JP5849643B2 - Toroidal continuously variable transmission - Google Patents

Description

  The present invention is, for example, a half-toroidal continuously variable transmission that is used as an automatic transmission for various industrial machines such as vehicles (automobiles), construction machines, generators used in airplanes, and pumps. Regarding improvements.

  Toroidal continuously variable transmissions that can be used as automatic transmissions for automobiles have been widely known. Also, it has been widely known that a continuously variable transmission device is configured by combining a toroidal type continuously variable transmission and a planetary gear type transmission, as described in Patent Document 1, for example. As shown in FIGS. 8 to 9, this continuously variable transmission includes a double cavity type toroidal continuously variable transmission 1 and a planetary gear type transmission 2 having units of three stages, a front stage, a middle stage, and a rear stage. The low speed clutch 3 and the high speed clutch 4 are combined. Then, the connection / disconnection state of both the clutches 3 and 4 is switched, and the gear ratio of the toroidal-type continuously variable transmission 1 is adjusted to make the gear ratio between the input shaft 5 and the output shaft 6 infinite. It is adjustable. That is, by adjusting the gear ratio of the toroidal continuously variable transmission 1 in the low speed mode state in which the low speed clutch 3 is connected and the high speed clutch 4 is disconnected, the input shaft 5 is moved in one direction. The output shaft 6 can be rotated in both directions with the stopped state in a state where the output shaft 6 is rotated. On the other hand, in the high speed mode state in which the high speed clutch 4 is connected and the low speed clutch 3 is disconnected, the speed ratio of the toroidal continuously variable transmission 1 is changed to the speed increasing side. The speed ratio of the continuously variable transmission as a whole is also changed to the speed increasing side.

  The toroidal type continuously variable transmission 1 incorporated in the continuously variable transmission as described above includes a pair of input disks 7a and 7b that rotate in synchronization with each other, and these input disks 7a and 7b. An output disk 8 that supports relative rotation with respect to both the input disks 7a and 7b and a plurality of power rollers 9 and 9 are provided. These power rollers 9 and 9 are supported on the inner surfaces of the trunnions 10a and 10b, respectively, via a plurality of rolling bearings so that they can be rotated and slightly displaced in the axial direction of the disks 7a, 7b and 8. In this state, a plurality of each are sandwiched between both axial sides of the output disc 8 and one axial side of the input discs 7a and 7b. The power rollers 9, 9 transmit power between the input disks 7a, 7b and the output disk 8 by rotating with the rotation of the input disks 7a, 7b.

  The gear ratio of the toroidal type continuously variable transmission 1 is adjusted by tilting the trunnions 10a and 10b concentrically provided at both ends of the trunnions 10a and 10b by hydraulic actuators 11 and 11, respectively. This is done by displacing the shafts 12 and 12 in the axial direction. When the trunnions 10a and 10b are displaced in the axial direction of the tilt shafts 12 and 12, the circumferential surfaces of the power rollers 9 and 9 supported by the trunnions 10a and 10b, the discs 7a, The direction of the tangential force acting on the rolling contact portions (traction portions) with the axial side surfaces of 7b and 8 changes with respect to the axial directions of the tilt shafts 12 and 12, respectively. Specifically, each traction portion is in a neutral position (the center of each traction portion includes the central axis of each of the disks 7a, 7b, 8 and a virtual straight line connecting the central axes of the respective tilting shafts 12, 12). If the position of the trunnion 10a, 10b is shifted to the deceleration side or the acceleration side about the tilting shafts 12, 12, depending on the direction of the deviation, Force in the direction to move is added. And the position of each said traction part changes regarding the radial direction of each said disk 7a, 7b, 8, and the said gear ratio changes. If the traction portions are returned to the neutral position in a state where the gear ratio has reached a desired value, the gear ratio of the toroidal continuously variable transmission 1 can be maintained at the desired value.

  As described above, the mechanism for adjusting the transmission ratio of the toroidal-type continuously variable transmission 1 to a desired value and maintaining the adjusted value will be described based on the description in Patent Document 2. As shown in FIG. 10, this mechanism includes a transmission ratio control valve 13, a stepping motor 14, and a recess cam 15. Of these, the transmission ratio control valve 13 is a combination of a spool 16 and a sleeve 17 so as to allow relative displacement in the axial direction. Based on the relative displacement between the spool 16 and the sleeve 17, the hydraulic power source 18, The supply / discharge state of the actuator 11 with the hydraulic chambers 19a, 19b is switched. The spool 16 and the sleeve 17 are relatively displaced by the movement of any one of the trunnions 10a and 10b and the stepping motor 14. The recess cam 15 is one of the rods 21a and 21b (left side in FIG. 9) connected to the pistons 20 and 20 of the actuators 11 and 11 continuously from the lower end of each trunnion 10a. The rod 21a is fixed to the tip (the lower end in FIG. 9). Then, the movement of the trunnion 10a coupled to the base end portion of any one of the rods 21a, that is, the displacement in the axial direction of the tilt shaft 12 and the swing displacement about the tilt shaft 12 are described above. The spool 16 is transmitted to the spool 16 via the recess cam 15 and the link arm 22 to be displaced in the axial direction, and the sleeve 17 is displaced in the axial direction by the stepping motor 14.

