JPS6283553A - Double row belt type continuously variable transmission for vehicle - Google Patents

Abstract

PURPOSE:To prevent production of a difference in a transmission ratio between continuously variable units and to improve durability of a transmission gear, by providing a common input rotary member, to which a power from an engine is inputted, and a differential gear device located between the input shafts of plural continuously variable transmission units. CONSTITUTION:A coupling shaft 20, coupled to a crank shaft 12 of an engine 10, is coupled to a pair of sleeves 34L and 34R through a differential gear device 36. The sleeve 34L is functioned as the input shaft of a belt type continuously variable transmission gear unit on the left, and a varying pulley 38L on the input side, having a varying engaging size, of a transmission belt 52L is provided. The varying pulley 38L on the input side is formed with a fixed rotary body 40L, secured to the sleeve 34L, and a moving rotary body 42L which forms a V-groove between the fixed rotary body 40L and the moving rotary body, and is mounted to the sleeve 34L so that it is axially movable but unmovable around a shaft. A sleeve 34R is situated in a similar manner described above.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a double-row belt type continuously variable transmission for a vehicle.

Conventional technology A belt-type continuously variable transmission that can provide a stepless gear ratio in order to control the transmission of a vehicle to the optimum gear ratio depending on the driving condition to maintain suitable drivability and increase fuel consumption efficiency. is being installed on vehicles. For example, JP-A-56
This is what is described in No.-46145. The transmission capacity of such a belt-type continuously variable transmission is limited to a range where the transmission belt does not slip.
In cases where the transmission requires a large power transmission capacity, such as when the vehicle itself is heavy or the vehicle is loaded with a large load, it is recommended to use a double-row belt type continuously variable transmission that has multiple sets of continuously variable transmission units. Conceivable. If this double-row belt type continuously variable transmission is used, power is transmitted through the transmission belts provided in parallel to the power transmission path, so a large power transmission capacity can be obtained as a whole.

Problems to be Solved by the Invention However, such conventional double-row belt-type continuously variable transmissions are configured with a plurality of input-side variable pulleys of the continuously variable transmission unit provided on a common input shaft. Power is directly transmitted from the shaft to a plurality of variable input booleans. As a result, variations in elongation and wear of the multiple power transmission belts wound around the variable input pulleys occur.
Variations in the gear ratio between multiple continuously variable transmission units may occur, resulting in slight slippage of the transmission belt or uneven torque distribution, which may cause the double-row belt type continuously variable transmission described above. However, sufficient durability was not always achieved.

Means for Solving the Problems The present invention has been made against the background of the above circumstances.
The gist is a double-row belt type continuously variable transmission for vehicles that is installed in the power transmission path from the engine to the drive wheels, and includes (1) an input shaft and an output shaft; A plurality of pairs of variable input pulleys and variable output pulleys each having a variable effective diameter, and a transmission belt wound around the variable input pulley and the variable output pulley. step-shift unit;
(2) a common input rotating member into which power from the engine is input, and (3) a common input rotating member provided between the input rotating member and the input shafts of the plurality of continuously variable transmission units, and inputting power to the input rotating member. and a differential gear device that divides the generated power and transmits the divided power to the input shafts of the continuously variable transmission units.

Operation and Effect of the Invention In this way, when the torque input from the engine to the common input rotating member is transmitted to the input shafts of the plurality of continuously variable transmission units through the differential gear device, the differential gear Since the torque is divided by the device, the torque is distributed evenly to multiple transmission belts. Therefore, even if there are variations in elongation or wear among multiple transmission belts, or variations in gear ratio between multiple continuously variable transmission units, the slight slippage of the transmission belts can be eliminated and the This increases the durability of the row belt type continuously variable transmission.

EXAMPLE Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a diagram showing a horizontally mounted engine transaxle, and the crankshaft 12 of the engine 10 is a flywheel with a damper! 4 to the forward/reverse switching device 16. The forward/reverse switching device 16 is constituted by a planetary gear mechanism, and includes a ring gear 18 integrally connected to the flywheel 14, a sun gear 22 fixed to the connecting shaft 2o, and a ring gear 18 and a sun gear 22 fixed to the connecting shaft 2o. A planetary gear 24 that meshes with the sun gear 22, and the planetary gear 24
a carrier 26 that rotatably supports the carrier 2;
6 and the ring gear 18, and a reverse brake 32 provided between the carrier 26 and the fixed axle housing 3o. 18
When the carrier 26 is connected, the planetary gear mechanism is fixed and the crankshaft 12 and the connecting shaft 20 are integrally connected, but when the rotation of the carrier 26 is prevented by the reverse brake 32, the crankshaft 12 and the connecting shaft 20 are connected together. The shaft 20 can be relatively rotated in opposite directions.

In this embodiment, the connecting shaft 20 functions as an input rotating member of a double-row belt type continuously variable transmission, and is connected to a pair of sleeves 34L and 34R provided concentrically with the connecting shaft 20 via a differential gear device 36. are connected to each other. The above-mentioned double-row belt type continuously variable transmission consists of a pair of belt type continuously variable transmission units that are configured similarly and symmetrically on the left and right sides. Regarding the type continuously variable transmission unit, the suffix L of the reference numeral on the left side will be replaced with R and the explanation will be omitted.

