JPH0392658A - Continuously variable transmission for vehicle - Google Patents

Abstract

PURPOSE:To eliminate clutch operation and to perform smooth gear shift by a method wherein a variable capacity pump and the pump rotor and the motor rotor of a motor are contained in a housing having an input shaft, the pump and the motor are interconnected through a closed circuit, and through operation of respective capacity varying means, a pump shaft and a motor shaft are selectively coupled to a change gear mechanism. CONSTITUTION:Cylinder parts 7 and 17 rotatably and axially unmovably engaged with a variable capacity pump rotor 8 and a motor rotor 18 are mounted on both sides of s housing 34 located in a transmission case 21 and having an input shaft 33. A pump and a motor have respective circuits interconnected through grooves 36 and 36a, a capacity of the pump and that of the motor are respectively varied by means of slide rings 1 and 11 coupled to swash plates 4 and 14 through rods 2 and 12, respectively, and a pump shaft 8a and a motor shaft 18a are connected to a change gear mechanism. Thus, through operation of the slide rings 1 and 11, the shafts are selectively connected to the change gear mechanism, clutch operation is eliminated, and smooth continuously variable gear shift is practicable.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a continuously variable transmission for vehicles that does not require clutch operation to shut off and connect the rotation of an internal combustion engine, and provides smooth starting and shifting. be.

[Prior Art] In the continuously variable transmission disclosed in Japanese Utility Model Application Publication No. 61-153053, a swash plate type constant displacement hydraulic pump and a swash plate type variable displacement hydraulic motor are connected by a leap circuit, and the internal combustion engine generates hydraulic pressure. When the pump is rotated, the oil discharged from the hydraulic pump is sent to the hydraulic motor, and at the same time, the oil from the hydraulic motor is sucked into the hydraulic bomb, causing the hydraulic motor to rotate, and the rotation of the hydraulic motor to the vehicle. Motorcycle〉
is transmitted to the rear wheels of the vehicle. When the swash plate of the hydraulic motor, which serves as a capacity changing means, is gradually tilted from a position perpendicular to the axis, the capacity of the hydraulic motor changes from 0 to the maximum value, and the gear ratio changes steplessly from 1 to the required value. .

In the above-mentioned continuously variable transmission for vehicles, the permissible transmission power for the capacity of the hydraulic pump and hydraulic motor is limited by the upper limit value of oil pressure and the upper limit value of rotation speed. A hydraulic pump and hydraulic motor are required. As the capacity of the hydraulic pump and hydraulic motor increases,
Oil flow loss increases and conduction efficiency decreases. In addition, the above-mentioned continuously variable transmission for vehicles requires a clutch valve that short-circuits the discharge port and suction port of the hydraulic pump to stop the rotation of the hydraulic motor when the vehicle is started, thereby ensuring smooth transmission of large power. has a difficult problem.

[Problems to be Solved by the Invention] An object of the present invention is to be able to smoothly transmit the rotation of an input shaft connected to an engine to an output shaft from a state of rotation speed O or the same rotation speed, and to transfer power by a clutch. It is an object of the present invention to provide a continuously variable transmission for a vehicle, which allows smooth starting without the need for disconnection or connection, and provides stepless speed change.

Means for Solving Problem E] In order to achieve the above object, the configuration of the present invention includes a variable displacement hydraulic bomb and a variable displacement hydraulic bomb which house a pump rotor and a motor rotor in a housing having an input shaft and are connected in a closed circuit. The shaft of the pump rotor and the shaft of the motor rotor are selected into multiple speed change gear mechanisms having a common output shaft by operating the capacity changing means provided in the hydraulic bomb and the hydraulic motor, respectively. This allows rotational coupling.

