JP2008309327A - Friction type planet power transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a friction type planetary power transmission capable of changing pushing force for pushing elements. <P>SOLUTION: In the friction type planetary power transmission, four planetary rollers 22A-22D are arranged on the circumference of a sun roller 16 so as to keep in contact with the sun roller 16, and a ring 28 is arranged on the circumference of the planetary rollers. Four planetary rollers are supported by a carrier so as to take first arrangement where contacts 36A-36D with the ring 28 become a square 38 and second arrangement with the ring 28 where contacts 40A-40D become a rectangle 42. The first square arrangement has a larger amount of deformation of the ring 28 rather than the first rectangle arrangement, and force (pushing force) of the ring acted on the planetary roller becomes larger. The pushing force can be changed by using this changed deformation. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a central element, a peripheral element disposed around the central element, a planetary element that contacts the outer peripheral surface of the central element and the inner peripheral surface of the peripheral element, and rotates to transmit torque by friction at the contact point. The present invention relates to a frictional planetary power transmission device that includes an element and a support element that supports the planetary element, and transmits and receives power between the central element, the peripheral element, and the support element.

The planetary gear (planetary element) of a known planetary gear type power transmission device is a rolling element such as a roller, and the sun gear (center element) and the ring gear (surrounding element) are cylinders with smooth surfaces. A friction type planetary power transmission device that transmits torque is known. The following Patent Document 1 shows a friction type planetary power transmission device as described above. In particular, in the device of this document, the central element and the peripheral element are decentered, and one element of the planetary element is pushed into the narrow space between these elements caused by the decentering, and the elements are pressed against each other. I am raising my power.
JP-A-10-281248

  In the apparatus described in Patent Document 1, the central element and the peripheral element are eccentric, which is a restriction on the apparatus layout. In addition, when the torque acts in the direction in which the planetary element bites into the part where the distance between the central element and the surrounding element is narrow, the pressing force between the elements can be increased, but when the reverse torque is applied, the planetary element is Torque acts in the direction of exclusion from the gap, and the pressing force is reduced.

  Furthermore, the planetary element needs to be located in a portion where the distance between the central element and the surrounding element is narrow, and cannot perform a revolving motion. Therefore, it is not possible to perform operations such as distributing the input torque from the central element to the surrounding elements and the supporting elements that support the planetary elements.

  The above problems are caused by increasing the pressing force between the elements by using a so-called “wedge effect” in which the planetary element is digged into a portion where the distance between the central element and the surrounding element is narrow. The present invention provides a friction type planetary power transmission device that controls the pressing force between elements based on a principle different from the wedge effect.

  The friction type planetary power transmission device according to the first aspect of the present invention has a plurality of planetary elements that contact a central element outer peripheral surface and a peripheral element inner peripheral surface arranged concentrically and perform torque transmission by rotating, The pressing force between the elements is controlled by changing the mutual arrangement. The surrounding elements are deformed in response to the reaction force of the pressing force against the planetary elements, and the larger the amount of deformation, the greater the force pressing the elements. By changing the arrangement of the planetary elements, the amount of deformation of the surrounding elements can be changed, and thereby the pressing force can be changed.

  For example, when there are three or more planetary elements, the pressing force can be changed by enabling the arrangement of planetary elements with different perimeter lengths of polygons connecting the contact points of the planetary elements and surrounding elements. Can do. The longer the circumference of this polygon, the greater the deformation of the surrounding elements and the higher the pressing force. In the case where there are two planetary elements, the pressing force becomes the largest when the two are arranged in the diameter direction of the central element, and the pressing force becomes smaller as the distance from this increases. The support element that supports the planetary element supports the planetary element so that the arrangement can be changed as described above. The arrangement in which the pressing force is increased, that is, the arrangement in which the circumference of the polygon is long when there are three or more planetary elements, and the arrangement in the diametrical direction when there are two planetary elements Called arrangement. On the contrary, the arrangement in which the pressing force is reduced is referred to as a second arrangement.

  When the torque to be transmitted is large, the first arrangement can be adopted, and when the torque is small, the second arrangement can be adopted.

  The supporting element supports a part of the planetary element so as to be movable in the circumferential direction with respect to the remaining planetary elements, and the circumferential movement of the planetary element is caused by the transmission torque. It is possible to shift from the second arrangement to the first arrangement.

  When three or more planetary elements are provided, the planetary element has a first group including at least one planetary element and a second group including at least one planetary element other than the first group. When the transmission torque acts in the first direction, the transmission torque enables the first group of planetary elements to move in the circumferential direction with respect to the other planetary elements, whereby the planetary elements are arranged in the second arrangement. To the first arrangement. In addition, when transmission torque acts in the second direction opposite to the first direction, this transmission torque enables the second group of planetary elements to move in the circumferential direction with respect to other planetary elements. This allows the planetary element to transition from the second arrangement to the first arrangement.

  The number of planetary elements can be four. The first group and the second group can be formed by planetary elements on a diagonal line. When the torque in the first direction is applied, the first group moves in the direction of the torque, and when the torque in the second direction opposite to the first direction is applied, the second group is in the reverse direction. It can be moved in the direction of

  The moving planetary element can be biased by the spring element in the direction of the second arrangement. The spring element may apply an urging force to the support shaft that rotatably supports the planetary element on the support element so that the planetary element is in the second arrangement. Moreover, a spring element can be used as the compression spring arrange | positioned in the compression state between the spindles arrange | positioned adjacent to the circumferential direction. Further, the spring element applies a biasing force to a portion of the movable element that moves in the circumferential direction following the planetary element that moves in the circumferential direction and that is located on the outer side in the radial direction from the support shaft of the planetary element. be able to. Still further, the spring element is configured to elastically deform in the axial direction of the center element, and the biasing force of the spring element in the circumferential direction with respect to the planetary element is set by the load conversion element so that the planetary element is in the second arrangement. Can be made to work.

  When the number of planetary elements is three or more, the first arrangement of planetary elements can be such that the polygon is a regular polygon.

  The friction type planetary power transmission device according to the second aspect of the present invention has a plurality of planetary elements that contact a central element outer peripheral surface and a peripheral element inner peripheral surface that are arranged concentrically and perform torque transmission by rotation. The pressing force between the elements is controlled by changing the mutual arrangement. The surrounding elements are deformed in response to the reaction force of the pressing force against the planetary elements, and the larger the amount of deformation, the greater the force pressing the elements. By changing the arrangement of the planetary elements, the amount of deformation of the surrounding elements can be changed, and thereby the pressing force can be changed.

  A polygon that connects the contact points of the planetary element and the surrounding elements by supporting a part of three or more planetary elements on the support element body via the movable element and rotating the movable element relative to the support element body. It is possible to realize the arrangement of the planetary elements having different perimeter lengths, and the pressing force can be changed as described above. The longer the circumference of this polygon, the greater the deformation of the surrounding elements and the higher the pressing force.

  The support elements include a first movable element that supports a pair of planetary elements arranged 180 degrees apart, a second movable element that supports a pair of planetary elements arranged 180 degrees apart, and a first A spring element disposed between the movable element and the second movable element or between the first and second movable elements and the support element body, and acting on the planetary element in response to a load torque It is configured such that at least one of the first movable member and the second movable element is rotated relative to the support element body to a position where the force acting in the circumferential direction of the element balances the biasing force of the spring element. Can do.

  Further, the support element includes a first movable element that supports some planetary elements, a second movable element that supports some other planetary elements, a first movable element, and a second movable element. A displacement conversion element that generates a relative displacement in the axial direction of the central element with relative rotation of the spring element, and a spring element that generates a biasing force that resists the displacement in the axial direction by being deformed in the axial direction, Depending on the load torque, the first movable member and the second movable element are moved relative to the support element body up to a position where the force acting in the circumferential direction of the central element acting on the planetary element and the biasing force of the spring element are balanced. At least one can be configured to be relatively rotated.

The friction type planetary power transmission device according to the third aspect of the present invention has a plurality of planetary elements that contact a central element outer peripheral surface and a peripheral element inner peripheral surface arranged concentrically and perform torque transmission by rotating. The pressing force between the elements is controlled by changing the mutual arrangement. The surrounding elements are deformed in response to the reaction force of the pressing force against the planetary elements, and the larger the amount of deformation, the greater the force pressing the elements. By changing the arrangement of the planetary elements, the amount of deformation of the surrounding elements can be changed, and thereby the pressing force can be changed.

