JP3748633B2 - Motorcycle power unit and rear wheel assembly - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motorcycle, a power unit mainly used for a scooter, and a rear wheel assembly, and more particularly, to a crankcase side of an internal combustion engine arranged immediately before the rear wheel and to a side of the rear wheel. A transmission case consisting of a vertical case part and a lateral case part bent so as to enter the rim of the rear wheel from the rear end thereof is connected, and a continuously variable transmission connected to the crankshaft of the internal combustion engine is accommodated in this transmission case. It is related to the improvement of a power unit comprising a power unit and a rear wheel hub attached to its output shaft.
[0002]
[Prior art]
In such a conventional assembly, for example, as disclosed in Japanese Utility Model Publication No. 2-17990, a belt-type continuously variable transmission is provided in the vertical case portion of the transmission case portion, and a gear reducer is provided in the lateral case portion. Each is housed.
[0003]
[Problems to be solved by the invention]
In the above-described conventional power unit and rear wheel assembly, the belt type continuously variable transmission has an axially movable portion, so that the lateral width is as wide as possible. Therefore, the vertical case portion that accommodates the belt inevitably has a lateral width. It becomes wide and this protrudes greatly to the side of the rear wheel, making it difficult to make the assembly compact.
[0004]
The present invention has been made in view of such circumstances, and the power unit for a motorcycle and the rear unit that are compactly arranged by rationally arranging a hydraulic continuously variable transmission in which input and output shafts are rotatably fitted to each other. An object is to provide a ring assembly.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a longitudinal case portion disposed on one side of a rear wheel on the side of a crankcase of an internal combustion engine disposed immediately before the rear wheel, and a rear wheel inside the rim of the rear wheel. A transmission case composed of a lateral case portion that bends so as to enter into the engine is connected, and a continuously variable transmission connected to the crankshaft of the internal combustion engine is accommodated in the transmission case to constitute a power unit, and the rear wheel is connected to the output shaft. A hydraulic continuously variable transmission in which an input shaft and an output shaft are rotatably fitted to a lateral case portion and arranged coaxially in an assembly of a motorcycle power unit and a rear wheel. A fixed transmission ratio winding transmission that connects between the input shaft and the crankshaft is housed in the vertical case, and the hydraulic continuously variable transmission is radially arranged on the cylinder body fixed to the input shaft. Plural first plungers provided The first pump which surrounds the first plungers and engages the outer ends of the first plungers so as to be relatively movable, reciprocates the first plungers as the cylinder body rotates, and adjusts the reciprocating strokes. A variable-capacity radial first hydraulic pump comprising a ring, a plurality of second plungers radially disposed on the cylinder body, and fixed to an output shaft and surrounding these second plungers, A fixed-type radial second hydraulic pump comprising a second pump ring that engages with the end so as to be movable relative to each other and provides a reciprocating motion of each second plunger with a constant stroke in accordance with relative rotation with the cylinder body. The cylinder body has a high-pressure oil passage through which hydraulic oil is drawn into the first hydraulic pump and discharged from the second hydraulic pump, and hydraulic oil from the first hydraulic pump. A low pressure oil passage sucked hydraulic oil to the second hydraulic pump with discharged that is provided to the feature.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples of the present invention shown in the accompanying drawings.
[0008]
First, the overall configuration of the power unit and rear wheel assembly will be described with reference to FIGS. This assembly is for a scooter and is configured by attaching a rear wheel W to the power unit U. The power unit U is supported by a rear end portion of the rear fork 50 that is pivotally supported by the vehicle body frame F and a lower end portion of a rear cushion unit 51 that is pivotally supported by the vehicle body frame F.
[0009]
The power unit U includes an internal combustion engine E disposed immediately before the rear wheel W, a winding transmission M disposed on the left side of the rear wheel W, and a hydraulic continuously variable transmission T disposed coaxially with the rear wheel W. ing.
