JPH10110803A - Continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a continuously variable transmission which is dimensionally small in the axial direction, compact, of simple construction, and capable of automatically performing ON-OFF of hydraulic transmission in response to the change in the number of revolutions of an input shaft. SOLUTION: A first plunger 14 group of a radial type first hydraulic pump P1 , and A second plunger 24 group of a radial type second hydraulic pump P2 connected to the first hydraulic pump P1 through a hydraulic closed circuit, are arranged on a common cylinder body 12 firmly locked to an input shaft 1, and the first pump ring 15 for operating the first plunger 14 group is journalled to a transmission case 5 so as to make the eccentric direction and the amount of eccentricity of the first pump ring 15 variable in relation to the cylinder body 12. Further, a radial crank valve hole which extends over a low-pressure oil path 28 and a high-pressure oil path 29 of the hydraulic closed circuit, is provided in the cylinder body 12, and a clutch valve for closing between both the oil passages 28, 29 by centrifugal action, is loaded in the crank valve hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a continuously variable transmission mainly applied to vehicles such as motorcycles and automobiles.

[0002]

2. Description of the Related Art As a continuously variable transmission, for example, Japanese Patent Publication No. 7-2
As disclosed in Japanese Patent No. 6676, there is known an axial hydraulic pump having a fixed capacity and an axial hydraulic motor having a variable capacity which are coaxially arranged and connected via a hydraulic closed circuit.

[0003]

In the continuously variable transmission as described above, the axial type hydraulic pump and the hydraulic motor, which extend relatively long in the axial direction, are arranged in the axial direction. And it is difficult to make it compact.

The present invention has been made in view of the above circumstances, and has a compact structure in which the axial dimension is greatly reduced, and has a simple structure to turn on and off the hydraulic transmission by the number of rotations of the input shaft. It is an object of the present invention to provide a continuously variable transmission that can be automatically performed according to a change in the transmission.

[0005]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a transmission case in which an input shaft and an output shaft are coaxially supported on a transmission case, and a cylinder body fixed to the input shaft is provided. A plurality of first plungers radially disposed on the body, and surrounding the first plungers so as to relatively movably engage with their outer ends, and reciprocate with each of the first plungers as the cylinder body rotates. Give
In order to adjust the reciprocating stroke, a radial type first hydraulic pump having a variable capacity is constituted by a first pump ring which is rotatably supported by a transmission case. A plurality of second plungers are fixed to the output shaft, surround the second plungers and engage with their outer ends so as to be relatively movable. A second hydraulic pump having a fixed capacity is constituted by a second pump ring for providing a reciprocating motion of a constant stroke to the two plungers. A high-pressure oil passage for discharging hydraulic oil from the pump and a low-pressure oil passage for discharging hydraulic oil from the first hydraulic pump and sucking hydraulic oil into the second hydraulic pump; A clutch valve hole extending in the radial direction of the cylinder body is provided between the two oil passages, and a radially inward position connecting the two oil passages to each other and a radial position connecting the two oil passages to each other are provided in the clutch valve holes. And a clutch spring for biasing the clutch valve inward in the radial direction is provided.When the rotation speed of the input shaft exceeds a predetermined value, the clutch valve is moved by its centrifugal force. It is characterized by moving outward in the radial direction.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

In FIG. 1, reference numeral 1 denotes an input shaft connected to a prime mover of a vehicle, and 2 denotes an output shaft connected to drive wheels of the vehicle. Both shafts 1 and 2 are coaxially arranged and have a continuously variable transmission according to the present invention. It is connected via the machine T.

At the inner end of the output shaft 2 is integrally formed a support cylinder 3 which concentrically surrounds the inner end of the input shaft 1, and between the support cylinder 3 and the input shaft 1. A ball bearing 4 is provided to allow relative rotation of.

The input and output shafts 1 and 2 are supported on left and right ends of a transmission case 5 accommodating the continuously variable transmission T via ball bearings 6 and 7, respectively. Is supported via a ball bearing 8 at an intermediate portion of the head. Oil seals 9 and 10 are interposed between the input and output shafts 1 and 2 and the transmission case 5 outside the ball bearings 6 and 8.

The continuously variable transmission T is constructed by connecting a radial first hydraulic pump P _{1 of} variable capacity and a radial second hydraulic pump P _{2 of} constant capacity via a hydraulic closed circuit. .

