset spring II 17 Seat II 15.

Chamber V is constituted between 16 left end relay piston II and the pump housing 18,16 right end of the relay piston III setting cup-shaped is close Sealing III 12 constitutes chamber IV between 16 middle part relay piston III and the pump housing 18.

Relay piston I 10 includes hydraulic port 10a, relay piston I 10 Inner Constitution the chamber III, the relay piston I Chamber II is constituted between 10 outsides and the pump housing 18, is connected between hydraulic port 10 and chamber III and chamber II.The relay piston I It is also equipped with relay piston III 22 in the pump housing 18 of 10 right ends, between relay piston III 22 and the relay piston I 10 Reset spring II 9 is set, chamber I is constituted between relay piston III 22 and the pump housing 18.

Cylinder body is divided into chamber I, chamber II, chamber III, chamber by above-mentioned cup seal I12 and cup seal II 14 everywhere IV, totally 5 chambers of chamber V, the flow direction of brake fluid is all unidirectional, direction as shown by the arrows in Figure 2 between adjacent chamber.

The reset spring II 9 is resisted against 22 left end relay piston III, the driven work by spring base II 21 Plug 22 left end III also sets up cup seal III 14, between the relay piston I 10 and the relay piston III 22 also It is provided with limited screw 8.The right end of the relay piston III 22 also is provided with cup seal II 12, the relay piston III 22 right ends include groove, and the optical axis portion of 2 left end of ball screw axis is accommodated in the groove.

It further include at least one oil inlet and at least one oil outlet on the pump housing 18, the oil inlet and the lubricating cup connect It is logical.

Lubricating cup 20 is located at the top of hydraulic pump 31, is connected by bolt and the pump housing 18, while passing through lubricating cup sealing element The 19 sealing pump housings.

The working principle of motor-driven brake actuator described in above-described embodiment:

Brake pedal is stepped on, and control system is according to the letter of the Hall sensor aperture of driver's pedal (sensor according to) Number, motor 7 is rotated, the gear I 5 being mounted on 7 output shaft of motor is driven to rotate.The rotation drive of gear I 5 is engaged with Gear II 4 is rotated, and ball screw nut 24 is interference fitted into gear II 4 and rotates together, and realizes ball screw axis 2 or so It slides (not rotating), when braking, ball screw axis 2 slides to the left.Limited screw 8 and relay piston III 22 are connected by screw thread It is connected together and slides left and right.

Brake fluid respectively enters chamber I, chamber IV through oil inlet I 32a, oil inlet II 32b from lubricating cup 20.Through cup seal I 12, cup seal II 14 reach chamber II.Ball screw axis 2 slides to the left, drives relay piston III 22 and limited screw 8 slide together to the left, and limited screw 8 slides to the left, and the space compression chamber III leads to the hydraulic increase of chamber III, and brake fluid is through 10a mouthfuls Indentation chamber II since relay piston III 22 moves downward compression chamber II, leads to hydraulic increase, chamber II brake fluid at the same time It is exported from oil outlet II 29b.

Relay piston I 10, relay piston II 16 are attached by piston fixed pin 11, relay piston I 10, driven Piston I I 16,11 three of piston fixed pin slide left and right together, referred to as piston component.

In addition, relay piston II 16 is equipped with piston stopper pin 13, which limits relay piston II's 16 Sliding scale prevents relay piston II 16 from excessively sliding to the right.It is especially adopted as a result, when intelligent hydraulic force aid system fails When being braked with fluid pressure type, when a thrashing, another system is prevented to fail, starting protection effect.With piston component As object, when not starting braking, piston component be in the leftmost side, reset spring I 17 act on the power of piston component greater than etc. The power of piston component is acted in reset spring II 9.When braking, relay piston III 22 compression chamber II and reset spring to the left II 9, when pressure is greater than left side pressure on the right side of piston component, piston component slides to the left, and compression chamber V causes Hydraulic increase, V brake fluid of chamber are exported from oil outlet I 29a.

