Continuously variable transmission

Abstract

The present invention relates to a continuously variable transmission that prevents interruption of power during gear shifting, minimizes load and impact due to gear shifting, and in particular, matches the rotation direction of an eccentric disk with that of an output shaft in order to prevent noise, vibration, and impact that may occur when the rotation direction of an eccentric disk that operates a link actuator is opposite to that of an output shaft. The transmission according to one embodiment of the present invention includes an input shaft 2 to which power is input from the outside, a planetary gear 4 to which a part of the power is transmitted from the input shaft 2, a driven shaft 3 to which a part of the power from the input shaft 2 is transmitted, a first link shaft 51 that rotates by receiving the power transmitted from the driven shaft 3, a link actuator that operates by the rotation of the first link shaft 51, a gear shift lever 6 for adjusting the gear ratio of the link actuator, and an output shaft 7 to which power is transmitted from the link actuator and the planetary gear 4, and the link actuator is arranged to rotate in a direction parallel to the axis of rotation of the link actuator. The eta includes an eccentric disk 501 which rotates eccentrically around the first link shaft 51, a cam 502 which reciprocates up and down due to the rotation of the eccentric disk 501, a first link 504 which is connected to the cam 502 and transmits power to the output shaft 7, and a one-way clutch 506 which is provided between the first link 504 and the output shaft 7 and transmits power only in a predetermined rotational direction of the output shaft 7. By rotating the first link shaft 51 by the driven shaft 3, a continuously variable transmission is provided in which the first link shaft 51 and the output shaft 7 rotate in the same direction.

Description

Technical Field

[0001] The present invention relates to a continuously variable transmission, which prevents interruption of power during shifting, minimizes load and impact caused by shifting, and particularly, relates to a continuously variable transmission in which the rotational direction of an eccentric disk that actuates a link actuator is made to coincide with the rotational direction of an output shaft in order to prevent noise, vibration, and impact that occur when the rotational direction of the eccentric disk is opposite to the rotational direction of the output shaft.

Background Art

[0002] Continuously variable transmissions can be utilized in various devices that utilize rotational power, such as bicycles, automobiles, motorcycles, and other means of transportation.

[0003] In recent years, the demand for continuously variable transmissions has been increasing in order to maximize the efficiency of engines, motors, and the like.

[0004] The applicant of the present invention has proposed Patent Document 1 for constructing a continuously variable transmission, and Patent Document 1 discloses a continuously variable transmission capable of both forward rotation and reverse rotation.

[0005] When constructing the continuously variable transmission according to Patent Document 1, as shown in FIG. 2 of Patent Document 1, the rotational directions of the input gear 310 and the output shaft 400 are configured to be opposite. In this case, forward and reverse rotations are possible, but large noise, vibration, and impact occur, and there are limitations in applying it to an actual product, and the cause of such noise, vibration, and impact could not be identified.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The applicant of the present invention has confirmed through long-term research and development that the causes of noise, vibration, and shock generated in the continuously variable transmission according to Patent Document 1 are due to the rotation in the reverse direction. Accordingly, the input gear (the second driven gear, the eccentric disk 501, or the first link shaft 51 in the present invention) and the output shaft 7 are configured to rotate in the same direction, thereby providing a continuously variable transmission with significantly reduced noise, vibration, and shock.

[0008] An object of the present invention is to provide a continuously variable transmission having a structure with significantly reduced noise, vibration, and shock in order to improve the limitations of the conventional continuously variable transmission described above.

Means for Solving the Problems

[0009] In order to improve the limitations of the conventional continuously variable transmission as described above, the present invention includes an input shaft to which power is input from the outside, a planetary gear to which a part of the power is transmitted from the input shaft, a driven shaft to which a part of the power is transmitted from the input shaft, a first link shaft that rotates by receiving the power transmitted from the driven shaft, a link actuator that operates by the rotation of the first link shaft, a shift lever for adjusting the transmission ratio of the link actuator, and an output shaft to which power is transmitted from the link actuator and the planetary gear. The link actuator includes an eccentric disk that eccentrically rotates around the first link shaft, a cam that reciprocates up and down by the rotation of the eccentric disk, a first link connected to the cam and transmitting power to the output shaft, and a one-way clutch provided between the first link and the output shaft 7 and transmitting power only in a predetermined rotation direction of the output shaft. By rotating the first link shaft by the driven shaft, the present invention provides a continuously variable transmission in which the first link shaft and the output shaft rotate in the same direction.