  The supporting shafts of at least two planetary elements of three or more planetary elements are supported so as to be able to displace relative to the supporting element body in the circumferential direction, and the amount of compression of the spring elements between the supporting shafts is changed. By rotating the support shaft relative to the support element body, the support element body is moved to a position where the force acting in the circumferential direction of the central element acting on the planetary element and the biasing force of the spring element are balanced according to the load torque. On the other hand, the planetary element is rotated relative to the support shaft.

  According to the present invention, the pressing force between elements can be controlled by changing the arrangement of a plurality of planetary elements.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of the friction type planetary power transmission device 10 of the present embodiment, and FIG. 2 is a cross-sectional view taken along line AA shown in FIG. A sun roller shaft 14 is rotatably supported on the case 12 via a bearing 13, and a sun roller 16 is integrally provided at the left end of the sun roller shaft 14 in the figure. The sun roller 16 has a cylindrical shape. A carrier 18 is fixed to the case 12, and the carrier 18 supports a cylindrical planetary roller 22 via a planetary roller shaft 20 as a support shaft. As shown in FIG. 2, four planetary rollers 22 are provided around the sun roller 16 so as to come into contact therewith. When it is necessary to distinguish the four planetary rollers, the following description will be made using the symbols 22A, 22B, 22C, and 22D. The planetary roller 22 is rotatably supported on the planetary roller shaft 20 via a needle roller bearing. The planetary roller shaft 20 is movable in the circumferential direction along an arcuate guide groove 24 provided in the carrier 18. The planetary roller shaft 20 is urged toward one end of the guide groove 24 by a spring 26. The direction of biasing by the spring 26 is different for each planetary roller 22. The planetary rollers 22A and 22B are urged clockwise in FIG. 2, and the planetary rollers 22C and 22D are urged counterclockwise. The movement of the planetary roller 22 relative to the carrier will be described in detail later.

  A ring 28 whose inner peripheral surface is in contact with each planetary roller 22 is disposed on the outer side of the planetary roller 22. The ring 28 is fixed to the cap 30, and the ring 30 is integrally provided with the cap 30. The ring side shaft 32 is rotatably supported by the carrier 18 via a bearing 34. The sun roller 16, the ring-side shaft 32, and the ring 28 are arranged concentrically, and the axis of the planetary roller 22 is arranged on a circumference having a common center with this axis. Further, the planetary roller 22 is movable along the guide groove 24 on this circumference.

  The planetary roller 22 contacts the cylindrical outer peripheral surface of the sun roller 16 and the cylindrical inner peripheral surface of the ring 28, and transmits torque by friction at these contact points. The power transmission operation of the friction type planetary power transmission device 10 is basically the same as that of a general planetary gear mechanism. In the planetary gear mechanism, torque transmission is performed by meshing of the gears. Is different by friction.

  When the case 12 is fixed (in a non-rotating state), that is, when the carrier 18 is fixed and the sun roller 16 is rotated, the planetary roller 22 rotates and the ring 28 rotates reversely with respect to the sun roller 16. At this time, the planetary roller shaft 20 is fixed, and the planetary roller 22 does not revolve around the sun roller 16. Further, the rotational speed of the ring 28 is decelerated with respect to the rotational speed of the sun roller 16 by the ratio of the radius of the sun roller outer peripheral surface and the ring inner peripheral surface. In addition, when the ring 28 is fixed, the planetary roller 22 rotates by the rotation of the sun roller 16, but the contact point of the planetary roller 22 with the ring 28 is constrained by the ring 28, so that a revolving motion occurs. As a result, the carrier 18 and the case 12 rotate. Further, if both the carrier 18 and the ring 28 are not fixed, the input from the sun roller 16 can be distributed to the carrier 18 and the ring 28. Although the above is a case where the sun roller 16 is used as an input, the carrier 18 can be used as an input or the ring 28 can be used as an input.

  As described above, in the apparatus of this embodiment, the relative arrangement of the four planetary rollers 22 can be changed. By changing the arrangement, the pressing force of the planetary roller 22, the ring 28 and the sun roller 16 can be changed. Hereinafter, the relationship between the arrangement of the planetary rollers 22 and the pressing force will be described.

  FIG. 3 is an explanatory diagram of the principle that the pressing force changes. The friction type planetary power transmission device 10 transmits power by friction between elements. For this reason, the ring 28 is interference-fitted to generate a pressing force between the elements. If the ring 28 is a complete rigid body, a complete cylindrical shape can be maintained as shown in FIG. However, in reality, it deforms in response to the tightening reaction force due to the interference fit, and as shown in FIG. 3B, the contact point with the planetary roller 22 bulges outward and deforms into a quadrangle with rounded corners.

  FIG. 3B shows a state in which four planetary rollers 22 are arranged at equal intervals in the circumferential direction, and contact points 36A to 36D between the planetary rollers 22A to 22D and the ring 28 are squares 38 (FIG. It becomes the vertex of d) see). FIG. 3C shows an arrangement in which the equally spaced arrangement is shifted so that the contact points are rectangular. By rotating the two planetary rollers 22C and 22D on one diagonal line counterclockwise from the square arrangement shown in FIG. 3B, the arrangement shown in FIG. 3C is obtained. At this time, the contact points 40A to 40D of the planetary rollers 22 are the vertices of the rectangle 42 (see FIG. 3D).

  The square 38 and the rectangle 42 have the same diagonal length, but the length of the outer periphery, that is, the total length of the four sides is longer for the square and shorter for the rectangle. This corresponds to the amount of extension of the circumference of the ring 28. That is, the amount of elastic deformation of the ring 28 is greater when the contact points are arranged in a square shape than when the contact points are in a rectangular shape. As a result, the pressing force generated between the elements becomes larger than that in the rectangular arrangement. In the rectangles having the same diagonal length, the circumference is the longest when the square is square, and becomes shorter as the rectangle becomes flat. The pressing force between elements also changes accordingly. That is, if the circumference of the quadrangle is increased, the pressing force can be increased, and if it is shortened, the pressing force can be decreased. By using this, the pressing force can be controlled.

  In the above, the two planetary rollers 22 are moved to change the circumference of the quadrangle, but the circumference can be changed even if one is moved. Further, the number of planetary rollers may be three or five or more. In this case, the circumference of the contact point between each planetary roller and the ring is longest when the regular polygon is arranged. Furthermore, it is possible to use two planetary rollers. In this case, when the two planetary rollers are arranged on one diameter of the sun roller, the deformation amount of the ring becomes the largest.

  FIG. 4 shows a model for analyzing a change in pressing force due to the arrangement of the planetary rollers 22A and 22C. For simplicity, the sun roller 16 and the planetary rollers 22A and 22C are handled as rigid bodies. The interval between the two planetary rollers 22A and 22C is an angle a. When the angle a is 90 °, four planetary rollers 22 are arranged in a square as shown in FIG.

  FIG. 5 is an enlarged view of the planetary roller 22C of FIG. The planetary roller 22C has been moved by an angle θ from the square arrangement in FIG. At this time, the contact point 40C between the planetary roller 22C and the ring 28 is shifted from the center O of the sun roller 16 and the straight line m passing through the center point P of the planetary roller 22C. The pressing force Fa acting on the contact point 40C is directed to the point P. That is, a moment around the center O is generated, and this generates a rotational force Na.

  When a clockwise torque Tin in the figure is input to the sun roller 16, this torque Tin acts to move the planetary roller 22C clockwise. When this action exceeds the rotational force Na, the planetary roller 22C starts to move in a direction to reduce the angle θ. That is, when the torque Tin input from the sun roller 16 increases, the four planetary rollers 22 shift from the rectangular arrangement to the square arrangement, and the pressing force increases. That is, when the transmission torque is large and it is necessary to increase the pressing force in order to prevent slippage at the contact point, the pressing force increases autonomously. As a result, when the transmission torque is small, the pressing force can be reduced and the contact surface pressure at the contact point between the elements can be reduced, which is advantageous for improving the durability. In addition, the fact that the pressing force is small means that the amount of deformation of the ring 28 is small, and the energy consumed for the deformation of the ring 28 can be reduced, which is advantageous in improving the transmission efficiency. Further, when a disturbance torque is input, the planetary roller is moved by this torque and the pressing force is increased. Therefore, even if a sudden disturbance torque is input, this can be handled autonomously. Therefore, the occurrence of slip due to disturbance torque is suppressed, which is advantageous in improving durability.