Brake pedal release, releases braking, (sensor is according to driver's pedal according to Hall sensor for control system Aperture) signal, rotate backward motor 7, the gear I 5 that is mounted on 7 output shaft of motor driven to rotate.Gear I 5 is rotated The gear II 4 being engaged with is driven to rotate, 4 interference of ball screw nut 24 and gear II, which presses to, to be rotated together, and realizes rolling Ballscrew axis 2 slides to the right.At this point, 22 left pressure of relay piston III be greater than right side, relay piston III 22 also together to Right sliding, reset spring II 9 gradually reset, and spring force gradually reduces, at this point, piston component left pressure is greater than right atrial pressure, Slideslip, chamber V, chamber II, the hydraulic reduction of chamber III, brake fluid are back to chamber V, chamber from 29a, 29b mouthfuls to piston component respectively to the right II, chamber III, lubricating cup 20 discharge supplement brake fluid to chamber IV, chamber I in the direction of the arrow, chamber IV, chamber I by cup seal I 12, Brake fluid is supplemented to chamber V, chamber II, chamber III by cup seal II 14, is finally reached original state.

A kind of embodiment 2.1: braking method of motor-driven brake actuator comprising

Step 1: brake pedal is stepped on, the opening amount signal for driver's pedal that control system is detected according to sensor, Rotate motor 7；The gear I 5 being mounted on 7 output shaft of motor is driven to rotate.

Step 2: the rotation of gear I 5 drives the gear II 4 being engaged with to rotate, ball screw nut 24 and gear II 4 It is interference fitted into and rotates together, realize that ball screw axis 2 horizontally slips, when braking, ball screw axis 2 slides to the left, and does not have Rotation；Limited screw 8 is together by a threaded connection with relay piston III 22 and slides left and right.

Step 3: brake fluid respectively enters chamber I, chamber IV through oil inlet I 32a and oil inlet II 32b from lubricating cup 20, and passes through Cup seal I 12, cup seal II 14 reach chamber II.

Step 4: ball screw axis 2 slides to the left, and relay piston III 22 is driven to slide together to the left with limited screw 8, Limited screw 8 slides to the left, the space compression chamber III, leads to the hydraulic increase of chamber III, brake fluid is through 10a mouthfuls of indentation chamber II, with this Simultaneously as relay piston III 22 moves downward compression chamber II, lead to hydraulic increase, chamber II brake fluid is defeated from oil outlet 29b Out.

Step 5: relay piston I 10, relay piston II 16 are attached by piston fixed pin 11, relay piston I 10, relay piston II 16,11 three of piston fixed pin slide left and right together.The piston stopper pin 13 of relay piston II 16 The sliding scale for limiting relay piston II 16, prevents relay piston II 16 from excessively sliding to the right.As a result, especially when intelligent liquid When pressing force aid system failure, when being braked using fluid pressure type, when a thrashing, another system is prevented to fail, starting Protective effect.

Step 6: brake pedal release releases braking, and control system keeps motor 7 reversed according to the signal of Hall sensor Rotation drives the gear I 5 being mounted on 7 output shaft of motor to rotate；The rotation of gear I 5 drives 4 turns of gear II be engaged with Dynamic, 4 interference of ball screw nut 24 and gear II, which presses to, to be rotated together, and realizes that ball screw axis 2 slides to the right.At this point, from 22 left pressure of piston III is greater than right side, and relay piston III 22 is also slided to the right together, and reset spring II 9 is gradually multiple Position, spring force gradually reduces, at this point, piston component left pressure is greater than right atrial pressure, piston component Slideslip to the right, chamber V, Chamber II, the hydraulic reduction of chamber III, brake fluid are back to chamber V, chamber II, chamber from oil outlet I 29a, 29b mouthfuls of oil outlet II respectively III, lubricating cup 20 discharge supplement brake fluid to chamber IV, chamber I in the direction of the arrow, and chamber IV, chamber I pass through cup seal I 12, cup-shaped Brake fluid is supplemented to chamber V, chamber II, chamber III by sealing element II 14, is finally reached original state.

Successively execute step 1- step 6.

Using piston component as object, when not starting braking, piston component is in the leftmost side, and reset spring I 17 is acted on The power of piston component is more than or equal to the power that reset spring II 9 acts on piston component.When braking, relay piston III 22 is to the left Compression chamber II and reset spring II 9, when pressure is greater than left side pressure on the right side of piston component, piston component is to the left Sliding, compression chamber V lead to hydraulic increase, and V brake fluid of chamber is exported from oil outlet I 29a.