[0010]
The internal combustion engine E is arranged with its crankshaft 52 parallel to the axis of the rear wheel W, and a transmission case 54 is connected to the left end of a crankcase 53 that houses and supports the crankshaft 52. The transmission case 54 is bent rearward from the left end of the crankcase 53 and is adjacent to the left side of the rear wheel W. The transmission case 54 is bent rightward from the rear end of the vertical case portion 54a and The vertical case portion 54a accommodates the winding transmission device M, and the horizontal case portion 54b accommodates the hydraulic continuously variable transmission T. The horizontal case portion 54b is inserted into the rim Wr.
[0011]
Crankcase 53 and the transmission case 54, which constitutes a series of casing 55 of the power unit U, the first block 55 ₁ to form the left half of the vertical case section 54a, the crank case 53, the right vertical casing portion 54a half and the second block 55 ₂ of the left half of the lateral casing section 54b had been integrally molded by being divided into a third block 55 ₃ forming the right half of the lateral casing section 54b, these blocks 55 _1, 55 ₂ and 55 ₃ are bolted so as to be separable. A side cover 56 that covers a generator 57 attached to the right end of the crankshaft 52 is joined to the right end of the crankcase 53.
[0012]
The left end portion of the crankshaft 52 protrudes toward the vertical case portion 54a so as to serve also as the drive shaft of the winding transmission device M. Further, the input shaft 1 of the hydraulic continuously variable transmission T supported on the left end wall of the horizontal case portion 54b via the bearing 61 protrudes toward the vertical case portion 54a so as to also serve as the driven shaft of the winding transmission device M. In the vertical case portion 54a, the drive pulley 65 and the driven pulley 66 are fixed to the crankshaft 52, and the cog belt 67 is wound around them to form a fixed transmission ratio winding transmission device M. The A tension pulley 68 for applying a constant tension to the belt 67 is disposed in the vertical case portion 54a.
[0013]
The output shaft 2 of the hydraulic continuously variable transmission T is supported coaxially with the input shaft 1 via a pair of left and right bearings 62 and 63 on the right end wall of the lateral case portion 54b. The output shaft 2 has a support cylinder 3 that surrounds the inner end of the input shaft 1, and a bearing 64 that supports the two is supported between the support cylinder 3 and the input shaft 1. The bearing 62 is disposed on the outer periphery of the support cylinder 3. Then, the hub Wh of the rear wheel W is detachably fitted to the outer end portion of the output shaft 2 and fixed by a nut 69.
[0014]
An oil seal 71 is interposed between the left end wall of the horizontal case portion 54b and the input shaft 1 on the outside of the bearing 61, and an oil seal is provided between the bearings 62, 63 between the right end wall of the horizontal case portion 54b and the output shaft 2. 72 is intervened. As a result, the drum type brake 75 is formed between the right end wall of the horizontal case portion 54b and the hub Wh of the rear wheel W. The vertical case portion 54a is a dry chamber and the horizontal case portion 54b is a wet chamber. . That is, the brake 75 includes a brake drum 76 that is integrally formed with the hub Wh, and a flange-like brake panel 77 that is integrally formed with the right end wall of the lateral case portion 54b so as to cover the open surface. As is well known, a brake shoe 78 housed in the brake drum 76 and a cam shaft 79 that operates to press the brake shoe 78 against the inner peripheral surface of the brake drum 76 are attached to the brake panel 77. Further, an operating lever 80 connected to a brake lever (not shown) of the scooter via an operation wire is fixed to the cam shaft 79. Therefore, by operating the brake lever, the brake 75 can be operated to brake the rear wheel W.
[0015]
Now, the configuration of the hydraulic continuously variable transmission T will be described with reference to FIGS. In FIG. 3, the hydraulic continuously variable transmission T is configured by connecting a variable-capacity radial first hydraulic pump P ₁ and a constant-capacity radial second hydraulic pump P ₂ to each other via a hydraulic closed circuit. Is done. As shown in FIGS. 3 and 4, the first hydraulic pump P ₁ is arranged radially on the cylinder body 12 concentrically connected to the input shaft 1 via the spline 11 so as to open to the outer peripheral surface thereof. A plurality of (in the illustrated example, five) first cylinder holes 13, first plungers 14 slidably fitted in these cylinder holes 13, and the outer ends thereof surrounding the plunger 14 group, A first pump ring 15 that is slidably engaged in the circumferential direction is provided, and a spring 16 that biases the first plunger 14 in the direction of engagement with the first pump ring 15 in each first cylinder hole 13. Stored.
