JPH0932901A - Power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain good operation of a hydraulic actuator of a traction-drive type continuously variable transmission mechanism even at a low temperature and to use an oil supplying means in common without impairing torque transferring performance, in the traction-drive type continuously variable transmission mechanism. SOLUTION: A toroidal-type continuously variable transmission mechanism 24 is lubricated by traction oil in the form of an oil bath. On the other hand, by using an oil supplying means, which supplies oil having low viscoelasticity to hydraulic cylinders for B1 and B2 of both a going forward/backward speed change mechanism 26 and a differential device 28 and to prescribed lubication parts, hydraulic cylinders for pushing/pressing and for a speed change of the toroidaltype continuously variable transmission mechanism 24 are supplied with oil so as to be operated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device, and more particularly to improvement of a power transmission device having a traction drive type continuously variable transmission mechanism and a gear type power transmission mechanism.

[0002]

(A) A traction drive type continuously variable transmission mechanism for transmitting torque through traction oil,
(B) continuously variable transmission hydraulic actuator provided in the continuously variable transmission mechanism, (c) gear type power transmission mechanism, (d)
A power transmission device having an oil supply means for supplying an oil different from the traction oil to a predetermined portion of the gear type power transmission mechanism is disclosed in, for example, Japanese Patent Laid-Open No. 62-11007.
No. 1 and other publications. As the traction drive type continuously variable transmission mechanism, a toroidal type is widely known, and the transmission ratio is continuously changed by changing the angle of a variator (roller) arranged between a pair of disks. It is usually equipped with a hydraulic actuator such as a hydraulic cylinder in order to press the disk and the variator with a predetermined pressing force or to change the angle of the variator. The continuously variable transmission mechanism is lubricated by the traction oil supplied by the traction oil supply means, and the hydraulic actuator is also operated by the traction oil supplied by the traction oil supply means. It is normal that The gear type power transmission mechanism is a gear type speed change mechanism that switches forward and backward or a gear ratio, a gear type speed reducer that simply reduces speed, a planetary gear type or bevel gear type differential device, etc., and is connected to the continuously variable transmission mechanism. The oil supplied by the oil supply means is used to lubricate the meshed portion or to operate a hydraulic actuator such as a hydraulic cylinder for switching between forward and backward movement. In this case, viscoelasticity is required. Because it does not, oil with lower viscoelasticity than traction oil is used.

[0003]

However, when the hydraulic actuator of the continuously variable transmission is operated by the traction oil in this way, the viscoelasticity is high and the fluidity is poor, so that an operation delay occurs especially at low temperatures. The shift control may be impaired. Further, since the oil supply means is provided for each of the continuously variable transmission mechanism and the gear type power transmission mechanism, there is a problem that the number of parts is increased and the cost is increased. When a common oil is supplied by using a single oil supply means, if traction oil having high viscoelasticity is used, sufficient fluidity cannot be obtained as described above. May cause a shift shock due to the delay in the operation of the hydraulic actuator, while the sufficient lubrication performance may not be obtained, but if lubricating oil with low viscoelasticity is used, the torque transmission performance of the traction drive type continuously variable transmission mechanism will be impaired. .

The present invention has been made in view of the above circumstances, and it is an object of the present invention to enable a hydraulic actuator of a traction drive type continuously variable transmission mechanism to operate well even at a low temperature. It is in. Another object is to standardize the oil supply means without impairing the operation and lubrication performance of the hydraulic actuator and the torque transmission performance of the traction drive type continuously variable transmission mechanism.

[0005]

In order to achieve such an object, the present invention provides: (a) a traction drive type continuously variable transmission mechanism; and (b) a continuously variable transmission hydraulic actuator.
In a power transmission device having (c) a gear type power transmission mechanism and (d) an oil supply means, the oil output from the oil supply means operates the hydraulic actuator for continuously variable transmission. And The continuously variable transmission mechanism is preferably lubricated by the traction oil in an oil bath system.

[0006]

In the power transmission device of the present invention as described above, the oil supply means for supplying the oil to the predetermined portion of the gear type power transmission mechanism is used, and the oil output from the oil supply means is used for the stepless operation. Since the speed change hydraulic actuator is operated, the operation delay at a low temperature or the like is eliminated as compared with the case where the traction oil having high viscoelasticity is used as in the conventional case.

