Patent Application
20220017057
The present disclosure relates generally to an actuator assembly which performs the operation of an electronic parking brake. More particularly, the present disclosure relates to an electronic parking brake actuator assembly in which a stator, a motor, and gears are assembled directly with a housing.
An electronic parking brake actuator of a vehicle is intended to operate a friction pad installed on a caliper of a disc brake device during parking. The electronic parking brake actuator is automatically operated by switch manipulation by a user using an electronic parking brake. To this end, the electronic parking brake actuator consists of a motor and a gear assembly (a power transmission device) to transmit the power of the motor.
As for how the electronic parking brake is used, when a driver depresses a parking brake switch, the rotational force of the motor of the actuator is transmitted to an input shaft of the caliper through the gear assembly (the power transmission device) such as a reduction gear. When the input shaft receiving the rotational force rotates, a press connection sleeve advances. Due to the advancement of the press connection sleeve, a piston which houses the press connection sleeve and a caliper housing move in directions approaching each other. Furthermore, a friction pad mounted to the piston and the caliper housing, respectively, presses and restrains each of the opposite surfaces of a disc such that the disc does not rotate, so the parking of a vehicle is performed.
Such an actuator is made through a complex assembly process. For example, parts constituting a motor are assembled with each other to make a motor assembly, and multiple gears are assembled with each other to make the gear assembly, and next, each of the motor assembly and the gear assembly is assembled with a separate housing and thus the actuator is made. Alternatively, multiple gears may be assembled directly with a housing.
However, in the case of such a conventional actuator, the number of parts constituting the actuator is great, so assembly man-hours increase. Accordingly, assemblability of the actuator is decreased and manufacturing costs thereof are increased, and further, there is limitation in decreasing the size of the actuator. Depending on a type of a vehicle, the required specification of the actuator may be changed. As the size of the actuator increases, the degree of freedom in design due to such specification change inevitably decreases.
Meanwhile, the actuator is composed of multiple rotating parts, and the rotating parts are engaged with each other to be rotated, so tolerance management thereof is important. This is because if distances between the centers of the rotating shafts of the rotating parts are out of an allowable range due to cumulative tolerance between the rotating parts, quality problems such as performance degradation or noise generation may occur. Particularly, the vibration of the motor generated during operation leads to vibration of parts such as gears due to the cumulative tolerance, which lowers the durability of the gears, so the durability of the product is decreased.
When assembling each component such as a built-in motor and gear, precise alignment between the shafts is difficult. Particularly, the gear assembly (or a gearbox) for a reduction function is configured as a part separate from the motor assembly, so the arrangement of the shafts of the parts spaced apart from each other is further difficult.
The present disclosure has been made keeping in mind the above problems occurring in the prior art, and the present disclosure is intended to propose an electronic parking brake actuator assembly in which a motor and multiple gears may not be preassembled with each other as a separate assembly but may be assembled directly with a housing of an actuator.
In addition, the present disclosure is intended to propose an electronic parking brake actuator assembly in which the gears constituting an actuator assembly may be assembled directly with the housing of the actuator to decrease assembly tolerance and improve the arrangement of shafts.
In order to accomplish the above objectives, according to one aspect of the present disclosure, the present disclosure provides an electronic parking brake actuator assembly including: a main housing constituted by a motor mounting part and a gear mounting part integrated with each other; a motor part assembled with the motor mounting part of the main housing; a gear part assembled with the gear mounting part of the main housing and rotated in engagement with the motor part by a rotational force of the motor part; and a cover assembled with the main housing and shielding the motor part and the gear part, wherein a brush card assembly is assembled directly with the motor mounting part, a terminal constituting the brush card assembly being insert-injected into the motor mounting part.
The brush card assembly may include: a brush holder assembled with the motor mounting part; a brush movably inserted to the brush holder and elastically supported by an elastic member in a direction toward a commutator of the motor part; and the terminal insert-injected into the motor mounting part and transmitting external power to the brush.
The brush holder and the brush may be installed in a lower installation space located at a lower side of the motor mounting part, and the motor part may be assembled directly with the motor mounting part at a center of the lower installation space, so the commutator of the motor part may be located to face the brush.
