JPS62224770A - Speed change control device for static hydraulic type continuously variable transmission - Google Patents

Abstract

PURPOSE:To reliably hold a motor cam plate at an arbitrary angle, by a method wherein the driving shaft of an electric motor is coupled to a trunnion shaft through a reduction gear brought into a locking state when a reverse load is applied thereon. CONSTITUTION:The driving shaft of an electric motor 86, being forward and reversely rotatable, is coupled to a trunnion shaft 70 through a reduction gear R brought into a locking state when a reverse load is applied thereof. This constitution enables smooth regulation of the angle of a motor cam plate 20 with the aid of a small electric motor 86. Besides, when running of the electric motor 86 is stopped, the motor cam plate 20 can be held at an arbitrary angle position through lock function of the reduction gear R. Thus, a low-cost and reliably-actuating transmission control device can be provided.

Description

Detailed Description of the Invention A1 Objective of the Invention fil Industrial Application Field The present invention forms a hydraulic closed circuit between a swash plate type hydraulic pump and a swash plate type hydraulic motor, and supports the motor swash plate of the hydraulic motor. In a hydrostatic transmission in which a swash plate holder is tiltably supported on a fixed structure via a trunnion shaft fixed to the swash plate holder, the angle of the motor swash plate is adjusted to control the gear ratio. The present invention relates to an improvement in a speed change control device that controls the capacity of a vehicle.

(2) Prior Art Conventionally, it has been known to connect a hydraulic servo motor to a motor swash plate so that the angle of the motor swash plate can be easily adjusted (see Japanese Patent Publication No. 59-38467).

(3) Problems to be Solved by the Invention In the conventional technology described above, the hydraulic servo motor has a complicated structure and is expensive, so the speed change control device inevitably becomes expensive.

The present invention has been made in view of the above circumstances, and it is possible to reliably adjust the angle of the motor swash plate using a relatively inexpensive small electric motor, thereby achieving the low-cost variable speed control system. 1) The purpose is to provide equipment.

B0 Structure of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention connects the drive shaft of an electric motor that can be forward and reverse to the trunnion shaft via a speed reduction device. The speed reduction device is characterized in that the rotation of the electric motor is reduced in speed and transmitted to the trunnion shaft, but is configured to be in a locked state when subjected to a reverse load.

(2) Operation When the electric motor rotates forward or reverse, its rotation is decelerated by the reduction gear and transmitted to the trunnion shaft, which tilts the motor swash plate in the upright direction or in the tilting direction. Even if the motor is small, the angle of the motor swash plate can be easily adjusted.

Furthermore, if the reduction gear receives a reverse load from the trunnion shaft, it becomes locked and does not allow the trunnion shaft to rotate, so as long as the electric motor is stopped, the motor swash plate can be reliably moved to any angular position. can be retained.

(3) Examples An embodiment of the present invention will be described below with reference to the drawings.

First, in FIGS. 1 and 2, the power of the engine E of the motorcycle is sequentially transmitted from the crankshaft 1 to the chain type primary reduction gear 2) to the hydrostatic continuously variable transmission T and to the chain type secondary reduction gear 3. The signal is then transmitted to the rear wheels (not shown).

The continuously variable transmission T includes a constant displacement swash plate hydraulic pump P and a variable displacement swash plate hydraulic motor M, and has a crankcase 4 supporting a crankshaft 1 as a casing.
accommodated in it.

The hydraulic pump P is connected to the output sprocket 2 of the primary reduction gear 2.
a, a cup-shaped input member 5 which is connected by three rivets 14, a pump cylinder 7 fitted to the inner circumferential wall of this input member 5 via a needle bearing 6 so as to be relatively rotatable, and this pump. A plurality of odd number of cylinder holes 8 arranged in an annular manner are provided in the cylinder 7 so as to surround its center of rotation.
．． Pump plungers 9.
9... and a pump swash plate 10 that abuts the outer ends of these pump plungers 9, 9....