  When adjusting the gear ratio of the toroidal continuously variable transmission 1, the sleeve 17 is displaced to a predetermined position by the stepping motor 14, and the gear ratio control valve 13 is opened in a predetermined direction. Then, pressure oil is supplied to and discharged from the hydraulic chambers 19a and 19b of the actuators 11 and 11 attached to the trunnions 10a and 10b in a predetermined direction, and the trunnions 10a and 10b are moved by the actuators 11 and 11. Are displaced in the axial direction of the respective tilting shafts 12, 12. As a result, the traction portions related to the power rollers 9 and 9 supported by the trunnions 10a and 10b are shifted from the neutral position, and the speed ratio starts to change. In this way, at the moment when each of these traction portions deviates from this neutral position and the transmission ratio starts to change, the open / close state of the transmission ratio control valve 13 is changed according to the axial displacement of each of the trunnions 10a, 10b. Switching to a direction opposite to the predetermined direction. Accordingly, the trunnions 10a and 10b start to move (return) toward the neutral position in the axial direction from the moment when the swing displacement starts to be performed for shifting. Then, in a state where the speed ratio has reached the desired value, the speed ratio control valve 13 is closed simultaneously with the return of the traction units to the neutral position. As a result, the gear ratio of the toroidal type continuously variable transmission 1 is maintained at the desired value.

  By the way, in order to transmit power between the input disks 7a, 7b and the output disk 8 by the toroidal-type continuously variable transmission 1 as described above, a sufficient surface pressure of each traction portion is ensured. There is a need. For this purpose, a hydraulic pressing device 23 is incorporated in the structure shown in FIG. During operation of the continuously variable transmission, one input disk 7 a (left side in FIG. 8) is rotated by the input shaft 5 via the pressing device 23. As a result, the two input disks 7a and 7b supported at both ends of the input rotating shaft 24 rotate in synchronization while being pressed in a direction approaching each other. The rotation is transmitted to the output disk 8 through the power rollers 9 and 9 and is taken out from the output disk 8.

  Regardless of whether it is incorporated in the continuously variable transmission as described above or used independently, when the toroidal continuously variable transmission 1 is operated, each member used for power transmission, that is, the input, The output disks 7a, 7b, 8 and the power rollers 9, 9 are elastically deformed based on the pressing force generated by the pressing device 23. With this elastic deformation, the input and output disks 7a, 7b, 8 are displaced in the axial direction. Further, the pressing force generated by the pressing device 23 increases as the torque transmitted by the toroidal-type continuously variable transmission 1 increases, and the elastic deformation amount of each member 7a, 7b, 8, 9 increases accordingly. Become more. Therefore, in order to properly maintain the contact state between the inner surface of each of the input and output disks 7a, 7b, 8 and the peripheral surface of each of the power rollers 9, 9 regardless of the fluctuation of the torque, A mechanism for displacing the power rollers 9 and 9 in the axial direction of the disks 7a, 7b and 8 with respect to 10a and 10b is required. In the case of the first example of the conventional structure described above, the tip half of each of the support shafts 25, 25 that support each of the power rollers 9, 9 is also oscillated and displaced about the base half as described above. Each power roller 9, 9 is displaced in the axial direction.

  In the case of the first example of the conventional structure as described above, the structure for displacing each of the power rollers 9 and 9 in the axial direction is complicated, and parts production, parts management, and assembly work are all troublesome and costly. It is inevitable that the volume increases. As a technique for solving such a problem, Patent Document 3 describes a structure as shown in FIGS. Since the present invention improves the second example of the conventional structure shown in FIGS. 11 to 16, the second example of the conventional structure will be described next. A feature of the second example of this conventional structure is a structure of a portion that supports the trunnion 10c so that the power roller 9a can be displaced in the axial direction of the input and output disks 7a, 7b, 8 (see FIG. 8). The structure and operation of the toroidal continuously variable transmission as a whole are the same as those of the first example of the conventional structure shown in FIGS.

  The trunnion 10c constituting the second example of the conventional structure exists between a pair of tilting shafts 12a, 12a provided concentrically with each other at both ends, and at least between these tilting shafts 12a, 12a. The side surface on the inner side (the upper side in FIGS. 12 and 16 to 16) in the radial direction (the vertical direction in FIGS. 12 and 14 to 16) of the input and output disks 7 a, 7 b and 8 (see FIG. 8) is a cylindrical convex surface 26. The support beam 27 is provided. Both the tilting shafts 12a and 12a are supported by support plates 28 and 28 (see FIGS. 8 to 9) via radial needle bearings 46 and 46, respectively, so as to be swingable.