The terminal may include: a connection part having at least a portion thereof exposed to the connector of the motor mounting part so as to receive external power; a body part connected to the connection part and located inside the motor mounting part; and a protruding part bent from the body part and exposed to an outer side of the motor mounting part such that the protruding part is connected to a choke coil, wherein the connection part, the body part, and the protruding part may be integrated with each other such that the external power is directly transmitted to the brush.
The gear part may rotate by receiving the rotational force of the motor part and may perform a deceleration function through multiple gears, wherein at least a portion of the gear part may be insert-injected into the gear mounting part to be fixed thereto.
The gear part may include: a drive gear integrated with the gear mounting part by surrounding an inner surface of the gear mounting part or assembled with the gear mounting part after the drive gear is made as a separate part; and multiple planetary gears configured to operate in contact with an inner surface of a ring gear.
The main housing may include: a frame part extending horizontally; the motor mounting part formed at a side of the frame part and allowing the motor part to be assembled therewith inside the motor mounting part; and the gear mounting part formed at a side opposite to the motor mounting part of the frame part, the gear mounting part extending in a direction parallel to the motor mounting part and allowing the gear part to be mounted thereto.
As described above, an electronic parking brake actuator assembly of the present disclosure may have the following effects.
In the present disclosure, the motor part and the gear part may not be preassembled with each other, but may be assembled directly with the main housing. This is possible since a structure for assembling the motor part and the gear part with the main housing is made in the main housing. Accordingly, the number of the parts of an actuator and assembly man-hours thereof may be decreased, thereby decreasing the manufacturing costs of the actuator.
Particularly, in the present disclosure, when the brush card assembly is mounted directly to the main housing and the motor part is fitted to the main housing, the brush card assembly and the motor part may be naturally assembled with each other. Accordingly, the assembly process of the motor part may be very simple, thereby lowering assembly difficulty.
In addition, in the present disclosure, the terminal constituting the brush card assembly may be insert-injected into the main housing to be integrated therewith, and a terminal connected to the outside and a terminal connected to the brush may be configured as one part, so the entire structure of the actuator may be simple. Particularly, the welding of the two terminals to each other may be omitted. Furthermore, the flow of an electric current may be prevented from being changed due to a welding result, so the operation reliability of a motor may be increased.
Furthermore, in the present disclosure, the gear part of the actuator assembly may be assembled directly with the main housing and at least a portion of the gear part may be insert-injected into the main housing to be prefixed thereto, so assembly tolerances between parts may be reduced, and due to the reduced assembly tolerance, the shaking or noise generation of the parts caused by rotational force supplied through a final output shaft may be decreased, thereby improving the quality of the actuator assembly.
In addition, in the present disclosure, a portion of parts may be insert-injected into the main housing, and the motor part and the gear part may be assembled directly with the main housing without a separate housing, so the entire size of the actuator may be decreased. Accordingly, the degree of freedom of design may be relatively large when changing the specification of the actuator assembly, thereby improving compatibility thereof.
Hereinafter, an embodiment of the present disclosure will be described in detail through exemplary drawings. In adding reference numerals to components of each drawing, it should be noted that the same components have the same numerals as possible even if they are indicated on different drawings. In addition, in describing the embodiment of the present disclosure, when it is determined that a detailed description of a related known configuration or function interferes with the understanding of the embodiment of the present disclosure, the detailed description thereof will be omitted.
In addition, in describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), (b) may be used. These terms are only for distinguishing the components from other components, and the nature, order, or order of each of the components is not limited by the term. When a component is described as being “connected” or “coupled” to another component, the component may be directly connected or coupled to the another component, but it should be understood that still another component may be “connected” or “coupled” to each of the components therebetween.
In the electronic parking brake actuator assembly (hereinafter referred to as “an actuator”) of the present disclosure, large rotational force may be generated by decelerating the operation of the motor and may be transmitted to the outside to perform the function of the electronic parking brake. To this end, a motor part 20 and a gear part 70 composed of multiple gears may be installed in the actuator assembly of the present disclosure. The motor part 20 to be described later may indicate an electric motor including a stator and a rotor, and the gear part 70 may indicate an entire structure composed of multiple gears.