[0016]
The first pump ring 15 is configured such that a boss 15a formed on one side thereof is supported by the lateral case portion 54b via a pivot 17 parallel to the input shaft 1, and is a predetermined distance e to one side with respect to the cylinder body 12. ₁ (see FIG. 9A) swings between a first eccentric position A that is eccentric and a predetermined distance e ₂ to the other side (see FIG. 12A) and a second eccentric position C that is eccentric. An eccentric position B (see FIG. 11A) B that is concentric with the cylinder body 12 exists between the two eccentric positions A and C. The first and second eccentric positions A and C of the first pump ring 15 are arranged such that the stopper arm 15b provided on the other side of the ring 15 has one and the other of the recesses 18 formed on the inner peripheral wall of the lateral case portion 54b. It is prescribed | regulated by contact | abutting to the inner end wall. A return spring 19 that constantly urges the first pump ring 15 toward the first eccentric position A is interposed between the lateral case portion 54 b and the ring 15, while resisting the urging force of the return spring 19. A shift lever 20 that can swing the ring 15 from the first eccentric position A to the second eccentric position C is pivotally supported 21 on the lateral case portion 54b. The shift lever 20 is operated manually or by an automatic actuator. Thus, when the cylinder body 12 rotates, the first pump ring 15 can reciprocate each first plunger 14 according to the amount of eccentricity of the ring 15 to repeat the suction and discharge strokes. .
[0017]
As shown in FIGS. 3 and 5, the second hydraulic pump P ₂ includes a plurality of (five in the illustrated example) second cylinder holes 23 arranged in an opening on the outer peripheral surface of the cylinder body 12, A second plunger 24 that is slidably fitted in each of the second cylinder holes 23, and a second pump ring that surrounds the second plunger 24 group and slidably engages with the outer ends thereof. 25, and a spring 26 for energizing each second plunger 24 in the direction of engagement with the second pump ring 25 is accommodated in each second cylinder hole 23.
[0018]
The second pump ring 25 is integrally connected to the support cylinder 3 of the output shaft 2 and is arranged to be eccentric from the cylinder body 12 by a predetermined distance e ₃ (see FIG. 9A) to one side. . Thus, when the cylinder body 12 rotates, the second pump ring 25 can reciprocate the second plungers 24 to repeat the suction and discharge strokes.
[0019]
As shown in FIG. 3, the first hydraulic pump P ₁ and the second hydraulic pump P ₂ are disposed apart from each other on one end side and the other end side of the cylinder body 12, and surround the input shaft 1 at an intermediate portion thereof. An annular low pressure oil passage 28 and an annular high pressure oil passage 29 further surrounding the low pressure oil passage 28 are provided. 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 cylinder body 12, and the high pressure oil passage 29 is formed in the cylinder body 12.
[0020]
The cylinder body 12 has the same number as the first cylinder holes 13 and the same number as the first valve holes 31 and the second cylinder holes 23 extending radially adjacent to the inside of the first cylinder hole 13 group. A second valve hole 32 extending radially is provided adjacent to the inside of the group of two cylinder holes 23. Each first valve hole 31 penetrates the high pressure oil passage 29 from the outer peripheral surface of the cylinder body 12 to reach the low pressure oil passage 28, and the first cylinder hole adjacent to the inner side surface of each first valve hole 31. A first pump port 33 extending laterally from 13 opens. Each second valve hole 32 also passes from the outer peripheral surface of the cylinder body 12 through the high-pressure oil passage 29 to the low-pressure oil passage 28, and the second valve hole 32 is adjacent to the adjacent second cylinder. A second pump port 34 extending laterally from the hole 23 opens.