  Further, as shown in FIGS. 12, 15 to 16, the central axis A of the cylindrical convex surface 26 is parallel to the central axis B of the both tilting shafts 12a and 12a, and the center of these tilting shafts 12a and 12a. It exists on the outer side (the lower side of FIGS. 12 and 15 to 16) with respect to the radial direction of each of the disks 7 a, 7 b and 8 than the axis B. Further, a concave portion 31 having a partially cylindrical surface is formed on the outer surface of the outer ring 30 constituting the thrust ball bearing 29 provided between the support beam portion 27 and the outer surface of the power roller 9a so as to cross the outer surface in the radial direction. It is provided in the state. And this recessed part 31 and the cylindrical convex surface 26 of the said support beam part 27 are engaged, The rocking | displacement displacement regarding the axial direction of each said disk 7a, 7b, 8 is made for the said outer ring 30 with respect to the said trunnion 10c. I support it as possible.

  In addition, a support shaft 25a is fixed to the central portion of the inner surface of the outer ring 30, and the power roller 9a is rotatable around the support shaft 25a via a radial needle bearing 32. I support it. Further, a pair of stepped surfaces 33 and 33 facing each other are provided on the inner surface of the trunnion 10c at a continuous portion between both end portions of the support beam portion 27 and the pair of tilting shafts 12a and 12a. . Then, these stepped surfaces 33 and 33 and the outer peripheral surface of the outer ring 30 constituting the thrust ball bearing 29 are brought into contact with or in close proximity to each other, and any traction force applied from the power roller 9a to the outer ring 30 is selected. These step surfaces 33 and 33 can be supported.

According to the toroidal type continuously variable transmission of the second example of the conventional structure configured as described above, the power roller 9a is displaced in the axial direction of each of the disks 7a, 7b, 8 to elastically deform the constituent members. A structure that can properly maintain the contact state between the peripheral surface of the power roller 9a and the disks 7a, 7b, and 8 regardless of the amount can be configured easily and at low cost.
That is, during operation of the toroidal-type continuously variable transmission, the input and output disks 7a, 7b, 8 and the power rollers 9a are elastically deformed so that the power rollers 9a are connected to the shafts of the disks 7a, 7b, 8 respectively. When it is necessary to displace in the direction, the outer ring 30 of the thrust ball bearing 29 that rotatably supports each of the power rollers 9a is formed between the concave portion 31 and the supporting beam portion 27 provided on the outer surface. While sliding the contact surface with the cylindrical convex surface 26, the cylindrical convex surface 26 is oscillated and displaced about the central axis a. Based on this oscillating displacement, the portion of the peripheral surface of each power roller 9a that is in rolling contact with one axial side surface of each disk 7a, 7b, 8 is the axial direction of each disk 7a, 7b, 8. To maintain the contact state appropriately.

  As described above, the central axis (a) of the cylindrical convex surface (26) is greater than the central axes (B) of the tilting shafts (12a, 12a) that are the swing centers of the trunnions (10c) during the shifting operation. It exists outside in the radial direction. Therefore, the radius of the rocking displacement around the central axis (a) of the cylindrical convex surface 26 is larger than the rocking radius during the speed change operation, and between the input disks 7a, 7b and the output disk 8. Has little effect on the gear ratio variation (can be ignored or can be easily corrected).

  In the case of the second example of the conventional structure shown in FIGS. 11 to 16, parts production, parts management, and assembly work are all easier than the first example shown in FIGS. Although easy to achieve, there is room for improvement in terms of stabilizing the shifting operation. The reason for this is that each stepped surface 33 provided in a pair at each end of each support beam 27 in order to smoothly swing and displace each outer ring 30 around each support beam 27. The distance D between the outer rings 30 is slightly larger than the outer diameter d of each outer ring 30 (D> d). The outer rings 30 and the power rollers 9a supported concentrically with the outer rings 30 are formed on the support beam portions 27 by the difference (D−d) between the distance D and the outer diameter d. Displaceable in the axial direction.

  On the other hand, during operation of a vehicle equipped with a toroidal-type continuously variable transmission, each power roller 9a is driven by the discs 7a, 7b and 8 in the opposite direction during acceleration and deceleration (when the engine brake is activated). Force ("2Ft" well known in the technical field of toroidal continuously variable transmissions) is applied. Then, due to this force 2Ft, each power roller 9a is displaced along with each outer ring 30 in the axial direction of each support beam portion 27. The direction of this displacement is the same as the displacement direction of each trunnion 10a, 10b (see FIG. 9) by each actuator 21, 21, and the shifting operation is started even if the displacement is about 0.1 mm. there is a possibility. When the shifting operation is started for such a reason, the shifting operation is not directly related to the driving operation, and the driver feels uncomfortable regardless of any correction.