First, referring to
As for the configuration of the main housing 30, as illustrated in
The cover 80 may be assembled with the upper side of the main housing 30, and a motor cover 10 may be coupled to a side of the motor mounting part 31. The motor cover 10 may cover the exterior of the motor part 20 to be described later such that the motor part 20 is not exposed to the outside. The frame of the motor cover 10 may be constituted by a cover body 11 having an approximate cylindrical shape, and a motor installation space 12 may be defined inside the motor cover 10. A motor casing 15 may be located between the motor cover 10 and the motor part 20. The motor casing 15 may be coupled to the motor part 20 by covering the motor part 20. An upper assembly part 17 located at the upper end of the motor casing 15 may be held in and mounted to the motor mounting part 31 of the main housing 30 to be described later, and a lower assembly part 18 located at the lower end of the motor casing 15 may be held in and mounted to the lower side of the motor part 20.
Next, the motor part 20 will be described. The motor part 20 may be a structure including the stator 23 and the rotor 25 rotating relative to each other. In
The rotor 25 located inside the stator 23 may rotate. When the rotor 25 rotates, the rotating shaft 21 may rotate with the rotor, and may transmit the rotational force thereof to the gear part 70. The rotating shaft 21 may be coupled to the center of the rotor 25, so the rotating shaft 21 may be considered as a rotating center of the rotor. The frame of the rotor 25 may be constituted by a core, and the core may be considered to have an approximate cylindrical shape surrounding the periphery of the rotating shaft 21 with the rotating shaft 21 placed at the center of the core. A coil may be wound on the core to constitute the rotor 25.
A commutator 27 may be coupled to the upper side of the rotor 25. The commutator 27 may be intended to change the direction of a current flowing through the coil, and may be considered as a component included in the rotor 25. The commutator 27 may be coupled to the rotating shaft 21, and may rotate with the core. While the commutator 27 rotates relative to the rotating shaft 21, the commutator 27 may be in discontinuous contact with a brush 52 of a brush card assembly 50 to be described later to be electrically connected thereto.
Looking back at the main housing 30, as illustrated in
Referring to
A gear groove 39 in which a first reduction means 73 and 74 is installed may be formed between the motor mounting part 31 and the gear mounting part 40 by extending therebetween. The gear groove 39 may be considered as a portion of the gear mounting part 40. The first reduction means 73 and 74 may be inserted to the gear groove 39 to be rotated.
The motor part 20 described above may be fitted to the motor mounting part 31 from a lower side thereof. When the motor part 20 is fitted to the motor mounting part 31, the commutator 27 of the motor part 20 may be naturally assembled with the brush card assembly 50. To this end, the brush card assembly 50 may be mounted to the motor mounting part 31 to be integrated therewith. That is, the brush card assembly 50 may be mounted directly to the motor mounting part 31 of the main housing 30.
The brush card assembly 50 may function to transmit power to the motor part 20. To this end, the brush card assembly 50 may be located between the connector 33 and the commutator 27. In this case, the brush card assembly 50 may be assembled integrally with the motor mounting part 31, so a separate housing or casing for installing the brush card assembly 50 may not be required. That is, the motor part 20, the gear part 70, and the brush card assembly 50 may all be assembled with the main housing 30 at once.
The configuration of the brush card assembly 50 assembled directly with the main housing 30 will be described. As illustrated in
The brush holder 51 may be assembled with the motor mounting part 31 and may be made of metal. The brush holder 51 may have the brush 52 therein and may have space in which the brush 52 can move. A bent part 51′ located at an end portion of the brush holder 51 may be bent after passing through the motor mounting part 31 such that the brush holder 51 may be fixed to the motor mounting part 31. For reference, in
The brush 52 may be movably inserted to the brush holder 51 and may be elastically supported by an elastic member S in a direction toward the commutator 27 of the motor part 20. The elastic member S may be located at a relatively rear side inside the brush holder 51, and when the brush holder 51 is assembled with the motor mounting part 31, an end of the brush holder 51 may be supported by the inner surface of the motor mounting part 31.