On the other hand, traction oil having a high viscoelasticity is required for lubrication of a traction drive type continuously variable transmission mechanism, and at least a part of the continuously variable transmission mechanism is lubricated by an oil bath system in which it is immersed in the traction oil. By doing so, one oil supply means can be provided without impairing the torque transmission performance, the number of parts can be greatly reduced, and the device can be configured simply and at low cost.

[0008]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a configuration diagram of a vehicle drive device 12 including a power transmission device 10 according to an embodiment of the present invention, which includes an internal combustion engine 14 such as a gasoline engine and an electric motor 16 functioning as an electric motor and a power source. It is for a so-called hybrid vehicle used as. The internal combustion engine 14 and the electric motor 16 are arranged so as to face each other on a common first axis, and their output shafts 14a and 16a are connected via a clutch C so as not to rotate relative to each other. A chain drive (sprocket) 20 is attached to the output shaft 16a of the electric motor 16, and torques thereof are transmitted to the power transmission device 10 via the chain 22. The power transmission device 10 includes a toroidal type continuously variable transmission mechanism 24 and a planetary gear type forward / reverse transmission mechanism 2 which are arranged along a second axis parallel to the first axis.
6 and a bevel gear type differential device 28, and the torque is transmitted to the toroidal type continuously variable transmission mechanism 24 via a chain driven (sprocket) 30 and is transmitted via a forward / reverse transmission mechanism 26 and a differential device 28. Output from the pair of transmission shafts 32 and 34 to drive wheels (not shown). The vehicle drive device 12 is mounted on a vehicle in a posture in which the first axis is substantially parallel to the width direction of the vehicle.

The toroidal type continuously variable transmission mechanism 24 is an example of a traction drive type continuously variable transmission mechanism that transmits torque through traction oil having high viscoelasticity. In this embodiment, a double cavity type full toroidal type transmission mechanism is used. Things are used. FIG. 2 is a schematic cross-sectional view of the toroidal type continuously variable transmission mechanism 24. The chain driven 30 is relatively rotatable and axially movable via a bearing 38 on an output shaft 36 concentric with the second axis O. A pair of input disks 40a and 40b are arranged so as not to rotate relative to the chain driven 30. The input disks 40a, 40b are arranged in opposite postures (back to back), and are opposed to the output disks 44a, 44b with a plurality of variators (rollers) 42a, 42b interposed therebetween. The output discs 44a and 44b are spline-fitted to the output shaft 36 such that they cannot rotate relative to each other and are movable in the axial direction. One of the output discs 44a is pushed to the left in the drawing by the pushing hydraulic cylinder 46. As a result, the variators 42a and 42b are sandwiched between the output disks 44a and 44b and the input disks 40a and 40b with a predetermined pressing force. The other output disc 44b is prevented from moving to the left by a snap ring 48. The pressing hydraulic cylinder 46 corresponds to a continuously variable hydraulic actuator.

The variators 42a and 42b are rotatably arranged around the center lines Sa and Sb, respectively, and when the input disks 40a and 40b are rotated around the second axis O, they are viscoelastic to the traction oil. The output disks 44a, 4 are rotated by the shearing force.
4b is rotated in the reverse direction of the input disks 40a, 40b, respectively. The variators 42a and 42b are also
A center line S is generated by the shifting hydraulic cylinder 50 (see FIG. 3).
The inclination angles of a and Sb, that is, the inclinations in the left-right direction in FIG.
0b and the diameter dimension from the contact point to the output discs 44a, 44b to the second axis O are continuously changed, so that the gear ratio (input side rotation speed / output side rotation speed) is continuously changed. Change. This shifting hydraulic cylinder 50 is also a continuously variable shifting hydraulic actuator.