  In order to suppress the occurrence of the speed change operation that is not directly related to the driving operation as described above, the difference (D−d) between the distance D and the outer diameter d is made small (for example, about several tens of μm). ) Can be suppressed. However, during operation of the half-toroidal toroidal continuously variable transmission, each trunnion 10c is caused by a thrust load applied from the traction portion to each support beam portion 27 via each power roller 9a and each outer ring 30. As exaggeratedly shown in FIG. 17, the side on which each outer ring 30 is installed is elastically deformed in a concave direction. As a result of this elastic deformation, the gap between the stepped surfaces 33, 33 provided for each trunnion 10c is reduced. Even in such a state, in order to prevent the distance D between the stepped surfaces 33 and 33 from becoming equal to or less than the outer diameter d of each outer ring 30, the normal state (the state where each trunnion 10c is not elastically deformed). It is necessary to ensure a certain difference between the distance D and the outer diameter d. As a result, a shift operation not directly related to the driving operation as described above is likely to occur.

  On the other hand, in Patent Document 3, the anchor piece locked to a part of the cylindrical convex surface provided on the support beam part side and the anchor groove formed on the inner surface of the concave part on the outer ring side are engaged with each other. A structure for supporting a force 2Ft is described. There is also a structure for supporting the force 2Ft by forming a plurality of balls between the rolling grooves each having an arcuate cross section formed in a portion where the cylindrical convex surface and the concave portion are aligned with each other. Have been described. However, in the case of the former structure, it is difficult to support and fix the anchor piece to the support beam portion with sufficient strength and rigidity to support the force 2Ft, and it is possible to reduce the cost and to provide sufficient reliability. It is difficult to secure. In the latter case, when the force 2Ft increases and the surface pressure of the rolling contact portion between the rolling surface of each ball and each rolling groove increases, an indentation is formed on the inner surface of each rolling groove. As a result, vibration may occur when each outer ring swings and displaces with respect to each trunnion.

JP 2009-30749 A JP 2006-283800 A JP 2008-25821 A

  In view of the circumstances as described above, the present invention was invented to realize a structure that facilitates parts production, parts management, and assembly work, facilitates cost reduction, and stabilizes the speed change operation. is there.

The toroidal type continuously variable transmission of the present invention includes at least a pair of disks, a plurality of trunnions, the same number of power rollers as each trunnion, the same number of thrust rolling bearings, and a pressing device.
Each of these disks supports the relative rotation freely concentrically with each other in the state in which the respective one side surfaces in the axial direction, each of which is a toroidal curved surface having an arc cross section, are opposed to each other.
Each trunnion includes a pair of tilting shafts, a support beam portion, and a pair of step surfaces. Of these, the two tilting shafts are provided concentrically with each other at both ends of each trunnion. Further, the support beam portion is present between the two tilt axes, and at least the inner side surface in the radial direction of each disk is parallel to the central axis of the two tilt axes and is more than the central axis. A cylindrical convex surface having a central axis existing outside in the radial direction of each disk is used. Further, the two step surfaces are provided at opposite ends of the support beam portion so as to face each other. Each of the trunnions having such a configuration is in a twisted position with respect to the central axis of each of the discs at a plurality of locations in the circumferential direction between the axial side surfaces of the respective discs in the axial direction. Oscillating displacement about both tilting axes is freely provided.
Each power roller is rotatably supported on the inner side surface of each trunnion via a thrust rolling bearing, and each circumferential surface formed as a spherical convex surface is provided on one side surface in the axial direction of each disk. They are in contact with each other.
Each thrust rolling bearing is provided between the support beam portion of each trunnion and the outer surface of each power roller. And, the outer ring provided on each support beam portion side, the outer ring raceway provided on the inner side surface of each outer ring, and the inner ring raceway provided on the outer side surface of each power roller, can freely roll. A plurality of rolling elements each provided.
In addition, the outer ring of each thrust rolling bearing engages the concave portion provided on the outer surface of each outer ring and the cylindrical convex surface of each support beam portion, and is provided at both ends of each support beam portion. In addition, each trunnion is disposed between a pair of stepped surfaces. Each trunnion is supported so as to be capable of swinging in the axial direction of each disk while restricting the axial displacement of each support beam.
Further, the pressing device presses the disks facing each other with the power rollers interposed therebetween in a direction approaching each other.

  In particular, in the toroidal type continuously variable transmission according to the present invention, at least one of the outer rings constituting each thrust rolling bearing, or the outer ring itself is coupled to and fixed to the outer ring and is synchronized with the outer ring. A part to be displaced is provided with a detected surface inclined with respect to the swinging direction of the outer ring with the support beam portion as the center. In addition, the displacement of the detected surface with respect to the axial direction of the support beam can be detected by a sensor supported by a fixed portion that does not displace during operation.