  Returning to FIG. 1 and FIG. 2, the operation of the friction type planetary power transmission device 10 of the embodiment will be described again. As described above, the four planetary rollers 22 are movable in the circumferential direction with respect to the carrier 18. The arrangement of the planetary rollers 22 in FIG. 2 is an arrangement when the transmission torque is low, and corresponds to the state of FIG. The planetary rollers 22A and 22B are located at the right end of the guide groove 24 when viewed from the center of the sun roller 16, and the planetary rollers 22C and 22D are located at the left end of the guide groove 24.

  When the sun roller 16 as the input element rotates clockwise as indicated by the arrow R1, the planetary rollers 22C and 22D move clockwise when the transmission torque exceeds a predetermined value. As a result, the arrangement of the four planetary rollers 22 shifts to the square arrangement shown in FIG. Conversely, when the sun roller 16 rotates counterclockwise as indicated by the arrow R2, the planetary rollers 22A and 22B move counterclockwise, and the four planetary rollers 22 shift to the square arrangement. In this way, when the planetary rollers 22A and 22B and the planetary rollers 22C and 22D are moved in opposite directions, the torque increases in response to torque input in either the forward or reverse direction. The pressing force can be increased.

  In addition, by appropriately setting the characteristics of the spring 26, when the transmission torque is equal to or greater than a predetermined value, the pressing force can be increased as the transmission torque is increased. FIG. 6 is a diagram illustrating an example of the relationship between the input torque and the pressing force. Until the input torque reaches Tb, the initial arrangement of the planetary rollers 22, that is, the rectangular arrangement is maintained. The input torque Tb is a value at which the planetary rollers 22C and 22D begin to move against the aforementioned rotational force Na and the initial biasing force of the spring 26. The input torque Tb can be changed by adjusting the initial biasing force of the spring 26. When the input torque exceeds Tb, the planetary rollers 22C and 22D are positioned so that the force generated by the input torque and the spring force are balanced. If the spring characteristics of the spring 26 are set so that the planetary rollers 22C and 22D reach the right end of the guide groove 24 at the assumed maximum input torque Tmax, the input torque is between the torque Tb and the maximum input torque Tmax. It can be set to increase the pressing force with the increase. The same applies to the reverse torque. As a result, in the range K where the input torque is small, the pressing force is constant, and when the input torque exceeds a predetermined value Tb, the pressing force increases as the input torque increases in the range L up to the maximum input torque. Can be given.

  Next, another embodiment of the present invention will be described. Note that parts and portions that are basically the same as those in the first embodiment or the above-described configuration are denoted by the same reference numerals as those in the first embodiment or the above-described configuration, and description thereof is omitted. The illustration may be omitted.

(Second Embodiment)
FIG. 7 shows a friction type planetary power transmission device 50 according to the second embodiment of the present invention in a perspective view in which the case 12, the cap 30 and the like are removed and a part of the ring 28 is cut away. Yes. As shown in this figure, in the friction type planetary power transmission device 50, instead of the carrier 18 in which the planetary roller shaft 20 is urged by a spring 26, a support plate 52 as a movable element that supports the planetary roller shaft 20, It differs from the friction type planetary power transmission device 10 according to the first embodiment in that 54 includes a carrier 58 biased by a spring 56. This will be specifically described below.

  The carrier 58 is configured such that both side portions in the axial direction with respect to the planetary roller 22 are symmetrical with respect to a plane perpendicular to the axial direction. For this reason, in the following description, the configuration on one side with respect to the planetary roller 22 will be mainly described. As shown in an exploded perspective view in FIG. 8, the carrier 58 includes a carrier body 60. The carrier body 60 is formed in a substantially annular plate shape, and a plurality of stopper portions 62 (the same number as the planetary rollers 22 in this embodiment, four in this embodiment) are formed in the circumferential direction so as to protrude in the plate thickness direction. Has been.

  More specifically, the stopper portions 62 are formed in an arc shape along the outer peripheral edge of the carrier body 60 and are arranged at equal intervals in the circumferential direction of the carrier body 60. As shown in FIG. 7, the carrier main bodies 60 on both sides in the axial direction with respect to the planetary roller 22 are connected to each other via connecting rods 64 at the respective stopper portions 62 so as to rotate integrally around the own axis. Further, as shown in FIG. 8, a long hole 60 </ b> A that allows the planetary roller shaft 20 to be angularly displaced in the circumferential direction of the carrier body 60 is formed between the stopper portions 62 of the carrier body 60.

  As shown in FIG. 8, the carrier 58 includes a support plate 52 as a movable element that supports the planetary roller shaft 20 of the planetary roller 22A and the planetary roller 22B, and a planetary roller shaft 20 of the planetary roller 22C and the planetary roller 22D. A support plate 54 is provided as a movable element to be supported. The support plate 52 includes a ring portion 52A provided in the axial center portion, and a pair of convex pieces 52B protruding outward from the ring portion 52A in the radial direction. Similarly, the support plate 54 includes a ring portion 54A provided in the axial center portion, and a pair of convex pieces 54B that protrude radially outward from the ring portion 52A. Each of the pair of convex pieces 52B and 54B is formed in a substantially arc shape around the axis of the ring portion 52A.

  The support plate 52 is in a state (not shown) that is directly or indirectly rotatably supported by the sun roller shaft 14 or the carrier-side shaft 65 (described later) in the ring portion 52A. Between the stopper portions 62 are slidable in the circumferential direction (slidable with the carrier body 60). On the other hand, the support plate 54 is in a state (not shown) that is directly or indirectly rotatably supported by the sun roller shaft 14 or the carrier-side shaft 65 (described later) in the ring portion 54A, and the pair of convex pieces 54B is a carrier. Between the stopper parts 62 of the main body 60, it arrange | positions so that a slide (sliding with the carrier main body 60) is possible in the circumferential direction.

  Each pair of convex pieces 52 </ b> B and 54 </ b> B is inserted between different stopper portions 62. That is, the convex pieces 52 </ b> B and 54 </ b> B are alternately arranged in the circumferential direction of the carrier 58. Of the four stopper portions 62, if a pair positioned 180 ° apart is a stopper portion 62A, and the other pair is a stopper portion 62B, the support plate 52 has a pair of convex pieces 52B that respectively contact different stopper portions 62A. The contact state and the contact state with the stopper portion 62B can be taken by rotation around the own axis. Similarly, the support plate 54 is configured to be able to take a state in which the pair of convex pieces 54B are in contact with different stopper portions 62A and a state of being in contact with the stopper portions 62B by rotation around its own axis.

  Also, as shown in FIG. 8, support holes 52C and 54C for supporting the planetary roller shaft 20 are formed in the pair of convex pieces 52B and 54B, respectively. In the carrier 58, the pair of convex pieces 52 </ b> B and 54 </ b> B on both sides in the axial direction are bridged by the planetary roller shaft 20 corresponding to the planetary roller 22. Each planetary roller shaft 20 supports the planetary roller shaft 20 rotatably.

  As described above, the carrier 58 is in a state where the four planetary rollers 22 are arranged in a rectangular shape as shown in FIG. 9B due to the relative angular displacement of the support plates 52 and 54 and in FIG. 9A. Thus, the four planetary rollers 22 can be changed to a square arrangement. In this embodiment, the carrier 58 is biased by the biasing force of the spring 56 so that the four planetary rollers 22 have a rectangular arrangement.

  Specifically, spring mounting holes 52D and 54D are formed on the outer sides in the radial direction of the pair of convex pieces 52B and 54B of the support plates 52 and 54 with respect to the support holes 52C and 54C, respectively. Spring receiving members 66 and 68 are attached to the spring attachment holes 52D and 54D, respectively. As shown in FIG. 7, a spring 56, which is a compression coil spring, is disposed in a compressed state between the spring receiving member 66 of the convex piece 52B adjacent to the circumferential direction and the spring receiving member 68 of the mounting hole 54D. That is, in this embodiment, unlike the friction type planetary power transmission device 10 that independently biases each planetary roller shaft 20 with respect to the carrier 18, the planetary roller shafts 20 (planetary rollers 22) adjacent in the circumferential direction are common. The spring 56 is biased.

  As described above, in the carrier 58, the four planetary rollers 22 are normally supported by the urging force of the spring 56 in a rectangular arrangement as shown in FIG. 9B. On the other hand, for example, when the clockwise torque Tin (≧ Tb) is input to the sun roller 16, the support plate 54 rotates clockwise as shown in FIG. The roller 22 is shifted to a square arrangement. Although illustration is omitted, for example, when a counterclockwise torque Tin (≧ Tb) is input to the sun roller 16, the support plate 52 rotates clockwise so that the four planetary rollers 22 are square. It is supposed to be moved to the arrangement. In the case of taking a square arrangement, each convex piece 54B of the support plate 54 or each convex piece 52B of the support plate 52 comes into contact with the stopper portion 62B.