On the other hand, the toroidal type continuously variable transmission 2
4 is housed in a pair of cases 52a, 52b fixedly mounted on the vehicle body, and at least a part of which is immersed in the traction oil filled with a predetermined amount to input the variators 42a, 42b. Disk 40a,
The contact points with the 40b and the output disks 44a, 44b are always lubricated by an oil bath method regardless of the gear ratio. Cases 52a, 52b and chain driven 3
The oil seals 54a and 54b are liquid-tightly sealed with oil seals 54a and 54b while permitting relative rotation.
b and the output shaft 36, oil seals 56a, 5 are provided.
A liquid-tight seal is provided by 6b while allowing relative rotation. The output shaft 36 is hollow, and the transmission shaft 32 is inserted through the output shaft 36. In addition, FIG.
Although only the upper half of the axis O is shown, the toroidal type continuously variable transmission mechanism 24 is configured substantially symmetrically about the second axis O. The power transmission device 10 of FIG. 1 is also a skeleton diagram showing only the upper half of the second axis O.

Returning to FIG. 1, the forward-reverse transmission mechanism 26 and the differential device 28 correspond to a gear type power transmission mechanism. The forward-reverse transmission mechanism 26 includes three sets of simple planetary gear devices 58, 60, 62. And a reverse brake B1 and a forward brake B2, and the output shaft 36 of the toroidal type continuously variable transmission mechanism 24 is integrally connected to the sun gear of the simple planetary gear devices 58 and 60. ing. Then, in accordance with a shift operation of a shift lever (not shown), the reverse brake B1 is engaged and the forward brake B2 is released to establish a reverse stage, and the forward brake B2 is engaged and reverse. The forward stage is established by releasing the brake B1, and the neutral stage (neutral) is established by releasing both brakes B1 and B2. Further, the forward / reverse speed change mechanism 26 reduces the forward speed and the reverse speed at a predetermined gear ratio (gear ratio>
1), and the simple planetary gear unit 62
Power is output to the differential device 28 from the carrier. In addition, in FIG. 1, three sets of simple planetary gear units 5 are provided.
Although the diameter dimensions (gear ratios) of the gears 8, 60 and 62 are equal to each other, the diameter dimensions are appropriately set according to a desired gear ratio and the like.

On the other hand, the vehicle drive device 12 is equipped with the hydraulic circuit shown in FIG. 3, and an oil sump 64 is provided at the bottom of a housing (not shown) that houses the forward / reverse transmission mechanism 26 and the differential device 28. Oil is pumped up by the oil supply means 66 from the above and supplied to the pressing hydraulic cylinder 46, the shifting hydraulic cylinder 50 and the like. The oil supply means 66 includes a pump 68 for pumping oil from the oil sump 64, and a hydraulic control circuit 70 having a pressure control valve for adjusting the hydraulic pressure of the pumped oil, a direction switching valve for switching the oil passage, and the like. , C hydraulic cylinder 7 for engaging the clutch C in addition to supplying oil of a predetermined hydraulic pressure to the pressing hydraulic cylinder 46 and the shifting hydraulic cylinder 50.
2, a B1 hydraulic cylinder 74 for engaging the reverse brake B1, a B2 hydraulic cylinder 76 for engaging the forward brake B2, and simple planetary gear devices 58, 60,
Oil is supplied to a lubricating oil passage 78 that guides the oil to the lubrication parts of the bearings and meshing portions of the differential device 28 and the differential device 28. Hydraulic cylinder 74 for B1,
The B2 hydraulic cylinder 76 is a hydraulic actuator that switches the operating state of the forward / reverse transmission mechanism 26 as a gear type power transmission mechanism. Since the oil in this case operates the hydraulic cylinder and lubricates the bearings, the meshing parts, etc., a lubricating oil whose viscoelasticity is sufficiently lower than that of the traction oil is used. The pump 68
Is the output shaft 14a of the internal combustion engine 14 or the electric motor 16.
Alternatively, a mechanical pump rotationally driven by 16a, an electric pump operated by electric energy from a battery, or the like is used.

Here, traction oil having high viscoelasticity is required for lubrication of the traction drive type toroidal type continuously variable transmission mechanism 24, but the pressing hydraulic cylinder 4 is required.
6 and the hydraulic actuator for continuously variable transmission of the hydraulic cylinder for shifting 50 do not require high viscoelasticity, and therefore the oil supply means 66 for supplying oil to a predetermined portion of the gear type power transmission mechanism is used. The oil output from 66 is used to operate the pressing hydraulic cylinder 46 and the shifting hydraulic cylinder 50, which are hydraulic actuators for continuously variable transmission. On the other hand, for lubrication of the toroidal type continuously variable transmission mechanism 24, an oil bath system in which at least a part of the continuously variable transmission mechanism is immersed in traction oil can be used, and a supply means for forcibly feeding out the traction oil is not always required. Since it is not necessary, lubrication is performed by the oil bath method in the present embodiment, which makes it possible to use only one oil supply means, greatly reduce the number of parts, and configure the apparatus simply and inexpensively. Since the toroidal type continuously variable transmission 24 is lubricated by the traction oil having high viscoelasticity, the torque transmission performance is not impaired.

