Assembly structure of disk and output unit of hollow-type cycloid reducer

Abstract

A hollow-type cycloid reducer according to the present invention comprises: a reducer case; a hollow shaft positioned to pass through the center of the reducer case and having, on the outer circumferential surface thereof, off-centered symmetric first and second eccentric cams; a ring gear pin groove having cycloidal teeth on the inner circumferential surface thereof; a plurality of ring gear pins that engage with the ring gear pin groove; ring-shaped first and second roller bearings eccentrically coupled around the first and second eccentric cams, respectively, and having a plurality of evenly spaced rollers installed therein; ring-shaped first and second disk gears provided on the outer circumferential surfaces of the first and second roller bearings, respectively, and having cycloidal teeth along the outer circumferences to engage with the ring gear pins to revolve eccentrically and rotate; a ring-shaped carrier provided between the first disk gear and a driving module; and a ring-shaped output flange provided on the outer side of the second disk gear.

Description

Assembly structure of the disk and output section of a hollow cycloid reducer

[0001] The present invention relates to a hollow cycloidal reducer, and more particularly, to an assembly structure of a cycloidal reducer in which an input shaft and an output shaft have hollow shafts.

[0002] A reducer is used to reduce the rotational speed of a high load transmitted through a drive shaft of a power source such as an electric motor or servo motor in automation and precision control equipment, and is usually used by combining involute spur gears in an external manner.

[0003] These reducers, in line with the trend toward miniaturization and precision, require a large number of gears in multiple stages to achieve a high reduction ratio, which increases their volume and requires high precision and complexity in processing.

[0004] In particular, among reducers, the cycloid reducer is a reducer widely used in the automobile, robot, and defense industries, and is particularly used as a major component in unmanned weapons in the defense industry.

[0005] Cycloid is a mathematical term that refers to the curve drawn by a point on a circumscribed circle when the circumscribed circle rotates along the surface of the circle. A cycloid reducer that utilizes this principle uses a reduction gear with cycloid teeth.

[0006] In general, most gear teeth use an involute curve, and planetary gears with this type of tooth shape are mainly used in reducers.

[0007] However, the cycloidal reducer uses gears that utilize a cycloidal curve to perform reduction, and the cycloidal reducer that uses a planetary gear reduction method uses the principle of using the reduction ratio obtained by the circumference by revolving around the inside of the ring gear pin groove by an eccentric shaft and inscribing it.

[0008] These cycloidal reducers have a rotary shaft with bearings installed on an input shaft connected to a driving means, and a plurality of rod-shaped input-side connecting ports are provided on the body of the rotary shaft and connected by being inserted into an input disk.

[0009] In addition, the input disc has a plurality of radially formed slide holes, and a plurality of lubricating members inserted into each of the slide holes, and the ends of the lubricating members are installed so as to be in sliding contact with the cycloid teeth formed on the inner periphery of a reduction rotating member (ring gear) provided on the outer side of the disc.

[0010] In addition, the above-mentioned reduction rotation member is provided with a plurality of output side connection ports to install an output disk, and an output shaft is provided on the output disk to perform reduction.

[0011] Often, a hollow reducer with an integrated motor is used in a cycloidal reducer with a planetary gear reduction method.

[0012] In the case of hollow reducers, cables and shafts can be arranged inside the hollow shaft, ensuring applicability and providing the advantage of lightweight and compact products.

[0013] However, in the case of a cycloidal reducer, when the hollow shaft is expanded, the hollow shaft hole of the disk through which the hollow shaft passes must also be enlarged, making it difficult to expand the hollow shaft due to the weakening of the disk structure.

[0014] In particular, as shown in Fig. 6, when there is a pinhole for power transmission around the hollow shaft hole of the carrier and the disk, there is a concern that the structural strength of the disk may be weakened if the hollow shaft hole is expanded, so the expansion of the hollow shaft is limited.

[0015] <Prior Art Literature>

[0016] (Patent Document 1) Republic of Korea Patent No. 10-0586451 (May 26, 2006) "High-efficiency, high-rigidity internal gear reducer using cycloidal tooth profile"

[0017] (Patent Document 2) Republic of Korea Registered Patent No. 10-2390832 (April 21, 2022) "Gear Device"

[0018] (Patent Document 3) Republic of Korea Patent No. 10-1164644 (July 4, 2012) "Hollow Cycloid Reducer"

[0019] Accordingly, an object of the present invention is to provide a hollow cycloidal reducer having a structure in which internal pins having a protruding shape on each disk gear are inserted into grooves formed in a carrier and an output flange, respectively, in order to improve the method of transmitting power from the disk to the output flange.

[0020] Another object of the present invention is to provide a hollow cycloidal reducer in which a block protruding from an output flange penetrates a disk gear and is coupled with a carrier to transmit power.