[Operation] The housings of the hydraulic pump and the hydraulic motor are connected to the crankshaft of the engine, and the shaft of the pump rotor and the shaft of the motor rotor are selectively connected to the input side of the gear transmission mechanism or the transmission case. Positioning the capacity changing means of the hydraulic pump and the capacity changing means of the hydraulic motor at maximum capacity and in a position where the communication relationship between the respective discharge ports and suction ports is in opposite phase to each other,
When the shaft of the pump rotor is fixed to the transmission case and the shaft of the motor rotor is connected to the input shaft of the gear transmission mechanism, the oil discharged from the hydraulic pump is simply circulated to the hydraulic pump via the hydraulic motor, -The motor rotor does not rotate even at night.

Also, in this state, even if the load torque of the output shaft acts on the shaft of the motor rotor via the gear transmission, and a load of 1-ruq is generated on the housing, which together with the output shaft constitutes the hydraulic motor,
Since the hydraulic pressure generated by this load torque is directly guided to the hydraulic pump, a driving torque of the same magnitude as the load torque is generated on the hydraulic pump side. This driving torque of 1~lux is supported by the pump rotor fixed to the transmission case, and a drive torque of the same magnitude as the load of 1~lux acting on the housing on the hydraulic motor side is applied to the housing on the hydraulic pump side. No load torque occurs on the crankshaft, which is integrally connected to both housings.

When the capacity of the hydraulic pump is gradually reduced to O using the capacity changing means, the driving torque generated in the housing on the hydraulic pump side decreases with respect to the load torque acting on the housing on the hydraulic motor side, and the crankshaft The load torque gradually increases.

Also, at this time, the discharge and suction volumes on the hydraulic pump side also decrease, so the amount of oil sent out from the hydraulic motor side will no longer match, and the amount of oil pumped out from the hydraulic pump side will not match until it reaches the same discharge volume as the suction volume on the hydraulic pump side. The relative rotational difference of the motor rotors is reduced.

In other words, when the motor rotor shaft gradually approaches the rotation speed of the input shaft from a stopped state, and the capacity of the hydraulic pump is O, the motor rotor is directly connected to the housing, and the rotation of the motor rotor corresponds to the gear position of one gear transmission mechanism. The transmission is transmitted to the output shaft at the same gear ratio, resulting in a smooth start.

At this time, no torque is applied to the pump rotor -5, so the clutch can be used to release the fixation of the pump rotor shaft from the transmission case and reconnect it to the gear input shaft of the other gear transmission mechanism. . Then, when the capacity of the hydraulic motor is set to O and at the same time the capacity of the hydraulic pump is set to the maximum value in the same phase as the hydraulic motor side, the torque of the motor rotor approaches O, and at the same time the rotation speed of the pump rotor approaches the rotation speed of the input shaft. The rotation of the pump rotor is transmitted to the output shaft via a gear transmission mechanism.

When the capacity of the hydraulic motor reaches O and the torque of the motor rotor shaft reaches O, the gear shift input shaft of the gear transmission mechanism to which the motor rotor shaft was connected is switched by a clutch to another new shift input shaft. I can do it.

As mentioned above, the capacities of the hydraulic pump and the hydraulic motor are alternately changed from O to the maximum value, and the rotation of the motor rotor and the rotation of the pump rotor are alternately transmitted to the tooth weight variable transmission mechanism. By switching the gears of the speed change gear mechanism connected to the shaft, a wide range of continuously variable speeds can be obtained.

