JP5385725B2 - Friction transmission - Google Patents

Description

The present invention is a transmission that is used for vehicles, industrial machines, and the like, and transmits a driving torque of an input shaft to an output shaft by frictional force, and continuously changes the rotational speed of the output shaft. It is about improvement.

Conventionally, friction transmissions are used in many drive systems including automobiles. For example, there is a friction transmission shown in Patent Document 1. In this friction transmission, the speed ratio changes steplessly from 0 to a relatively large value as the transmission ring moves, and the torque transmission ratio changes approximately in inverse proportion to the change in the speed ratio. In particular, the intersection of the straight line parallel to the center line of the conical trochanter through the point where the raceway ring abuts on the head of the conical trochanter and the generatrix or its extension line deviates from the predetermined region of the truncated cone portion. Because the position is set to be a position, a large torque transmission ratio that is approximately inversely proportional to the speed ratio is secured even when the transmission ring moves to a position where the speed ratio is near 0 within a predetermined region, and the output torque performance Is kept good.

JP 2004-036853 A JP 2003-227559 A

  In such a friction transmission, the noise is lower than that of a transmission that transmits drive torque via a gear or a belt, the gear ratio can be adjusted steplessly, and the input shaft is rotating. Zero rotation in which the output shaft stops can be realized. In the invention disclosed in Patent Document 1, although the torque transmission ratio can be increased substantially in inverse proportion to the speed ratio when the speed ratio is near 0, the conical trochanter is supported by the bearing and is moved in a planetary motion. The pressing force applied to each contact surface of the trochanter greatly acts on these bearings. Normally, a normal force that reaches at least 10 times the transmission force acts on these contact surfaces, and if this normal force is not reliably received, the loss of the pressing force applied to the contact surfaces increases. This leads to a decrease in transmission torque.

  For this reason, conventionally, this is the reason why the load capacity of the bearing has to be increased. In particular, in this type of friction transmission having a planetary mechanism, a bearing having a large capacity is provided due to the internal space. This is difficult due to the structure, and has been increased in size and increased in weight due to the increase in size.

  In this regard, there is a so-called Kopp K type continuously variable transmission shown in Patent Document 2. This continuously variable transmission has a structure in which a plurality of double cones are arranged at equal intervals in the circumferential direction, and the double cones are slidably provided on the support shaft of the carrier. In each double cone, the sun roller and the outer ring are in contact with the respective cone buses. In a state where power is transmitted from the input shaft to the outer ring and the output shaft through the sun roller and the double cone, the carrier is moved in the input / output shaft direction, thereby increasing / decreasing the output shaft relative to the input shaft.

  The Kopp K-type continuously variable transmission has a relatively wide speed range, the sun roller and outer ring are in contact with the same vertical line of each cone bus of the double cone, and the moment does not act on the double cone. There is an advantage that it is not affected by large normal force. In addition, all the components of the continuously variable transmission are self-rotating and have no revolution component. For this reason, traction oil having a high viscosity and a large traction coefficient can be used as a traction drive, and a large torque can be obtained with a small normal force.

  On the other hand, because the normal force of the same magnitude acts on the input side and the output side of the double cone due to the structure in which the sun roller and the outer ring are in contact with the same vertical line of the cone bus, the output torque ratio is limited. There is. This is because a traction drive that applies a large normal force and transmits power via an oil film requires a large tangential force that is obtained from the normal force on the output side during deceleration, but the input side also has the same magnitude method. This is due to the fact that it is impossible to apply a large normal force because it is a line force. For this reason, there has been a problem that the torque does not increase or decreases conversely as the vehicle decelerates.

Further, since the Kopp K type continuously variable transmission can increase and decrease speed, it is necessary to provide a pressure adjusting mechanism for applying a normal force on both the input side and the output side. For this reason, there has been a problem that a stable normal force cannot be obtained because the pressure regulating mechanism on the input side and the pressure regulating mechanism on the output side interact with each other.