[0021]
As shown in FIGS. 3 and 6, a spool-type first switching valve 35 is slidably fitted in the first valve hole 31, and surrounds the outer ends of these first switching valves 35. The first switching ring 37 is engaged so as to be slidable in the circumferential direction. As shown in FIG. 4, the first switching ring 37 is fixed to the lateral case portion 54 b with a bolt 39 at a position eccentric from the cylinder body 12 by a predetermined distance e ₄ .
[0022]
Thus, when the cylinder body 12 rotates, each first switching valve 35 is kept in engagement with the first switching ring 37 due to its own centrifugal force and the centrifugal hydraulic pressure of the hydraulic oil in the low-pressure oil passage 28. Be drunk. Accordingly, the first switching ring 37 reciprocates each first switching valve 35 between the radially inner position and the outer position of the cylinder body 12 as the cylinder body 12 rotates.
[0023]
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 communicates with the low pressure oil passage 28 by the first switching valve 35. On the other hand, the second pump port 34 corresponding to the second plunger 24 during the intake stroke is communicated with the high-pressure oil passage 29 by the first switching valve 37.
[0024]
On the other hand, if the first pump ring 15 occupies the second eccentric position C, the first pump port 33 corresponding to the first plunger 14 during the discharge stroke is connected to the high-pressure oil by the first switching valve 35. While communicating with the passage 29, the first pump port 33 corresponding to the first plunger 14 during the intake stroke is communicated with the low-pressure oil passage 28 by the first switching valve 35.
[0025]
As shown in FIGS. 3 and 7, similarly, a spool-type second switching valve 36 is slidably fitted in the second valve hole 32, and the second switching valve 36 surrounds the second switching valve 36. The second switching ring 38 is engaged so as to be slidable in the circumferential direction. The second switching ring 38 is integrally connected to the first pump ring 25 and arranged so as to be eccentric from the cylinder body 12 by a predetermined distance e ₅ .
[0026]
Thus, when the cylinder body 12 rotates, each second switching valve 36 is kept in engagement with the second switching ring 38 due to its own centrifugal force and the centrifugal hydraulic pressure of the hydraulic oil in the low-pressure oil passage 28. Be drunk. Accordingly, the second switching ring 38 reciprocates each second switching valve 36 between the radially inward position and the outward position of the cylinder body 12 in accordance with the relative rotation with the cylinder body 12. The second switching valve 36 allows the second pump port 34 corresponding to the second plunger 24 during the intake stroke to communicate with the low pressure oil passage 28, while the second pump port corresponding to the second plunger 24 during the discharge stroke. 34 communicates with the high-pressure oil passage 29.
[0027]
In the above, low, high pressure oil passage 28 and 29, first, second valve holes 31, 32 and the first and the second pump port 33, 34 hydraulic connecting the first, second hydraulic pump P _1, P ₂ between A closed circuit is constructed.
[0028]
In FIG. 3 again, the low-pressure oil passage 28 communicates with the oil reservoir 41 at the bottom of the lateral case portion 54b through a series of replenishment oil passages 40 formed on the input shaft 1 and the side wall of the lateral case portion 54b. 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 lateral case portion 54 b.
[0029]
3, 4, and 8, the cylinder body 12 includes three blocks 12 a, which are axially stacked to form the low and high pressure oil passages 28 and 29 and the first and second pump ports 33 and 34. 12b and 12c, and these are coupled by a plurality of bolts 47 with seal rings 45 and 46 interposed therebetween. That is, as clearly shown in FIG. 8, the high-pressure oil passage 29 intersects with a pair of annular grooves 29a and 29b formed on both end faces of the central block 12b and the first and second valve holes 31 and 32 adjacent to each other. The annular grooves 29a and 29b communicate with each other, and a plurality of through holes 29c communicate with each other. The open surfaces of the annular grooves 29a and 29b are closed by the outer blocks 12a, 12b and 12c. The first and second pump ports 33 and 34 are formed on the opposing surfaces of the blocks 12a, 12b and 12c.
