JP3972453B2 - Trunnion drive unit for double cavity type toroidal continuously variable transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a trunnion drive device for adjusting a tilt angle of a rotation shaft of each power roller provided in two sets of toroidal transmission mechanisms in a double cavity toroidal continuously variable transmission used as a transmission of an automobile, for example. About.
[0002]
[Prior art]
A toroidal-type continuously variable transmission, which has been studied mainly as a transmission for automobiles, has an input disk and an output disk each having an arc-shaped concave cross section on the surfaces facing each other, and between these two disks. A toroidal speed change mechanism having a structure combined with a rotatable power roller held between the two. The input disk is drivingly coupled to the torque input shaft so as to be movable in the direction of the torque input shaft, while the output disk is rotatable relative to the torque input shaft and away from the input disk. It is mounted opposite the input disk so that movement is restricted.
[0003]
In the toroidal type transmission mechanism as described above, when the input disk rotates, the output disk rotates in reverse via the power roller. Therefore, the rotational motion input to the torque input shaft is transmitted to the output disk as a reverse rotational motion. And taken out from the output gear that rotates integrally with the output disk. At this time, the speed of rotation from the torque input shaft to the output gear is increased by changing the inclination angle of the rotating shaft of the power roller so that the peripheral surface of the power roller is in contact with the vicinity of the outer periphery of the input disk and the center of the output disk On the contrary, the torque input shaft is changed by changing the tilt angle of the rotating shaft of the power roller so that the peripheral surface of the power roller is in contact with the vicinity of the center of the input disk and the outer periphery of the output disk. To the output gear. Further, an intermediate gear ratio can be obtained almost steplessly by appropriately adjusting the inclination angle of the rotating shaft of the power roller.
[0004]
The toroidal transmission mechanism includes at least two power rollers symmetrically arranged around a torque input shaft on a plane orthogonal to the torque input shaft, and each power roller has a bearing by a trunnion. It is supported via a torsion. A trunnion is a member having a substantially U-shaped cross-section with a recess for housing the power roller in the center, and the power held in the recess with the tilting shaft connected to both sides as the center. It is tilted and rotated integrally with the roller. Since the tilt axis is coupled to the casing via the spherical ring, the trunnion can be slightly slid in the direction along the tilt axis. Two or more trunnions arranged on the same plane perpendicular to the torque input shaft are interconnected by yokes that connect the ends of the tilting shafts of adjacent trunnions to form an annular trunnion set.
[0005]
Furthermore, a double cavity type toroidal continuously variable transmission has been devised in which two trunnion sets described above are provided to reduce the rotational torque of the power roller. In the toroidal type continuously variable transmission of this type illustrated in FIG. 4, two operation spaces of a front cavity and a rear cavity are formed around one output gear 3, and the toroidal disposed in each cavity. The mold transmission mechanisms 1 and 2 each have one trunnion set. The output disks 1b and 2b of each toroidal transmission mechanism are connected in parallel so as to be back to back with the output gear 3 sandwiched therebetween, and input from the respective input disks 1a and 2a. The driven torque is shifted by each power roller and then taken out from the drive gear 4 that meshes with the output gear 3 through the output shaft 5. In this example, the valve body of the trunnion drive device is disposed on the same side as the output shaft 5 with respect to the torque input shaft 9.
[0006]
Each trunnion set includes a hydraulic drive unit that slides the trunnion, a control valve that adjusts the hydraulic pressure supplied to the hydraulic drive unit, a hydraulic pressure setting unit that sets a target hydraulic pressure for the control valve, and a tilt of each trunnion A pair of trunnion driving devices each including a hydraulic control unit that feeds back an angle to a control valve are arranged adjacent to each other. By controlling the tilt rotation of the trunnion around the tilt shaft by the trunnion drive device, the tilt angle of the power roller rotation shaft is adjusted, and an arbitrary gear ratio of the toroidal continuously variable transmission can be obtained.