-6 [Embodiments of the Invention] Fig. 1 is a plan sectional view showing a hydraulic transmission device for steplessly transmitting the rotation of an engine to a gear transmission mechanism. The hydraulic transmission device houses a variable displacement swash plate type hydraulic pump on the left side of a housing 34 inside the transmission case 21 which is common to the gear transmission mechanism, and a variable displacement type swash plate type hydraulic motor on the right side, so that they are not connected to each other in an open circuit. and become fluidly connected. In reality, the functions of the hydraulic pump and the hydraulic motor are reversed based on the operation of the capacity changing means, which will be described later. An input shaft 33 coupled to the crankshaft of the engine is supported by the end wall 21a of the transmission case 21, and
combined with the wall. The housing 34 has a cylindrical portion 7 into which the pump rotor 8 is rotatably but immovably fitted in the axial direction on the left side of the central partition wall 35, and a cylindrical portion 17 into which the motor rotor 18 is rotatably but immovably fitted in the axial direction on the right side. Each can be prepared. Screws 10 are slidably fitted into a plurality (preferably an odd number) of cylinders 9 arranged in parallel at equal intervals in the circumferential direction of the pump port motor 8 . A shoe 6a is coupled to the outer end of a piston 10 protruding from the cylinder 9 via a ball joint 6. The shoe 6a is forcefully pressed against the swash plate 4, which is tiltably supported on the housing 34 by the truss shaft 5, by known means. Swash plate 4 is connected via links 3 to rods 2 slidably supported on the end wall of housing 34. The outer end of the rod 2 is connected to a sliding ring 1 which is fitted onto an input shaft 33. In order to control the inclination of the swash plate 4, a bifurcated shift arm of an actuator (not shown) is engaged with an annular groove of the sliding ring 1.

The configuration of the hydraulic motors is also similar to that of the hydraulic pumps, and preferably have the same maximum capacity. That is, motor rotor 1
The piston 2 is installed in a plurality of cylinders 19 arranged in parallel in the circumferential direction.
0 is fitted, and the shoe 168 connected to the outer end of the screw l~n 20 by the ball joint 16 is pressed by known means to be able to slide against the swash plate 14 supported by the trunnion shaft 15 in the housing 34. . Swashplate 14 is connected via links 13 to rods 12 slidably supported in the end walls of housing 34. The outer end of the rod 12 is the motor shaft 18a
It is combined with the sliding ring 11 extrapolated to . In order to υjall the inclination of the swash plate 14, a bifurcated shift arm (not shown) of an actuator is engaged with the annular groove of the vJ ring 11.

A pump shaft (pump rotor shaft) 8 a is coupled to the pump rotor 8 and extends through the partition wall 35 and the motor rotor 18 and projects to the outside of the housing 34 . Motor shaft (motor rotor shaft) 18a that fits onto the motor rotor 18 and the pump shaft 8a
are combined. Grooves 36 and 368 are provided in the partition wall 35 to fluidly connect the cylinders 9 and 19.

FIG. 2 shows the structure of the partition wall 35 when eight cylinders 9 and 19 are provided for the hydraulic pump and the hydraulic motor, respectively. For each cylinder 9, a pair of arc-shaped grooves 36 that communicate with each other the three passages 9a on both the left and right sides (when each rotor has eight cylinders), for each rotor passage 9a that communicates with one cylinder. .36a are provided respectively.

As shown in FIG. 1, oil is supplied from an external oil pump to the groove 36 in order to replenish oil leakage from the sliding portion between the cylinder 9 and the piston 10. That is, the oil bomb is inserted into the passage 22 of the end wall 21a of the transmission case 21.
, annular 23, passage 24 of input shaft 33, housing 34
It is connected to the groove 36 through passages 25, 26, a check valve 27 which is normally closed by a spring 28, and a passage 29.

A relief valve 30 which is normally closed by a spring 31 is disposed inside the check valve 27, and when the hydraulic pressure inside the cylinder 9 becomes excessive, the passage 26 passes through the ig36a, the passage 29a, and the relief valve 30. be released to.

FIG. 3 is a structural diagram of a gear transmission connected to the motor shaft 18a and pump shaft 8a of the above-mentioned hydraulic transmission device. The south wheel transmission consists of a parallel gear mechanism 75 and a planetary gear mechanism 74. The parallel gear mechanism 75 includes a gear 45 meshing with the gear 44 of the motor shaft 18a, a gear 48 coupled to the gear 45 by a boss 47 supported by the shaft 46, and a gear 48 rotatably supported by the shaft 58. It consists of gears 49 that mesh with each other. The planetary gear mechanism 74 is a ring connected to the shaft 69 @wheel 6
9a and a sun gear 58a10 coupled to the shaft 58, a planetary gear 71 is meshed with the sun gear 58a10. The shaft 72 of the planetary gear 71 is supported by a carrier 64a coupled to the shaft 64 and a carrier 64b coupled to the output shaft 73.