  In this embodiment, the sun roller 16 is a torque input element and the carrier 58 is an output element. Accordingly, the friction type planetary power transmission device 50 includes a carrier side shaft (output rotation shaft) 65 as shown in FIG. 7 instead of the ring side shaft 32, and the carrier side shaft 65 is coaxial with the carrier body 60. (Not shown). Other configurations of the friction type planetary power transmission device 50 are the same as the corresponding configurations of the friction type planetary power transmission device 10.

  Therefore, also by the friction type planetary power transmission device 50 according to the second embodiment, basically the same effect can be obtained by the same operation as the friction type planetary power transmission device 10 according to the first embodiment. That is, in the friction type planetary power transmission device 50, when the input torque is small, the four planetary rollers 22 are arranged in a rectangular shape so that the pressing force from the ring 28 side to the planetary roller 22 side is suppressed to be small. Contributes to the improvement of sex. On the other hand, when the input torque increases (exceeds the absolute value of the predetermined value Tb), the planetary roller 22 shifts to a square arrangement due to the torque, and the transmission torque increases.

  Further, in the friction type planetary power transmission device 50, the biasing force of the spring 56 is applied to the outer side in the radial direction with respect to the planetary roller shaft 20, so that a relatively small spring 56 can resist a large input torque. It becomes possible. In particular, in the friction type planetary power transmission device 50, since the spring 56 is configured to generate a biasing force between the support plates 52 and 54, in other words, the four planetary rollers 22 shift from a rectangular arrangement to a square arrangement. Therefore, it is necessary to resist the urging force of all the springs 56, so that it is sufficient to resist the urging force of some (two) springs 26, which is larger than the friction type planetary power transmission device 10. It becomes possible to make it the structure which can resist.

  Accordingly, in the friction type planetary power transmission device 50, for example, the spring 56 that is required to have a deflection rate of about 30% while receiving a load of several [kN] at the maximum, a compression coil having an outer diameter of several tens [mm]. This can be realized with a spring.

  In this way, the configuration in which the urging force of the spring 56 is applied to the outer side in the radial direction with respect to the planetary roller shaft 20, and the configuration in which the support plate 52, 54 that is movable with respect to the carrier body 60 is urged by the spring 56, respectively. This contributes to miniaturization of the frictional planetary power transmission device 50. Further, the setting of the pressing force according to the transmission torque (the urging force of the spring 56 according to the pressing force) can be optimized, which contributes to the improvement of the torque transmission rate and the life of the friction type planetary power transmission device 50.

(First Modification of Second Embodiment)
FIG. 10A shows an exploded perspective view of a main part of a carrier 70 according to a first modification that constitutes the friction type planetary power transmission device 50 according to the second embodiment of the present invention. As shown in this figure, the carrier 70 is different from the carrier 58 configured to include the two springs 56 in that the carrier 70 includes four springs 56 on one side in the axial direction with respect to the planetary roller 22.

  Specifically, the carrier 70 has support plates 72 and 74 formed in substantially annular plate shapes (as the outer diameters of the ring portions 52A and 54A are enlarged), respectively, instead of the support plates 52 and 54. . The support plates 72 and 74 are overlapped in the plate thickness direction, and are supported by the sun roller shaft 14 or the ring side shaft 32 so as to be rotatable coaxially independently of each other directly or indirectly.

  The support plate 72 is formed with a support hole 72A for supporting the planetary roller shafts 20 of the planetary rollers 22A and 22B, and the support plate 74 supports the planetary roller shafts 20 of the planetary rollers 22C and 22D. A support hole 74A is formed. The support plate 72 is formed with an arc-shaped elongated hole 72B for avoiding buffering with the planetary roller shaft 20 supported by the support plate 74 due to relative angular displacement with the support plate 74.

  On the other hand, four spring holes 74B are formed on the outer side in the radial direction of the support plate 74 than the support holes 74A. In the first modification, the spring hole 74B is formed in an arc shape. Further, from the support plate 72, spring receiving pieces 72C that protrude into the respective spring holes 74B so as to be relatively displaceable in the circumferential direction are projected. In the carrier 70, a spring 56 is disposed in each spring hole 74B. As shown in FIG. 10B, each spring 56 has a hole wall 74C on one side in the circumferential direction of the spring receiving piece 72C and the spring hole 74B. It is arranged in a compressed state between. The support plate 72 is provided with a spring hole corresponding to the spring hole 74B, and a spring receiving piece that enters the spring hole so as to be relatively displaceable in the circumferential direction is projected from the support plate 74, so that the spring receiving piece of the support plate 72 is provided. A spring 56 may be disposed between 72C and the spring receiving piece of the support plate 74.

  As described above, the carrier 70 has a configuration in which the planetary roller 22 has a rectangular arrangement at the time of low load by the urging force of the four springs 56. FIG. 11 schematically shows this state. The carrier body 60 constituting the carrier 70 is configured such that the stopper pieces 72D and 74D extending from the support plates 72 and 74 are positioned between the stopper portions 62 adjacent in the circumferential direction. The relationship between the dimension and arrangement of the stopper pieces 72D and 74D and the stopper 62 in the circumferential direction is the same as the relation between the dimension and arrangement of the pair of convex pieces 52B and 54C and the stopper 62 in the circumferential direction.

  In the carrier 70 according to the first modification described above, the planetary roller 22 can be urged by the four springs 56, so that a configuration that resists the required torque by the smaller spring 56 with respect to the carrier 58 is realized. be able to.

(Second modification of the second embodiment)
12 (A) and 12 (B) are schematic views showing the main part of a carrier 75 according to a second modification constituting the friction type planetary power transmission device 50 according to the second embodiment of the present invention. It is shown. As shown in this figure, the carrier 75 is different from the carrier 70 in that it has support plates 76 and 78 in which rectangular spring holes 76A and 78A are formed instead of the support plates 72 and 74, respectively.

  The support plates 76 and 78 are overlapped in the plate thickness direction, and are supported by the sun roller shaft 14 or the ring side shaft 32 so as to be coaxially and independently rotatable directly or indirectly. Each spring 56 is disposed in a compressed state between a hole wall 76B on one circumferential side of the spring hole 76A and a hole wall 78B on the other circumferential side of the spring hole 78A. In the second modified example, as shown in FIG. 12A, the four planetary rollers 22 are arranged in a rectangular shape with the circumferential positions of the spring holes 76A and 78A matching. On the other hand, when a torque equal to or greater than a predetermined value Tb is input, the four planetary rollers 22 are shifted to a square arrangement as shown in FIG. Other configurations of the carrier 75 are the same as the corresponding configurations of the carrier 70 including a portion not shown.

  The carrier 75 described above has a simple structure in which a linearly formed compression coil spring is used as the spring 56, and a configuration in which the planetary roller 22 is arranged in a rectangular shape at the time of low load by the urging force of the four springs 56 is realized. can do.

(Third Modification of Second Embodiment)
FIG. 13 is a schematic view showing a main part of a carrier 80 according to a third modification that constitutes the friction type planetary power transmission device 50 according to the second embodiment of the present invention. As shown in this figure, the carrier 80 is different from the carrier 70 in that a urethane spring 82 is provided instead of the spring 56 that is a compression coil spring.

  The urethane spring 82 is formed in a cylindrical shape that is curved in an arc shape with, for example, a load-resistant soft urethane foam, and the spring receiving piece 72C of the support plate 72 and the hole wall 74C of the support plate 74 in the spring hole 74B. It is arranged between. Other configurations of the carrier 80 are the same as the corresponding configurations of the carrier 70 including a portion not shown.

  In the carrier 80 described above, since the urethane spring 82 having a large spring constant against compression is used while being flexible with respect to bending, the carrier 58, 70 is configured to resist a required torque with a smaller spring 56. Can be realized.

(Third embodiment)
FIG. 14 shows a friction type planetary power transmission device 90 according to a third embodiment of the present invention in a perspective view in which the case 12, the cap 30, and the ring 28 are removed. FIG. 15 is a schematic front view showing the carrier 92 constituting the friction type planetary power transmission device 90. As shown in these drawings, in the friction type planetary power transmission device 90, each planetary roller shaft 20 is independent in that a urethane spring 82 is provided as a spring element between the planetary roller shafts 20 adjacent in the circumferential direction. Thus, the friction planetary power transmission device 10 is configured to be biased by a spring 26 against the carrier 18. This will be specifically described below.