[0010] Further, the link actuator includes a plurality of link sets including the eccentric disk, the cam, the first link, and the one-way clutch. The link set includes a hinge portion connected to one side of the cam, and a second link connected so that one end extends from the hinge portion. One end of the first link is connected to the hinge portion, the other end of the first link is connected to the one-way clutch, and a second link shaft connected to the other ends of the plurality of second links. The position of the second link shaft may be adjusted by the shift lever.

[0011] And the shift lever may include a second link shaft adjustment portion connected to both ends of the second link shaft, a second link shaft adjustment shaft fixed at a position spaced a predetermined distance from the second link shaft, and an operation portion extending in a direction perpendicular to the second link shaft adjustment shaft from one side of the second link shaft adjustment shaft and rotating within a predetermined angle range with respect to the second link shaft adjustment shaft.

[0012] Furthermore, the planetary gear includes an annular gear externally engaging with a first driving gear formed on the input shaft and having gear teeth formed on an outer peripheral surface and an inner peripheral surface, a plurality of satellite gears internally engaging with the annular gear, a sun gear located at the center of the annular gear and externally engaging with the satellite gears, and a carrier connected to the plurality of satellite gears, having a central axis concentric with the input shaft, and having a predetermined hollow formed so that the input shaft penetrates therethrough. The one-way clutch may be configured to transmit power to the carrier and not be directly connected to the output shaft.

[0013] Also, the input shaft includes a first driving gear for transmitting power to the planetary gear. The driven shaft includes a first driven gear connected to the first driving gear and having a gear ratio such that the driven shaft accelerates compared to the input shaft, a bearing supporting the driven shaft at a predetermined distance from the input shaft so that a central axis is parallel to the input shaft, and a second driving gear formed to have a diameter larger than that of the first driven gear. The first link shaft may be connected to the second driving gear and may include a second driven gear having a gear ratio such that the first link shaft accelerates compared to the driven shaft.

Advantages of the Invention

[0014] According to the embodiment of the present invention, by configuring the second driven gear, the eccentric disk 501 or the first link shaft 51 to rotate in the same direction as the output shaft 7, noise, vibration, and shock can be significantly reduced.

[0015] In addition, in order to solve the problem that the speed change is unstable when the input rotation speed is low due to the characteristics of the link actuator, by providing a predetermined multi-stage speed change gear, the rotation speed transmitted to the link actuator can be increased to improve the speed change stability.

[0016] And, by arranging the pivot point (the second link shaft adjustment shaft 62) for adjusting the speed change ratio of the link actuator outside the link actuator, interference between members can be prevented.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0018] Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings. However, this does not limit the technology disclosed in this specification to specific embodiments, and it should be understood that various modifications, equivalents, and / or alternatives of the embodiments of the present invention are included. In the description of the drawings, similar components are denoted by similar reference numerals.

[0019] In this specification, expressions such as "having", "may have", "including", "may include", etc. indicate the presence of the feature (for example, a component such as a numerical value, a function, an operation, a part, etc.), and do not exclude the presence of other features.

[0020] In this specification, expressions such as "A or B", "at least one of A or / and B", or "one or more of A or / and B" include all possible combinations of the items listed together. For example, "A or B", "at least one of A and B", or "at least one of A or B" include (1) those including at least one A, (2) those including at least one B, and (3) those including both at least one A and at least one B.

[0021] Expressions such as "first", "second", "first", or "second" used in this specification can modify various components regardless of order and / or importance, and are used only to distinguish one component from another component, and are not intended to limit the corresponding component. For example, the first user device and the second user device may indicate different user devices regardless of order or importance. For example, without departing from the scope of the rights described in this specification, the first component can be named the second component, and similarly, the second component can be replaced and named the first component.

[0022] When a component (e.g., a first component) is referred to as being "(operatively or communicatively) coupled with / to" another component (e.g., a second component), it should be understood that the said component may be directly coupled to the other component or may be coupled via yet another component (e.g., a third component). On the other hand, when a component (e.g., a first component) is referred to as being "directly coupled" to another component (e.g., a second component), it can be understood that there is no other component (e.g., a third component) between the said component and the other component.