The gear 42 of the motor shaft 18a is in the illustrated position and the clutch 4
3, it is switched to a position where it is coupled to the gear 41 fixed to the wall of the housing 34.

The gear 52 of the pump shaft 8a is connected to the gear 50 of the fixed part by the clutch 51 and is in the non-rotatable position shown in the figure.
0 to a released rotatable position.

Bomb shaft 8a can be rotatably coupled to output shaft 73 of planetary gear mechanism 74 or sun gear shaft 58 by clutch 56. That is, the annular clutch gear 55 that is always engaged with the internal gear 54 of the pump shaft 8a is connected to the gear 53 of the output shaft 73.
and a position where it meshes with the gear 57 of the sun gear wheel 58.

The output gear 49 of the parallel m-wheel mechanism 75 can be rotatably coupled to the sun gear shaft 58 or carrier support shaft 64 of the planetary gear mechanism 74 by a clutch 61.

In other words, the annular clutch gear 59 that is constantly engaged with the four gears and the Ikkyu internal gear 60 is connected to the gear 6 of the sun gear shaft 58.
3 and a position where it meshes with the gear 62 of the carrier support shaft 64.

Preferably, the gear 66 is provided on the shaft 69 of the ring gear 69a of the planetary gear mechanism 74, and the gear 66 is connected by a clutch 67.
6 is switched to a position where it is coupled to the gear 68 of the fixed part, and a position where the gear 66 is coupled to the gear 65 of the carrier support shaft 64.

Next, the operation of the continuously variable transmission for a vehicle according to the present invention will be explained. As shown in FIG. 1, when the swash plate 4 as the pump capacity changing means is at the maximum capacity position, and the swash plate 14 as the motor capacity changing means is at the maximum capacity position in the opposite phase to the hydraulic bomb side, The rotation of the input shaft 33 does not apply torque to either the pump shaft 8a or the motor shaft 18a. That is,
When the housing 34 and the swash plate 4 are rotated together with the input shaft 33 connected to the internal combustion engine, half of the pistons 10 are pushed to the right by the swash plate 4 every half rotation of the swash plate 4. While the oil in the cylinder 9 is discharged into the groove 36a, half of the screws 1 to 10 are pulled to the left and suck the oil in the groove 36. The oil in the groove 368 is sent to the cylinder 19 of the hydraulic motor and pushes half the pistons 20 to the right. At the same time, the oil in half of the cylinders 19 is returned to the groove 36. At this time, the swash plate 14 of the hydraulic motor rotates synchronously to allow the reciprocating movement of the screws 19, so the oil simply circulates from the hydraulic pump to the hydraulic pump via the pressure motor as described above. Therefore, no torque is generated in either the pump rotor 8 or the motor rotor 18, and the motor rotor 18 rotates at the same speed as the pump rotor 8 in the opposite direction, and when one is stopped, the other is also stopped.

Therefore, as shown in FIG. 3, there is no problem even if the pump shaft 8a is fixed by the clutch 51. Kuratsuji 6
1, the rotation of the motor shaft 18a can be transmitted to the sun gear shaft 58 of the planetary gear machine m74 via the parallel drawing wheel mechanism 75.

-13 Running in 1st gear: When starting the vehicle, the pump port motor 8 is fixed and the swash plate 4 is
When slowly brought to the vertical position (as shown in FIG. 4), the displacement of the hydraulic pump is reduced, the hydraulic motor receives torque from the housing 34 through the swash plate 14 and the screws 1-20, and the motor rotor 18 is rotated.

At this time, since the amount of oil discharged from the cylinder 9 of the hydraulic pump per unit time is equal to the amount of oil sent to one cylinder of the hydraulic motor, the relationship between the rotation speed of the housing 34 and the rotation speed of the motor rotor 18 is is expressed by the following formula.