  The carrier 92 has carrier plates 94 arranged on both sides of the planetary roller 22 in the axial direction. The carrier plate 94 has slits 94A formed in an arc shape. In this embodiment, a slit 94A for entering the planetary roller shaft 20 of the planetary rollers 22A, 22D and a slit 94A for entering the 22D planetary roller shaft 20 of the planetary rollers 22B, 22C are formed in each carrier plate 94, respectively. ing.

  In each slit 94A, a urethane spring 82 is disposed in a compressed state, and the urethane spring 82 urges the planetary roller shafts 20 in the same slit 94A away from each other. As shown in FIG. 15, the four planetary rollers 22 are arranged in a rectangular shape with each planetary roller shaft 20 positioned at the longitudinal end of the slit 94 </ b> A. In the friction type planetary power transmission device 90, when the four planetary rollers 22 shift to the square arrangement, the urethane spring 82 is compressed in accordance with the torque input direction as in the above embodiments and modifications. It has become.

  As shown in FIG. 14, a spring retainer plate 96 is fixed to the carrier plate 94 so that the urethane spring 82 is not bent during this compression. The spring retainer plate 96 is configured to close at least a substantially middle portion of each slit 94A in the longitudinal direction.

In this embodiment, the sun roller 16 is a torque input element and the carrier 92 is an output element. Therefore, the friction type planetary power transmission device 50 includes a carrier side shaft 65 as shown in FIG. 14 instead of the ring side shaft 32, and the carrier side shaft 65 is coaxially fixed to the carrier plate 94. (Not shown). Other configurations of the friction type planetary power transmission device 90 are the same as the corresponding configurations of the friction type planetary power transmission device 10.

  Therefore, the friction type planetary power transmission device 90 according to the third embodiment can basically obtain the same effect by the same operation as the friction type planetary power transmission device 10 according to the first embodiment. That is, in the friction type planetary power transmission device 90, when the input torque is small, the four planetary rollers 22 are arranged in a rectangular shape so that the pressing force from the ring 28 side to the planetary roller 22 side is suppressed to be small. Contributes to the improvement of sex. On the other hand, when the input torque increases (exceeds the absolute value of the predetermined value Tb), the planetary roller 22 shifts to a square arrangement due to the torque, and the transmission torque increases.

  In addition, since the urethane spring 82 is configured to generate an urging force between the support plates 52 and 54, in other words, when the four planetary rollers 22 shift from the rectangular arrangement to the square arrangement, all the springs 56 Since it is necessary to resist the urging force, a configuration capable of resisting a large input torque as compared with the friction type planetary power transmission device 10 that only needs to resist the urging force of some (two) springs 26 is adopted. Is possible. In particular, the friction type planetary power transmission device 90 uses the urethane spring 82 that is flexible with respect to bending but has a large spring constant with respect to compression. Can withstand torque.

  Accordingly, in the friction type planetary power transmission device 90, for example, the urethane spring 82 that requires a deflection rate of about 30% while receiving a load of several [kN] at the maximum, is a soft one having an outer diameter of several tens [mm]. It can be realized with urethane.

  The configuration in which the urging force of the urethane spring 82 acts between the planetary roller shafts 20 in this way contributes to the downsizing of the friction type planetary power transmission device 90. Further, the setting of the pressing force according to the transmission torque (the urging force of the urethane spring 82 according to the pressing force) can be optimized, which contributes to the improvement of the torque transmission rate and the life of the friction type planetary power transmission device 90. .

(Fourth embodiment)
FIG. 16 is a schematic front view showing a friction type planetary power transmission device 100 according to a fourth embodiment of the present invention. As shown in this figure, the friction type planetary power transmission device 100 is arranged between the four planetary roller shafts 20 so as to abut against the four planetary roller shafts 20 in place of the springs 26 supported by the carrier 18. It differs from the friction type planetary power transmission device 10 which concerns on 1st Embodiment by the point provided with the elliptical ring type spring 102 made.

  The elliptical ring spring 102 is disposed between the four planetary roller shafts 20 in a compressed state in a direction in which the dimension in the minor axis direction is reduced with respect to the free state, so that the planetary roller at the time of low load. 22 is biased to a rectangular arrangement. When the four planetary rollers 22 are moved to the square arrangement, the elliptical ring spring 102 is further compressed in the short axis direction. Other configurations of the friction type planetary power transmission device 100 are the same as the corresponding configurations of the friction type planetary power transmission device 10.

  Therefore, the friction type planetary power transmission device 100 according to the fourth embodiment can basically obtain the same effect by the same operation as the friction type planetary power transmission device 10 according to the first embodiment. That is, in the friction type planetary power transmission device 100, when the input torque is small, the four planetary rollers 22 are arranged in a rectangular shape so that the pressing force from the ring 28 side to the planetary roller 22 side is suppressed to be small. Contributes to the improvement of sex. On the other hand, when the input torque increases (exceeds the absolute value of the predetermined value Tb), the planetary roller 22 shifts to a square arrangement due to the torque, and the transmission torque increases.

  Further, the friction type planetary power transmission device 100 has a configuration in which the four planetary rollers 22 can be arranged in a rectangular shape with a simple structure in which the elliptical ring springs 102 are simply arranged between the four planetary roller shafts 20. Realized. In addition, the elliptical ring spring 102 is made of a spring constant (attached) while maintaining its compactness by changing the material and thickness, or by multiplying (double in this example) as illustrated in FIG. (Power) can be changed.

  This point will be supplemented with reference to the diagrams shown in FIGS. 18 (A) and 18 (B). 18A shows the relationship between the revolution angle θ of the planetary roller 22 relative to the carrier 18 and the rotational force Na described above, and FIG. 18B shows the revolution angle θ and the elliptical ring spring 102. The relationship with the stress acting on is shown. As shown in FIG. 18A, when the elliptical ring spring 102 is used, the rotational force Na described above (see FIGS. 4 and 5) increases as the revolution angle θ increases (closer to the square arrangement). It turns out that becomes large. Then, as shown in FIGS. 18A and 18B, for example, an elliptical ring spring having a thickness of 1.5 mm as compared with a configuration using an elliptical ring spring 102 having a thickness of 2.0 mm alone. It can be seen that with the configuration in which 102 is used in triplicate, the rotational force Na can be increased while maintaining the same stress acting on the elliptical ring spring 102. That is, by multiplexing the elliptical ring spring 102, it is possible to obtain a large rotational force Na while ensuring low stress. Further, with the configuration using the triple elliptical ring spring 102, the outer shape of the elliptical ring spring 102 is not increased, and a compact configuration is maintained.

(First Modification of Fourth Embodiment)
19 (A) and 19 (B) schematically show the main parts of a carrier 110 according to a first modification constituting the friction type planetary power transmission device 100 according to the fourth embodiment of the present invention. It is shown in the front view. As shown in these drawings, the carrier 110 includes a carrier body 60 and support plates 52 and 54. In this carrier 110, the elliptical ring spring 102 is not in contact with the four planetary roller shafts 20, and each of the four spring receiving members 112 attached to the attachment holes 52D and 54D of the support plates 52 and 54, respectively. It is in contact with.

  In this carrier 110, the urging force of the elliptical ring spring 102 is applied to the outer side in the radial direction than the planetary roller shaft 20, so that a larger urging force can be applied as compared with the friction type planetary power transmission device 100. Become.

(Second modification of the fourth embodiment)
FIG. 20 is a schematic front view showing a second modification of the friction type planetary power transmission device 100 according to the fourth embodiment of the present invention. As shown in this figure, in this modification, instead of the elliptical ring spring 102 provided inside the four planetary roller shafts 20, the elliptical ring spring 104 provided outside the four planetary roller shafts 20. This is different from the fourth embodiment in that

  That is, the elliptical ring spring 104 is in contact with each of the four planetary roller shafts 20 as described above in a state where the dimension in the minor axis direction is extended with respect to the free state. When the four planetary rollers 22 are moved to the square arrangement, the elliptical ring spring 104 is further extended in the short axis direction. In other words, the elliptical ring type spring 104 is a tension type elliptical ring type spring as opposed to the compression type elliptical ring type spring 102.

