Coupling structure of ball nut and damper and hydraulic supply apparatus employing the same

Abstract

In a hydraulic supply apparatus, one or more fitting grooves are formed along the outer circumferential surface of a ball nut, and corresponding fitting protrusions are formed on the inner circumferential surface of a damper coupled to the ball nut. This configuration minimizes damper movement, thereby reducing vibration and noise caused by collision with a bushing member during axial movement of the ball nut.

Claims

1. A hydraulic supply apparatus comprising: a screw rotatably provided by receiving a rotational force generated by a motor, a ball nut threadedly coupled to the screw to move linearly along an axial direction of the screw through rotation of the screw; a piston coupled to the ball nut to move linearly together with the ball nut to generate hydraulic pressure; a bushing member provided between the piston and a rotor and having one end portion fixed to a modulator block; and a damper tightly coupled to an outer circumferential surface of the ball nut to prevent the ball nut from rotating by being supported in a rotational direction by the bushing member and prevent deviation in the axial direction from the ball nut when the ball nut moves linearly, wherein the ball nut comprises one or more fitting grooves formed on an outer circumferential surface thereof in a circumferential direction with a predetermined width, and the damper comprises one or more fitting protrusions formed on an inner circumferential surface thereof at positions corresponding to the fitting grooves, and wherein the fitting protrusions are provided in any one of 2 to 8 pieces and are disposed at predetermined intervals on the inner circumferential surface of the damper.

2. The hydraulic supply apparatus of claim 1, wherein the ball nut is provided in a hollow cylindrical shape, the ball nut includes one end portion coupled to the damper and the other end portion coupled to the piston, and the one or more fitting grooves are formed between the one end portion and the other end portion.

3. The hydraulic supply apparatus of claim 2, a screw groove is formed on an inner circumferential surface of the ball nut to correspond to a screw thread formed on the outer circumferential surface of the screw, and a ball is inserted between the screw thread and the screw groove.

4. The hydraulic supply apparatus of claim 3, wherein the other end portion of the ball nut is formed to have an outer diameter smaller than the one end portion and is coupled to an end portion of the piston.

5. The hydraulic supply apparatus of claim 3, wherein the damper is formed in a cylindrical shape having an inner diameter equal to or larger than an outer diameter of one end portion of the ball nut.

6. The hydraulic supply apparatus of claim 2, at least one guide protrusion protruding outward in a radial direction is formed on an outer circumferential surface of the ball nut on the one end portion that is coupled to the damper.

7. The hydraulic supply apparatus of claim 6, wherein the guide protrusions are formed in a pair and are symmetrically positioned on the outer circumferential surface of the ball nut.

8. The hydraulic supply apparatus of claim 7, a slot is formed on an outer circumferential surface of the damper and the guide protrusion formed on an outer circumferential surface at one end portion of the ball nut is fitted to the slot to protrudes outside the damper.

9. The hydraulic supply apparatus of claim 1, wherein the fitting protrusions are provided in four pieces and are disposed at every 90 interval on the inner circumferential surface of the damper.

10. The hydraulic supply apparatus of claim 1, wherein the bushing member includes a body part formed in a hollow cylindrical shape penetrated vertically and a flange part extending radially outward from the upper end portion of the body part.

11. The hydraulic supply apparatus of claim 10, a plurality of protrusions protruding from an upper end portion to a lower end portion in a longitudinal direction are formed on an outer surface of the body part, the plurality of protrusions are disposed at a predetermined interval along a circumferential direction of the body part, and a plurality of guide grooves are recessed in positions corresponding to the protrusions on an inner surface of the body part.

12. The hydraulic supply apparatus of claim 11, wherein the protrusions and the guide grooves are each provided in four places and are disposed at each interval of 90 along a circumference of the body part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a cross-sectional view of one embodiment of a hydraulic supply apparatus according to the related art.

(2) FIG. 2 is a view showing a state in which a screw, a ball nut, a piston, and a rotation prevention member are combined in the hydraulic supply apparatus of FIG. 1.