[0011] As shown in FIGS. 1, 2 and 6, the first hydraulic pump P ₁ is the cylinder body 12 that is coupled coaxially through a spline 11 to the input shaft 1, opened to the outer peripheral surface (Five in the illustrated example) of the first cylinder holes 13 provided in a radial arrangement as shown in FIG.
The first plungers 14 slidably fitted to the respective 3
And a first pump ring 15 surrounding the group of plungers 14 and slidably engaging with the outer ends thereof in the circumferential direction. Each first cylinder hole 13 has a first plunger 14.
1 for urging the spring in the direction of engagement with the first pump ring 15
6 are stored.

The first pump ring 15 has a boss 15 a formed on one side thereof supported by the transmission case 5 via a pivot 17 parallel to the input shaft 1. Distance e ₁ (maximum eccentricity, see FIGS. 2 and 9 (a)) Eccentric first eccentric position A and a predetermined distance e ₂ toward the other side (see FIGS. 2 and 12 (a)) It can swing between the second eccentric position C and a non-eccentric position which is concentric with the cylinder body 12 between the eccentric positions A and C (see FIG. 11A).
B exists. The first and second eccentric positions A and C of the first pump ring 15 correspond to one and the other of the concave portions 18 formed on the inner peripheral wall of the transmission case 5 by the stopper arm 15 b protruding from the other side of the ring 15. It is defined by contacting the inner end wall. A return spring 19 that constantly biases the first pump ring 15 toward the first eccentric position A is interposed between the transmission case 15 and the ring 15 while resisting the biasing force of the return spring 19. A transmission lever 20 capable of swinging the ring 15 from the first eccentric position A to the second eccentric position C is supported by the transmission case 5. The shift lever 20 is operated by a manual or automatic actuator. Thus, when the cylinder body 12 rotates, the first pump ring 15 reciprocates each first plunger 14 with a stroke twice as much as the eccentric amount of the ring 15 to repeat the suction and discharge strokes. be able to.

As shown in FIGS. 1 and 3, the second hydraulic pump P ₂ includes a plurality of (five in the illustrated example) radially arranged second openings provided on the outer peripheral surface of the cylinder body 12.
A cylinder hole 23, a second plunger 24 slidably fitted in each of the second cylinder holes 23, and circumferentially slidably engaged with outer ends of the second plungers 24 surrounding the group of the second plungers 24. And a spring 26 that urges each second plunger 24 in the direction of engagement with the second pump ring 25 in each second cylinder hole 23.
Is stored.

The second pump ring 25 is integrally connected to the support cylinder 3 of the output shaft 2 and is a predetermined distance e ₃ (fixed eccentricity, FIGS. 3 and 11) to one side of the cylinder body 12.
(See (a)) It is arranged to be eccentric. When the cylinder body 12 rotates, the second pump ring 25 reciprocates each second plunger 24 with a stroke twice as much as the eccentric amount of the ring 25 to repeat the suction and discharge strokes. Can be done.

As shown in FIG. 6, the outer diameter d ₁ of the first plunger 14 is set smaller than the outer diameter d ₂ of the second plunger 24. As shown in FIGS. 2 and 3, the maximum eccentricity e ₁ of the first pump ring 15 is
5 is set larger than the fixed eccentric amount e ₃ , that is, the maximum stroke of the first plunger 14 is set larger than the stroke of the second plunger 24. Thus a first maximum displacement of the hydraulic pump P ₁ and fixed capacity of the second hydraulic pump P ₂ is substantially equal to.

As shown in FIG. 1, a first hydraulic pump P ₁ and a second hydraulic pump P ₂ are arranged apart from each other at one end and the other end of a cylinder body 12, and an input shaft is provided at an intermediate portion therebetween. 1 and an annular high-pressure oil passage 29 further surrounding the low-pressure oil passage 28.

The cylinder body 12 has the same number as the first cylinder holes 13, the first valve holes 31 radially extending adjacent to the inside of the first cylinder holes 13, and the second cylinder holes 23. A second valve hole 32 extending radially adjacent to the inside of the second cylinder hole group 23 is provided. Each first valve hole 31 penetrates from the outer peripheral surface of the cylinder body 12 through the high-pressure oil passage 29 to reach the low-pressure oil passage 28.
A first pump port 33 extending laterally from the adjacent first cylinder hole 13 is opened on the inner surface of the valve hole 31. Each second valve hole 32 also penetrates from the outer peripheral surface of the cylinder body 12 through the high-pressure oil passage 29 to reach the low-pressure oil passage 28.
A second pump port 34 extending laterally from the adjacent second cylinder hole 23 opens on the inner surface of the valve hole 32.