The pump swash plate 10 is aligned with a virtual trunnion axis 0.0, which is orthogonal to the axis of the pump cylinder 7. Pump cylinder 7 centered on
The back side of the input member 5 is rotatably supported via a thrust roller bearing 1) on the inner end wall of the input member 5 in a posture inclined at a certain angle with respect to the axis of the input member 5, and when the input member 5 rotates, the pump plungers 9, 9... Reciprocating motion can be applied to repeat the suction and discharge strokes.

Incidentally, in order to improve the followability of the pump plunger 9 with respect to the pump swash plate 10, a spring that biases the pump plunger 9 in the expansion direction may be compressed in the cylinder hole 8.

The input member 5 has a thrust roller bearing 1 on its back side.
It is supported by the support cylinder 13 via 2.

On the other hand, the hydraulic motor M includes a motor cylinder 17 disposed coaxially with the pump cylinder 7 and to the left thereof, and a plurality of odd number of cylinder holes arranged in an annular arrangement surrounding the rotation center of the motor cylinder 17. 18. Motor plungers 19, 19... are slid together with 18, 18..., respectively.
, a motor swash plate 20 that comes into contact with the outer ends of these motor plungers 19, 19..., a swash plate holder 22 that supports the back surface of this motor swash plate 20 via a thrust roller bearing 21, and further this swash plate. The swash plate anchor 23 supports the holder 22.

The motor swash plate 20 is capable of tilting between an upright position perpendicular to the axis of the motor cylinder 17 and a maximum tilt position where the motor cylinder 17 is tilted at an angle. With the rotation, the motor plungers 19, 19... can be given reciprocating motion to repeat the expansion and contraction strokes.

Incidentally, in order to improve the followability of the motor plunger 19 with respect to the motor swash plate 20, a spring that biases the motor plunger 19 in the extension direction may be compressed in the cylinder hole 18.

The pump cylinder 7 and the motor cylinder 17 constitute an integrated cylinder block B, and the output shaft 25 is passed through the center of the cylinder block B.

Then, the outer end of the motor cylinder 17 is brought into contact with a flange 25a that is integrally formed on the outer periphery of the output shaft 25, and the pump cylinder 7 is spline-fitted to the output shaft 25. By locking the clip 26 to the output shaft 25, the cylinder block B is fixed to the output shaft 25.

The output shaft 25 also passes through the manpower member 5 and rotatably supports the member 5 via a needle bearing 27.

The support cylinder 13 is attached to the key 2 on the outer periphery of the right end of the output shaft 2.5.
8 and fixed with a nut 30.

The right end portion of the output shaft is rotatably supported by the crankcase 4 via the support tube 13 and roller bearing 31.

Further, the output shaft 25 is connected to the motor swash plate 20 and the swash plate holder 22.
and a thrust roller bearing 3 that passes through the center of the swash plate anchor 23, and a thrust roller bearing 3 that connects the back surface of the swash plate anchor 23 to the left end thereof.
A support cylinder 33 supported via 2 is spline fitted,
The output shaft 25 is fixed together with the input sprocket 3a of the secondary reduction gear 3 by a nut 34, and the left end portion of the output shaft 25 is rotatably supported by the crankcase 4 via the support cylinder 33 and roller bearing 35.

A hemispherical centering body 36 that engages with the inner circumferential surface of the pump swash plate 10 so as to be tiltable in all directions is slidably fitted onto the output shaft 25 by a spline. This centering body 36 presses the pump swash plate 10 against the thrust roller bearing 1) by the force of the plurality of disc springs 38, and thereby the pump swash plate 10
It always exerts an aligning effect on the

Further, a hemispherical centering body 37 that engages with the inner circumferential surface of the motor swash plate 20 so as to be tiltable in all directions is slidably fitted onto the output shaft 25 by a spline. This centering body 37 presses the motor swash plate 20 against the thrust roller bearing 21 by the force of the plurality of disc springs 39, thereby constantly applying an alignment action to the motor swash plate 20.

The alignment effect of each swash plate 10, 20 is strengthened, and the rotation direction between the pump swash plate 10 and the pump plungers 9, 9... group, and the motor swash plate 20 and the motor plunger 19, 19... group is enhanced. To prevent slippage, each swashplate 10.20 is provided with a spherical end 9a, 19a of the corresponding plunger 9.19.
Spherical recesses 10a and 20a are respectively formed to engage the spherical recesses 10a and 20a.