[0007]
FIG. 5 shows an enlarged vertical sectional structure of the rear cavity portion in the toroidal-type continuously variable transmission of the type illustrated in FIG. Each hydraulic drive unit includes two sets of cylinder units arranged in a common valve body. Each cylinder unit includes a cylinder chamber 11 and a hydraulic piston 12 fitted in the cylinder chamber 11. Consists of The hydraulic piston 12 of each cylinder unit is coupled to one end of each tilting shaft 7 provided in two adjacent trunnions 6 of the trunnion set via a drive rod 13 and a control valve (not shown). The trunnions 6 are driven in the opposite directions along the tilting axis 7 by the pressure of the control oil supplied through). The driving torque applied to the two adjacent trunnions 6 is all equal to the other trunnions constituting the same trunnion set by the action of the yoke 8 that joins the ends of the tilt shafts 7 to each other. Therefore, the entire trunnion set undergoes rotational displacement in the circumferential direction around the torque input shaft 9.
[0008]
In the common valve body, a control valve is provided together with each hydraulic drive unit, and by opening and closing the oil supply hole of the control valve according to the tilting rotation movement of the trunnion, each cylinder unit of the hydraulic drive unit The amount of oil flowing in is increased or decreased. In addition, a hydraulic control unit for feedback control of the state of the oil supply hole based on the tilt rotation motion of the trunnion is connected to the control valve, and the hydraulic pressure setting unit for defining the target hydraulic pressure controlled by the control valve is controlled. Connected to the end of the valve. The tilt angle of the trunnion is transmitted to the hydraulic control unit by, for example, a combination of a recess cam and a link mechanism for taking out the tilt rotation motion of the trunnion and converting it into a linear displacement. It is desirable that the control valve is disposed close to each cylinder unit in order to increase the accuracy of hydraulic control.
[0009]
The valve body is composed of an upper body 14a positioned at the upper portion and a lower body 14b positioned at the lower portion, and both are fixed to each other with a screw or the like in a state of being superposed vertically. Each of the upper body 14a and the lower body 14b is made of a single plate continuously formed from the front cavity side to the rear cavity side, and the upper body 14a is located at a position corresponding to each trunnion tilting shaft 7 inside. A total of four cylinder chambers 11 are provided for arranging the hydraulic pistons 12 described above. Oil paths for supplying control oil to the cylinder chambers are stretched around the joint surfaces of the upper body 14a and the lower body 14b.
[0010]
[Problems to be solved by the invention]
In a general toroidal continuously variable transmission, an output shaft 5 for taking out drive torque toward a drive wheel is arranged in parallel with the torque input shaft 9 and occupies a part of the space in the rear cavity. Therefore, when the valve body of the trunnion drive device is disposed on the same side as the output shaft 5 with respect to the torque input shaft 9, the interference between the output shaft 5 and the rear cavity side of the valve body is taken into consideration. The arrangement of each component must be determined. Conventionally, in this type of double-cavity toroidal-type continuously variable transmission, the output shaft 5 can penetrate the rear cavity side of the valve body through an opening 15 provided in advance to prevent interference between the two. It was.
[0011]
However, it is not easy to provide the upper body 14a and the lower body 14b, each of which is formed of a single plate, with the elongated opening 15 along the axial direction for allowing the output shaft 10 to pass therethrough. The workability of the valve body is greatly impaired. Further, in the region where the opening 15 is formed, a thin portion is generated due to a decrease in the effective dimension in the thickness direction, and thus a local decrease in the valve body strength is inevitable. Furthermore, in the thin wall portion, it is not possible to ensure a large cross-sectional area of the oil passage for supplying the control oil to the cylinder chamber. On the other hand, when the thin wall portion is bypassed, the oil passage layout becomes complicated. It becomes difficult to keep the control hydraulic pressure of each cylinder unit equal.