(3) FIG. 3 is a view showing a rotation prevention member in the hydraulic supply apparatus of FIG. 1.

(4) FIG. 4 is a view showing a state in which the rotation prevention member of FIG. 3 is viewed from the front.

(5) FIG. 5 is a cross-sectional view of one embodiment of a hydraulic supply apparatus according to the present disclosure.

(6) FIG. 6 is a view showing a state in which a screw, a ball nut, a piston, and a damper are combined in the hydraulic supply apparatus of FIG. 5.

(7) FIG. 7 is a view showing a ball nut in the hydraulic supply apparatus according to the present disclosure.

(8) FIG. 8 is a view showing a damper in the hydraulic supply apparatus according to the present disclosure.

(9) FIG. 9 is a view showing a state in which the damper of FIG. 8 is viewed from the front.

(10) FIG. 10 is a view showing a state in which a ball nut, a damper, and a bushing member are combined in the hydraulic supply apparatus according to the present disclosure.

(11) FIG. 11 is a view showing a bushing member in the hydraulic supply apparatus according to the present disclosure.

DETAILED DESCRIPTION

(12) Hereinafter, a preferred embodiment of a coupling structure of a ball nut and a damper and a hydraulic supply apparatus employing the same according to the present disclosure will be described in detail based on the attached drawings. For reference, the terms and words used in this specification and claims should not be interpreted as limited to ordinary or dictionary meanings, but should be interpreted as meanings and concepts consistent with the technical idea of the present disclosure based on the principle that the inventor can properly define the concept of the term in order to describe his/her own disclosure in the best way. In addition, it should be understood that the embodiments and drawings shown in this specification are only those of the most preferred embodiments of the present disclosure, and not all technical ideas of the present disclosure are representative, so there may be various equivalents and modifications that can replace them at the time of this application.

(13) FIG. 5 is a cross-sectional view of one embodiment of a hydraulic supply apparatus according to the present disclosure.

(14) The hydraulic supply apparatus is an apparatus that provides hydraulic pressure from an electronic brake system to a wheel cylinder (not shown).

(15) The hydraulic supply apparatus is coupled to a modulator block (not shown) in which a flow path and valve for controlling braking hydraulic pressure are provided.

(16) This modulator block is a housing for implementing a brake system by regulating braking hydraulic pressure. Such a modulator block includes a plurality of solenoid valves (not shown), an accumulator that temporarily stores oil discharged from the wheel cylinder, and an electronic control unit (ECU) that controls the driving of the solenoid valves and the motor.

(17) In addition, the motor housing and the chamber housing are fastened to both sides of the modulator block. Since the configuration of the motor housing and the chamber housing is described in detail in Korean Patent Publication No. 10-2022-0005909 filed and disclosed by the present applicant, detailed descriptions thereof will be omitted here.

(18) The hydraulic supply apparatus according to the present disclosure includes a screw 1, a ball nut 2, a piston 3, a damper 4, and a bushing member 5.

(19) The screw 1 is provided to be rotatable by receiving the rotational force generated by the motor, and the screw 1 has a screw thread 1a that can be engaged with a screw groove 2c formed in the ball nut 2 to be described later on the outer circumferential surface of the screw 1.

(20) The end portion of the rotor 6 is coupled to the screw 1 to transmit a rotational force to the screw 1 when the rotor 6 rotates to rotate together.

(21) The motor generates rotational force when power is supplied and includes a stator (not shown) that receives power and forms a magnetic field and a rotor 6 that rotates by changes in the magnetic field, and the rotor 6 is arranged to be spaced apart inside the stator.

(22) The ball nut 2 is screwed with the screw 1 to be linearly movable along the axial direction of the screw 1 by the rotation of the screw 1.

(23) The ball nut 2 includes one or more fitting grooves 2b formed on an outer circumferential surface thereof in a circumferential direction with a predetermined width, and the damper 4 includes one or more fitting protrusions 4a formed on an inner circumferential surface thereof at positions corresponding to the fitting grooves 2b.

(24) When a plurality of fitting protrusions 4a are formed on the inner circumferential surface of the damper 4, the fitting protrusions are spaced apart from each other along the circumferential direction.