Further, as described above, the pressing hydraulic cylinder 46 and the shifting hydraulic cylinder 50 are operated by the oil having a relatively low viscoelasticity such as the lubricating oil output from the oil supply means 66. As compared with the conventional case where the traction oil having high viscoelasticity is used, the operation delay at a low temperature is eliminated.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be implemented in other modes.

For example, in the toroidal type continuously variable transmission mechanism 24 of the above embodiment, a predetermined pressing force is generated by the pressing hydraulic cylinder 46, but a pressing force is generated by the loading cam device or the like. You can also do it. The shift hydraulic cylinder 50 is not always essential, and may be equipped with at least one hydraulic actuator.

In the above embodiment, the toroidal type continuously variable transmission mechanism 24 is lubricated by the oil bath method. However, in carrying out the invention according to claim 1, a mechanical or electric compact type is adopted. The second oil supply means for supplying traction oil by the pump may be used for lubrication.

Further, although the continuously variable transmission mechanism 24 of the above-mentioned embodiment is a double cavity type full toroidal type, it may be a single cavity type or a half toroidal type. A traction drive type continuously variable transmission mechanism other than the toroidal type can also be adopted.

Further, in the above embodiment, the planetary gear type forward / reverse transmission mechanism 26 and the differential device 28 are provided as the gear type power transmission mechanism, but the contents of the gear type power transmission mechanism may be appropriately changed as necessary. obtain. Regarding the relationship with the toroidal type continuously variable transmission mechanism 24, although they are arranged on the same axis and connected in series in the above-mentioned embodiment, they can be appropriately changed.

The gear type power transmission mechanism of the above embodiment is a hydraulic actuator, that is, a hydraulic cylinder 74 for B1.
And a hydraulic cylinder 76 for B2,
The lubricating oil passage 78 is provided with the lubricating portion to which the lubricating oil is supplied. However, if at least the oil is supplied from the oil supply means to the predetermined portion, such a hydraulic actuator and the lubricating portion are provided. Is not always required.

Further, the power transmission device 10 of the above-described embodiment is for a so-called hybrid vehicle which uses the internal combustion engine 14 and the electric motor 16 as drive sources, but a traction drive type continuously variable transmission mechanism and a gear type power transmission system. The present invention can be similarly applied to other power transmission devices having a mechanism. It can be applied not only to vehicles but also to power transmission devices of industrial machines.

Although not illustrated one by one, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a configuration of a vehicle drive device including a power transmission device according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of a toroidal type continuously variable transmission mechanism in the power transmission system of FIG.

FIG. 3 is a diagram illustrating a hydraulic circuit included in the power transmission device of FIG. 1.

[Explanation of symbols]

10: Power transmission device 24: Toroidal type continuously variable transmission mechanism (traction drive type continuously variable transmission mechanism) 26: Forward and backward transmission mechanism (gear type power transmission mechanism) 28: Differential device (gear type power transmission mechanism) 46: Pressing Hydraulic cylinder (continuously variable hydraulic actuator) 50: variable speed hydraulic cylinder (continuously variable hydraulic actuator) 66: oil supply means

Claims (2)

[Claims] 1. A traction drive type continuously variable transmission mechanism for transmitting torque via traction oil, and a continuously variable transmission hydraulic actuator provided in the continuously variable transmission mechanism.
A power transmission device having a gear type power transmission mechanism and an oil supply means for supplying an oil different from the traction oil to a predetermined portion of the gear type power transmission mechanism, wherein the oil output from the oil supply means A power transmission device characterized in that a hydraulic actuator for continuously variable transmission is operated. 2. The power transmission device according to claim 1, wherein the continuously variable transmission mechanism is lubricated by the traction oil in an oil bath system.