WO2003044390A1

WO2003044390A1 - Decelerator for automobile actuator

Info

Publication number: WO2003044390A1
Application number: PCT/KR2002/000344
Authority: WO
Inventors: Hyuk-Joon Ro
Original assignee: Pro Quip International Korea Co., Ltd.
Priority date: 2001-10-16
Filing date: 2002-02-28
Publication date: 2003-05-30
Also published as: KR100405632B1; KR20030031731A; AU2002236329A1

Abstract

This invention relates to a decelerator for automobile actuator which decelerates velocity of actuator by pressing constant rotation velocity and torque from power source- such as a motor-to gear train. The decelerator includes unit housing (20) provided with motor axis hole at upper side, high-speed rotation axis at bottom side and eccentric cam at the longitudinal section of said high-speed rotation axis; cycloid plate (30) having cycloid tooth form; outer ring gear (40) provided with tooth form corresponding to said tooth form of cycloid plate at the circumferential internal side; clutch plate (50); clutch spring (60); low-speed rotation circle plate (70) having low-speed rotation axis and decelerating pin; and unit cover (10). According to this invention, it is possible to prevent injury of motor and protect actuator when overload happens in output.

Description

DECELERATOR FOR AUTOMOBILE ACTUATOR

Technical Field

The present invention relates to a decelerator for automobile actuator, in particular, to a decelerator for automobile actuator including a clutch for protecting from overload which decelerates the output by pressing constant rotation velocity and torque from power source-such as a motor-to a gear train, and which protects damage of motor and actuator in a case that overload above predetermined standard occurs in the output.

Background Art

In general, an actuator for automobile has a decelerator, which receives the power from power source such as a motor and generates constant velocity and torque. A planetary gear and a gear train are used inside of the decelerator.

Fig. 3 is a perspective view showing the decelerator for automobile actuator according to the previous art. As shown in Fig. 3, the power of a motor 1 received to a pinion gear 2 geared with axis of the motor 3 rotates a planetary gear 3 circumscribed with the pinion gear 2. The planetary gear 3 rotates according to the tooth form of inner gear 4 and rotates the

inner gear 4.

The driven inner gear 4 is slid and rotates an output inner gear 5. The constant rotation number and the output torque, which is determined from gear ration between the

planetary gear 3 and the inner gear 4, are conveyed to output gear 6.

A slide circle plate 7 is provided with sliding to the inner gear 4. A spring 8 supports the slide circle plate 7 to adhere closely to the inner gear 4. In a case that overload occurs in the output, the slide circle plate 7 pushes the spring 8 so that the inner gear 4 does

not rotate together and protects the motor 1 and the actuator.

As described above, since the power generated by a motor according to the previous art has a lot of loss on conveyance to the output, efficiency decrease. In a case of conveyance of high torque, a tooth form of gear is overloaded and is fragile.

Since a gear enlarges for high deceleration ratio, composition such as a gear train, a clutch circle plate and a spring is separated, and the process of production and assembling increases and production expense increases. In addition to, in a clutch for protecting from an overload, distribution of clutch power can increase by pressing a spring according to assembling method.

Disclosure of the Invention

To solve the above problems, the present invention provides the decelerator for automobile actuator having a unit, a cycloid plate, an outer ring gear, a clutch plate, a clutch spring, a low-speed rotation circle plate, and a unit cover.

The unit housing includes a motor axis hole provided with the upper side, a highspeed rotation provided with the lower side, and an eccentric cam provided with the longitudinal section of the high-speed rotation axis. The cycloid plate includes an input hole penetrating through the center of circle, a large number of output holes penetrating through the circumference having a predetermined radius from the center of circle, and a cycloid tooth form.

The outer ring gear includes a tooth form, which is provided with inner circumference, corresponding to the tooth form of said cycloid plate.

The clutch plate has a circle ring shape. The low-speed rotation circle plate includes a low-speed rotation axis, which is projected outer on the center of the lower side, and a decelerating pin having a large number of the small projection, which is projected outer inside the circumference from the center of circle.

The unit cover that a side is closed and the other side is open is a cylindrical shape, and includes a female screw provided with inner circumference and a penetrating hole provided with the center of the closed side.