[0021] In order to achieve the above object, a hollow cycloidal reducer according to the present invention comprises: a reducer case; a hollow shaft disposed to penetrate the center of the reducer case and having a first eccentric cam and a second eccentric cam eccentrically formed symmetrically on an outer circumference thereof; a ring gear pin groove having a cycloidal tooth shape on an inner circumference of the reducer case; a plurality of ring gear pins meshed with the ring gear pin grooves; a first roller bearing and a second roller bearing formed in a ring shape and eccentrically coupled around the first eccentric cam and the second eccentric cam, respectively, and having a plurality of rollers internally provided at regular intervals; a first disk gear and a second disk gear formed in a ring shape and provided on the outer circumferences of the first roller bearing and the second roller bearing, respectively, having a cycloidal tooth shape formed along the outer circumference thereof, meshing with the ring gear pins and rotating while eccentrically revolving; a carrier formed in a ring shape and provided between the first disk gear and a drive module; In a hollow cycloidal reducer including an output flange formed in a ring shape and provided on the outer side of the second disk gear, a first inner pin is formed protrudingly on the first disk gear and an end is inserted into a carrier groove formed on the carrier to transmit power, and a second inner pin is formed protrudingly on the second disk gear and an end is inserted into an output flange groove formed on the output flange to transmit power.

[0022] Preferably, the first bushing is coupled to the end of the first inner pin and inserted into the carrier groove, and the second bushing is coupled to the end of the second inner pin and inserted into the output flange.

[0023] And, in the present invention, it is preferable that a block protruding from the output flange and penetrating the first and second disk gears and coupled to the carrier is further included.

[0024] In addition, the first inner pin and the second inner pin may each be configured to protrude integrally from the first disk gear and the second disk gear, or may be configured to have a structure in which a separate pin-shaped member is pressed in and fixed.

[0025] According to the present invention described above, the following effects are achieved.

[0026] First, since the power transmission utilizes a protruding internal pin rather than a conventional penetrating disc gear, there is no need to form multiple holes in the disc gear. This improves the structural rigidity of the disc gear and enhances the expandability of the hollow shaft.

[0027] Second, the carrier and output shaft have a grooved structure, eliminating through-holes. This improves rigidity and allows for greater expandability of the hollow shaft. Furthermore, the expansion of the hollow shaft increases space utilization, enabling weight reduction.

[0028] Third, the block formed on the output flange is connected to the carrier while penetrating the disk gear without contact, thereby enabling accurate transmission, and since the block penetrates the disk but does not contact the block hole, unnecessary friction during operation is eliminated, thereby preventing a decrease in efficiency.

[0029] Figure 1 is a cross-sectional perspective view showing a hollow cycloid reducer according to one embodiment of the present invention.

[0030] Figure 2 is an exploded perspective view of the present invention shown in Figure 1.

[0031] Figure 3 is a perspective view showing the hollow shaft of the present invention illustrated in Figure 1.

[0032] Figure 4 is a cross-sectional perspective view showing the internal pin coupling structure of the present invention illustrated in Figure 1.

[0033] Figure 5 is a cross-sectional perspective view showing the block joint structure of the present invention illustrated in Figure 1.

[0034] Figure 6 is a perspective view of a conventional disk.

[0035] <Explanation of symbols>

[0036] 100: Reducer case

[0037] 200: Hollow shaft 210: Eccentric cam

[0038] 211: First eccentric cam 212: Second eccentric cam

[0039] 300: Ring gear pin home

[0040] 400: Ring gear pin 410, 420: Tapered bearing

[0041] 500: Roller bearing

[0042] 510: First roller bearing 520: Second roller bearing

[0043] 600: Disc gear 610: First disc gear

[0044] 611: First inner pin 612: First bushing

[0045] 620: Second disc gear 621: Second inner pin

[0046] 622: Second bushing 630: Block hole

[0047] 700: Carrier 710: Carrier Home

[0048] 800: Output flange 810: Output flange groove

[0049] 820: Block 830: Location pin

[0050] The following examples of the present invention are provided to facilitate a better understanding of the present invention and are not intended to limit the scope of the present invention. In other words, the following examples are provided to ensure a complete disclosure of the present invention and to fully inform those skilled in the art of the invention of the scope of the invention. The present invention is defined solely by the scope of the claims.

[0051] The terminology used herein is for the purpose of describing embodiments and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise. As used herein, the terms "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components in addition to the components mentioned.

[0052] Additionally, unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with meanings commonly understood by those of ordinary skill in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0053] In addition, when explaining the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the present invention, the detailed description may be omitted.

[0054] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. Fig. 1 is a cross-sectional perspective view showing a hollow cycloid reducer according to one embodiment of the present invention, and Fig. 2 is an exploded perspective view of the present invention shown in Fig. 1.