[0030]
The operation of this embodiment will be described. In FIG. 2, when the internal combustion engine E is operated, the power is transmitted from the crankshaft 52 to the input shaft 1 via the winding transmission M having a fixed rotation ratio, and the hydraulic continuously variable. The gear is appropriately shifted by the transmission T and output from the output shaft 2 to the rear wheel W to drive it. That is, the rear wheel W can be driven by the output of the power unit U and the scooter can be driven.
[0031]
Thus, in such a power unit U, the winding transmission device M having a fixed rotation ratio has no axially movable portion, and therefore its axial width is extremely narrow compared to a belt type continuously variable transmission. In addition, the lateral width of the vertical case portion 54a that accommodates the winding transmission device M can be significantly reduced as compared with the conventional case. Therefore, the amount of protrusion of the vertical case portion 54a to the side of the rear wheel W can be greatly reduced, and the assembly of the power unit U and the rear wheel W can be made compact. Further, the hydraulic continuously variable transmission T accommodated in the lateral case portion 54b is formed by coaxially arranging the input and output shafts 1 and 2 so as to be rotatable with respect to each other. Is also relatively small, which contributes to the compactness of the horizontal case portion 54b and the reduction of the amount of protrusion of the vertical case portion 54a toward the rear wheel W side.
[0032]
Next, the operation of the hydraulic continuously variable transmission T will be described with reference to FIGS. In each of the above drawings, (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 .
[0033]
<Continuously large gear ratio (see FIG. 9)>
In this state, the capacity of the first hydraulic pump P ₁ is controlled to be equal to that of the second hydraulic pump P ₂ by shifting the first pump ring 15 to the first eccentric position A (see FIG. 4).
[0034]
Therefore, if the input shaft 1 is rotated, the cylinder body 12 that rotates integrally with the input shaft 1 causes relative rotation between the first pump ring 15 and the second pump ring 25. At this time, the first pump port 33 corresponding to the first plunger 14 in the discharge stroke as the first in the hydraulic pump P ₁ described above corresponds to the low pressure oil passage 28 and the first plunger 14 in the suction phase Since one pump port 33 communicates with the high-pressure oil passage 29, the hydraulic oil is sucked from the high-pressure oil passage 29 and discharged to the low-pressure oil passage 28.
[0035]
On the other hand, the second pump port 34 in the second hydraulic pump P _2, the second pump port 34 corresponding to the second plunger 24 in the intake stroke corresponding to the second plunger 24 of the low pressure oil passage 28, also during the discharge stroke Are respectively connected to the high-pressure oil passage 29, so that the hydraulic oil is sucked from the low-pressure oil passage 28 and discharged to the high-pressure oil passage 29.
[0036]
In addition, since the capacities of both the hydraulic pumps P ₁ and P ₂ are equal, the total 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 transferred to the second hydraulic pump P ₂ . The entire amount of hydraulic oil that is sucked and discharged from the second hydraulic pump P ₂ to the high-pressure oil passage 29 is sucked into the first hydraulic pump P ₁ . Accordingly, the first and second plungers 14 and 24 repeatedly reciprocate, and simply slide on the inner peripheral surfaces of the first and second pump rings 15 and 25, and no rotational torque is generated. 2 remains stopped.
[0037]
<State where gear ratio is 2, for example (see FIG. 10)>
The first pump ring 15 is shifted to an intermediate position between the first eccentric position A (see FIG. 4) and the non-eccentric position B, that is, a position where the amount of eccentricity becomes en, and the capacity of the first hydraulic pump P ₁ is changed to the second hydraulic pressure. Control to half the capacity of the pump P ₂ . In this way, during one rotation of the cylinder body 12, the amount of hydraulic oil that the first hydraulic pump P ₁ sucks from the high pressure oil passage 29 is the amount of hydraulic oil that the second hydraulic pump P ₂ discharges to the high pressure oil passage 29. Therefore, the reaction force when the second hydraulic pump P ₂ discharges the remaining half of the hydraulic oil acts on the second pump ring 25 from the second plunger 24 during the discharge stroke, The output shaft 2 is rotated. As a result, during one rotation of the input shaft 1, the output shaft 2 is rotated halfway.