In addition to, the cycloid consists of two, and each cycloid has a phase difference of 180° from the root of the tooth. And the cycloid plate and the outer ring gear are piled up more two bundles with single group.

Brief Description of the Drawings

Fig. 1 is a perspective view showing the decelerator for automobile actuator according to the present invention.

Fig. 2 is a perspective view, partly in section, showing assembling structure of the decelerator for automobile actuator according to the present invention.

Fig. 3 is a perspective view showing the decelerator for automobile actuator according to the previous art.

Preferred Embodiments of the invention

The preferred embodiments of the decelerator in accordance 'with the present invention are described below in detail referring to the accompanying drawings. Fig. 1 is a perspective view showing the decelerator for automobile actuator according to the present invention, and Fig. 2 is a perspective view, partly in section,

showing assembling structure of the decelerator for automobile actuator according to the present invention. As shown in Fig. 1 and Fig.2, the decelerator according to the present invention is a cylinder shape that a side is closed and the other side is open. The external form of the decelerator comprises a female screw 12, a unit cover 10, a male screw 22, and a unit housing. The female screw 12 is provided with an inner cylindrical surface, and the unit cover 10 has a penetrating hole 14 on a center of the closed surface. The male screw 22 projected outer has a screw thread corresponding to the female screw of the inner cylindrical surface. The unit housing 20 has a motor axis hole 24 at the center of the upper

side.

A high-speed rotation axis 26 connected at a live spindle with a motor 80, which is inserted through the motor axis hole 24 at a center of the male screw 22 on a low side of the unit housing 20, is geared with the motor 80 and rotates at the same number of rotation, and is projected outer. An eccentric cam 28 projected outer to the down at a predetermined distance from the center of circle is provided with the longitudinal section of the highspeed rotation axis 26.

A cycloid plate 30 is provided with low side of the high-speed rotation axis 26,

and a penetrating input hole 32 is provided with a center of the cycloid plate 30, and a large number of penetrating output holes 34 are provided with circumference having a certain radius from the center of circle.

The cycloid plate 30 is a gear having cycloid tooth. The cycloid is the trace that one point on circumference draws when a perfect circle rotates on a straight line. The cycloid tooth has a crown of tooth, which is a epicycloids rotating according to the outer circumference of circle, and a root of tooth, which is a hypocycloid rotating according to the inner circumference of circle. The cycloid plate 30 can be comprised of two plate of the same form. Two cycloid plates are overlapped at certain distance so that each cycloid plate has a phase

difference of 180° from the root of tooth.

An outer ring gear 40 is provided with outside the tooth form of the cycloid 30. The outer ling gear 40 includes a tooth form corresponding to the tooth form of the cycloid 30 on inner circumference of circle.

A clutch plate 50, as a plate of doughnut shape, is provided with the lower side of the outer ring gear 40. A clutch spring 60 having a certai tension is provided with the lower side of the clutch plate 50.

A low-speed rotation circle plate 70, as a circle plate, is provided with the lower side of the clutch spring 60. The low-speed rotation circle plate 70 has a low-speed rotation axis 72 projected outer on the center of the lower side, and a decelerating pin 74 having a large number of small projection projected outer inside circumference of circle from the center of circle on the upper side. It is preferable that the number of decelerating pin 74 is same with the number of the output hole 34 provided with the cycloid plate 30. The unit cover is provided with the lower side of the low-speed rotation circle plate 70. The low-speed rotation axis 72 formed on the low-speed rotation circle plate 70 is disclosed through the penetrating hole 14 formed on the closed side of the unit cover 10.

As above described, the decelerator according to the present invention locates the unit cover 10 at the lowest side, and locates the low-speed rotation axis 72 to be disclosed through the penetrating hole 14 of the unit cover 10. Then, the clutch spring 60, the clutch plate 50, the cycloid plate 30, and the outer ring gear 40 are piled up one after another, and the unit housing is located at the highest side. Then, the decelerator is screwed through the male screw 22 of the unit housing 20 and the female screw of the unit cover 12.

At this time, the cycloid plate 30 is geared with inner side of the outer ring gear 40.

In addition to, a large number of decelerating pins 74 provided with the low-speed rotation circle plate 70 are inserted into the output hole 34 formed on the cycloid plate 30. The eccentric cam of the high-speed rotation axis 26 provided with the high-speed rotation circle plate 20 is inserted into the input hole 32 formed on the cycloid plate 30.