A hydraulic closed circuit is formed between the hydraulic pump P and the hydraulic motor M as follows.

In the cylinder block B, there are cylinder holes 8, 8, . . . groups of the pump cylinder 7 and cylinder holes 1 of the motor cylinder 17.
8.18...An annular inner oil passage 40 and outer oil passage 41 arranged concentrically around the output shaft 25 between the groups
and the same number of first valve holes 42 as the cylinder holes 8, 8, . . . and 18, 18, . ,4
2... and the second valve holes 43, 43... and the adjacent cylinder holes 8, 8... and the first valve holes 42, 42..., a large number of pump boats a, a..., adjacent cylinder holes 18°18... and second valve holes 43, 43
A large number of motor boats b, b... which communicate with each other.
・And is provided.

At that time, the inner oil passage 40 is formed between the opposing peripheral surfaces of the cylinder block B and the output shaft 25, and the outer oil passage 41 is fitted and welded to the cylinder block B and its outer periphery. It is formed between the circumferential surfaces facing the sleeve 44. The inner and outer oil passages 40,41 correspond to the low pressure and high pressure oil passages of the present invention.

A first distribution valve 45°4 is provided in the first valve holes 42, 42...
5, and second distribution valves 46, 46, . . . are slidably engaged with the second valve holes 43, 43, .

Each of the first distribution valves 45 is formed in a spool shape as shown in FIG. 8, and when it occupies a position radially outward of the first valve hole 42 in FIG. communicates with the passage 41 and disconnects from the inner oil passage 40, and communicates the corresponding cylinder hole 8 only with the outer oil passage 41,
When the first valve hole 42 occupies the radially inner position, the corresponding pump boat a is communicated with the inner oil passage 40 and disconnected from the outer oil passage 41, and the corresponding cylinder hole 8 is connected only to the inner oil passage 40. When the first valve hole 42 is in communication with the first valve hole 42 and the first valve hole 42 is in the center position, the pump boat a is not communicated with both the arm passages 40 and 41.

In order to impart such a movement to each first distribution valve 45, a first eccentric 47 is engaged around the group of first distribution valves 45, 45... at their outer ends, and the eccentric ring 47 A follower shaft 47' that is concentric with the first distribution valve 45, 45... is disposed inside the group and engages the engagement grooves 45a, 45a, 45a, 45a, 45a, 45a, 45a, 45a, 45a, 45a, 45a, etc.
..., and this engagement prevents each first distribution valve 45 from rotating.

The follower shaft 47' is made of steel wire and is arranged to urge the first distribution valves 45, 45, . . . in the direction of engagement with the first eccentric wheel 47. Note that this follower shaft 47' may be provided with one cut in order to absorb manufacturing errors in its diameter.

The first eccentric wheel 47 is rotatably supported by a first control ring 51 connected to the input member 5 via a ball bearing 48, and normally, as shown in FIG. A constant distance ε from the center of the output shaft 25 along the trunnion axis 0.

It is arranged at a first eccentric position ile which is eccentric by . Therefore, when a relative rotation occurs between the input member 5 and the pump cylinder 7, each first distribution valve 45 strokes a distance twice the eccentricity ε of the first eccentricity 47 within its valve hole 42. It reciprocates between an outer position and an inner position.