[0038]
<State where the gear ratio is 1 (see FIG. 11)>
The first pump ring 15 is shifted to the eccentric position B (see FIG. 4), and the capacity of the first hydraulic pump P ₁ is controlled to zero. In this case, the hydraulic oil discharged from the second hydraulic pump P ₂ to the high-pressure oil passage 29 is not sucked into the first hydraulic pump P ₁ at all and loses its destination, so that all the second plungers 24 are in the hydraulic lock state. As a result of the cylinder body 12 and the second pump ring 25 entering and connecting the output shafts 1 and 2 together, the shafts 1 and 2 rotate at the same speed.
[0039]
<State where gear ratio is 0.66 (see FIG. 12)>
The first pump ring 15 is shifted to the second eccentric position C (see FIG. 4), and the suction area and the discharge area of the first hydraulic pump P ₁ are reversed, and the capacity thereof is changed to the second hydraulic pump. It is set to one-half of the capacity of the 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 The hydraulic oil is discharged from the hydraulic pressure passage 33 to the high pressure oil passage 29 and supplied to the second pump port 34 corresponding to the second plunger 24 that has been in the discharge stroke in the second hydraulic pump P ₂ until then. The plunger 24 moves to the expansion stroke, and the second pump ring 25 is increased in the rotation direction of the cylinder body 12 by a half rotation by the expansion thrust. Eventually, the gear ratio is 1: 1.5 = 0.66, and the speed is increased.
[0040]
As is clear from the above, the first pump ring 15 is continuously shifted from the first eccentric position A to the second eccentric position C, so that the transmission ratio between the input and output shafts 1 and 2 is infinite (neutral state). ) To a speed increasing state, the vehicle can be started smoothly, and overdrive can be achieved at high speeds to reduce fuel consumption.
[0041]
Further, during the rotation of the cylinder body 12, the oil in the oil reservoir 41 is sucked into the low-pressure oil passage 28 from the replenishment oil passage 40 and stored. Accordingly, hydraulic fluid leakage from the sliding surfaces of the first and second plungers 14 and 24 and the first and second switching valves 35 and 36 is immediately supplied from the low-pressure oil passage 28.
[0042]
By the way, since the hydraulic continuously variable transmission T is composed of the radial type first and second hydraulic pumps P ₁ and P ₂ on the common cylinder body 12, the conventional axial type hydraulic pump is used. Compared with a combination of a motor and a motor, the axial dimension can be greatly shortened and the size can be reduced. In addition, the support cylinder 3 formed at the inner end of the output shaft 2 is supported by the lateral case portion 54 b via the bearing 62, and the support cylinder 3 supports the inner end of the input shaft 1 via the bearing 4. The inner ends of both shafts 1 and 2 can be firmly supported by the lateral case portion 54b in a small axial space, and the support rigidity can be increased. The lateral case portion 54b that accommodates the continuously variable transmission T can be greatly downsized, particularly in the axial direction. Therefore, most of the lateral case portion 54b is accommodated in the rim Wr of the rear wheel W, and can be disposed close to the rear wheel W of the vertical case portion 54a having a small lateral width. Further, the compact power unit U and the rear wheel W can be provided. Can be obtained.
[0043]
The present invention is not limited to the above embodiments, and various design changes can be made without departing from the scope of the invention. For example, the winding transmission M having a fixed rotation ratio can be configured as a V-belt type or a chain type.
[0044]
【The invention's effect】
According to the onset light as described above, the lateral casing section of the transmission case houses a hydrostatic transmission arranged coaxially fitted rotatably to the input shaft and the output shaft to each other, the input Since the winding transmission device having a fixed rotation ratio for connecting the shaft and the crankshaft is accommodated in the vertical case portion of the transmission case, the horizontal width of the vertical case portion 54a can be reduced, and the axial dimension of the hydraulic continuously variable transmission can be reduced. By shortening, the amount of protrusion of the vertical case portion toward the rear wheel side can be suppressed to a small size, and the assembly of the power unit and the rear wheel can be made compact.