[0023] The terms used in this specification are for the purpose of describing particular embodiments only and are not intended to limit the scope of other embodiments. Singular expressions include plural expressions unless otherwise specified. Terms used in the present invention, including technical or scientific terms, are used in a meaning commonly understood by those having ordinary knowledge in the technical field to which the present invention pertains. Among the terms used in this specification, terms defined in commonly used dictionaries are to be interpreted in the same or similar meaning as the contextual meaning in the related art and should not be interpreted in an ideal or overly formal meaning unless otherwise specified. In some cases, terms defined in this specification should not be interpreted so as to exclude embodiments of the present invention.

[0024] It goes without saying that various modifications can be made by those having ordinary knowledge in the technical field to which the present invention pertains without departing from the gist of the present invention claimed in the claims of the present invention, and such modifications should not be construed as being separate from the technical idea and perspective of the present invention.

[0025] The "reciprocating motion up and down, upper end, lower end" and the like used in the description of the invention are defined in the drawings, and the shape and position of each component are not limited by these terms.

[0026] A transmission according to an embodiment of the present invention includes an input shaft 2 to which power is input from the outside, a planetary gear 4 to which part of the power is transmitted from the input shaft 2, a driven shaft 3 to which part of the power from the input shaft 2 is transmitted, a first link shaft 51 that rotates by receiving the power transmitted from the driven shaft 3, a link actuator that operates by the rotation of the first link shaft 51, a shift lever 6 for adjusting the gear ratio of the link actuator, and an output shaft 7 to which power is transmitted from the link actuator and the planetary gear 4. The link actuator includes an eccentric disk 501 that eccentrically rotates about the first link shaft 51, a cam 502 that reciprocates vertically by the rotation of the eccentric disk 501, a first link 504 that is connected to the cam 502 and transmits power to the output shaft 7, and a one-way clutch 506 that is provided between the first link 504 and the output shaft 7 and transmits power only in a predetermined rotation direction of the output shaft 7. By rotating the first link shaft 51 by the driven shaft 3, a continuously variable transmission is provided in which the first link shaft 51 and the output shaft 7 rotate in the same direction.

[0027] According to the above configuration, as shown in FIG. 5, the first link shaft 51 and the output shaft 7 rotate in the same direction.

[0028] Thereby, since the acting point (particularly, the eccentric disk 501) in the process of transmitting power to the output shaft 7 by the first link shaft 51, the eccentric disk 501, the second link shaft adjustment shaft 62, the second link shaft 52, the first link 504, etc. is different from that in Patent Document 1, noise, vibration, and impact are significantly reduced as compared with the prior art.

[0029] The input shaft 2, the shift lever 6, the link actuator, etc. may be fixed to the frame 1 with a central axis (rotation axis) etc. by members such as bearings.

[0030] Part of the power transmitted by the input shaft 2 (such as human power, power of an engine / motor) may be transmitted to the output shaft 7 by the planetary gear 4, and energy may be transmitted to the required place of power by members such as a gear, a sprocket 71 provided at the end of the output shaft 7.

[0031] The remaining power excluding the losses due to friction etc. is transmitted to the link actuator via the driven shaft 3 and is shifted within a predetermined range.

[0032] The shift lever 6 may adjust the gear ratio by adjusting the operating radius of the link actuator. At this time, since the shift lever 6 is not in a form fastened to a specific stage but rotates with respect to a second link shaft adjustment shaft 62 described later, stepless shifting without "stages" becomes possible.

[0033] Further, the link actuator includes a plurality of link sets including the eccentric disk 501, the cam 502, the first link 504, and the one-way clutch 506. The link set includes a hinge portion 503 connected to one side of the cam 502 and a second link 505 connected so that one end extends from the hinge portion 503. One end of the first link 504 is connected to the hinge portion 503, the other end of the first link 504 is connected to the one-way clutch 506, and a second link shaft 52 connected to the other ends of the plurality of second links 505. The position of the second link shaft 52 may be adjusted by the shift lever 6.