As shown in FIGS. 1 and 4, the first valve hole 31
A first switching valve 35 of a spool type is slidably fitted to the first switching valve 35, and a first switching ring 37 surrounding the first switching valve 35 is slidably engaged with the outer end of the first switching valve 35 in the circumferential direction. You. The first switching ring 37 is fixed to the transmission case 5 with bolts 39 at a position eccentric by a predetermined distance e _{4 with} respect to the cylinder body 12 as shown in FIG.

When the cylinder body 12 rotates, each of the first switching valves 35 engages with the first switching ring 37 by the centrifugal force of itself and the centrifugal oil pressure of the working oil in the low-pressure oil passage 28. Kept in state. Therefore, the first switching ring 37
As the cylinder body 12 rotates, each first switching valve 35 is reciprocated between a radially inner position and an outer position of the cylinder body 12 in the radial direction.

At this time, if the first pump ring 15 occupies the first eccentric position A, the first pump port 33 corresponding to the first plunger 14 during the discharge stroke is moved by the first switching valve 35 to the low pressure oil passage. , The second pump port 34 corresponding to the second plunger 24 during the suction stroke.
Is connected to the high-pressure oil passage 29 by the first switching valve 37.

When the first pump ring 15 occupies the second eccentric position C, on the contrary, the first pump port 33 corresponding to the first plunger 14 during the discharge stroke is connected to the first switching valve 35. While communicating with the high pressure oil passage 29,
The first pump port 33 corresponding to the first plunger 14 during the suction stroke is connected to the low-pressure oil passage 28 by the first switching valve 35.

As shown in FIGS. 1 and 5, the second valve hole 32
A second switching valve 36, which is also of a spool type, is slidably fitted to the second switching valve 36, and a second switching ring 38 surrounding the second switching valve 36 is slidably engaged with the outer end of the second switching valve 36 in the circumferential direction. Is done. The second switching ring 38 is integrally connected to the second pump ring 25 and is connected to the cylinder body 12.
Are disposed so as to be eccentric with respect to a predetermined distance e ₅ .

When the cylinder body 12 rotates, each of the second switching valves 36 engages with the second switching ring 38 by the centrifugal force of itself and the centrifugal oil pressure of the working oil in the low-pressure oil passage 28. Kept in state. Therefore, the second switching ring 38
Reciprocates each second switching valve 36 between a radially inner position and an outer position of the cylinder body 12 with the relative rotation with respect to the cylinder body 12. By the second switching valve 36, the second pump port 34 corresponding to the second plunger 24 during the suction stroke is connected to the low-pressure oil passage 28, while the second pump port corresponding to the second plunger 24 during the discharge stroke. Reference numeral 34 communicates with the high-pressure oil passage 29.

As shown in FIGS. 4, 7 and 8, the cylinder body 12 has one or more clutches which penetrate the high pressure oil passage 29 from the outer peripheral surface of the body 12 and reach the low pressure oil passage 28. A valve hole 50 is provided. The clutch valve hole 50 has an annular locking groove 50b near the outer periphery of the cylinder body 12 and an annular step portion 50a near the inner periphery of the body 12. A clutch valve 51 of a spool type is slidably fitted therein, and a clutch spring 52 for urging the clutch valve 51 toward the step portion 50a is housed therein. Then, a retaining ring 53 supporting the fixed end of the clutch spring 52 is mounted in the locking groove 50b. The clutch valve 51 has an annular groove 5 on its outer periphery.
4. A blind hole 55 located at the center and facing the open end to the low-pressure oil passage 28, and a lateral hole 56 connecting the annular groove 54 and the blind hole 55.
In the clutch-off position (the state shown in FIG. 7) where the valve 51 abuts on the step 50a, the annular groove 54 matches the high-pressure oil path 29, and the short-circuit path 57
At the clutch-on position (the state shown in FIG. 8) where the valve 51 is close to the stop ring 53 (the state shown in FIG. 8), the annular groove 54 is displaced from the high-pressure oil passage 29 so that the oil passages 28 and 29 communicate.
Communication between the 29 has been cut off. A predetermined weight is applied to the clutch valve 51 and a predetermined set load is applied to the clutch spring 52.
When the number of rotations exceeds a predetermined value, the clutch valve 51 is displaced from the clutch off position to the clutch on position.