When carrying out the toroidal type continuously variable transmission of such a present invention, specifically, performs pressure oil supply and discharge of the hydraulic actuator based on the switching of speed change ratio control valve, said trunnions By shifting in the axial direction of the tilt shafts provided at both ends, these trunnions are oscillated and displaced around these tilt shafts, and the gear ratio between the disks is changed. A ratio control means is provided. The transmission ratio control valve switches a hydraulic circuit based on the relative displacement in the axial direction between the spool and the sleeve, and a pair of pistons sandwiching a piston constituting a hydraulic actuator provided for each trunnion. Pressure oil shall be supplied to and discharged from the hydraulic chamber. Then, any one member of the spool and the sleeve is displaced in the axial direction by the first electric actuator for setting the gear ratio, and the other member is controlled based on the detection signal of the sensor. The second electric actuator for feedback is displaced in the axial direction.

Preferably, as in the invention described in claim 2 , the support beam portion that supports the outer ring so as to be able to swing and displace is loosened (to allow the outer ring to swing and displace around the support beam portion). ) An arched bracket to be detected is supported and fixed to the outer ring while straddling. And the said to-be-detected surface is provided in the one side surface of this to-be-detected bracket regarding the axial direction of this support beam part.

According to the toroidal-type continuously variable transmission of the present invention configured as described above, it is easy to manufacture parts, manage parts, and assemble work, easily reduce costs, and stabilize the speed change operation. realizable.
Of these, cost reduction is easy to achieve for the same reason as in the second example of the conventional structure shown in FIGS.

  Further, the speed change operation can be stabilized by detecting the displacement of the detection surface provided on the outer ring itself or a part of the member coupled and fixed to the outer ring. Since the outer ring is displaced in synchronism with the power roller with respect to the axial direction of the support beam portion of the trunnion, even if the outer ring is displaced in the axial direction of the support beam portion, the position of the power roller with respect to the axial direction is determined. Can be detected correctly. In other words, as in the case of measuring the position of the power roller via the trunnion as in the conventional structure, the gap existing between the trunnion and the power roller leads to an error related to the position measurement of the power roller. There is no.

Therefore, on the basis of a signal representing the attitude of the outer ring detected by sensor, by performing the switching of the transmission ratio control valve, irrespective of the gap that exists between the power roller and the trunnion, toroidal-type continuously variable The gear ratio of the transmission can be adjusted with high accuracy.
Further, as in the invention described in claim 2 , if the arched bracket to be detected is supported and fixed to the outer ring in a state straddling the support beam portion, the structure is relatively simple and the sensor can be easily installed. The structure which requires the displacement of the outer ring can be realized. Moreover, the trunnion and the outer ring can be prevented from separating even before the toroidal-type continuously variable transmission is assembled. Therefore, the portion including the trunnion and the outer ring can be handled as a subassembly unit, and the assemblability of the toroidal continuously variable transmission can be improved.

The perspective view which took out the trunnion, the thrust ball bearing, and the power roller which show the 1st example of embodiment of this invention, and was seen from the radial direction outer side of each disk. The perspective view similarly seen from the inner side about the circumferential direction and radial direction a little. Similarly, an orthographic projection viewed from the outside in the radial direction. Similarly orthographic view seen from the circumferential direction. The perspective view which took out the thrust ball bearing and the power roller similarly, and was seen from the radial direction outer side of each disk. The perspective view similarly seen from a different angle. The perspective view which shows the state before couple | bonding the outer ring | wheel which comprises a thrust ball bearing, and a to-be-detected bracket in the state seen from a different direction regarding FIG. Sectional drawing which shows the 1st example of a conventional structure. XX sectional drawing of FIG. FIG. 3 is a schematic cross-sectional view of a hydraulic control device portion for gear ratio control. The perspective view which looked at the trunnion which supported the power roller via the thrust ball bearing which shows the 2nd example of the conventional structure from the radial direction outer side of each disk. Similarly, the orthographic view shown in the state seen from the circumferential direction of the disk. The top view seen from the upper part of FIG. The side view seen from the right side of FIG. FIG. 14 is a YY sectional view of FIG. 13. ZZ sectional drawing of FIG. The sectional view seen from the same direction as Drawing 15 exaggeratingly showing the state where the trunnion was elastically deformed based on the thrust load applied from a power roller.

  1 to 7 show an example of an embodiment of the present invention. The feature of this example is that the power roller 9a is swayed with respect to the support beam 27a of the trunnion 10d via a thrust ball bearing 29a for rotatably supporting the thrust load while supporting the thrust load. With the structure that is supported so as to be able to move dynamically, the displacement of the power roller 9a is measured as the displacement of the outer ring 30a constituting the thrust ball bearing 29a. The overall configuration of the toroidal continuously variable transmission is the same as that of a conventionally known toroidal continuously variable transmission including the structures shown in FIGS. Further, the structure for supporting the outer ring 30a constituting the thrust ball bearing 29a so as to be swingable and displaceable with respect to the support beam portion 27a of the trunnion 10d is basically shown in FIGS. This is the same as the second example of the conventional structure. As for the structure and operation of the parts that have been widely known in the past, as described above or described in Patent Documents 1 to 3, the illustration and description are omitted or simplified. The description will focus on the features of