  Therefore, the present inventor has been able to achieve the present invention as a result of intensive studies in view of the above problems, and the feature thereof is that it has an input shaft and an output shaft that are rotatably supported by the casing, A double cone supported slidably on a carrier support shaft provided coaxially with the input / output shaft, and disposed coaxially with the input / output shaft and driven to rotate by the input shaft. An input ring for contacting the inner periphery of the double cone, and a speed change means for slidingly displacing the carrier in the axial direction of the input / output shaft. In the friction transmission that increases and decreases the speed by the displacement of the radius ratio of the double cone with which the output ring abuts, the input double cone that abuts the carrier on the input ring and the output double cone that abuts on the output ring are aligned in the circumferential direction. An intermediate having a plurality of each and having a contact point between the input double cone and the output double cone on a conical surface passing through these contact points and orthogonal to the respective cone buses of the input double cone and the output double cone. There is a ring.

  Here, the “double cone” as used in the present specification is a support that can be rotated and slidably supported on a support shaft of a carrier provided coaxially with the input / output shaft. It is. Basically, the truncated cones of the same shape are overlapped. However, as long as the apex angles are the same, a combination of large and small may be used.

  In the present invention, a plurality of double cones are arranged on two concentric circles around the axis of the input ring. One is brought into contact with the input ring as an input double cone, and the other is brought into contact with the output ring as an output double cone. Each double cone is slidably supported on a support shaft provided on the carrier as in the conventional case. The number and relative size provided in the circumferential direction of each double cone is not particularly limited, but the output double cone arranged on the outer circumference side of the input double cone is enlarged from the space point, or the number is Distribute a lot. Further, the input double cone and the output double cone are not necessarily provided on a straight line in the radial direction, and may be arranged at a shifted position.

The “intermediate ring” refers to a member that is interposed between the input double cone and the output double cone to transmit power. The position where the intermediate ring is provided is basically provided at a position having a contact point on a line connecting the contact points where the input double cone and the output double cone contact the input ring and the output ring, and is supported rotatably at this position. Actually, each double cone may be arranged such that the cone bus is inclined with respect to the input / output axis, and the input double cone and the output double cone may not be provided on a straight line in the radial direction. For this reason, the input double cone and the output double cone pass through a contact point where the input double cone and the output ring come into contact with each other. An intermediate ring is arranged at a position having a contact point between the output double cone and the output double cone. The speed increase / decrease by the speed change means only needs to move the carrier in the input / output axis direction as in the past, and the input double cone and output double cone contacting the input ring, output ring and intermediate ring are changed Increase and decrease speed.

  The friction transmission according to the present invention includes an intermediate ring in which a plurality of input double cones that contact the input ring and a plurality of output double cones that contact the output ring are arranged in the circumferential direction, and are interposed between the input double cone and the output double cone. By providing the rotator so as to be rotatable, the shift range can be made extremely large.

In addition, the above-described problem is solved by interposing the intermediate ring between the input ring and the output ring. This is because the input double cone is in contact with the inner peripheral side of the intermediate ring and the output double cone is in contact with the outer peripheral side of the intermediate ring, so that the input side and the output side are separated and independent. Accordingly, the normal force on the input side and the normal force on the output side act on the inner peripheral side and the outer peripheral side of the intermediate ring, and are arbitrarily set without affecting each other by the respective pressure regulating mechanisms on the input side and the output side. be able to.

It is one Example of the friction type transmission which concerns on this invention, and is a longitudinal cross-sectional view which shows an acceleration position. It is one Example of the friction type transmission which concerns on this invention, and is a longitudinal cross-sectional view which shows the deceleration position. It is a horizontal fragmentary sectional view which shows the arrangement | positioning state of an input double cone and an output double cone. It is a partial side view which shows the normal force which acts on an input double cone and an output double cone via an intermediate ring. It is the partial side view which showed the radial dimension which calculates the reduction ratio of the friction type transmission which concerns on this invention.

According to the present invention, in a friction transmission type transmission, a plurality of input double cones that contact the input ring and output double cones that contact the output ring are arranged in the circumferential direction, and an intermediate ring is provided between the input double cone and the output double cone. By arranging, the above-mentioned problems were solved.