[0045]
Particularly hydraulic continuously variable transmission power units also radial fixed displacement driving a radial type first hydraulic pump of the variable capacity which is connected to the input shaft, the output shaft is coupled thereto via a hydraulic closed circuit Since the second hydraulic pump is used, it is possible to further reduce the amount of protrusion of the vertical case portion toward the rear wheel side and further reduce the size of the assembly of the power unit and the rear wheel.
[Brief description of the drawings]
FIG. 1 is a side view of a scooter power unit and a rear wheel assembly according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 4 is a sectional view taken along line 4-4 in FIG. 3. FIG. 5 is a sectional view taken along line 5-5 in FIG. 3. FIG. 6 is a sectional view taken along line 6-6 in FIG. FIG. 8 is a partially enlarged view of FIG. 3. FIG. 9 is an explanatory diagram of the operation in the infinite gear ratio state. FIG. 10 is an explanatory diagram of the operation in the state of the gear ratio 2. FIG. Action explanation diagram [FIG. 12] Action explanation diagram in the state of gear ratio 0.66 [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Input shaft 2 ... Output shaft 12 ... Cylinder body 13 ... First cylinder hole 14 ... First plunger 15 ... First pump ring 23 2nd cylinder hole 24 ... 2nd pump ring 28 ...... low pressure oil passage 29 ... high pressure oil passage 52 ... crankshaft 53 ... ... Crankcase 54 ... Transmission case 54a ... Vertical case part 54b ... Horizontal case part E ... Internal combustion engine P ₁ ... First hydraulic pump P ₂ ... Second hydraulic pump T
T ... Hydraulic continuously variable transmission U ... Power unit W ... Rear wheel Wh ... Hub Wr ... Rim

Claims (1)

A vertical case portion (54a) arranged on one side of the rear wheel (W) on the one side of the crankcase (53) of the internal combustion engine (E) arranged just before the rear wheel (W) and the rear wheel from the rear end A transmission case (54) comprising a lateral case portion (54b) bent so as to enter the rim (Wr) of (W) is connected, and the crankshaft of the internal combustion engine (E) is connected to the transmission case (54). A power unit for a motorcycle and a rear unit, in which a continuously variable transmission connected to (52) is accommodated to form a power unit (U), and a hub (Wh) of a rear wheel (W) is mounted on the output shaft (2). In the wheel assembly,
The horizontal case portion (54b) accommodates the hydraulic continuously variable transmission (T) in which the input shaft (1) and the output shaft (2) are rotatably fitted to each other and arranged coaxially, and the input shaft ( 1) A winding device (M) having a fixed rotation ratio that connects between the crankshaft (52) is accommodated in the vertical case portion (54a),
Hydraulic continuously variable transmission (T)
A plurality of first plungers (14) arranged radially on a cylinder body (12) fixed to the input shaft (1), and surrounding these first plungers (14), move relative to their outer ends. A variable capacity comprising a first pump ring (15) capable of engaging and reciprocating each first plunger (14) as the cylinder body (12) rotates and adjusting the reciprocating stroke. A radial type first hydraulic pump (P ₁ );
A plurality of second plungers (24) arranged radially on the cylinder body (12), and fixed to the output shaft (2), surround the second plungers (24), and are relative to their outer ends. A fixed-capacity radial type second comprising a second pump ring (25) that is movably engaged and that reciprocates with a constant stroke to each second plunger (24) with relative rotation with the cylinder body (12). It consists of a hydraulic pump (P ₂ ),
The cylinder body (12) includes a high pressure oil passage (29) through which hydraulic oil is drawn into the first hydraulic pump (P ₁ ) and discharged from the second hydraulic pump (P ₂ ), and a first hydraulic pressure. A power unit for a motorcycle and a rear unit, characterized in that a hydraulic oil is discharged from the pump (P ₁ ) and a low-pressure oil passage (28) through which the hydraulic oil is sucked into the second hydraulic pump (P ₂ ). Ring assembly .

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