  The toroidal continuously variable transmission includes a plurality of sets of power roller units 34 each formed by combining a trunnion 10d and a power roller 9a via a thrust ball bearing 29a. The specifications of each of the power roller units 34 are the same for each set as long as the specifications relate to the relative displacement between the trunnion 10d and the power roller 9a. Specifically, at least the following specifications (1) to (3) are the same, and when the toroidal continuously variable transmission is operated, the trunnion 10d and the power roller 9a are connected to all the power roller units. The relative displacement is made by the same amount between the 34 members. The reason for this is to control the movement of all trunnions 10d by feeding back the movement of any one trunnion 10d (the combined value of the axial displacement and the tilt angle). In this point, in the case of the above-described conventional structure, the precess cam 15 (see FIG. 9) is installed only in one trunnion 10a among the plurality of trunnions 10a, 10b, and the one trunnion 10a The operation is fed back to the gear ratio control valve 13 (see FIG. 10) to control the movement of all trunnions 10a and 10b.

(1) The support beam in the space D between the step surfaces 33a and 33a formed in each trunnion 10d and a portion of the outer ring 30a disposed between the step surfaces 33a and 33a. The difference “D−d” from the dimension d in the axial direction of the portion 27a
Making this difference “D−d” the same means that the thrust rollers supporting the power rollers 9a (with respect to the trunnions 10d are supported by all the power roller units 34 during the operation of the toroidal type continuously variable transmission. This is important in order to displace the outer ring 30a) of the ball bearing 29a by the same amount with respect to the axial direction of the support beam 27a. In the illustrated example, since the outer peripheral surface shape of the outer ring 30a is a simple circle, the outer diameter of the outer ring 30a is the dimension d in the axial direction. On the other hand, in order to suppress the surface pressure of the contact portion with the two step surfaces 33a and 33a at two positions on the radially opposite side of the outer peripheral surface of the outer ring 30a, In some cases, a pair of opposing flat surfaces that are parallel to each other are formed. In such a case, the distance between the two flat surfaces is the dimension d in the axial direction.

(2) Rigidity of the support beam portion 27a of each trunnion 10d As described above with reference to FIG. 17, the trunnion 10d is recessed on the inner surface side of each support beam portion 27a when the toroidal continuously variable transmission is operated. Is elastically deformed in the direction to become the distance D between the two step surfaces 33a and 33a. If the elastic deformation amount of each support beam portion 27a between the power roller units 34, and the change amount of the distance D are different, the trunnions between the power roller units 34 are different. There is a difference in the amount of displacement of each power roller 9a with respect to 10d. In order to prevent such a difference from occurring, it is important that the rigidity of each of the support beam portions 27a, in particular, the bending rigidity in the radial direction of each disk is the same.

(3) Radial rigidity of each thrust ball bearing 29a During operation of the toroidal type continuously variable transmission, a force called 2Ft is applied to each power roller 9a as described above. This force 2Ft is supported by any step surface 33a provided on each trunnion 10d via each thrust ball bearing 29a. At this time, the force 2Ft is applied to the thrust ball bearings 29a in the radial direction. Each of these thrust ball bearings 29a is a thrust angular ball bearing, and can support a radial load in addition to a thrust load. However, it is inevitable that the power rollers 9a and the outer rings 30a are displaced slightly in the radial direction (rotating direction of each disk) based on the radial load. As will be described later, what is fed back for the gear ratio control in the structure of this example is the displacement amount of any one of the outer wheels 30a, but is actually related to the gear shift. The displacement to be performed is the amount of displacement of each power roller 9a. Therefore, the number, diameter, and contact angle of the balls constituting each thrust ball bearing 29a are the same between the thrust ball bearings 29a, and the radial rigidity of each thrust ball bearing 29a is the same.

  As described above, the thrust ball bearing incorporated in any one of the plurality of power roller units 34 among the plurality of sets of power roller units 34 having the same specifications associated with the relative displacement between the trunnion 10d and the power roller 9a. An arch-shaped bracket 35 to be detected is supported and fixed to an outer ring 30a constituting 29a. The detected bracket 35 includes a detected portion 36 and a pair of leg portions 37 a and 37 b that are bent in the same direction from both ends of the detected portion 36. The detected portion 36 has a partial arc shape concentric with the central axis of the tilt shaft 12a concentrically provided at both end portions of the trunnion 10d in a state where the detected bracket 35 is supported and fixed to the outer ring 30a. One side is a detected surface 38. The detected surface 38 is an inclined surface that is inclined with respect to the circumferential direction with the central axis of the inclined shaft 12a as the center, and the power roller unit 34 is assembled with a change in position in the circumferential direction. Thus, the axial position of the support beam portion 27a changes.