[0012]
The present invention has been made under the circumstances described above, and prevents the output shaft from penetrating the valve body even when the valve body is disposed on the same side as the output shaft with respect to the torque input shaft. An object of the present invention is to provide a trunnion drive device for a double cavity type toroidal continuously variable transmission that prevents deterioration in valve body strength and workability and maintains uniformity in control hydraulic pressure.
[0013]
[Means for Solving the Problems]
The present invention provides at least two power rollers disposed around a torque input shaft and at least two power rollers rotatably supported by the power rollers while being rotatably supported by the power rollers. Cylinder chambers, which are incorporated in a double-cavity toroidal continuously variable transmission having one trunnion set composed of two trunnions in the front and rear cavities, and are arranged for each trunnion set; A hydraulic drive unit having two sets of hydraulic pistons fitted in the cylinder chamber, a control valve for adjusting the hydraulic pressure in each cylinder chamber, a hydraulic pressure setting unit for setting a target hydraulic pressure of the control valve, and a tilt angle of each trunnion And a hydraulic control unit that feeds back to the control valve The present invention relates to a trunnion drive device for a double-cavity toroidal continuously variable transmission that controls the tilting and rotational movement of the trunnion about each tilt axis, and the object of the present invention is to provide each hydraulic drive unit and each control valve. Are arranged in the same direction as the output shaft with respect to the torque input shaft, and the front valve body in the front cavity without the output shaft is integrally formed. In order to avoid interference with the output shaft, a rear valve body in a rear cavity where the output shaft exists is divided and formed by two valve body elements, and the cylinder chamber and the hydraulic piston are provided in each valve body element. This is achieved by providing one set each.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
A trunnion drive device for a double cavity toroidal continuously variable transmission according to the present invention includes a hydraulic drive unit that slides the trunnion, a control valve that adjusts the hydraulic pressure supplied to the hydraulic drive unit, A hydraulic pressure setting unit that sets the target supply hydraulic pressure of the valve and a hydraulic pressure control unit that feeds back the tilt angle of each trunnion to the control valve are provided and are arranged adjacent to each trunnion set. In addition, as in the conventional case, the tilt angle of the power roller rotating shaft is adjusted by controlling the tilting rotation of the trunnion around the tilting shaft by these respective components, so that any speed change of the toroidal-type continuously variable transmission can be achieved. A ratio can be obtained.
[0015]
1 and 2 show vertical sectional structures of a rear cavity portion and a front cavity portion of a double cavity type toroidal continuously variable transmission in which the trunnion drive device of the present invention is incorporated. FIG. 3 shows a horizontal sectional structure of the entire valve body of the double cavity type toroidal continuously variable transmission shown in FIGS. 1 and 2. In each of these drawings, the components denoted by the same reference numerals as those shown in FIGS. 4 and 5 have the same functions as those of the conventional trunnion driving device, and therefore detailed description thereof will be omitted below. .
[0016]
In the trunnion drive device of the present invention, the valve body in which each cylinder unit of the hydraulic drive unit and the control valve are disposed is disposed on the same side as the output shaft 5 with respect to the torque input shaft 9 and is disposed in the front cavity. The front side valve body 21 is located in a large part and the rear side valve body 22 is located in the rear cavity. Both the front side valve body 21 and the rear side valve body 22 are bonded with screws or the like, with the upper body constituting the upper part and the lower body constituting the lower part overlapped, as in the conventional valve body. Consists of. A drive gear 4 is disposed in a gap formed between the front side valve body 21 and the rear side valve body 22.
,
Cylinder chambers 11 are formed at positions facing the trunnion tilting shaft 7 of the front side valve body 21, and constitute two sets of cylinder units together with the hydraulic pistons 12 fitted in the cylinder chambers. Further, the middle part of the two cylinder chambers 11 is provided with a post mounting hole 210 through which a post for fixing the yoke to the casing is inserted. The two sets of cylinder units are respectively coupled to the trunnion set in the front cavity via the drive rod 13.