  FIG. 1 is a sectional view showing an embodiment of a friction transmission 1 according to the present invention. The friction transmission 1 includes an input shaft 2 that is rotationally driven by a drive source such as an engine or an electric motor, an input ring 4 that is connected to the input shaft 2 via a pressure regulating mechanism 3, and an input ring 4 Oppositely, an output shaft 6 is provided via the output ring 5 and the pressure adjusting mechanism 3. An input double cone 41 that contacts the input ring 4 and an output double cone 51 that contacts the output ring 5 are slidably provided on a support shaft 71 provided on the carrier 7. The input double cone 41 and the output double cone 51 are arranged in the radial direction of the input / output shafts 2 and 6, respectively, and are provided at equal intervals in the circumferential direction. And the intermediate ring 8 provided between each input double cone 41 and each output double cone 51 and making it contact | abut to these is supported rotatably.

  In this example, the input ring 4 is in contact with the small diameter portion of the input double cone 41, the intermediate ring 8 is in contact with the large diameter portion of the input double cone 41 and the small diameter portion of the output double cone 51, The ring 5 is in contact with the large diameter portion of the output double cone 51. In this state, as shown in FIG. 2, when the speed change shaft 91 screwed to the carrier 7 by the speed change means 9 is rotated by the speed change gear 92 and the carrier 7 is moved in the direction of the output ring 5, the speed is reduced.

  The number and arrangement positions of the input double cones 41 and the output double cones 51 are not particularly limited. For example, as shown in FIG. 3, four input double cones 41 and eight output double cones 51 are provided. In this example, the output double cone 51 is arranged on a straight line in the radial direction of each input double cone 41, but it is also possible to arrange it at an intermediate position.

  Since speed increase is possible with a double cone transmission, when the pressure adjusting mechanism 3 is provided only on the output side, the normal force on the input side decreases during speed increase, and slippage is likely to occur. Since the friction transmission 1 according to the present invention has a structure in which the intermediate ring 8 is interposed between the input double cone 41 and the output double cone 51, the normal force Wp applied to the input side as shown in FIG. The normal force Ws applied to the output side can be separated by the intermediate ring 8, and independent normal forces by the pressure adjusting mechanism 3 can be applied to the input side and the output side, respectively.

  The input double cone 41 and the output double cone 51 shown in FIG. 5, the radial dimensions of the input ring 4, the output ring 5, and the intermediate ring 8 in contact therewith, and the radial dimensions from the center of the input / output shaft of these contact portions The reduction ratio is as follows.

As described above, the friction transmission 1 according to the present invention can achieve an extremely large reduction ratio, and when the maximum value of the ratio between the output torque and the input torque in the shift range is set as the torque magnification, the friction transmission 1 is 50 times or more. Torque magnification can be obtained. The conventional continuously variable transmission that can achieve zero rotation has an infinite shift range, but the torque magnification is only about 10 times. For this reason, the friction transmission 1 according to the present invention aims at a continuously variable transmission that achieves a remarkably large torque magnification without obtaining zero rotation. The torque magnification of the conventional continuously variable transmission is shown below. It has been found in an electric vehicle test by the present inventor that if the torque magnification can be obtained about 30 times, it is possible to start without providing a clutch or the like without obtaining zero rotation.

Model name Torque magnification Bayer B type 3.8 times Disco B type 3.4 times Kopp K type 6.5 times Sympo RX type 6.0 times half toroidal type 5.5 times

DESCRIPTION OF SYMBOLS 1 Friction-type transmission 2 Input shaft 3 Pressure regulation mechanism 4 Input ring
41 Input double cone 5 Output ring
51 Output double cone 6 Output shaft 7 Carrier
71 Support shaft 8 Intermediate ring 9 Speed change means
91 Transmission shaft
92 Transmission gear

Claims (1)

  A double cone having an input shaft and an output shaft rotatably supported by the casing, and slidably supported by a carrier support shaft provided coaxially with the input / output shaft; and coaxial with the input / output shaft An input ring that is rotationally driven by the input shaft and abuts the outer peripheral surface on the double cone, an output ring that abuts the inner peripheral surface on the double cone, and the carrier shaft of the input / output shaft In a friction transmission that is configured to include a speed change means that slides in a direction, and that accelerates or decelerates by a displacement of a radius ratio of a double cone in which an input ring and an output ring contact by the speed change means, an input that makes the carrier contact the input ring A plurality of output double cones in contact with the double cone and the output ring are provided in the circumferential direction, and the cones of the input double cone and the output double cone pass through these contact points. On the conical surface which is perpendicular to the line, a friction-type transmission apparatus is characterized in that arranged intermediate ring having a contact point with the input double cone and output a double cone.

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