(25) Accordingly, by minimizing the axial motion of the damper 4, it is possible to suppress vibration and noise caused by collision with the bushing member 5 generated while the ball nut 2 moves in the axial direction of the screw 1.

(26) The piston 3 is coupled to the ball nut 2 to enable linear movement together with the ball nut 2 and provides hydraulic pressure.

(27) The damper 4 is formed of an elastic material such as plastic or rubber. Such a damper 4 is coupled on the outer circumferential surface of the ball nut 2 so as to be in close contact with the ball nut 2 and supported in the rotation direction by the bushing member 5 to prevent the ball nut 2 from rotating and is provided so as not to deviate in the axial direction from the ball nut 2 when the ball nut 2 moves linearly.

(28) The bushing member 5 is provided between the piston 3 and the rotor 6 and has one end portion fixed to the modulator block.

(29) FIG. 6 is a view showing a state in which a screw, a ball nut, a piston, and a damper are combined in the hydraulic supply apparatus of FIG. 5, and FIG. 7 is a view showing a ball nut in the hydraulic supply apparatus according to the present disclosure.

(30) The fitting grooves 2b having a predetermined width are formed on the outer circumferential surface of the ball nut 2 along the circumferential direction. When the damper 4 is coupled to the ball nut 2, one or more fitting protrusions 4a are formed on the inner circumferential surface of the damper 4 at positions corresponding to the fitting grooves 2b formed in the ball nut 2. When the plurality of fitting protrusions 4a are formed, the fitting protrusions are disposed to be spaced apart from each other along the circumferential direction.

(31) The ball nut 2 is provided in a hollow cylindrical form. The ball nut 2 includes one end portion 2-1 to which the damper 4 is coupled and the other end portion 2-2 to which the piston 3 is coupled. The fitting grooves 2b are formed between the one end portion 2-1 and the other end portion 2-2 of the ball nut 2.

(32) The fitting protrusions 4a are provided in any one of 2 to 8 pieces and are disposed at predetermined intervals on the inner circumferential surface of the damper.

(33) Preferably, the fitting protrusions 4a formed on the inner circumferential surface of the damper 4 are provided in four pieces and are disposed at each interval of 90 on the inner circumferential surface of the damper 4.

(34) As described above, the fitting grooves 2b are formed in the circumferential direction on the outer circumferential surface of the ball nut 2 and the four fitting protrusions 4a are formed on the inner circumferential surface of the damper 4, which is exemplary, and anything may be replaced as long as the movement of the damper 4 in the axial direction can be suppressed.

(35) For example, the plurality of fitting grooves may be formed on the outer circumferential surface of the ball nut 2 to be spaced apart from each other along the circumferential direction, and the fitting protrusions may be formed on the inner circumferential surface of the damper 4 to correspond to the plurality of fitting grooves.

(36) Meanwhile, a screw groove 2c is formed on the inner circumferential surface of the ball nut 2 to correspond to the screw thread 1a formed on the outer circumferential surface of the screw 1. A ball is inserted between the screw thread 1a and the screw groove 2c.

(37) In addition, at least one guide protrusion 2a protruding outward in the radial direction is formed on the outer circumferential surface of one end portion 2-1 of the ball nut 2 to which the damper 4 is coupled. Preferably, the guide protrusions 2a are formed in a pair and are located symmetrically on the outer circumferential surface of the ball nut 2.

(38) Such the guide protrusions 2a are inserted into a guide grooves 5b of the bushing member 5 to be described later. When the ball nut 2 rotates, the guide protrusions 2a are closely attached to the guide grooves 5b to prevent the ball nut 2 from rotating.

(39) At this time, the width of the guide protrusions 2a are formed to be smaller than the width of the guide grooves 5b and spaced apart from the guide grooves 5b with a fine gap.

(40) Accordingly, the guide protrusions 2a may prevent rotation by contacting the guide grooves 5b only when the ball nut 2 rotates at a predetermined angle or more because a large load occurs in the motor. In normal times, vibration and noise generated during friction between the ball nut 2 and the bushing member 5 can be reduced by reducing friction with the bushing member 5 as much as possible.