In FIGS. 1 to 3, the first control ring 51 is
A pivot 1 formed by extending one end of one of the rivets 14 that connects the sprocket 2a to the input member 5.
It is swingably connected to the input member 5 via 4a. That is, in FIG. 3, this first control ring 51 swings between a clutch-on position g and a clutch-off position around a pivot shaft 148, and in the clutch-on position 1g, the first control ring 51
A first eccentric position We where the eccentric wheel 47 is eccentric by a distance ε1 from the center of the output shaft 25 along the virtual trunnion axis oI
At the clutch off position Hh, the first eccentric shaft 47 is moved from the center of the output shaft 25 to the virtual trunnion axis 0. The second eccentricity is controlled to a second eccentricity 1r, which is eccentric by a distance ε1 along the perpendicular to . In order to restrict the swing range of the first control ring 51, as shown in FIGS. 5 and 6, the control ring 51
A guide pin 52 that is fixed to and protrudes from the inner circumferential surface of the
It is slidably engaged with a guide groove 53 formed on the outer periphery of the manpower member 5 and extending in the circumferential direction thereof. And the first control ring 5
A leaf spring 54 is interposed between the first control ring 51 and the input member 5 so as to spring the input member 5 toward the clutch-on position g, and the center portion of the leaf spring 54 is fixed to the first control ring 51 with a rivet 55. be done.

A roller 56 is attached to the guide pin 52,
A pushing arm 58 protruding from an example of an operating ring 57 is engaged with this roller 56 . As shown in FIG. 2, the operating ring 57 is slidably and rotatably fitted to the outer peripheral surface of the input member 5 on the opposite side of the first control ring 51 across the sprocket 2a, and is bored in the sprocket a. The pushing arm 58 is passed through the through hole 59.

The pushing arm 58 has a concave portion 60 at its tip engaged with one side of the roller 56 so that the first control ring 51 can be swung toward the clutch-off position lh (see FIG. 6). Further, the pushing arm 58 has a mountain shape whose circumferential width decreases toward its tip, and one slope 58a forming the mountain shape is connected to the recess 60, and the other slope 58b is connected to the through hole 58.
It is slidably engaged with a guide slope 59a formed on the inner wall of 9.

In FIG. 2, a release ring 62 is rotatably attached to the outer periphery of the operating ring 57 via a release bearing 61, and the outer end of the release ring 62 is attached to the crankcase 4.
A pressing protrusion 6.4a of an annular clutch lever 64, which is pivotably supported 63 and surrounds the input member 5, comes into contact with the pressing protrusion 6.4a.

As shown in FIGS. 2 and 7, at the swing end of the thalassotile lever 64, an inner lever 66a of a bell crank 66 that is pivotally supported 65 on the crankcase 4 pushes the clutch lever 64 toward the release ring 62. A return spring 67 is connected so as to move the clutch lever 64 toward the opposite side of the release ring 62.

The bell crank 66 includes the above-mentioned inner lever 66a disposed inside the crankcase 4 and an outer lever 66b disposed outside the crankcase 4, and the outer lever 66b has a clutch operated by the operator. An operating lever (not shown) is connected via wire 68.

Each of the second distribution valves 46 is also formed in the same spool shape as the first distribution valve 45, as shown in FIG. ) b communicates with the outer oil passage 41 and disconnects from the inner oil passage 40, communicates the corresponding cylinder hole 18 only with the outer oil passage 41, and occupies a position radially inward of the second valve hole 43. , the corresponding motor boat b is communicated with the inner oil passage 40 and disconnected from the outer oil passage 41, the corresponding cylinder hole 18 is communicated only with the inner oil passage 40, and furthermore, when it occupies the central position between the above repositions, , the corresponding motor boat 6 is disconnected from both the inner and outer oil passages 40 and 41.

In order to impart such a movement to each second distribution valve 46, a second eccentric 49 is engaged around the group of second distribution valves 46, 46, at their outer ends, and A follow-up width 49' concentric with the second distribution valve 46, 46...
a..., and by this engagement, each second distribution valve 4
6 is prevented from rotating.

The follower shaft 49' is made of steel wire and is arranged to urge the second distribution valves 46, 46, . . . in the direction of engagement with the second eccentric shaft 49. Note that this following width 49' may also be provided with one cut like the following width 47'.

As shown in FIG.
output shaft 2 along the tilting axis o2, that is, the trunnion axis o2.
An eccentric position l eccentric by a certain distance ε2 from the center of 5,
It is controlled to a concentric position m concentric with the output shaft 25.