Housing rotation speed/motor rotor rotation speed -1,000Hydraulic pump capacity/hydraulic motor capacity As shown in Figure 4,
When the swash plate 4 is in the vertical position (pump capacity 10), the cylinder 19
There is no oil flowing in and out of the motor, and the motor port 18 is rotated integrally with the housing 34. When the swash plate 4 is slowly tilted from the maximum capacity position to the capacity O position, the rotation of the input shaft 33 is gradually transmitted to the motor shaft 18a. As shown in FIG. 3, the rotation of the motor shaft 18a is transmitted to the sun gear shaft 58 of the planetary gear 8N side 74 via the parallel gear machine Ill 75, and as the planetary gear 71 rotates, the output supports the carrier 64b. is transmitted to the wheels via the shaft 73,
The vehicle can be started smoothly (first gear).

Running in 2nd gear: As shown in FIG. 4, when the swash plate 4 is in the vertical position, the pump rotor 8 does not receive torque from the housing 34, so the clutch 51 is released and the clutch 56 is activated to drive the pump shaft 8a.
There is no problem even if the output shaft 73 is rotatably coupled to the shaft 58.
There is no change in the rotation speed. Therefore, if the swash plate 4 of the hydraulic pump is tilted again to the maximum capacity position and at the same time the swash plate 14 of the hydraulic motor is placed in the vertical position (the state shown in Fig. 5), there will be a gap between the hydraulic bomb and the hydraulic motor during this operation. Oil circulation occurs, and as the torque of the motor rotor 18 approaches O, the rotational speed of the pump rotor 8 approaches the rotational speed of the housing 34.

As shown in FIG. 5, when the swash plate 14 is in the vertical position, the screws 1 to 10 of the hydraulic pump are locked, and the housing 34 and the pump rotor 8 temporarily rotate.

The rotation of the pump shaft 8a is controlled by the clutch 56 and the planetary gear mechanism 74.
The signal is transmitted to the output shaft 73 via the sun gear shaft 58, and a shift to the second gear is obtained. The output shaft 73 is continuously and slowly increased in speed from the first speed to the second speed.

Traveling in 3rd gear: As shown in FIG. 5, when the swash plate 14 is in the vertical position, the motor rotor 18 does not receive torque from the housing 34, so the output gear of the parallel south wheel mechanism 75 connected to the motor shaft 18a 49 can be switched to a position where it is rotationally coupled to the carrier support shaft 64 from the J-height sun gear shaft 58 to the clutch 61 without any problem. Therefore, when the swash plate 4 of the hydraulic bomb is placed in the vertical position and the swash plate 14 of the hydraulic motor is tilted at the same time (as shown in Fig. 4), during this operation, oil circulation occurs between the hydraulic bomb and the hydraulic motor, and the motor rotor While the rotational speed of the pump rotor 8 approaches the rotational speed of the housing 34, the torque of the pump rotor 8 approaches O.

As shown in FIG. 4, when the swash plate 4 is in the vertical position, the motor rotor 18 rotates integrally with the housing 34. The rotation of the motor shaft 18a passes through the parallel gear mechanism 75 to the planetary gear mechanism 4.
The output shaft 73 is transmitted to the carrier support shaft 64 of M74, and the output shaft 73 is rotated integrally with the carrier support shaft 64, thereby obtaining the third gear shift.

Running in 4th gear: As shown in FIG. 4, when the swash plate 4 is in the vertical position, the pump rotor 8 does not receive torque from the housing 34, so the bomb shaft 8a is output from the sun gear shaft 58 by the clutch 56. There is no problem even if it is switched to a position where it is rotatably coupled to the shaft 73. Therefore, when the swash plate 4 of the hydraulic pump is tilted and the swash plate 14 of the hydraulic motor is placed in the vertical position at the same time, oil circulation occurs between the hydraulic bomb and the hydraulic motor, and the rotational speed of the pump port motor 8 increases to the housing 34. While the rotational speed of the motor rotor 18 approaches , the 1-lux of the motor rotor 18 approaches 0.