Claims (8)

1. a kind of motor-driven brake actuator, it is characterised in that: including motor (7), lubricating cup (20), driving mechanism (30), Hydraulic pump (31), the driving mechanism (30) include: gear-box rear cover (1), ball screw axis (2), ball screw axis (2) end Equipped with screw rod positioning pin (28), a part of the ball screw axis (2) and screw rod positioning pin (28) are set in screw rod positioning sleeve (27) in, the end of the screw rod positioning sleeve (27) is resisted against gear-box rear cover (1) inside, the head of the screw rod positioning sleeve (27) End is also set up ball screw nut (24), is set with rolling bearing (3) on the outside of the ball screw nut (24), the ball screw It is also equipped with gear II (4) on the outside of nut (24), the gear I (5) that the driving shaft end of gear II (4) and motor (7) is set with is nibbled It closes, the gear-box rear cover connection gear tank shell (6), gear II (4), ball screw nut (24), rolling bearing (3) pass through Interference mode, becomes a component, and screw rod positioning sleeve (27) is cooperated by interference mode and gear-box rear cover (1).

2. motor-driven brake actuator as described in claim 1, it is characterised in that: gear I (5) and motor (7) cooperate As a component, hydraulic pump (31) includes the pump housing (18), and the gear box casing (6) in the pump housing (18) and driving mechanism is even It connects, hydraulic pump (31) further includes limited screw (8), reset spring II (9), relay piston I (10), piston fixed pin (11), cup Shape sealing element I (12), it piston stopper pin (13), cup seal II (14), spring base I (15), relay piston II (16), resets Spring I (17), spring base II (21), relay piston III (22), the pump housing (18) are equipped with oil outlet and oil inlet；The driven work It fills in and cup seal I is housed on III (22), relay piston III (22) left end is sequentially arranged with spring base II (21), reset spring II (9), relay piston I (10), piston fixed pin (11), piston stopper pin (13), relay piston II (16), reset spring I (17)； Relay piston I (10) is linked together by limited screw (8) with relay piston III (22), relay piston I (10) and driven work Plug II (16) is fixed together by piston fixed pin (11), becomes a component, the adjustable reset bullet of limited screw (8) The starting force of spring II (9).

3. motor-driven brake actuator as described in claim 1, it is characterised in that: in the pump housing (18) from left to right successively It is arranged reset spring I (17), one end of reset spring I (17) is set in the left end of (16) relay piston II, the relay piston The right end of II (16) connects relay piston I (10)；Between (16) left end relay piston II and the pump housing (18) constitute chamber V, it is described from Chamber IV is constituted in the middle part of piston II (16) between the pump housing (18).

4. motor-driven brake actuator as claimed in claim 3, it is characterised in that: relay piston I (10) includes hydraulic Mouthful, relay piston I (10) Inner Constitution chamber III, relay piston I (10) are external to constitute chamber II, driven work between the pump housing (18) It fills in and is also equipped with relay piston III (22) in the pump housing (18) of I (10) right end, relay piston III (22) and relay piston I (10) Between be arranged reset spring II (9), between relay piston III (22) and the pump housing (18) composition chamber I.

5. motor-driven brake actuator as claimed in claim 4, it is characterised in that: cup seal I (12) and cup-shaped Cylinder body is divided into chamber I, chamber II, chamber III, chamber IV, chamber V totally five chambers by sealing element II (14), the stream of brake fluid between adjacent chamber To being all unidirectional.

6. motor-driven brake actuator as claimed in claim 2, it is characterised in that: the relay piston III (22) is right End includes groove, and the optical axis portion of ball screw axis (2) left end is accommodated in the groove.

7. motor-driven brake actuator as described in claim 1, it is characterised in that: further include at least one on the pump housing (18) A oil inlet and at least one oil outlet, the oil inlet are connected to the lubricating cup (20).

8. motor-driven brake actuator as described in claim 1, it is characterised in that: lubricating cup (20) is located at hydraulic pump (31) Top.