Thus, when the second eccentric wheel 49 occupies the first eccentric position l, when the motor cylinder 17 rotates, each second distribution valve 46
is 2 of the eccentricity ε2 of the second eccentric wheel 49 within the valve hole 43.
When reciprocating between the outer position and the inner position with a stroke of twice the distance and occupying the concentric position m, the rotation of the motor cylinder 17 causes the entire second distribution valve 49.49.
... is kept at the central position.

Referring again to FIG. 2, at both ends of the swash plate holder 22,
A pair of upper and lower trunnion shafts 80.80' aligned on the trunnion axis OX of the motor swash plate 20 are integrally protruded, and these trunnion shafts 80.80' are connected to the roller bearings 71.
They are rotatably supported on both side walls of a cylindrical motor housing 72, which is integral with the crankcase 4, through respective cylindrical motor housings 71'. In other words, these trunnion axes 80, 80' define the trunnion axis oz. The motor housing 72 also rotatably supports the motor cylinder 17 via a needle bearing 73.

In the above configuration, when the first control ring 51 occupies the clutch-on position g, the first eccentric shaft 47 is moved to the first eccentric position e.
On the other hand, when the second eccentric wheel 49 occupies the first eccentric position e, when the input member 5 of the hydraulic pump P is rotated from the primary reduction gear 2, the pump plungers 9, 9 are controlled by the pump swash plate IO. ... are given alternately suction and discharge strokes, and the suction stroke region S and discharge stroke region of this hydraulic pump P are shown in FIG. and the first one in the suction stroke region S.
The distribution valve 45 is actuated to the inward position by the cooperation of the first eccentric wheel 47 and the following width 47', and
The distributor valve 45 is actuated to the outward position by the cooperation of the first eccentric 47 and the follower shaft 47'.

Therefore, each pump plunger 9 sucks hydraulic oil from the inner oil passage 40 into the cylinder hole 8 during the suction stroke, and pumps the hydraulic oil from the cylinder hole 8 to the outer oil passage 41 during the discharge stroke.

The high pressure hydraulic oil sent to the outer oil passage 41 is supplied to the hydraulic motor M.
is supplied to the pump boat a existing in the expansion stroke region Ex (see FIG. 9) via the second distribution valve 46 which is controlled to the outward position by the second eccentric transfer 49 and the follower shaft 49'; The hydraulic oil discharged from the motor boat b in the contraction stroke region sh (see FIG. 9) is directed to the inside via the second distribution valve 46, which is controlled to the inside position by the second eccentric wheel 49 and the follower wheel 49'. It is guided to the oil path 40.

During this period, the pump cylinder 7 receives reaction torque from the pump swash plate lO via the pump plunger 9 in the discharge stroke, and the motor cylinder I7 receives the reaction torque from the pump plunger 1 in the expansion stroke.
The cylinder block B is rotated by the sum of the reaction torque received from the motor swash plate 20 via the motor 9, and the rotational torque is transmitted from the output shaft 25 to the secondary reduction gear 3.

In this case, the gear ratio of the output shaft 25 to the input member 5 is given by the following equation.

Capacity of Hydraulic Pump P Therefore, if the capacity of hydraulic motor M is changed to a value consisting of zero, the transmission ratio can be changed to a required value consisting of one.

By the way, the capacity of the hydraulic motor M is the motor plunger 19.
Therefore, by tilting the motor swash plate 20 from an upright position to an inclined position, the gear ratio can be controlled steplessly up to a value of 1.

During such operation, if the clutch lever 64 is swung toward the release ring 62 via the wire 68 and the bell crank 66 against the force of the return spring 67 by operating a clutch operating lever (not shown), The pressing force applied to the release ring 62 is applied to the operating ring 57 via the release bearing 61.
The push arm 58 is pushed deeply into the through hole 59 of the sprocket 2a by sliding it to the left as indicated by the arrow 74 in FIG. 6. Then, due to the pressing action of the inner slope 59a of the through hole 59 against the slope 58b of the pusher arm 58 and the pressing action of the slope 58a of the pusher arm 58 against the roller 56, even if the axial displacement 74 of the operating ring 57 is small, the roller 56 is A large circumferential displacement 75 can be applied, thereby swinging the first control ring 51 from the clutch-on position g to the clutch-off position 1h against the force of the leaf spring 54.