The brush 52 may be electrically connected to the commutator 27 while being selectively in contact therewith, and in the process, may supply electric current to the commutator 27. The choke coil 53 may be connected to the brush 52, and may function to connect the brush 52 to the terminal 56 therebetween. That is, the choke coil 53 may be electrically connected to the terminal 56, and may function to supply electric current supplied from the terminal 56 to the brush 52. In the embodiment, a first end part 53a of the choke coil 53 may be connected to the brush 52, and a second end part 53b of the choke coil 53 may be spot-welded to the terminal 56. To this end, a protruding part 56c of the terminal 56 and the second end part 53b of the choke coil 53 may protrude to the upper side of the motor mounting part 31 and may be spot-welded to each other. This is illustrated in
As a result, in the brush card assembly 50, power is supplied through the following path. Power may be supplied consecutively to the terminal 56, the choke coil 53, the brush 52 mounted to the brush holder 51, the commutator 27, and to a coil wound on a core of the motor part 20 so as to rotate a motor.
Referring to
Meanwhile, in the present disclosure, the terminal 56 of the brush card assembly 50 may be insert-injected to the motor mounting part 31. As for the structure of such a terminal 56, the terminal 56 may largely include the connection part 56a, a body part 56b, and the protruding part 56c. Here, the connection part 56a may have a portion thereof exposed to the inner space 33′ of the connector 33 of the motor mounting part 31 such that the connection part 56a receives the external power. Accordingly, the connection part 56a may be connected to a corresponding terminal of the corresponding connector.
In addition, the body part 56b of the terminal 56 may be a part connected to the connection part 56a and located inside the motor mounting part 31. The body part 56b may be considered as a part provided in the main housing 30 by being insert-injected thereinto. Since the body part 56b may be firmly fixed to the main housing 30 by being insert-injected thereto, the terminal 56 may not be required to go through a separate assembly process.
The protruding part 56c of the terminal 56 may be a part exposed to an outer side of the motor mounting part 31 by being bent from the body part 56b so as to be connected to the choke coil 53. Accordingly, in the present disclosure, the terminal 56 may be insert-injected into the main housing 30 to be integrated therewith, and the terminal 56 connected to the outside and the terminal 56 connected to the brush 52 may not be configured as separate parts, but may be configured as one part, so the entire structure of the actuator may be simple, and particularly, the welding of the two terminals 56 to each other may be omitted. Furthermore, the connection part 56a, the body part 56b, and the protruding part 56c of the terminal 56 may be configured to be integrated therewith, and thus may be insert-injected into the main housing 30 to be fixed thereto. Additionally, the flow of an electric current may be prevented from being changed due to a welding result, so the operation reliability of the motor may be increased.
Next, as for the gear part 70, the gear part 70 may rotate by receiving the rotational force of the motor part 20, and may perform a deceleration function through multiple gears. At least a portion of the gear part 70 may be insert-injected into the gear mounting part 40 to be fixed thereto. For example, a bearing of the gear part 70 (not shown) may be insert-injected into the gear mounting part 40 of the main housing 30.
As for the configuration of the gear part 70, the gear part 70 may include: the first reduction means 73 and 74 composed of a motor gear 71 fitted over the rotating shaft 21 of the motor part 20, an idle gear 74, and a worm gear 73; a drive gear 75; and a planetary gear assembly which is a second reduction means. Here, the motor gear 71 may be considered as a part of the motor part 20. The idle gear 74 of the first reduction means 73 and 74 may be engaged with the motor gear 71 to change a rotating direction of the motor gear 71, which may cause first deceleration. Furthermore, the worm gear 73 may be engaged with the drive gear 75. The worm gear 73 and the drive gear 75 may be considered as a worm and a worm wheel. When the worm gear 73 is engaged with the drive gear 75, the rotating direction of the worm gear 73 may be changed and a second deceleration may be realized.
The planetary gear assembly rotating in engagement with the drive gear 75 may be composed of a sun gear 76, planetary gears 77b, and a carrier 78. The components of the planetary gear assembly may be laminated in the center space 41 of the gear mounting part 40. Here, the sun gear 76 may protrude downward from the drive gear 75 and may rotate the planetary gears 77b in engagement therewith. In this case, operation space is defined in a lower surface of the drive gear 75 by being recessed therefrom, so the planetary gears 77b may rotate inside the operation space. Reference numeral 77a may indicate a ring gear 77a surrounding the planetary gears 77b, and may be integrated with or be assembled with the gear mounting part 40 of the main housing 30. Reference numeral 78 may indicate the carrier supporting the planetary gears 77b, and reference numeral 77b′ may indicate the rotating shafts of the planetary gears 77b.