In the above, the low pressure oil passage 28 and the high pressure oil passage 2
9, the first and second valve holes 31 and 32 and the first and second pump ports 33 and 34 constitute a closed hydraulic circuit that connects the first and second hydraulic pumps P ₁ and P ₂ .

Referring again to FIG. 1, the low-pressure oil passage 28 is connected to the oil reservoir 4 at the bottom of the transmission case 5 through a series of supply oil passages 40 formed on the input shaft 1 and the side wall of the transmission case 5.
Communicate with 1. An oil filter 42 is installed at the inlet of the replenishing oil passage 40, and a dust reservoir 44 communicating with the oil reservoir 41 through the through hole 43 is provided in the bottom wall of the transmission case 5.
Is provided.

1, 2, 4 and 6, the cylinder body 12 has a central block 12 b having first and second valve holes 31 and 32 and a clutch valve hole 50, and a first cylinder hole 13. The first block 12a is overlapped on the left side of the central block 12b, and the second block 12c is overlapped on the right side of the central block 12b with the second cylinder hole 23. In the illustrated example, the first side block 12 a is connected to the input shaft 1 via a spline 11. And these three blocks 12a, 12b, 12c are provided with seal rings 45, 4
6 are connected by a plurality of bolts 47. At this time, as clearly shown in FIG. 6, the high-pressure oil passage 29 has a pair of first and second annular grooves 29a and 29b formed on both end surfaces of the central block 12b, and adjacent first and second annular grooves 29a and 29b. Valve hole 31,
32, and both annular grooves 29 intersecting with the clutch valve hole 50.
The first and second annular grooves 29a and 29b are closed by the first and second side blocks 12a and 12c, respectively. Further, the first and second pump ports 33, 34 are formed in the respective opposing surfaces of the blocks 12a, 12b, 12c.

On the other hand, the low-pressure oil passage 28 is defined by an annular groove formed on the outer peripheral surface of the input shaft 1 and the inner peripheral surface of the central block 12b.

The plurality of bolts 47 are substantially arranged on an annular arrangement line of the through holes 29c so as to be alternately arranged with the plurality of through holes 29c, and the annular grooves 29a and 29b bypass these bolts 47. Therefore, it is formed in a petal shape partially curved inward in the radial direction (see FIG. 4).

Next, the operation of this embodiment will be described with reference to FIGS. In each of the above figures,
(A) is a schematic cross-sectional view of the first and second hydraulic pumps, and (b) is a developed schematic view of the first and second hydraulic pumps P ₁ and P ₂ .

<Clutch off state (see FIG. 7)> Input shaft
In the idling range of 1, the centrifugal force acting on the clutch valve 51
Is small, the clutch valve 51 is
Abuts the step portion 50a of the clutch valve hole 50 due to the cut load.
Is held at the radially inward position.
The annular groove 54 of the high pressure oil passage 29
The distance between the low-pressure oil passage 28 and the high-pressure oil passage 29 via the junction path 57 is short.
Get entangled. Therefore, the first and second hydraulic pumps P₁,
P _TwoThere is no hydraulic transmission between the two.

<Clutch-on state (see FIG. 8)> When the rotation speed of the input shaft 1 exceeds a predetermined value higher than the idling rotation region and increases, the clutch valve 51 causes the clutch spring 52 to increase due to the increased centrifugal force. Since it gradually moves outward in the radial direction so as to balance with the spring force, the annular groove 54 of the clutch valve 51 gradually shifts from the high-pressure oil passage 29, and finally, the high and low pressure oil passages due to the short-circuit passage 57. Communication between 28 and 29 is cut off. Therefore, the first and second hydraulic pumps P ₁ , P _1
2 is in a completely hydraulic transmission state through a mutual half-clutch state, and smooth automatic start is possible. <State where the gear ratio is continuously variable (see FIG. 9)> In this state,
By shifting the first pump ring 15 to the first eccentric position A (see FIG. 2), the first volume of the hydraulic pump P ₁ is controlled equal to that of the second hydraulic pump P _2.

Therefore, when the input shaft 1 is rotated, the cylinder body 12 which rotates integrally with the input shaft 1 generates relative rotation between the first pump ring 15 and the second pump ring 25. At this time, the corresponding first plunger 14 in the discharge stroke as the first in the hydraulic pump P ₁ above 1
The pump port 33 communicates with the low-pressure oil passage 28, and the first pump port 33 corresponding to the first plunger 14 during the suction stroke communicates with the high-pressure oil passage 29.
The hydraulic oil is sucked into the low pressure oil passage 28 and discharged.