As a result, the first eccentric wheel 47 is shifted from the first eccentric position e to the second eccentric position, and as shown in FIG. 2
Half of the pump boat a group is connected to the inner oil passage 40 by the distribution valves 46, 46, and the other half is connected to the outer oil passage 41.
As a result, the hydraulic pump P becomes short-circuited, and therefore, the high-pressure hydraulic oil discharged from the pump boat a in the discharge stroke region of the hydraulic pump P immediately flows to the pump boat a in the suction stroke region S. Since the hydraulic fluid is sucked in, the transfer of hydraulic fluid between the hydraulic pump P and the hydraulic motor M is stopped, and a clutch-off state occurs in which power transmission from the hydraulic pump P to the hydraulic motor M is cut off.

While the hydraulic pump P and hydraulic motor M are in operation, the pump swash plate 1
0 receives thrust loads in opposite directions from the pump plungers 9, 9... groups, and the motor swash plate 20 receives thrust loads in opposite directions from the motor plungers 19, 19... groups, but the thrust load that the pump swash plate IO receives is due to the thrust rollers. Bearing 1), input member 5, thrust roller bearing 12) are supported by output shaft 25 via support cylinder 13 and nut 30, and thrust load received by motor swash plate 20 is transmitted through thrust roller bearing 21, swash plate holder 22) Board anchor 2
3. Thrust roller bearing 32) Similarly output shaft 25 via support tube 33, sprocket 3a and nut 34.
supported by. Therefore, the thrust load merely causes tensile stress on the output shaft 25 and does not act on the crankcase 4 supporting the shaft 25 at all.

In FIGS. 1, 10, and 1), a speed change control device 80 for controlling the angle of the motor swash plate 20 is connected to the trunnion shaft 70 via the trunnion shaft 70. This speed change control device 80 includes a sector gear 81 that is rotatably supported on a trunnion shaft 70, and a sector gear 81 that is rotatably supported on a trunnion shaft 70.
0 and the crankcase 4.
A worm gear 85 is supported via bearings 84 and 84' on a bracket plate 83 fixed to the bracket plate 83 with bolts 83 and meshes with the sector gear 81, and a direct current electric motor 8 capable of forward and reverse rotation is connected to the worm gear 85 with a drive shaft 86a.
6, the stator 86 of this electric motor 86
b is fixed in place on the crankcase 4.

In the above, the sector gear 81 and the worm gear 85 can decelerate the rotation of the drive shaft 86a and transmit it to the trunnion shaft 80, but constitute a deceleration bag UR that becomes locked when receiving a reverse load from the trunnion shaft 80.

The damper 82 includes a damper main body 89 having a fan-shaped buffer chamber 87 centered on the trunnion shaft 70 and fixed to the trunnion shaft 70 with bolts 88, and a pair of rubber buffer members loaded in the buffer chamber 87. 90 and 90', and the sector gear 81 is provided between the buffer members 90 and 90'.
A transmission piece 91 protruding from one side is inserted.

Therefore, when the electric motor 86 is rotated forward or reverse, the rotation is transmitted from the worm gear 85 to the sector gear 81 at a reduced speed, and further to the transmission piece 91, the buffer member 90 or 9.
0', and can be transmitted to the trunnion shaft 70 via the damper body 89 to rotate it in the upright direction or tilting direction of the motor swash plate 20.

At that time, the motor plunger... is removed from the motor swash plate 20 from the group.
If pulsations occur in the thrust load applied to the shock absorber 90, 90', the pulsations are absorbed by the elastic deformation of the buffer members 90, 90'.
Thereby, the burden on the worm gear 85 and sector gear 81 can be reduced.

Furthermore, when the electric motor 86 is stopped and the motor swash plate 20 is held at an arbitrary angle, the motor swash plate 20 receives a moment from the motor plungers 19, 19, etc. in the upright or tilting direction, and the moment is transferred to the trunnion shaft. Since the sector gear 81 cannot drive the worm gear 85 even if the transmission is transmitted to the sector gear 81 through the sector gear 70, both gears 81 and 85 are in a locked state and do not allow rotation of the trunnion shaft 70, and therefore the motor swash plate 20 is securely held in its current position.