  In the frictional planetary power transmission device 100 using the elliptical ring spring 104, as shown in FIG. 21 (A) and FIG. 21 (B) in comparison with FIG. 18 (A) and FIG. The rotational force Na is saturated when the revolution angle θ of the roller 22 with respect to the carrier 18 is in the range of 10 ° to 20 ° (about half of 25 ° leading to the square arrangement). The same applies when the elliptical ring spring 104 is multiplexed. For this reason, it is preferable that the friction type planetary power transmission device 100 includes an elliptic ring spring 102.

(Fifth embodiment)
FIG. 22 shows a friction type planetary power transmission device 120 according to a fifth embodiment of the present invention in a perspective view in which the case 12, the cap 30 and the like are removed and a part of the ring 28 is cut away. Yes. As shown in this figure, in the friction type planetary power transmission device 120, a disc spring 122 and a disc spring 122 that generate an urging force in the axial direction are used in place of the springs 26 and 56 and the urethane spring 82 that generate an urging force in the circumferential direction. It differs from the friction type planetary power transmission device 10 according to the first embodiment in that it includes a load conversion element for causing the urging force to act on the planetary roller 22 in the circumferential direction and a cam mechanism 124 as a displacement conversion mechanism. This will be specifically described below.

  The friction type planetary power transmission device 120 includes a carrier 126 for supporting the four planetary rollers 22. One side in the axial direction (the sun roller shaft 14 side) of the carrier 126 with respect to the planetary roller 22 is configured in the same manner as the carrier 58. On the other hand, a cam mechanism 124 is incorporated on the other side of the planetary roller 22 in the carrier 126, that is, on the carrier side shaft 65 side.

  As shown in an exploded sectional view in FIG. 23, the cam mechanism 124 includes a cylindrical shaft portion 128 that is coaxially extended from the ring portion 54 </ b> A of the support plate 54 along the axial direction, and is rotatable to the shaft portion 128. And a cam roller unit 132 that rotates integrally with the support plate 54, a disc spring 122, a disc spring presser plate 134, and a presser plate 134. A retaining member 136 for holding it is configured as a main component.

  As shown in FIG. 22, the cam plate 130 is coaxial and integral with the support plate 52 by inserting the radially outer ends of the pair of convex pieces 52B between the engagement pieces 130A protruding from the peripheral edge. It is designed to rotate. Further, the cam plate 130 is abutted against the stopper portion 62 of the carrier body 60 and is not displaced toward the carrier body 60 that can be placed in the axial direction with respect to the carrier body 60. As shown in FIG. 23, a cam surface 130B is formed on the surface of the cam plate 130 facing away from the carrier body 60, and the amount of protrusion in the axial direction is continuously changed along the circumferential direction. ing. In this embodiment, four cam surfaces 130B are provided at equal intervals in the circumferential direction as shown in FIG.

  As shown in FIG. 23, the cam roller unit 132 includes a substantially cylindrical unit body 138, a shaft member 140 mounted on the unit body 138 along the radial direction, and a shaft member 140 rotatably supported by the shaft member 140. Cam roller 142. Four shaft members 140 and cam rollers 142 are provided corresponding to the cam surface 130B. Each shaft member 140 is fitted in a long hole 128 </ b> A that is long in the axial direction formed in the shaft portion 128. As a result, the cam roller unit 132 rotates coaxially and integrally with the shaft portion 128, that is, the support plate 54, and relative displacement in the axial direction is allowed.

  The cam roller unit 132 is in contact with the cam plate 130 (the cam surface 130B or the cam surface 130B) only at the cam roller 142. Thereby, in the cam mechanism 124, relative angular displacement of the cam roller unit 132 with respect to the cam plate 130 is caused in association with relative displacement in the axial direction of the cam roller unit 132 with respect to the cam plate 130.

  The disc spring 122 is sandwiched between a flange 138 </ b> A extending in the radial direction from the unit body 138 of the cam roller unit 132 and the disc spring pressing plate 134. In a state where the retaining member 136 is fixed (for example, screwed) to the tip of the cylindrical shaft portion 128, the disc spring 122 is compressed by a predetermined amount.

  In the friction type planetary power transmission device 120, the urging force acting in the axial direction of the disc spring 122 is supported by the cam plate 130 and the cam roller unit 132 (the above-described displacement conversion mechanism of the cam mechanism 124). The four planetary rollers 22 are configured to take a rectangular arrangement when the load is low. In the carrier 126, the cam roller 142 of the cam roller unit 132 is brought into contact with a portion of the cam surface 130B of the cam plate 130 where the protrusion amount from the general surface 130C (see FIG. 24) is small in the rectangular arrangement. As described above, the dimensions, arrangement, and the like of the pair of convex pieces 52B and 54B and the stopper portion 62 are determined.

  As described above, in the carrier 126, the four planetary rollers 22 are normally supported in a rectangular arrangement by the biasing force of the disc spring 122. On the other hand, when a torque Tin greater than or equal to a predetermined value Tb is input to the sun roller 16, either one of the support plate 52 and the support plate 54 causes a relative angular displacement with respect to the other according to the input direction of the torque. The four planetary rollers 22 are shifted to a square arrangement while compressing the disc spring 122 in the axial direction.

  The other configuration of the friction type planetary power transmission device 120 corresponds to the configuration of the friction type planetary power transmission device 50 (the friction type planetary power transmission device 10 except that the carrier side shaft 65 is provided instead of the ring side shaft 32). Is the same.

  Therefore, the friction type planetary power transmission device 120 according to the fifth embodiment can basically obtain the same effect by the same operation as that of the friction type planetary power transmission device 10 according to the first embodiment. That is, in the friction type planetary power transmission device 120, when the input torque is small, the four planetary rollers 22 are arranged in a rectangular shape so that the pressing force from the ring 28 side to the planetary roller 22 side is suppressed to be small. Contributes to the improvement of sex. On the other hand, when the input torque increases (exceeds the absolute value of the predetermined value Tb), the planetary roller 22 shifts to a square arrangement due to the torque, and the transmission torque increases.

  The friction type planetary power transmission device 120 includes a disc spring 122 that deforms in the axial direction, and a cam mechanism 124 that converts the biasing force of the disc spring 122 into a biasing force in the circumferential direction between the support plates 52 and 54. The degree of freedom in setting the urging force by the disc spring 122 is high. That is, a required spring constant corresponding to the transmission torque can be obtained with a simple structure. In addition, the disc spring 122 has less dimensional restrictions due to the radial dimension of the carrier 126 (ring 28) than the springs 26 and 56, the urethane spring 82, the elliptical ring springs 102 and 104, etc., and is a large spring. Easy to set constants.

  Thus, the friction type planetary power transmission device 120 including the disc spring 122 and the cam mechanism 124 can reduce the size of the entire device. Further, the setting of the pressing force according to the transmission torque (the urging force of the disc spring 122 according to the pressing force) can be optimized, which contributes to the improvement of the torque transmission rate and the life of the friction type planetary power transmission device 120. .

(Sixth embodiment)
FIG. 25 is a perspective view showing a friction type planetary power transmission device 150 according to a sixth embodiment of the present invention. FIG. 26 shows a carrier 156 constituting the friction type planetary power transmission device 150. The main part is shown in a sectional view. As shown in these figures, the friction type planetary power transmission device 150 includes a plurality of springs 152 and cam mechanisms 154 that are compression coil springs in place of the disc spring 122 and the cam mechanism 124. Different from the transmission device 120. This will be specifically described below.

  The cam mechanism 154 of the carrier 156 constituting the friction type planetary power transmission device 150 includes a cylindrical shaft portion 158 extending in the axial direction from the ring portion 52A of the support plate 52. A cylindrical tubular body 160 provided so as to rotate coaxially and integrally with the support plate 54 is supported on the shaft portion 158 so as to be relatively rotatable. A flange 160A extends radially outward from the end of the cylindrical tubular body 160 on the support plate 54 side.

  Furthermore, the cam mechanism 154 includes an annular spring receiving member 162 that is supported by the shaft portion 158 so as to be relatively rotatable. As shown in FIG. In the embodiment, twelve springs 152 are arranged at equal intervals in the circumferential direction (FIG. 25 shows a part of the springs 152 removed). A retaining member 164 is attached to the end portion of the shaft portion 158, and the spring receiving member 162 is pressed against the retaining member 164 by the biasing force of the spring 152.