[0055] Referring to the drawing, the present invention can be implemented by including a reducer case (100), a hollow shaft (200), a ring gear pin groove (300), a ring gear pin (400), a roller bearing (500), a disk gear (600), a carrier (700), an output flange (800), a first inner pin (611), a second inner pin (621), and a block (820).

[0056] First, the reduction gear case and hollow shaft will be described with reference to Fig. 3. Fig. 3 is a perspective view showing the hollow shaft of the present invention illustrated in Fig. 1.

[0057] The above-mentioned reducer case (100) has a cylindrical shape with both ends open, and a cover can be assembled and connected to one end.

[0058] Or, it may have a fastening structure that can be directly or indirectly connected to a driving means (not shown) such as a motor.

[0059] The hollow shaft (200) is accommodated by penetrating the inner center of the above-mentioned reduction gear case (100).

[0060] The above hollow shaft (200) has a hollow tube shape and operates as an input shaft. That is, the above hollow shaft (200) is linked to the high-speed rotation shaft of the driving means and operates as an input to the reducer.

[0061] And it is preferable to have an eccentric shaft structure in which a pair of eccentric cams (210) are formed on the outer surface of the hollow shaft (200).

[0062] To this end, the eccentric cam (210) is formed symmetrically at 180° with a first eccentric cam and a second eccentric cam that are divided to form an eccentricity with respect to the center of the hollow shaft (200) on the outer surface of the hollow shaft (200).

[0063] Next, the ring gear pin home (300) and ring gear pin (400) will be described.

[0064] The above ring gear pin groove (300) is a semicircular groove formed on the inner surface of the reducer case (100). In addition, the above ring gear pin (400) has a roller shape, and a plurality of them are each inserted into and supported in the above ring gear pin groove (300).

[0065] At this time, the ring gear pins (400) are arranged at regular intervals in a parallel manner in a circle, and both ends can be fixed with tapered bearings (410, 420) in the shape of circular rings. The outer circumference of each of the tapered bearings (410, 420) is coupled to the inner circumference of the reducer case (100), and the inner circumference rotatably supports the carrier (700) and the output flange (800), respectively.

[0066] Next, the above roller bearing will be described.

[0067] A roller bearing (500) is connected to the above eccentric cam (210).

[0068] The above roller bearing (500) has a circular ring shape so that the hollow shaft (200) passes through it, and is provided as a pair of a first roller bearing (510) and a second roller bearing (520) of the same shape, and is provided to surround the outer periphery of the first eccentric cam (211) and the second eccentric cam (212), respectively. A plurality of rollers are installed at regular intervals in the roller bearing (500).

[0069] Accordingly, the roller bearing (500) is also linked to the eccentric cam (210) and rotates eccentrically in different phases. For reference, the rollers of the first roller bearing (510) and the second roller bearing (520) are arranged to be misaligned from each other.

[0070] Next, the above disk gear will be described with reference to FIG. 4. FIG. 4 is a cross-sectional perspective view showing the internal pin coupling structure of the present invention illustrated in FIG. 1.

[0071] The above disk gear (600) has a circular ring shape so that the hollow shaft (200) passes through it, and an (epi) cycloidal tooth shape is formed along the outer circumference, and a pair of first disk gears (610) and second disk gears (620) are provided in parallel with each other.

[0072] At this time, the first disk gear (610) is provided to surround the outer circumference of the first roller bearing (510), and the teeth are in rolling contact with the ring gear pin (400). Similarly, the second disk gear (620) is provided to surround the outer circumference of the second roller bearing (520), and the teeth are in rolling contact with the ring gear pin (400).

[0073] At this time, the first disk gear (610) and the second disk gear (620) also mesh with the ring gear pin (400) with different phases, and rotate eccentrically with a phase difference of 180° according to the rotation of the roller bearing (500). In addition, since they come into contact with the ring gear pin (400), they rotate eccentrically with different phases due to the difference in the number of teeth of the disk gear (600) and the number of ring gear pins.

[0074] What is important is that one or more internal pins are formed protrudingly on the side of the above-mentioned disk gear (600).

[0075] At least one first inner pin (611) is formed protrudingly on the side surface of the first disk gear (610), and at least one second inner pin (621) is formed protrudingly on the side surface of the second disk gear (620), wherein the first inner pin (611) and the second inner pin (621) each protrude toward the outside.

[0076] It is preferable that a first bushing (612) and a second bushing (622) are respectively coupled to the ends of the first inner pin (611) and the second inner pin (621).

[0077] In another embodiment, the first inner pin (611) and the second inner pin (621) may not be formed integrally with the first disk gear (610) and the second disk gear (620), but may be fixed by pressing a separate pin-shaped member into the first disk gear (610) and the second disk gear (620).

[0078] Next, the carrier and output flange will be described with reference to FIG. 5. FIG. 5 is a cross-sectional perspective view showing the block coupling structure of the present invention illustrated in FIG. 1.