In order to regulate the upright position and tilted position of the motor swash plate 20 by the electric motor 86, an arc-shaped regulation groove 92 concentric with the sector gear 81 is bored, and the sector gear 81 is slidably engaged with the regulation groove 92. A matching regulation collar 93 is fixed to the bracket plate 83 with bolts 94.

In FIGS. 2 and 9, the second eccentric shaft 49 is rotatably supported by a second control ring 95 via a bearing 50. As shown in FIGS. This second control ring 95 is connected to the trunnion axis 0.
It has a pair of ears 96 and 96' on both sides of the direction, and one ear 96 is formed with a U-shaped guide groove 97 extending in the direction of the trunnion axis 0□. A guide pin 98 that is slidably inserted is fixed to the crankcase 4. A second guide hinge 99 is fixed to the other ear 96', and a U-shaped guide groove 1 engages with the guide pin 99 and extends in the direction of the trunnion axis 02.
A support portion 101 having a number 00 is provided to protrude from the inner wall of the crankcase 4. In this way, the second control ring 95 can be displaced in the direction of the trunnion axis 02, and by this displacement, the second eccentric wheel 49 can be controlled to the eccentric position 1tIl and the concentric position m.

A return spring 102 made of a temporary spring is pressed against the guide pin 99, which is integral with the second control ring 95, in order to spring the second control ring 95 toward the eccentric position 1 of the second eccentric wheel 49.

Furthermore, a cam hole 103 is provided in the ear portion 96', and a control lever 104 is fixed to the trunnion shaft 70'.
is inserted into this cam hole 103.

The cam hole 103 has a slope 103a on which the inner surface of the return spring 102 engages with the control lever 104, and is pressed by the control lever 104 in conjunction with the upright movement of the motor swash plate 20. According to the pressure, the second control ring 95 is displaced against the force of the return spring 102, and the second eccentric wheel 49 is moved to the eccentric position i! ! l toward the concentric position m, and when the motor swash plate 20 is upright, the second eccentric 49 is controlled to the concentric position rf1m.

When the second eccentric wheel 49 reaches the concentric position m, all the second distribution valves 46, 46... are closed as shown in FIG. 9A, and both the high pressure oil passage 41 and the low pressure oil passage 40 are closed. The hydraulic motor M is cut off. As a result, the volume of the low-pressure circuit communicating with the hydraulic pump P is reduced by the volume of the hydraulic motor M, so even if there are some air bubbles in the hydraulic oil, the amount of compression of the hydraulic oil by the hydraulic pump P is extremely small, and the input Relative rotation between the member 5 and the output shaft 25 can be suppressed to a minimum,
Therefore, the transmission efficiency can be increased at a speed ratio of 1.

In this case, in the illustrated example, the displacement of the second eccentric wheel 49 to the concentric position is caused by the action of the slope 103a of the cam hole 103.
Since this is performed in a stepless manner in conjunction with the rising operation of the motor swash plate 20, the second distribution valves 46, 46, . . . also perform stepless closing operations, and reach the closed state. Therefore, since the improvement in transmission efficiency begins slowly before the valve closes, it is possible to prevent a shift shock from occurring when the valve closes. However, if the shift shock is tolerable, the second distribution valve 46
．． The valves 46, . . . may be closed rapidly.

Again, in FIG. 1, the output shaft 25 has an oil passage 1) 0 bored in its center with a dead end at the back.
)0 is connected to an oil pan (not shown) at the bottom of the crankcase 4 via a replenishment pump 1)1, and the replenishment pump 1)1 is driven from the input member 5. Therefore, oil in the oil pan is supplied to the oil passage 1) 0 by the supply pump 1) 1 while the input member 5 is rotating.

The oil passage 1) 0 communicates with the inner oil passage 40 via a radial supply hole 1) 2 bored in the output shaft 25.

Also, a check valve 1) 3 is installed in the acid oil passage 1) 0 to prevent backflow of oil to the replenishment pump 1) 1 side.