As shown in FIG. 5, when the swash plate 14 is in the vertical position, the pump rotor 8 rotates integrally with the housing 34. The rotation of the bomb shaft 8a is transmitted to the output shaft 73 of the planetary gear machine V474, and a speed change is obtained in which the rotation speeds of the human power shafts 33 and 17 of the output shaft 73 in the 4th gear match.In this case, the clutch 67 When the shaft 69 of the ring gear 69a of the planetary gear machine M474 and the carrier support shaft 64 are rotationally coupled, the planetary gear mechanism 74 as a whole rotates integrally with the output shaft 73, and power loss due to unnecessary rotation of the planetary gear 71 is reduced. Avoided.

When the pressure of the hydraulic motor is lost: When the pressure of the hydraulic motor is lost, clutch 4 is
3, when the motor shaft 18a is directly connected to the housing 34, the rotation of the housing 34 is transmitted to the sun gear 58a of the planetary gear mechanism 74 via the parallel gear mechanism 75, thereby enabling running in the first gear.

In addition, in the above-mentioned embodiment, a transmission was shown in which a parallel gear mechanism 75 equipped with a clutch 61 and a planetary gear mechanism 74 equipped with a clutch 56 were combined, but as shown in FIG. Even if the output shaft is connected to the output shaft via two sets of parallel gear mechanisms and a two-phase clutch, a four-stage speed change can be obtained as in the case described above.

In the above embodiment, a combination of a variable displacement swash plate type screw pump and the same piston motor was used as the hydraulic transmission device, but a combination of a variable displacement radial piston bomb and the same piston motor, or a variable displacement radial piston bomb and the same piston motor, or A combination of a capacity type vane bomb and the same vane motor may also be used.

[Effects of the Invention] As described above, the present invention includes a variable displacement hydraulic pump and a variable displacement hydraulic motor, which are connected in a closed circuit by accommodating a pump rotor and a motor rotor in a housing having an input shaft. The shaft of the pump rotor and the shaft of the motor rotor can be selectively and rotationally connected to a plurality of transmission gear mechanisms having a common output shaft by operating the capacity changing means provided in the hydraulic pump and the hydraulic motor, respectively. A state in which the rotation of the pump rotor is transmitted to the transmission and a state in which the rotation of the motor rotor is transmitted to the transmission by alternately changing the swash plate of the pump and the swash plate of the hydraulic motor between an inclined position and a vertical position. By switching the gear position of the transmission during this time, smooth starting and after-starting are achieved without requiring clutch operation (cutting off the transmission from the engine) like in conventional manual transmissions. Provides smooth continuously variable speed.

In particular, if the clutch included in a gear transmission is automatically controlled in response to engine load, vehicle speed, etc., automatic gear shifting that does not require manual operation can be achieved.

[Brief explanation of drawings]

FIG. 1 is a side cross-sectional view of a hydraulic transmission device that serves a continuously variable transmission for vehicles according to the present invention, FIG. 2 is a front view of a partition between a hydraulic pump and a hydraulic motor in the hydraulic transmission device, and FIG. Figure 3 is a configuration diagram of a gear transmission connected to a hydraulic transmission device;
, 5 is an explanatory diagram of the operation of the hydraulic power transmission, and FIG. 6 is a configuration diagram showing a modified embodiment of the gear transmission. 4.14: Swash plate 8: Pump rotor 8a: Pump shaft (
Pump rotor shaft> 18: Motor rotor 18a: Motor shaft (motor rotor shaft>) 33: Human power shaft 34: Housing 56, 61: Clutch 73: Output shaft 74
: Planetary gear mechanism lit 75: Parallel gear mechanism (Ll” one)

Claims (1)

[Claims] A variable displacement hydraulic pump and a variable displacement hydraulic motor are constructed by accommodating a pump rotor and a motor rotor in a housing having an input shaft and connected in a closed circuit, and operation of displacement changing means provided in the hydraulic pump and the hydraulic motor, respectively. A continuously variable transmission for a vehicle, characterized in that the shaft of the pump rotor and the shaft of the motor rotor can be selectively and rotationally coupled to a plurality of variable speed gear mechanisms having a common output shaft.