  The above-described detected bracket 35 has columnar protrusions 39, 39 projecting from the front end surfaces of the both leg portions 37a, 37b, and shoulders present on both sides of the recess 31 in the outer surface of the outer ring 30a. By press-fitting into circular concave holes 41, 41 formed in the portions 40, 40, they are supported and fixed at predetermined positions on the outer surface of the outer ring 30a. Prior to supporting and fixing the detected bracket 35 to the outer ring 30a, the concave portion 31 of the outer ring 30a and the cylindrical convex surface 26a of the support beam portion 27a are engaged (the outer ring 30a and the Combined with trunnion 10d). Further, in a state where the detected bracket 35 is supported and fixed to the outer ring 30a, elastic deformation of each member is caused between the detected bracket 35 and the support beam portion 27a during operation of the toroidal type continuously variable transmission. Based on the above, a gap that allows the swinging displacement of the outer ring 30a relative to the support beam portion 27a is interposed.

  As described above, when the outer ring 30a and the trunnion 10d are combined and the detected bracket 35 is supported and fixed to the outer ring 30a, the trunnion can be used even before the toroidal continuously variable transmission is assembled. It can prevent that 10d and the said outer ring | wheel 30a isolate | separate. Further, the outer ring 30a, the other components of the thrust ball bearing 29a, and the power roller 9a are not separated by a retaining ring 44 and a washer 45 which are locked to the tip of a support shaft 25b integral with the outer ring 30a. Are combined. For this reason, the power roller unit 34 portion including the trunnion 10d and the outer ring 30a can be handled as a non-separated sub-assembly unit, and the assemblability of the toroidal continuously variable transmission can be improved. .

  The power roller unit 34 incorporating the detected bracket 35 as described above, together with other power roller units not provided with such a detected bracket 35, for example, as shown in FIGS. The toroidal type continuously variable transmission 1 is configured by being incorporated between the input disks 7a and 7b and the output disk 8. A displacement amount of the outer ring 30a constituting the power roller unit 34 is obtained by a combination of the detected bracket 35 and the sensor 42, and the toroidal continuously variable transmission 1 is obtained based on a signal representing the displacement amount. Is controlled by feedback control. This feedback control can correct a so-called torque shift in which the gear ratio of the toroidal continuously variable transmission 1 deviates from a target value based on elastic deformation of each component of the toroidal continuously variable transmission 1. Gear ratio control can be performed. The sensor 42 may be an inner surface of a casing 43 (see FIGS. 8 and 9) in which the toroidal continuously variable transmission 1 is housed or a bracket supported and fixed in the casing 43. It is supported on the part that will not be displaced during the operation of 1.

  The detection signal of the sensor 42 is, for example, a hydraulic control device for gear ratio control shown in FIG. 10 described above, and the spool 16 of the gear ratio control valve 13 is axially set to a predetermined amount (corresponding to the displacement amount of the outer ring 30a). It is used for displacement. That is, in the case of the conventional structure shown in FIG. 10, the displacement of the trunnion supporting the power roller is mechanically transmitted to the spool 16. In such a structure, as described above, the gear ratio control becomes unstable in the case of the structure shown in FIGS. On the other hand, in this example, not the displacement of the trunnion 10d but the displacement of the outer ring 30a is measured. The displacement amount of the outer ring 30a and the displacement amount of the power roller 9a are not exactly the same, but the difference is negligibly small. Therefore, if the spool 16 of the transmission ratio control valve 13 is displaced based on the displacement of the outer ring 30a, the transmission ratio control of the toroidal continuously variable transmission 1 can be performed stably. This transmission ratio control is a difference “D−d” between the distance D between the step surfaces 33a and 33a and the dimension d of the portion of the outer ring 30a disposed between the two step surfaces 33a and 33a. It is not affected by the size. However, this difference “D−d” needs to be equal among all the power roller units 34.

  In order to displace the spool 16 on the basis of the output signal of the sensor 42, a stepping motor for feedback control is provided separately from the stepping motor 14 for setting the gear ratio in the structure shown in FIG. The gear ratio setting stepping motor 14 uses the feedback control stepping motor in the same manner as the sleeve 17 of the gear ratio control valve 13 is displaced in the axial direction by a linear motion mechanism such as a feed screw mechanism. The spool 16 is displaced in the axial direction.

  The structure for controlling the transmission ratio of the toroidal type continuously variable transmission based on the output signal of the sensor is not limited to the structure shown in the figure. Further, like the structure shown in the figure, in the structure in which the spool 16 and the sleeve 17 of the speed ratio control valve 13 are displaced in the respective axial directions by the stepping motor 14 for setting the speed ratio and the stepping motor for feedback control. The members 16 and 17 displaced by the respective stepping motors can be reversed.

Further, the installation position of the detected bracket 35 for measuring the displacement of the outer ring 30a is not limited to the center position of the outer ring 30a as shown in the figure, and may be the upper end position or the lower end position, and the sensor can be installed. If so, it is also possible to provide the detected surface directly on a part of the outer ring.
Furthermore, as the sensor structure, any of a non-contact type and a contact type can be adopted as long as the displacement amount can be accurately measured. A non-contact sensor is preferable in order to ensure sufficient durability regardless of the rocking displacement of the outer ring 30a. On the other hand, during operation of a toroidal-type continuously variable transmission, a large amount of splash of traction oil floats on the sensor installation part. May not be reliable. In such a case, it is preferable to use a contact type sensor.