  Therefore, the spring receiving member 162 is not displaced in the axial direction with respect to the shaft portion 158, that is, the support plate 52. On the other hand, the cylindrical body 160 is displaceable in the axial direction with respect to the shaft portion 158, that is, the support plate 52, and the amount of compression of the spring 152 is changed by this displacement. Further, a guide rod 166 having one end fixed to the flange 160A is inserted into the guide hole 162A provided in the spring receiving member 162 so as to be relatively changeable in the axial direction. Thereby, the cylindrical body 160 is configured to rotate coaxially and integrally with the spring receiving member 162 in the circumferential direction and relatively displace in the axial direction.

  The cam mechanism 154 is formed on the cylindrical body 160 so as to be long in a direction intersecting the circumferential direction and the axial direction, and is protruded from the outer peripheral surface of the shaft portion 158 and is also cam groove 168. The main part is a cam projection 170 that is slidably inserted into the slidable member. As a result, in the cam mechanism 154, relative angular displacement of the cylindrical body 160 with respect to the shaft portion 158 is generated in accordance with relative displacement of the cylindrical body 160 with respect to the shaft portion 158.

  In the frictional planetary power transmission device 150, the biasing force acting in the axial direction by the plurality of springs 152 is generated by the cam protrusion 170, the cylindrical body 160, and the cam groove 168 of the shaft portion 158 (the displacement conversion mechanism described above of the cam mechanism 154). Thus, the four planetary rollers 22 are arranged in a rectangular shape when the load is low by being converted into the urging force in the circumferential direction between the support plate 52 and the support plate 54. In the carrier 156, the gap between the tip of the cylindrical body 160 and the spring receiving member 162 is maximized in the state of taking this rectangular arrangement, and the cam protrusion 170 is near the end of the cam groove 168 on the cam groove 168 side ( For example, in this embodiment in which the relative angular displacement is approximately 25 ° from the rectangular arrangement to the square arrangement, the dimensions, arrangement, etc. of each part are determined so as to be located at the contact point S) shown in FIG.

  As described above, in the carrier 156, the four planetary rollers 22 are normally supported in a rectangular arrangement by the biasing forces of the plurality of springs 152. On the other hand, when a torque Tin greater than or equal to a predetermined value Tb is input to the sun roller 16, either one of the support plate 52 and the support plate 54 causes a relative angular displacement with respect to the other according to the input direction of the torque. The four planetary rollers 22 are shifted to a square arrangement while compressing the plurality of springs 152 in the axial direction.

  Another configuration of the friction type planetary power transmission device 150 is that of the friction type planetary power transmission device 50, 120 (the friction type planetary power transmission device 10 except that the carrier side shaft 65 is provided instead of the ring side shaft 32). The configuration is the same as

  Therefore, the friction type planetary power transmission device 150 according to the fifth embodiment can basically obtain the same effect by the same operation as the friction type planetary power transmission device 10 according to the first embodiment. That is, in the friction type planetary power transmission device 150, when the input torque is small, the four planetary rollers 22 are arranged in a rectangular shape so that the pressing force from the ring 28 side to the planetary roller 22 side is suppressed to be small. Contributes to the improvement of sex. On the other hand, when the input torque increases (exceeds the absolute value of the predetermined value Tb), the planetary roller 22 shifts to a square arrangement due to the torque, and the transmission torque increases.

  The friction planetary power transmission device 150 includes a plurality of springs 152 that are deformed in the axial direction, and a cam mechanism 154 that converts the urging forces of the plurality of springs 152 into a urging force in the circumferential direction between the support plates 52 and 54. Therefore, the degree of freedom of setting the urging force by the plurality of springs 152 is high. That is, by setting the number of springs 152 or a single spring constant according to the transmission torque, a required spring constant (the spring constant of the parallel spring) can be obtained with a simple structure.

  Thus, the friction type planetary power transmission device 150 including the plurality of springs 152 and the cam mechanism 154 can reduce the size of the entire device. In addition, the setting of the pressing force according to the transmission torque (the urging force of the plurality of springs 152 according to the pressing force) can be optimized, which contributes to the improvement of the torque transmission rate and the life of the friction type planetary power transmission device 150. To do.

  In each of the above-described embodiments and modifications, the four planetary rollers 22 are divided into two groups, and one group moves in the circumferential direction corresponding to the transmission torque in the first direction. This group moves in accordance with the transmission torque in the second direction opposite to the above. However, one of the four may move corresponding to the transmission torque in the first direction, and the other may correspond to the torque in the second direction. At this time, the remaining two do not move in the circumferential direction for torque in either the forward or reverse direction. Further, as described above, the number of planetary rollers is not limited to four. In applications where torque is transmitted only in one direction, the circumferential position is constant with respect to the carrier 18, the carrier body 60, and the carrier plate 94. (Not performed) The configuration may include a planetary roller 22 and at least one planetary roller 22 that can contact and separate in the circumferential direction so as to correspond to the transmission torque in the first direction with respect to the planetary roller 22.

  In each of the above-described embodiments and modifications, the planetary element is a device using a roller, that is, a cylindrical rolling element, but the planetary element may be a ball. Further, the change in the arrangement of the planetary roller 22 is self-supporting due to the relationship between the rotational force Na, Nb, the springs 26 and 56, the urethane spring 82, the spring force of the elliptical ring springs 102 and 104, the disc springs 122 and 152, and the transmission torque. However, the arrangement of the planetary rollers 22 can be forcibly changed from the outside by providing a fluid pressure actuator or the like.

  Further, in the above-described second, fifth, and sixth embodiments and the modifications, the urging force of the spring 56, the disc spring 122, and the plurality of springs 156 acts between the support plate 52 and the support plate 54. For example, an urging force may be applied between the carrier body 60 and the support plate 52 and between the carrier body 60 and the support plate 54.

It is sectional drawing of the friction type planetary power transmission device of the 1st Embodiment of this invention. It is sectional drawing by the AA line of FIG. It is explanatory drawing of the principle from which pressing force changes. It is a figure which shows a FEM analysis model. It is explanatory drawing of the generation principle of rotational force Na. It is a figure which shows an example of the relationship between input torque and pressing force. It is a perspective view of the friction type planetary power transmission device of the 2nd Embodiment of this invention. It is a disassembled perspective view which shows the principal part of the carrier which comprises the friction type planetary power transmission device of the 2nd Embodiment of this invention. It is a figure which shows the carrier which comprises the friction type planetary power transmission device of the 2nd Embodiment of this invention, Comprising: (A) is a schematic diagram of square arrangement | positioning, (B) is a schematic diagram of rectangular arrangement | positioning. It is a figure which shows the 1st modification of the carrier which comprises the friction type planetary power transmission device of the 2nd Embodiment of this invention, (A) is a disassembled perspective view, (B) is sectional drawing of the principal part. . It is a schematic diagram which shows the 1st modification of the carrier which comprises the friction type planetary power transmission device of the 2nd Embodiment of this invention. It is a figure which shows the 2nd modification of the carrier which comprises the friction type planetary power transmission device of the 2nd Embodiment of this invention, Comprising: (A) is a schematic diagram of rectangular arrangement | positioning, (B) is a schematic diagram of square arrangement | positioning. It is. It is a schematic diagram which shows the 3rd modification of the carrier which comprises the friction type planetary power transmission device of the 2nd Embodiment of this invention. It is a perspective view of the friction type planetary power transmission device of the 3rd Embodiment of this invention. It is a schematic diagram which shows the carrier which comprises the friction type planetary power transmission device of the 3rd Embodiment of this invention. It is a front view which shows typically the friction type planetary power transmission device of the 4th Embodiment of this invention. It is a front view which shows typically the example which made the elliptical ring type spring which comprises the friction type planetary power transmission device of the 4th Embodiment of this invention double. It is a figure which shows the characteristic of the friction type planetary power transmission device of the 4th Embodiment of this invention, Comprising: (A) is a diagram which shows the relationship between a revolution angle and rotational force, (B) is a revolution angle and spring stress. FIG. It is a figure which shows typically the 1st modification of the friction type planetary power transmission device of the 4th Embodiment of this invention, Comprising: (A) is a front view of square arrangement | positioning, (B) is a front view of rectangular arrangement | positioning. is there. It is a front view showing typically the 2nd modification of a friction type planetary power transmission device of a 4th embodiment of the present invention. It is a figure which shows the characteristic of the 2nd modification of the friction type planetary power transmission device of the 4th Embodiment of this invention, Comprising: (A) is a diagram which shows the relationship between a revolution angle and rotational force, (B) is It is a diagram which shows the relationship between a revolution angle and a spring stress. It is a perspective view of the friction type planetary power transmission device of the 5th Embodiment of this invention. It is a disassembled sectional view which shows the principal part of the carrier which comprises the friction type planetary power transmission device of the 5th Embodiment of this invention. It is an expanded view of the cam plate which comprises the friction type planetary power transmission device of the 5th Embodiment of this invention. It is a perspective view of the friction type planetary power transmission device of the 6th Embodiment of this invention. It is sectional drawing which shows the principal part of the carrier which comprises the friction type planetary power transmission device of the 6th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Friction type planetary power transmission device, 16 Sun roller (center element), 18 Carrier (support element), 22 Planet roller (planet element), 24 Guide groove, 26 Spring (spring element, compression spring), 28 Ring (ambient element) 36, 40 Contact point, 50/90/100/120/150 Friction type planetary power transmission device, 52/72/76 Support plate (movable element, first movable element), 54/74/78 Support plate (movable) Element, first movable element), 58, 70, 75, 80, 92, 110, 126, 156 carrier (support element), 56 spring (spring element, compression spring), 82 urethane spring (spring element, compression spring) , 102 Elliptical ring spring (spring element, compression spring), 104 Elliptical ring spring (spring element), 122 Disc spring (spring element), 124, 154 Cam mechanism (load conversion mechanism, displacement conversion mechanism)