[0018]
On the other hand, the rear side valve body 22 is constituted by two valve body elements 220 distributed to both sides of the torque input shaft. Each of the two valve body elements 220 is formed with one cylinder chamber 11 and a hydraulic piston 12 is fitted into each cylinder chamber 11 to constitute a cylinder unit. The end portions of the two tilting shafts 7 of the trunnion set arranged in the rear cavity and the hydraulic piston 12 are connected to each other by a drive rod 13. The output shaft 5 is accommodated in a gap formed between the two valve body elements.
[0019]
With the above configuration, in the trunnion drive device of the present invention, even when the valve body of the trunnion drive device is disposed on the same side as the output shaft 5 with respect to the torque input shaft 9, the rear side valve body 22 in the rear cavity. And the output shaft 5 do not interfere with each other. Moreover, since the front side valve body 21 and each valve body element 220 are independently fixed to the casing, alignment during assembly is facilitated.
[0020]
【The invention's effect】
As described above, according to the trunnion drive device for a double cavity type toroidal continuously variable transmission according to the present invention, even when the valve body is arranged on the same side as the output shaft with respect to the torque input shaft, the output shaft It is possible to prevent the valve body from penetrating. As a result, it is not necessary to provide an opening on the rear cavity side, and the workability is improved. In addition, since the thin portion is not formed in the valve body, a local decrease in the valve body strength is eliminated, and the oil passage can be formed evenly and deeply. Uniformity is maintained.
[Brief description of the drawings]
FIG. 1 is a vertical sectional view showing a structure of a rear cavity portion in a double cavity type toroidal continuously variable transmission in which a trunnion driving device of the present invention is incorporated.
2 is a vertical sectional view showing a structure of a front cavity portion in the double cavity type toroidal continuously variable transmission of FIG. 1; FIG.
3 is a horizontal sectional view showing the structure of the entire valve body in the double cavity toroidal continuously variable transmission of FIG. 1;
FIG. 4 is an axial sectional view showing an overall structure of a double cavity type toroidal continuously variable transmission in which a conventional trunnion driving device is incorporated.
5 is a vertical sectional view showing a structure of a rear cavity portion in the double cavity type toroidal continuously variable transmission of FIG. 4;
[Explanation of symbols]
1, 2 Toroidal transmission 1a, 2a Input disk 1b, 2b Output disk 3 Output gear 4 Drive gear 5 Output shaft 6 Trunnion 7 Tilt shaft 8 Yoke 9 Torque input shaft 11 Cylinder chamber 12 Hydraulic piston 13 Drive rod 14a Upper body 14b Lower body 15 Opening 21 Front side valve body 22 Rear side valve body 210 Post mounting hole 220 Valve body element

Claims (1)

At least two power rollers disposed around the torque input shaft and at least two trunnions that rotate and rotate integrally with the power rollers around the respective tilting shafts while rotatably supporting the power rollers. Are incorporated into a double cavity type toroidal-type continuously variable transmission having one pair of trunnion sets in the front cavity and rear cavity, and arranged in each trunnion set in the cylinder chamber and the cylinder chamber. A hydraulic drive unit including two sets of fitted hydraulic pistons, a control valve for adjusting the hydraulic pressure in each cylinder chamber, a hydraulic pressure setting unit for setting a target hydraulic pressure of the control valve, and a tilt angle of each trunnion Each trunnio by a hydraulic control unit that feeds back to In the trunnion drive device of a double cavity type toroidal continuously variable transmission for controlling the tilting and rotational movement about each tilting shaft, a front side valve body provided with each of the hydraulic drive units and the control valves therein, and Both the rear side valve bodies are arranged in the same direction as the output shaft with respect to the torque input shaft, the front side valve body in the front cavity where the output shaft does not exist is integrally formed, and the output shaft exists. The rear side valve body in the rear cavity is divided into two valve body elements in order to avoid interference with the output shaft, and each of the cylinder body and the hydraulic piston is provided in each valve body element. A trunnion drive device for a double-cavity toroidal-type continuously variable transmission.

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