The sleeve 34L functions as an input shaft of the left belt-type continuously variable transmission unit, and is provided with an input-side variable pulley 38L whose effective diameter, ie, the diameter of the transmission belt 52L, is variable. Input side variable pulley 38L
is a fixed rotating body 40L fixed to a sleeve 34L,
A movable rotary body 42L is provided in the sleeve 34L with a groove formed between the fixed rotary body 40L and movable in the axial direction, but not rotatable about the axis. On the other hand, output shaft 4
4t is also provided with an output side variable boob +750L consisting of a fixed rotating body 46L and a movable rotating body 48t, similar to the input side variable pulley 38L, and a transmission bell is connected between the input side variable pulley 38L and the output side variable boob U30L. l
-52L is wrapped around it. And sleeve 34
t is provided with an input side hydraulic cylinder 54L that provides thrust to the movable rotary body 42L, and an output side hydraulic cylinder 56 that provides thrust to the movable rotary body 48L is provided on the output shaft 44L.
L is provided.

In the double-row belt type continuously variable transmission configured as described above, for example, the output side hydraulic cylinders 56L and 56
．． A line oil pressure determined based on the output torque of the engine 10 and the actual speed ratio of the double-row belt type continuously variable transmission is supplied from a hydraulic control circuit (not shown) to the transmission bell! -52L and 52. The tension, that is, the clamping force on the transmission belts 52L and 52R is exclusively controlled to eliminate power loss as much as possible. Also,
The input side hydraulic cylinder 54L is controlled by the above hydraulic control circuit.
and 54. By supplying hydraulic oil to or discharging hydraulic oil from the input hydraulic cylinders 54L and 548, the gear ratio of the double-row belt type continuously variable transmission is controlled steplessly.

The output shaft 44L of the left belt type continuously variable transmission unit is connected to the axle 62L via reduction gears 58L and 60L, and transmits power to the drive wheels 64L. In addition, the output shaft 44 of the right belt type continuously variable transmission unit is connected to the reduction gear 58.
and 60. via axle 62. , : are connected,
Drive wheel 64. transmits power to.

In the transaxle configured as above,
Connecting shaft 20! This transmitted power is transmitted to the sleeves 34L and 34R via the differential gear device 36, but the differential gear device 36 is connected to the differential pinion 66 that rotates together with the connecting shaft 20, and to the sleeves 34L and 34R. Since it is composed of a pair of large differential gears 68L and 68 that are fixed and mesh with the small differential gear 66, the torque transmitted to the connecting shaft 20 is divided equally and the torque is transmitted to the sleeve 34.
L and 34N, respectively. For this reason, even if the transmission belt 52L or 52. Even if there is a difference in the gear ratio between the pair of belt-type continuously variable transmission units due to variations in the elongation or wear of the differential gear 36,
Since the rotation difference is absorbed in the transmission belt 52L or 52R, minute slippage in the transmission belt 52L or 52R is eliminated, and the durability of the double-row belt type continuously variable transmission is increased.

Further, according to this embodiment, there is no need to provide a differential gear device between the axles 62L and 62.1 for absorbing the rotation difference between them as in the conventional case. Since the device 36 is provided at the front stage of the double-row belt type continuously variable transmission, it has the advantage of having a small torque capacity and small size.

Next, another embodiment of the present invention will be described. In the following description, parts common to those in the above-described embodiments are designated by the same reference numerals, and the description thereof will be omitted.

Figure 2 shows a vertical transaxle, in which the power output from the crankshaft to the engine (not shown) is transmitted to the propeller shaft 7 via the forward/reverse switching device (not shown).
0. A drive pinion 72 which together with a ring gear 74 constitutes a hypoid reducer is provided at the shaft end of the propeller shaft 70 so that the ring gear 74 rotates integrally with the differential pinion 66 of the differential gear unit 36. It has become. This differential small gear 66 is a differential large gear 68L and 68.6 fixed to input shafts 76L and 7.6R corresponding to the sleeves 34L and 34R.
It is intertwined with. The input shafts 76 and 76 are connected to the input side variable boolean IJ38 of each belt type continuously variable transmission unit. and 384 are provided, respectively.

Therefore, also in this embodiment, the torque transmitted to the ring gear 74 functioning as an input rotating member is equally divided by the differential gear device 36 and transmitted to the input shafts 76L and 76, respectively, and the belt type continuously variable transmission unit Since the differential gear device 36 is provided in the preceding stage, the same effects as in the previous embodiment can be obtained.

Although the embodiment of the present invention has been described above based on the drawings, the present invention can be applied to other embodiments as well.

For example, in the above-mentioned embodiment, two sets of belt-type continuously variable transmission units constituted a double-row belt-type continuously variable transmission for a vehicle; It is also possible to configure a row belt type continuously variable transmission.

Furthermore, in the transaxle of the above-described embodiment, it goes without saying that the power transmission elements may be changed or removed, or other power transmission elements may be added, as necessary.

Note that the above-mentioned embodiment is merely one embodiment of the present invention, and various modifications may be made to the present invention without departing from the spirit thereof.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the configuration of a transaxle including one embodiment of the present invention. FIG. 2 is a diagram corresponding to FIG. 1 including another embodiment of the present invention. 36: Differential gear device applicant Toyota Motor Corporation Figure 2

Claims (1)

[Scope of Claims] A double-row belt type continuously variable transmission for vehicles installed in a power transmission path from an engine to drive wheels, comprising an input shaft, an output shaft, and an effective a plurality of sets of continuously variable transmission units including a pair of variable input pulleys and variable output pulleys with variable diameters, and a transmission belt wound around the variable input pulleys and the variable output pulley; and the engine. a common input rotating member into which power is inputted; and a common input rotating member provided between the input rotating member and the input shafts of the plurality of continuously variable transmission units, and dividing the power input to the input rotating member to A double-row belt type continuously variable transmission, comprising: a differential gear device that transmits transmission to each input shaft of the continuously variable transmission unit.