The cycloid plate 30 and the outer ring gear 40 can be arranged in two more with group. This case has a higher deceleration ratio than the singular arrangement.

Fig. 2 is a perspective view, partly in section, showing assembling structure of the decelerator for automobile actuator according to the present invention. An operation of the decelerator according to the present invention is described

below.

The rotation power received from the axis of the motor 80 makes the high-speed rotation axis 26 provided with the unit housing 20 to rotate. The eccentric cam 28 provided with longitudinal section of the high-speed rotation axis 26 is slid to inner circumference of the input hole 32 of the cycloid plate 30, and makes the cycloid plate 30 with eccentric to rotate.

Since the rotation of the cycloid 39 rotates in gear with the inner tooth form of the outer ring gear 40, the constant decelerating ratio is output by the number of the tooth form of the cycloid plate 30 and the number of the tooth form of the outer ring gear 40. This makes the low-speed rotation circle plate 70 rotate with decreased the number of the rotation and torque through the decelerating pin 74, which is geared with the output hole 34 provided with the cycloid plate 30. Then, it makes the low-speed rotation circle plate 70 and the low-speed rotation axis 72 provided with the live spindle, and transfers the decelerating ratio and torque to the outside.

Next, in a case of the overload, an operation of the decelerator is described below.

In a case that overload occurs in the output or the gear train, the clutch plate 50 pushes the outer ring gear 40 to the upper side by an elastic force of the clutch spring 60. Then, the decelerating pin 74 provided with the low-speed rotation circle plate 70 is separated from the output hole 34 of the cycloid plate 30, and then the outer ring gear 40 and the cycloid plate 30 rotate idle inside the unit housing 20.

Therefore, since the rotation force received from the motor 80 is not transferred to the output, a lasting force about the overload of the output can be temporally interrupted, and damage of the motor 80 or the actuator is protected.

In the operation of protecting from the overload such as above, the predetermined

quantity about the overload is determined by the connection power between the male screw 22 and the female screw 12 provided with the unit housing 20 and the unit cover 10. Namely, the elastic force of the clutch spring 60 is controlled by the size of the space formed between the unit housing 20 and the unit cover 10 according to the .screw connection. Therefore, the extent of the overload is determined by controlling the connection between the unit housing 20 and the unit cover 10.

Although the present invention has been described above with respect to particular embodiments, it is not limited tiiereto, allowing modifications, changes, adaptations, etc. within the scope of the present invention, as those skilled in the art will understand.

Industrial Applicability

The present invention miniaturizes a decelerator by using the tooth fomi of the cycloid and is simpler structure for the deceleration according to previous planetary gear or gear arrangement. The present invention has excellent deceleration ability without noise and vibration, and transfers high torque. In addition to, the decelerator according to the present invention protects from the overload with simple structure by locating the clutch to inside the decelerator, and protects damage of the actuator or the gear train, and increases the temi of use. The decelerator gets constant clutch power according to the connection extent of the decelerator.

Claims

What is claimed is:

1. The decelerator for automobile actuator comprising:

A unit housing which includes a motor axis hole provided with the upper side, a high-speed rotation provided with the lower side, and an eccentric cam provided with the longitudinal section of the high-speed rotation axis;

A cycloid plate which includes an input hole penefrating through the center of circle, a large number of output holes penefrating through the circumference having a predetermined radius from the center of circle, and a cycloid tooth form;

An outer ring gear including a tooth form, which is provided with inner circumference, corresponding to the tooth form of said cycloid plate; A clutch plate having a circle ring shape; A clutch spring;

A low-speed rotation circle plate including a low-speed rotation axis, which is projected outer on the center of the lower side, and a decelerating pin having a large

number of the small projection, which is projected outer inside the circumference from the center of circle;

A unit cover, as a cylindrical shape that a side is closed and the other side is open, which includes a female screw provided with inner circumference and a penetrating hole provided with the center of the closed side.

2. The decelerator for automobile actuator as set forth in Claim 1, wherein said cycloid consists of two and each cycloid has a phase difference of 180° from the root

of the tooth.

3. The decelerator for automobile actuator as set forth in Claim 1, wherein said cycloid plate and said outer ring gear are piled up more two bundles with single group.