On the other hand, in the second hydraulic pump P ₂ , the second pump port 3 corresponding to the second plunger 24 during the suction stroke
4 is connected to the low-pressure oil passage 28, and the second pump port 34 corresponding to the second plunger 24 during the discharge stroke is connected to the high-pressure oil passage 29. The hydraulic oil is discharged to the passage 29.

In addition, since the capacity of both hydraulic pumps P ₁ and P ₂ is equal, the entire amount of hydraulic oil discharged from the first hydraulic pump P ₁ to the low-pressure oil passage 28 during one rotation of the cylinder body 12 is reduced by the _second hydraulic pump P _1. P ₂ and the second hydraulic pump P ₂
There will be the total amount of the hydraulic oil to be discharged to the high pressure oil passage 29 is sucked into the first hydraulic pump P _1. Therefore, the first and second plungers 14 and 24 repeat reciprocating motions, respectively. The first and second plungers 14 and 24 merely slide on the inner peripheral surfaces of the first and second pump rings 15 and 25 and do not generate a rotational torque, so that the output shaft is not generated. 2 keeps the stopped state.

<State where the gear ratio is, for example, 2 (see FIG. 10)> The first pump ring 15 is positioned at an intermediate position between the first eccentric position A (see FIG. 2) and the non-eccentric position B, that is, the position where the eccentric amount becomes en shifts to the first displacement of the hydraulic pump P ₁ second
Controlled to half the capacity of the hydraulic pump P _2. In this way, during one rotation of the cylinder body 12, the hydraulic oil amount first hydraulic pump P ₁ is sucked from the high-pressure oil passage 29, the second
Since the hydraulic pump P ₂ is half of the amount of hydraulic oil to discharge the high pressure oil passage 29, the second plunger 24 a reaction force in the discharge stroke when the second hydraulic pump P ₂ is discharged the other half of the hydraulic oil Acts on the second pump ring 25 from the
, The output shaft 2 is rotated. As a result, during one rotation of the input shaft 1, the output shaft 2 makes a half rotation.

<State where the gear ratio is 1 (see FIG. 11)>
The pump ring 15 shifts to the non-eccentric position B (see FIG. 2), controls the first volume of the hydraulic pump P ₁ to zero. In this way, hydraulic fluid second hydraulic pump P ₂ is discharged to the high pressure oil passage 29 is not at all taken into the first hydraulic pump P _1,
To lose the place to go, all the second plungers 24 are in the hydraulic lock state, and the input and output shafts 1 and 2 are integrally connected by the cylinder body 12 and the second pump ring 25. It rotates at the same speed.

<State where the gear ratio is, for example, 0.66 (FIG. 12)
2) The first pump ring 15 is moved to the second eccentric position C (see FIG. 2).
It shifted reference), and the suction region and the discharge region of the first hydraulic pump P ₁ until the same time be reversed, to set the volume to half the second displacement of the hydraulic pump P _2. In this way, during one rotation of the cylinder body 12, the first pump port with one volume of 2 minutes of the first hydraulic pump P ₁ in the second hydraulic pump P _2, corresponding with the first plunger 14 in the discharge stroke 33 discharging the hydraulic oil to the high pressure oil passage 29 from, since is supplied to the second pump port 34 corresponding to the second plunger 24 that were in the discharge stroke in the second hydraulic pump P ₂ before, the second Plunger 2
4 moves to the expansion stroke, and the second pump ring 25 is accelerated by a half rotation in the rotation direction of the cylinder body 12 by the expansion thrust. As a result, the gear ratio becomes 1: 1.5 = 0.66, and the speed is increased.

As is clear from the above, by shifting the first pump ring 15 from the first eccentric position A to the second eccentric position C steplessly, the speed ratio between the input and output shafts 1 and 2 is infinite. The control can be performed steplessly from the (neutral state) to the speed increasing state, so that the vehicle can be started smoothly, and at the time of high speed, overdrive can be performed to reduce fuel consumption.

During the rotation of the cylinder body 12, the oil in the oil reservoir 41 is sucked from the replenishing oil passage 40 into the low-pressure oil passage 28 by the action of centrifugal force and stored. Therefore, the first and second
Plungers 14, 24 and first and second switching valves 35, 36
The amount of leakage of hydraulic oil from the sliding surface or the like is immediately supplied from the low-pressure oil passage 28.