(41) In addition, the other end portion 2-2 of the ball nut 2 is formed to have a smaller outer diameter than the one end portion 2-1 and is pressed into and coupled to the end portion of the piston 3.

(42) FIG. 8 is a view showing a damper in the hydraulic supply apparatus according to the present disclosure, and FIG. 9 is a view showing a state in which the damper of FIG. 8 is viewed from the front.

(43) The damper 4 is formed in a cylindrical shape and is coupled to the outside of the ball nut 2 to prevent the damper from rotating by the bushing member 5. Accordingly, when the screw 1 is rotated, the ball nut 2 does not rotate together.

(44) The ball nut 2 is inserted into the inner side of the damper 4, and the inner circumferential surface of the damper 4 is closely attached on the outer circumferential surface of the ball nut 2.

(45) Accordingly, it is preferable that the inner diameter of the damper 4 be equal to or greater than the outer diameter of the one end portion 2-1 of the ball nut 2.

(46) In addition, a slot 4b is formed on the outer circumferential surface of the damper 4, and the guide protrusions 2a formed on the outer circumferential surface of the one end portion 2-1 of the ball nut 2 are fitted to the slot to protrude outside the damper 4.

(47) As such, the guide protrusions 2a of the ball nut 2 protruding to the outside through the slot 4b are inserted into the guide grooves 5b formed in the bushing member 5.

(48) In addition, at least one locking protrusion 4c inserted into the guide grooves 5b of the bushing member 5 is formed to protrudes from the outer circumferential surface of the damper 4.

(49) By inserting the locking protrusions 4c into the guide grooves 5b of the bushing member 5 and closely adhering to the guide groove 5b, it is possible to prevent the damper 4 from rotating.

(50) FIG. 10 is a view showing a state in which a ball nut, a damper, and a bushing member are combined in the hydraulic supply apparatus according to the present disclosure, and FIG. 11 is a view showing a bushing member in the hydraulic supply apparatus according to the present disclosure.

(51) The bushing member 5 includes a body part 5-1 formed in a hollow cylindrical shape penetrated vertically and a flange part 5-2 extending radially outward from an upper end portion of the body part 5-1.

(52) A plurality of protrusions 5a protruding along the longitudinal direction from the upper end portion to the lower end portion are formed on the outer surface of the body part 5-1 of the bushing member 5. The plurality of protrusions 5a are disposed at predetermined intervals along the circumferential direction of the body part 5-1. The plurality of guide grooves 5b are recessed in positions corresponding to the protrusions 5a on the inner surface of the body part 5-1.

(53) The locking protrusions 4c of the damper 4 are inserted in some of the plurality of guide grooves 5b and the guide protrusions 2a of the ball nut 2 are inserted in the remainder thereof.

(54) At this time, the protrusions 5a and the guide grooves 5b of the bushing member 5 are each provided at four places and preferably disposed at a 90 interval along the circumference of the body part 5-1.

(55) As such, in the present disclosure, the fitting grooves 2b having a predetermined width along the circumferential direction are formed on the outer circumferential surface of the ball nut 2, and at least one fitting protrusion 4a is formed on the inner circumferential surface of the damper 4 at a position corresponding to the fitting groove 2b when the damper 4 is coupled to the ball nut 2. Accordingly, by minimizing the movement of the damper 4, and it is possible to suppress vibration and noise caused by the collision with the bushing member 5 generated while the ball nut 2 is moved in the axial direction of the screw 1.

(56) The present disclosure described above is not limited by the above-described embodiments and the accompanying drawings, and it will be apparent to those skilled in the art that various substitutions, modifications, and changes are possible within the scope of the technical idea of the present disclosure.

DESCRIPTION OF SYMBOLS

(57) 1: screw 2: ball nut 2a: guide protrusion 2b: fitting groove 3: piston 4: damper 4a: fitting protrusion 4b: slot 4c: locking protrusion 5: bushing member 6: rotor