Claims (16)

A central element having an outer peripheral surface with a circular cross section;
A peripheral element having an inner peripheral surface that is concentric with the outer peripheral surface of the central element and has a circular cross-section facing the outer peripheral surface;
At least three planetary elements that contact the outer peripheral surface of the central element and the inner peripheral surface of the surrounding element, rotate and transmit torque by friction at the contact point;
A supporting element for supporting each planetary element with a predetermined relative relationship on a circumference concentric with the outer peripheral surface of the central element;
Including a friction type planetary power transmission device,
The support element can support the planetary element in at least two arrangements having different perimeter lengths of a polygon connecting the contact points of each planetary element and the surrounding element.
Friction type planetary power transmission device. It is a friction type planetary power transmission device according to claim 1,
The support element supports each planetary element in a first arrangement in which the circumference of the polygon becomes long when the transmission torque of the transmission device is large, and when the transmission torque is small, Support in a second arrangement that reduces the perimeter,
Friction type planetary power transmission device. It is a friction type planetary power transmission device according to claim 2,
The supporting element supports a part of the planetary element so as to be movable in the circumferential direction with respect to the remaining planetary elements. When the planetary element is moved in the circumferential direction by the transmission torque and the transmission torque increases, the second arrangement To the first arrangement,
Friction type planetary power transmission device. It is a friction type planetary power transmission device according to claim 2,
The planetary element has a first group including at least one planetary element and a second group including at least one planetary element other than the first group,
When the transmission torque acts in the first direction, the support element supports the first group of planetary elements movably in the circumferential direction with respect to the other planetary elements by the transmission torque. To move the planetary element from the second configuration to the first configuration,
The support element can also move the second group of planetary elements in the circumferential direction with respect to other planetary elements when the transmission torque acts in a second direction opposite to the first direction. And the planetary element is shifted from the second arrangement to the first arrangement by this circumferential movement.
Friction type planetary power transmission device. The friction type planetary power transmission device according to claim 4,
The number of planetary elements is four, and the first group and the second group are formed by planetary elements arranged on a common diagonal of the quadrilateral polygon.
Friction type planetary power transmission device. The friction type planetary power transmission device according to any one of claims 3 to 5,
The planetary element supported so as to be movable in the circumferential direction has a spring element that urges the planetary element in the direction of the second arrangement.
Friction type planetary power transmission device.   The friction type planetary power transmission device according to any one of claims 2 to 6, wherein the polygon is a regular polygon when the planetary element is in the first arrangement. . A central element having an outer peripheral surface with a circular cross section;
A peripheral element having an inner peripheral surface that is concentric with the outer peripheral surface of the central element and has a circular cross-section facing the outer peripheral surface;
Two planetary elements that contact the outer peripheral surface of the central element and the inner peripheral surface of the surrounding element, rotate and transmit torque by friction at the contact point;
A supporting element for supporting each planetary element with a predetermined relative relationship on a circumference concentric with the outer peripheral surface of the central element;
Including a friction type planetary power transmission device,
The supporting element can support two planetary elements in a first arrangement in which the outer peripheral surface of the central element is arranged on one diameter and a second arrangement that is deviated from the first arrangement.
Friction type planetary power transmission device. It is a friction type planetary power transmission device according to claim 6,
The spring element applies a biasing force so that the planetary element is in the second arrangement with respect to the support shaft that rotatably supports the planetary element on the support element.
Friction type planetary power transmission device. It is a friction type planetary power transmission device according to claim 9,
The spring element is a compression spring arranged in a compressed state between the support shafts arranged adjacent to each other in the circumferential direction.
Friction type planetary power transmission device. It is a friction type planetary power transmission device according to claim 6,
A movable element that moves in the circumferential direction with respect to the support element following the planetary element supported so as to be movable in the circumferential direction;
The spring element applies a biasing force to the portion of the movable element that is located radially outside the support shaft that rotatably supports the planetary element with respect to the support element so that the planetary element is in the second arrangement. ,
Friction type planetary power transmission device. The friction type planetary power transmission device according to claim 6 or 11,
The spring element is configured to elastically deform in the axial direction of the central element,
A load conversion element that causes an urging force accompanying deformation of the spring element to act on the planetary element supported so as to be movable in the circumferential direction in a direction in which the planetary element is in the second arrangement;
Friction type planetary power transmission device. A central element having an outer peripheral surface with a circular cross section;
A peripheral element having an inner peripheral surface that is concentric with the outer peripheral surface of the central element and has a circular cross-section facing the outer peripheral surface;
At least three planetary elements that contact the outer peripheral surface of the central element and the inner peripheral surface of the surrounding element, rotate and transmit torque by friction at the contact point;
A supporting element for supporting each planetary element with a predetermined relative relationship on a circumference concentric with the outer peripheral surface of the central element;
Including a friction type planetary power transmission device,
The support element has a support element main body, and a movable element that is provided so as to be relatively rotatable about the axis of the central element with respect to the support element main body and supports a part of the planetary element, and the movable support element supports By rotating relative to the element body, the at least three planet elements can be supported in at least two arrangements having different perimeter lengths of polygons connecting the contact points between the planet elements and the surrounding elements.
Friction type planetary power transmission device. It is a friction type planetary power transmission device according to claim 13,

The support elements include a first movable element that supports a pair of planetary elements arranged 180 degrees apart, a second movable element that supports a pair of planetary elements arranged 180 degrees apart, and a first A spring element disposed between the movable element and the second movable element or between the first and second movable elements and the support element body,
Depending on the load torque, the first movable member and the second movable element are moved relative to the support element body up to a position where the force acting in the circumferential direction of the central element acting on the planetary element and the biasing force of the spring element are balanced. A friction type planetary power transmission device in which at least one of them is relatively rotated. The friction type planetary power transmission device according to claim 13 or 14,

The support element includes a first movable element that supports some planetary elements, a second movable element that supports some other planetary elements, and a relative relationship between the first movable element and the second movable element. A displacement conversion element that generates relative displacement in the axial direction of the central element with rotation; and a spring element that generates an urging force that resists displacement in the axial direction when the displacement conversion element is deformed in the axial direction.
Depending on the load torque, the first movable member and the second movable element are moved relative to the support element body up to a position where the force acting in the circumferential direction of the central element acting on the planetary element and the biasing force of the spring element are balanced. A friction type planetary power transmission device in which at least one of them is relatively rotated. A central element having an outer peripheral surface with a circular cross section;
A peripheral element having an inner peripheral surface that is concentric with the outer peripheral surface of the central element and has a circular cross-section facing the outer peripheral surface;
At least three planetary elements that contact the outer peripheral surface of the central element and the inner peripheral surface of the surrounding element, rotate and transmit torque by friction at the contact point;
A supporting element for supporting each planetary element with a predetermined relative relationship on a circumference concentric with the outer peripheral surface of the central element;
Including a friction type planetary power transmission device,
The support element supports a support shaft that rotatably supports at least two of the at least three planetary elements so as to be relatively displaceable in the circumferential direction with respect to the support element body, and a spring element between the support shafts adjacent in the circumferential direction. Are arranged in a compressed state, and the planetary element is moved relative to the support element body up to a position where the force acting in the circumferential direction of the central element acting on the planetary element and the biasing force of the spring element are balanced according to the load torque. The relative angular displacement was rotated in the circumferential direction of the support element body.
Friction type planetary power transmission device.

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