Incidentally, the continuously variable transmission T is
Al-type first and second hydraulic pumps P ₁, P_TwoThe common
Since it is constructed on the Linda body 12,
Combination of conventional axial type hydraulic pump and motor
Compared with, the axial dimension is greatly reduced, making it more compact.
Can be planned. Moreover, as described above, the first pump
Gear ratio can be increased from infinity by simply shifting ring 15
Since it can be controlled in a continuous manner up to the speed state,
The range of application to both is extremely wide.

In addition, since the short circuit and the cutoff between the low pressure and high pressure oil passages 28 and 29 are performed by the centrifugal operation of the clutch valve 51 provided in the cylinder body 12, the first and second hydraulic pumps have a simple structure. On / off of the hydraulic transmission between P ₁ and P ₂ can be automatically and smoothly performed according to a change in the rotation speed of the input shaft 1.

A support cylinder 3 formed at the inner end of the output shaft 2 is supported by a transmission case 5 via a ball bearing 4, and the support cylinder 3 connects the inner end of the input shaft 1 via a ball bearing 7. Since the bearings are supported, the inner ends of the two shafts 1 and 2 can be firmly supported by the transmission case 5 within a small axial space, and the supporting rigidity can be increased. In addition, since the second pump ring 25 is integrally connected to the support cylinder 3, the thrust of the second plunger 24 and its reaction force can be supported between the support cylinder 3 and the input shaft 1. 5 can be reduced, and its thickness and weight can be reduced.

Further, the cylinder body 12 includes first and second cylinders.
The central block 12b having the valve holes 31 and 32 and the clutch valve hole 50, the first block 12a having the first cylinder hole 13, and the second block 12c having the second cylinder hole 23 are divided into three blocks. First and second annular grooves 29a and 29b formed on the joint surface of the block
And a plurality of annularly arranged through holes 2 formed in the central block 12b so as to communicate between the annular grooves 29a and 29b and to intersect the first and second valve holes 31 and 32 and the clutch valve hole 50.
9c, an annular high-pressure oil passage 29 is formed, and the first and second pump ports 33, 34 are formed in the joint surfaces of the three blocks 12a, 12b, 12c. , 34 can be easily formed and no blind plug is required.

On the other hand, since the low-pressure oil passage 28 is constituted by an annular groove formed on the peripheral surface of the input shaft 1 and the central block 12b opposed to each other, it can be easily formed.

The three blocks 12a, 12b, 12
c are joined to each other by a plurality of bolts 39 substantially arranged on the annular arrangement line of the plurality of through holes 29c.
Since the second annular grooves 29a and 29b are partially formed in a petal shape curved inward in the radial direction, the cylinder body 12
Can be prevented from interfering with the bolt 39 and the high-pressure oil passage 29.

Further, since the first side block 12a or the second side block 12c is formed integrally with the input shaft 1, torque transmission between the input shaft 1 and the cylinder body 12 can be performed quietly without play.

The present invention is not limited to the above embodiment, and various design changes can be made without departing from the gist of the present invention. For example, in the above embodiment, the first and second annular grooves 29a and 29b of the high-pressure oil passage 29 are
, But these are first and second side blocks 12a, 1
2c can also be provided. In addition, brazing or caulking can be used for joining the center block 12b and the first and second side blocks 12a and 12c. In addition, the annular groove constituting the low-pressure oil passage 28 can be provided on the inner peripheral surface of the central block 12b. Also, the first side block 12
a can be formed integrally with the input shaft 1.

[0049]

As described above, according to the characteristics of the present invention, the input shaft and the output shaft are coaxially supported on the transmission case.
A cylinder body fixed to the input shaft, a plurality of first plungers radially arranged on the cylinder body, and a pair of first plungers surrounding the first plungers and movably engaged with outer ends thereof; A radial type first hydraulic pressure having a variable capacity is provided by a first pump ring rotatably supported by a transmission case in order to reciprocate each first plunger with the rotation of the cylinder body and adjust the reciprocating stroke. A pump, wherein said cylinder body, a plurality of second plungers radially disposed on said cylinder body, and fixed to the output shaft and surrounding said second plungers and being opposed to their outer ends; Movably engaged,
A second pump ring that provides a reciprocating motion of a constant stroke to each second plunger with the relative rotation with respect to the cylinder body constitutes a fixed-capacity radial-type second hydraulic pump. A high-pressure oil passage through which hydraulic oil is sucked and hydraulic oil is discharged from the second hydraulic pump; and a low-pressure oil passage through which hydraulic oil is discharged from the first hydraulic pump and hydraulic oil is sucked into the second hydraulic pump. Provided, the axial dimension is smaller and more compact than that of a conventional combination of an axial hydraulic pump and a hydraulic motor, and the speed ratio can be steplessly controlled by shifting the first pump ring. A continuously variable transmission can be provided.