DESCRIPTION OF SYMBOLS 1 Toroidal type continuously variable transmission 2 Planetary gear type transmission 3 Low speed clutch 4 High speed clutch 5 Input shaft 6 Output shaft 7a, 7b Input disk 8 Output disk 9, 9a Power roller 10, 10a, 10b, 10c, 10d Trunnion DESCRIPTION OF SYMBOLS 11 Actuator 12, 12a Tilt axis | shaft 13 Gear ratio control valve 14 Stepping motor 15 Princess cam 16 Spool 17 Sleeve 18 Hydraulic source 19a, 19b Hydraulic chamber 20 Piston 21a, 21b Rod 22 Link arm 23 Pressing device 24 Input rotary shaft 25, 25a , 25b Support shaft 26, 26a Cylindrical convex surface 27, 27a Support beam portion 28 Support plate 29, 29a Thrust ball bearing 30, 30a Outer ring 31 Recess 32 Radial needle bearing 33, 33a Stepped surface 34 Power roller unit 35 Detected bracket 36 the detected portion 37a, 37b leg portion 38 the sensed surface 39 projection 40 shoulder 41 recessed holes 42 sensor 43 casing 44 the retaining ring 45 Washer 46 radial needle bearing

Claims (2)

At least one pair of disks, a plurality of trunnions, the same number of power rollers as each trunnion, the same number of thrust rolling bearings, a pressing device, and a gear ratio control means ,
Each of these discs is a toroidal curved surface having a circular arc cross section, with the axial one side surfaces facing each other, concentrically supported and freely supported by relative rotation,
Each trunnion exists between a pair of tilting shafts provided concentrically with each other at both ends, and between these tilting shafts, and at least the inner side surface in the radial direction of each disk A support beam portion having a cylindrical convex surface having a center axis that is parallel to the center axis of both tilting shafts and outside the center axis in the radial direction of each disk, and both ends of the support beam portion are mutually connected. Provided with a pair of stepped surfaces for each trunnion provided in a state of being opposed to each other, and with respect to the circumferential direction of the positions between the axial side surfaces of each disk in the axial direction, Oscillating displacement about the two tilting shafts in a twisted position with respect to the central axis of the disc is freely provided,
Each of the power rollers is rotatably supported on the inner side surface of each trunnion via a thrust rolling bearing, and each circumferential surface having a spherical convex surface is brought into contact with one axial side surface of each disk. And
Each thrust rolling bearing is provided between the support beam portion of each trunnion and the outer surface of each power roller, and an outer ring provided on each support beam portion side, and an inner ring of each outer ring. A plurality of rolling elements are provided between the outer ring raceway provided on the side surface and the inner ring raceway provided on the outer side surface of each of the power rollers, respectively.
The outer ring of each thrust rolling bearing engages the concave portion provided on the outer side surface of each outer ring with the cylindrical convex surface of each support beam portion, and the above described provided on both ends of each support beam portion. By arranging between each pair of stepped surfaces for each trunnion, with respect to each trunnion, the axial displacement of each disk is controlled in a state where the axial displacement of each support beam is restricted. Supported to enable displacement,
The pressing device, each of said discs each other facing each other in the state sandwiching the power rollers state, and are not pressed towards each other,
The gear ratio control means switches the hydraulic circuit based on the relative displacement in the axial direction between the spool and the sleeve constituting the gear ratio control valve, and sandwiches the piston constituting the hydraulic actuator provided for each trunnion. Pressure oil is supplied to and discharged from a pair of provided hydraulic chambers, and the trunnions are displaced in the axial direction of the tilt shafts provided at both ends by the actuators. axis is swung displaced around the said a der Ru toroidal type continuously variable transmission that changes the gear ratio between each disk between,
At least one of the outer rings constituting each thrust rolling bearing itself or a part of a member coupled and fixed to the outer ring and displaced in synchronization with the outer ring, the outer ring centered on the support beam portion. In addition to providing a surface to be detected that is inclined with respect to the rocking direction, it is possible to detect the displacement of the surface to be detected with respect to the axial direction of the support beam by means of a sensor that is supported by a fixed portion that does not displace during operation. And
Either one of the spool and the sleeve is displaced in the axial direction by a first electric actuator for setting a gear ratio, and the other member is controlled based on a detection signal of the sensor; A toroidal continuously variable transmission that is displaced in the axial direction by a second electric actuator for feedback . An arch-shaped bracket to be detected is supported and fixed to the outer ring in a state in which the outer ring is supported so as to be swingable and displaceable, and the detected bracket with respect to the axial direction of the support beam. of the one side, the detected face is provided, the toroidal type continuously variable transmission according to claim 1.

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