[0034] The more appropriate the number of link sets is, the more the shift shock can be minimized. The drawings show an embodiment provided with four link sets. In the case of a conventional form having three link sets, some shift shocks occur. Also, in the case of having five or more link sets, the stepless transmission becomes unstable, the structure is complicated, and there are problems in terms of maintainability and durability.

[0035] In order to minimize the shift shock, as shown in FIG. 5, it is preferable that the eccentric disk 501 is fixedly coupled eccentrically in different directions (at different positions) with respect to the first link shaft 51.

[0036] When the first link shaft 51 rotates, the eccentric disk 501 rotates eccentrically, and a cam 502 (hinge portion 503) connected in a hinge-bearing form to the outside of the eccentrically rotating eccentric disk 501 reciprocates up and down with respect to the first link shaft 51.

[0037] The one-way clutch 506 restricts only the movement in one direction of the movement of the first link 504 from being transmitted to the planetary gear 4 (carrier 44).

[0038] The shift lever 6 may include a second link shaft adjustment portion 61 connected to both ends of the second link shaft 52, a second link shaft adjustment shaft 62 fixed at a position separated from the second link shaft 52 by a predetermined distance, and an operation portion 63 extending in a direction perpendicular to the second link shaft adjustment shaft 62 from one side of the second link shaft adjustment shaft 62 and rotating within a predetermined angle range with respect to the second link shaft adjustment shaft 62.

[0039] When the end of the operation portion 63 is located at the upper end, the second link shaft 52 is also fixed at the relatively highest position, whereby the height of the bottom dead center of the hinge portion 503 increases and the length of the stroke decreases. Therefore, the length and speed transmitted from the first link 504 to the one-way clutch become shorter, and it serves as a low-speed gear.

[0040] Conversely, when the end of the operation portion 63 is located at the lower end, the second link shaft 52 is also fixed at the relatively lowest position, whereby the height of the bottom dead center of the hinge portion 503 decreases and the length of the stroke increases. Therefore, the length and speed transmitted from the first link 504 to the one-way clutch become longer (higher), and it serves as a high-speed gear.

[0041] In the "operation part 63 that extends in a direction perpendicular to the second link shaft adjustment shaft 62 from one side of the second link shaft adjustment shaft 62 and rotates within a predetermined angular range with respect to the second link shaft adjustment shaft 62", the "perpendicular direction" is not limited to "perpendicular" in the geometric sense, and also includes a shape and structure equivalent to a configuration that rotates the second link shaft adjustment shaft 62 with a relatively small force by a predetermined moment force.

[0042] The "predetermined angular range" means the range of the angle formed when connecting the point when the second link shaft 52 is located at the uppermost position, the center point of the second link shaft adjustment shaft 62, and the point when the second link shaft 52 is located at the lowermost position. The angular range is preferably formed in the range of 25 degrees to 50 degrees.

[0043] Furthermore, the planetary gear 4 includes an annular gear 41 that is externally engaged with a first driving gear 21 formed on the input shaft 2 and has gear teeth formed on its outer peripheral surface and inner peripheral surface, a plurality of satellite gears 42 that are internally engaged with the annular gear 41, a sun gear 43 that is located at the center of the annular gear 41 and is externally engaged with the satellite gears 42, and a carrier 44 that is connected to the plurality of satellite gears 42, has a central axis concentric with the input shaft 2, and is formed with a predetermined hollow so that the input shaft 2 penetrates therethrough. The one-way clutch 506 may be configured to transmit power to the carrier 44 and not be directly connected to the output shaft 7.

[0044] By organically combining the detailed configuration of the link actuator and the detailed configuration of the planetary gear 4, the effects of the present invention can be achieved.

[0045] According to the structure of the planetary gear 4, forces from two locations may generate a resultant force without interfering with each other. Since a part of the power of the input shaft 2 is transmitted through the outside of the annular gear 41 and the power transmitted from the link actuator is transmitted to the satellite gears 42 through the carrier 44, the power is transmitted to the output shaft 7 without interfering with each other and a resultant force is generated.