Therefore, if hydraulic oil leaks from the hydraulic closed circuit between the hydraulic pump P and the hydraulic motor M during normal load operation, the hydraulic oil is replenished from the oil passage 1) 0 to the inner oil passage 40 through the supply hole 1) 2. .

During reverse load operation, that is, during engine braking, the hydraulic motor M performs a pumping action and the hydraulic pump P performs a motor action, so that the outer oil passage 41 is at low pressure and the inner oil passage 4 is at low pressure.
0 changes to high pressure, and the hydraulic oil attempts to flow back from the inner oil passage 40 to the oil passage 1) 0, but this back flow is blocked by the check valve 1) 3. Therefore, the reverse load can be reliably transmitted from the hydraulic motor M to the hydraulic pump P, and a good engine braking effect can be obtained.

Note that 1) 4 and 1) 5 in Fig. 1 are holes drilled in the output shaft 25 in order to supply lubricating oil from the oil passage 1) 0 to the contact parts of the plunger 9.19 and the swash plate 10.20. This is an orifice hole.

C3 Effects of the Invention As described above, according to the present invention, the drive shaft of the electric motor, which is capable of forward and reverse rotation, is connected to the trunnion shaft via the reduction gear,
This reduction gear reduces the rotation of the electric motor and transmits it to the trunnion shaft, but it is configured so that it locks when it receives a reverse load, so the angle of the motor swash plate can be easily adjusted using a small electric motor. Moreover, if the operation of the electric motor is stopped, the motor swash plate can be held at any angular position by the locking function of the reduction gear, thus providing a speed change control device that operates reliably at low angles. .

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal sectional plan view of a hydrostatic continuously variable transmission installed in the power transmission system of a motorcycle, and FIG. 2 is a longitudinal sectional rear view of the same transmission. , Figure 3 is the second
Fig. 3A is the operation diagram of Fig. 3, Fig. 4 is
Figures 5, 6 and 7 are the IV-N line of Figure 2,
The sectional views taken along lines V-V, Vl-■, and ■-■, and FIG. A perspective view of the second distribution valve, Figure 9 is IX-IX in Figure 2.
9A is an operational diagram of FIG. 9, and FIGS. 10 and 1) are sectional views taken along line X-X and Xl-XI of FIG. 2. E...Engine, M...Hydraulic motor, P...Hydraulic pump, R...Reduction device, T...Continuously variable transmission L...
・Crankshaft, 7...Pump cylinder, 9...Pump plunger, 10...Pump swash plate, 1'7...Motor cylinder, 19-...Motor plunger, 20...
- Motor swash plate, 22... Swash plate holder, 70... Trunnion shaft, 80... Speed change control device, 81... Sector gear, 82... Damper, 85... Worm gear, 8
6...Electric motor patent applicant: Honda Motor Co., Ltd. '3A Prisoner No. 3F, -'. Figure 4 m Figure 7 Figure 6 Figure 5 Stud diagram Figure 9

Claims (3)

[Claims] (1) A hydraulic closed circuit is formed between the swash plate type hydraulic pump and the swash plate type hydraulic motor, and the swash plate holder that supports the motor swash plate of the hydraulic motor is fixed via a trunnion shaft fixed thereto. In a hydrostatic continuously variable transmission supported tiltably on the trunnion shaft, the drive shaft of an electric motor that can be rotated in forward and reverse directions is connected to the trunnion shaft via a reduction device, and this reduction device transfers the rotation of the electric motor to the trunnion shaft. A speed change control device for a hydrostatic continuously variable transmission, characterized in that it is configured to decelerate and transmit data, but to enter a locked state when a reverse load is applied. (2) In what is stated in claim (1),
The speed reduction device is a speed change control device for a hydrostatic continuously variable transmission, which consists of a sector gear connected to a trunnion shaft, and a worm gear meshing with the sector gear and connected to the drive shaft of the electric motor. (3) In what is stated in claim (1),
The reduction gear is a speed change control device for a hydrostatic continuously variable transmission connected to the trunnion shaft via a damper.