[0079] The carrier (700) is formed in a circular ring shape so that the hollow shaft (200) passes through it, and is provided on the outside of the first disk (610).

[0080] The above output flange (800) is also formed in a circular ring shape so that the hollow shaft (200) passes through it, and is provided on the outside of the second disk gear (620).

[0081] Accordingly, the first disk gear (610) and the second disk gear (620) are arranged facing each other between the carrier (700) and the output flange (800).

[0082] Here, a carrier groove (710) is formed on the side of the carrier (700) so that the end of the first inner pin (611) can be inserted, and an output flange groove (810) is formed on the side of the output flange (800) so that the end of the second inner pin (621) can be inserted.

[0083] If the first bushing (612) and the second bushing (622) are provided, the first bushing (612) will be inserted into the carrier home (710), and the second bushing (622) will be inserted into the output flange home (810).

[0084] Preferably, the first bushing (612) and the second bushing (622) are formed to be smaller than the inner diameter of the carrier groove (710) and the output flange groove (810), respectively, and are inserted. That is, a gap is formed between the first bushing (612) and the carrier groove (710) and between the second bushing (622) and the output flange groove (810).

[0085] In addition, a block (820) having a protruding shape is formed on the side of the output flange (800), and the block (820) penetrates the first and second disk gears (610, 620) and is coupled with the carrier (700), so that the carrier (700) and the output flange (800) can be firmly coupled to each other. It is important to note that it is preferable that the block (820) penetrates the first and second disk gears (610, 620) without contacting them to avoid friction.

[0086] At this time, the block (820) is formed to have a cross-section that is approximately a long rectangle or track shape, and one or more of the blocks may be formed to be arranged radially from the center of the output flange (800).

[0087] And, in the first and second disk gears (610, 620), a block hole (630) having a corresponding shape is formed so that the block (820) can pass through it.

[0088] Preferably, the width and depth of the block (820) are formed relatively small compared to the width and depth of the block hole (630), so that there is a gap between the block (820) and the block hole (630).

[0089] Additionally, the block (820) can be aligned with the carrier (700) by a position pin (830).

[0090] Since it is structured in this way, when the disk gear (600) rotates eccentrically, the carrier (700) rotates in the same phase by the first inner pin (611), and at the same time, the output flange (800) also rotates in the same phase by the second inner pin (621).

[0091] And the rotational power of the carrier (700) is transmitted to the output flange (800) by the block (820). This output flange (800) is connected to an output shaft (not shown) to obtain a reduced output.

[0092] Although the present invention has been described with reference to drawings according to embodiments thereof, those skilled in the art will be able to make various applications and modifications within the scope of the present invention based on the above contents.

Claims

1. A reducer case; a hollow shaft disposed to penetrate the center of the reducer case and having a first eccentric cam and a second eccentric cam eccentrically formed symmetrically on an outer circumference; a ring gear pin groove formed in a semicircle on an inner circumference of the reducer case; a plurality of ring gear pins inserted and supported in the ring gear pin grooves; a first roller bearing and a second roller bearing formed in a ring shape and eccentrically coupled around the first eccentric cam and the second eccentric cam, respectively, and having a plurality of rollers provided internally at regular intervals; a first disk gear and a second disk gear formed in a ring shape and provided on the outer circumferences of the first roller bearing and the second roller bearing respectively, and having a cycloidal tooth shape formed along the outer circumference to mesh with the ring gear pin and rotate while eccentrically revolving; a carrier formed in a ring shape and provided on the outer side of the first disk gear; In a hollow cycloidal reducer including an output flange formed in a ring shape and provided on the outer side of the second disk gear, An assembly structure of a disk and an output section of a hollow cycloidal reducer, characterized in that the first disk gear has a first internal pin protrudingly formed and an end thereof is inserted into a carrier groove formed in the carrier to transmit power, and the second disk gear has a second internal pin protrudingly formed and an end thereof is inserted into an output flange groove formed in the output flange to transmit power.

2. In paragraph 1, An assembly structure of a disk and an output section of a hollow cycloidal reducer, characterized in that a first bushing is inserted into the carrier groove while being coupled to an end of the first inner pin, and a second bushing is inserted into the output flange while being coupled to an end of the second inner pin.

3. In paragraph 2, An assembly structure of a disk and an output section of a hollow cycloidal reducer, characterized in that it further includes a block that protrudes from the output flange, penetrates the first and second disk gears, and is coupled to the carrier, and the block does not contact the first and second disks.

4. In paragraph 1, An assembly structure of a disk and an output section of a hollow cycloidal reducer, characterized in that the first inner pin and the second inner pin are each formed by integrally protruding from the first disk gear and the second disk gear or by pressing and fixing a separate pin-shaped member.

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