[0046] Further, the input shaft 2 includes a first driving gear 21 that transmits power to the planetary gear 4, and the driven shaft 3 is connected to the first driving gear 21 and includes a first driven gear 31 having a gear ratio such that the driven shaft 3 accelerates compared to the input shaft 2, a bearing 32 that supports the driven shaft 3 at a predetermined distance from the input shaft 2 so that the central axis is parallel to the input shaft 2, and a second driving gear 33 formed to have a diameter larger than that of the first driven gear 31. The first link shaft 51 may be connected to the second driving gear 33 and include a second driven gear 511 having a gear ratio such that the first link shaft 51 accelerates compared to the driven shaft 3.

[0047] As described above, by accelerating and transmitting the power transmitted to the link actuator in advance, the number of rotations input to the link actuator significantly increases, enabling stable speed change.

Explanation of Signs

[0048] 1 Frame 2 Input Shaft 21 First Driving Gear 3 Driven Shaft 31 First Driven Gear 32 Bearing 33 Second Driving Gear 4 Planetary Gear 41 Ring Gear 42 Satellite Gear 43 Sun Gear 44 Carrier 501 Eccentric Disk 502 Cam 503 Hinge Portion 504 First Link 505 Second Link 506 One-Way Clutch 51 First Link Shaft 511 Second Driven Gear 52 Second Link Shaft 6 Shift Lever 61 Second Link Shaft Adjustment Portion 62 Second Link Shaft Adjustment Shaft 63 Operation Portion 7 Output shaft 71 Sprocket

Claims

1. An input shaft to which power is input from the outside, A planetary gear to which a part of the power is transmitted from the input shaft, A driven shaft to which a part of the power is transmitted from the input shaft, A first link shaft that rotates by receiving the power transmitted from the driven shaft, A link actuator that operates by the rotation of the first link shaft, A shift lever for adjusting the gear ratio of the link actuator, An output shaft to which power is transmitted from the link actuator and the planetary gear, and includes, The link actuator is, An eccentric disk that eccentrically rotates about the first link shaft, A cam that reciprocates up and down by the rotation of the eccentric disk, A first link connected to the cam and transmitting power to the output shaft, A one-way clutch provided between the first link and the output shaft and transmitting power only in a predetermined rotation direction of the output shaft, and includes, A continuously variable transmission in which the first link shaft and the output shaft rotate in the same direction by rotating the first link shaft by the driven shaft.

2. The link actuator includes a plurality of link sets including the eccentric disk, the cam, the first link, and the one-way clutch, The link set is, A hinge portion connected to one side of the cam, A second link connected so that one end extends from the hinge portion, and includes, One end of the first link is connected to the hinge portion, The other end of the first link is connected to the one-way clutch, A second link shaft connected to the other ends of the plurality of second links, The continuously variable transmission according to claim 1, wherein the position of the second link shaft is adjusted by the shift lever.

3. The shift lever is, A second link shaft adjustment portion connected to both ends of the second link shaft, A second link shaft adjustment shaft fixed at a position separated from the second link shaft by a predetermined distance, An operation portion that extends in a direction perpendicular to the second link shaft adjustment shaft from one side of the second link shaft adjustment shaft and rotates within a predetermined angle range with respect to the second link shaft adjustment shaft, the continuously variable transmission according to claim 2.

4. The planetary gear is, An annular gear that externally engages with a first driving gear formed on the input shaft and has gear teeth formed on its outer peripheral surface and inner peripheral surface, A plurality of satellite gears that internally engage with the annular gear, A sun gear located at the center of the annular gear and externally engaging with the satellite gears, A carrier connected to the plurality of satellite gears, having a central axis concentric with the input shaft, and having a predetermined hollow formed so that the input shaft penetrates therethrough; The continuously variable transmission according to claim 1, wherein the one-way clutch is configured to transmit power to the carrier and not to be directly connected to the output shaft. **Claim 5** The input shaft includes a first driving gear that transmits power to the planetary gear; The driven shaft includes a first driven gear connected to the first driving gear and having a gear ratio such that the driven shaft accelerates as compared with the input shaft; a bearing that supports the driven shaft at a predetermined distance from the input shaft so that the central axis is parallel to the input shaft; and a second driving gear formed to have a diameter larger than that of the first driven gear. The first link shaft includes a second driven gear connected to the second driving gear and having a gear ratio such that the first link shaft accelerates as compared with the driven shaft, the continuously variable transmission according to claim 1.

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