Such a structure of the gear part 70 may be provided only as an embodiment, but may be variously modified. For example, the planetary gears 77b of the planetary gear assembly may be configured to have two or three layers, and the first reduction means 73 and 74 may be a simple spur gear structure.
The assembly process of the electronic parking brake actuator assembly of the present disclosure will be described. First, the brush card assembly 50 may be assembled with the motor mounting part 31 of the main housing 30. The terminal 56 of the brush card assembly 50 may be insert-injected into the main housing 30 to be integrated therewith, so a separate assembly of the terminal 56 with the main housing 30 may not be required. When the brush holder 51 is assembled with the motor mounting part 31, the brush 52 and the elastic member S may be inserted into the brush holder 51.
In addition, during the installation of the choke coil 53, the first end part 53a of the choke coil 53 may be connected to the brush 52, and the second end part 53b of the choke coil 53 may be welded to the protruding part 56c of the terminal 56. Here, the protruding part 56c of the terminal 56 and the second end part 53b of the choke coil 53 may protrude at the upper side of a motor assembly part, so a worker may easily perform the welding of the protruding part 56c and the second end part 53b to each other.
In this state, the motor part 20 may be assembled with the motor mounting part 31. With the stator 23 and the rotor 25 already assembled with each other inside the motor casing 15, the motor part 20 may be fitted to the motor mounting part 31. A separate housing for assembling the motor part 20 may not be required, and may be connected directly to the motor mounting part 31. In this case, as illustrated in
Finally, the gear part 70 may be assembled with the gear mounting part 40 of the main housing 30. The gear part 70 composed of multiple components may not be assembled with a separate housing, but may be directly connected to the main housing 30 as the case of the motor part 20. When the motor gear 71 constituting the gear part 70 and fitted over the rotating shaft 21 of the motor part 20, the first reduction means 73 and 74 composed of the idle gear 74 and the worm gear 73, the drive gear 75, and the planetary gear assembly which is the second reduction means are assembled with the gear mounting part 40, the assembly of the gear part 70 is completed. When the assembly of the gear part 70 is completed, the rotational force of the motor may be transmitted consecutively to the motor gear 71, the first reduction means 73 and 74, the drive gear 75, and the second reduction means (the planetary gear assembly), and may finally be output to the lower space 41′ of the gear mounting part 40 through the final output shaft.
Accordingly, in the present disclosure, the gear part 70 of the actuator assembly may be assembled directly with the main housing 30, and at least a portion of the gear part 70 may be insert-injected into the main housing 30 to be pre-fixed thereto, so assembly tolerances between parts may be reduced, and due to the reduced assembly tolerances, the shaking or noise generation of the parts caused by the rotational force supplied through the final output shaft may be decreased.
Particularly, the parts of the motor part and the gear part may all be installed in the main housing 30, so the assembly of a motor housing or a gear housing with the main housing 30 may not be required, so tolerances which may occur between the housings may also be reduced.
In the above, all the components constituting the electronic parking brake actuator assembly according to the embodiment of the present disclosure have been described as being combined integrally with each other or operating in combination with each other, the present disclosure is not necessarily limited to this embodiment. That is, within the scope of the purpose of the present disclosure, at least two of all of the components may be selectively combined with each other to be operated. In addition, terms such as “include”, “composed of”, or “have” described above mean that corresponding components may be present unless otherwise stated. Further, it should be interpreted that the terms may not exclude other components, but may further include the other components. All terms, including technical or scientific terms, have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs, unless otherwise defined. Generally used terms, such as terms defined in a dictionary, should be interpreted as being consistent with the context of the relevant technology, and in the present disclosure, unless explicitly defined, should not be interpreted as ideal or excessively formal meanings.
The above description is merely illustrative of the technical idea of the present disclosure, and those skilled in the art to which the present disclosure belongs may make various modifications without departing from the essential characteristics of the present disclosure. Accordingly, the embodiment disclosed in the present disclosure is not intended to limit the technical idea of the present disclosure, but to explain the technical idea, and the scope of the technical idea of the present disclosure is not limited by this embodiment. The scope of protection of the present disclosure should be construed by the scope of the claims below, and all technical ideas within the scope of the present disclosure should be construed as being included in the scope of the claims of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2018-0159700 | Dec 2018 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2019/003459 | 3/25/2019 | WO | 00 |