Further, the cylinder body is provided with a clutch valve hole extending in the radial direction of the cylinder body between the low-pressure and high-pressure oil passages. A clutch valve capable of moving between a radial position where the roads are not communicated with each other is fitted, and a clutch spring for biasing the clutch valve radially inward is provided, and the rotational speed of the input shaft exceeds a predetermined value. And the clutch valve is moved radially outward by the centrifugal force, so that the hydraulic transmission between the first and second hydraulic pumps can be turned on and off by the input shaft speed with a simple structure having a small number of parts. Can be automatically and smoothly performed in response to changes in

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a continuously variable transmission according to the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 1;

FIG. 4 is a sectional front view taken along line 4-4 of FIG. 1;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 1;

FIG. 6 is a partially enlarged view of FIG. 1;

7 is an enlarged view of a portion 7 in FIG. 4 and shows a clutch-off state.

8 is an enlarged view of a portion 7 in FIG. 4 and shows a clutch-on state.

FIG. 9 is an explanatory diagram of an operation in an infinite speed ratio state.

FIG. 10 is an operation explanatory view in a state of a gear ratio 2;

FIG. 11 is an explanatory diagram of an operation in a state of a speed ratio of 1;

FIG. 12 is an explanatory diagram of an operation in a state of a gear ratio of 0.66.

[Explanation of symbols]

1 ... input shaft 2 ... output shaft 3 ... support cylinder 5 ... transmission case 12 ... cylinder body 13 ... first cylinder hole 14 ... ... 1st plunger 15 ... 1st pump ring 23 ... 2nd cylinder hole 24 ... 2nd plunger 25 ... 2nd pump ring 28 ... low-pressure oil passage 29 ····· High pressure oil passage 50 ··· Clutch valve hole 51 ··· Clutch valve 52 ··· Clutch spring P ₁ ··· First hydraulic pump P ₂ ··· Second hydraulic pump T .... Continuously variable transmission

Claims (1)

[Claims] An input shaft (1) is mounted on a transmission case (5).
And the output shaft (2) is coaxially supported, and its input shaft (1)
A cylinder body (12), a plurality of first plungers (14) radially disposed on the cylinder body (12), and outer ends thereof surrounding the first plungers (14). To reciprocate the first plunger (14) with the rotation of the cylinder body (12), and can rotate to the transmission case (5) to adjust the reciprocating stroke. radially arranged constitutes a radial type first hydraulic pump of the variable displacement out the first pump ring (15) supported (P _1), also with the cylinder body (12), to the cylinder body (12) A plurality of second plungers (24), which are fixed to the output shaft (2), and
4) and movably engage with their outer ends around
A second reciprocation of a constant stroke to each second plunger (24) with relative rotation with respect to the cylinder body (12).
The pump ring (25) constitutes a fixed-capacity radial second hydraulic pump (P ₂ ), and further comprises a cylinder body (1).
The 2), a high pressure oil passage (29) to be discharged hydraulic oil from the second hydraulic pump while being sucked hydraulic oil to the first hydraulic pump (P ₁₎ (P _2), the first hydraulic pump (P A low-pressure oil passage (28) through which hydraulic oil is discharged from ₁ ) and hydraulic oil is sucked into the second hydraulic pump (P ₂ ) is provided, and a cylinder body (28) is provided between these two oil passages (28, 29). 12)
The clutch valve hole (50) extending in the radial direction is provided in the clutch valve hole (50). The clutch valve hole (50) has a radially inner position communicating the oil passages (28, 29) and the oil passages (28, 29). And a clutch valve (51) that can move between a radially outer position and a clutch valve (5).
A clutch spring (52) for biasing 1) radially inward is provided, and when the rotation speed of the input shaft (1) exceeds a predetermined value, the clutch valve (51) moves radially outward due to its centrifugal force. A continuously variable transmission, characterized in that: