WO2002006704A1 - Transmission hydraulique a variation continue et vehicule machine de chantier - Google Patents

Transmission hydraulique a variation continue et vehicule machine de chantier Download PDF

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Publication number
WO2002006704A1
WO2002006704A1 PCT/JP2001/005215 JP0105215W WO0206704A1 WO 2002006704 A1 WO2002006704 A1 WO 2002006704A1 JP 0105215 W JP0105215 W JP 0105215W WO 0206704 A1 WO0206704 A1 WO 0206704A1
Authority
WO
WIPO (PCT)
Prior art keywords
plunger
hydraulic
cylinder block
continuously variable
variable transmission
Prior art date
Application number
PCT/JP2001/005215
Other languages
English (en)
Japanese (ja)
Inventor
Shuji Shiozaki
Takeshi Oouchida
Hiroshi Matsuyama
Kunihiko Sakamoto
Takeaki Nozaki
Yukio Kubota
Original Assignee
Yanmar Diesel Engine Co., Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Yanmar Diesel Engine Co., Ltd. filed Critical Yanmar Diesel Engine Co., Ltd.
Priority to AU2001274547A priority Critical patent/AU2001274547A1/en
Publication of WO2002006704A1 publication Critical patent/WO2002006704A1/fr

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H39/00—Rotary fluid gearing using pumps and motors of the volumetric type, i.e. passing a predetermined volume of fluid per revolution
    • F16H39/04—Rotary fluid gearing using pumps and motors of the volumetric type, i.e. passing a predetermined volume of fluid per revolution with liquid motor and pump combined in one unit
    • F16H39/06—Rotary fluid gearing using pumps and motors of the volumetric type, i.e. passing a predetermined volume of fluid per revolution with liquid motor and pump combined in one unit pump and motor being of the same type
    • F16H39/08—Rotary fluid gearing using pumps and motors of the volumetric type, i.e. passing a predetermined volume of fluid per revolution with liquid motor and pump combined in one unit pump and motor being of the same type each with one main shaft and provided with pistons reciprocating in cylinders
    • F16H39/10—Rotary fluid gearing using pumps and motors of the volumetric type, i.e. passing a predetermined volume of fluid per revolution with liquid motor and pump combined in one unit pump and motor being of the same type each with one main shaft and provided with pistons reciprocating in cylinders with cylinders arranged around, and parallel or approximately parallel to the main axis of the gearing
    • F16H39/14—Rotary fluid gearing using pumps and motors of the volumetric type, i.e. passing a predetermined volume of fluid per revolution with liquid motor and pump combined in one unit pump and motor being of the same type each with one main shaft and provided with pistons reciprocating in cylinders with cylinders arranged around, and parallel or approximately parallel to the main axis of the gearing with cylinders carried in rotary cylinder blocks or cylinder-bearing members

Definitions

  • the present invention relates to a hydraulic continuously variable transmission that can be widely used for various machines such as industrial machines and vehicles, and a work implement vehicle equipped with the transmission.
  • FIG. 14 shows a conventional example in which HST is used as a continuously variable transmission.
  • the variable displacement hydraulic pump P1 and the fixed displacement hydraulic motor Ml constituting the HST form a closed hydraulic circuit.
  • FIG. 15 shows the relationship between the stroke volume of the variable displacement hydraulic pump P1 in the continuously variable transmission of FIG.
  • the stroke volume refers to the amount of hydraulic oil exchanged per rotation of the hydraulic pump P1.
  • the output rotation speed shown in FIG. is a boundary of 0, which means that the + side indicates forward running and the one side indicates reverse running.
  • + and-of the stroke volume mean the flow direction of the hydraulic oil in the hydraulic closed circuit.
  • VMmax indicates the maximum stroke volume.
  • a conventional hydraulic continuously variable transmission shown in FIG. 16 is also known. This device includes a variable displacement hydraulic pump P2 and a variable displacement hydraulic motor M2.
  • the hydraulic pump P2 and the hydraulic motor M2 form a closed hydraulic circuit. That is, the hydraulic oil discharged from the hydraulic pump P 2 is pumped to the hydraulic motor M 2, and after the hydraulic motor M 2 is operated by the hydraulic oil, the hydraulic oil is again supplied to the hydraulic pump P 2 via the hydraulic closed circuit. The two have been to go back.
  • the output shaft of the engine EG is connected to the hydraulic pump P2, and a reduction mechanism Ga is provided between the output shaft of the hydraulic motor M2 and a final reduction device (not shown). In this device, forward / backward switching can be performed by operating a shift lever (not shown).
  • Fig. 17 shows the stroke volume per 1 'rotation of the hydraulic pump P2 and the hydraulic motor M2 in the continuously variable transmission shown in Fig.
  • NP X VMmax NMX 0-5 VMmax
  • variable displacement hydraulic motor M2 rotates twice as fast as the variable displacement hydraulic pump P2.
  • the best value of the total efficiency is about 0.8 due to the same oil leakage.
  • the hydraulic continuously variable transmission shown in FIGS. 14 and 16 it is necessary to circulate the hydraulic oil in the hydraulic closed circuit as shown in FIGS. 15 and 17 in order to obtain a predetermined output speed. This results in oil leaks and reduced efficiency.
  • the output rotation speed is obtained only by circulating the hydraulic oil, when high-speed rotation is required, a large amount of oil is inevitably required, resulting in an increase in the size of the device.
  • the conventional device has a problem that only about 0.8 can be obtained as the best value of the total efficiency.
  • a work implement vehicle such as a tractor or loader, originally, the work implement
  • the high-speed running area is not the main working area
  • the main working speed area is the running area as shown in Figure 19.
  • Fig. 19 shows the distribution of the working area of agricultural work equipment vehicles
  • the vertical axis represents the load torque required for the work equipment vehicles
  • the horizontal axis represents the traveling speed (speed). It can be seen that the main working speed range of many work equipment vehicles is concentrated in the working range where the traveling speed is in the forward range and about 2 km / h to 10 kmZh.
  • a vehicle equipped with a conventional continuously variable transmission consisting of HST force performs forward traveling and reverse traveling with the output rotational speed being zero. Referring to Fig.
  • HST ⁇ U (1) can only cover up to 2-4 kmZh at the time of forward running, and eventually HST sub 2 The shift is switched to (2).
  • the HST sub 2 (2) shift switching causes the device to operate in a state where the overall efficiency is lower than 0.8. Will have to be used. In other words, it is not a preferable use condition from the viewpoint of overall efficiency. In order to solve such a problem regarding the overall efficiency, it is necessary to increase the overall capacity of the pump and motor of the HST shown in Fig. 14 and the continuously variable transmission shown in Fig.
  • An object of the present invention is to, when the discharge amount of hydraulic oil from a first hydraulic device of a variable displacement type is zero, connect an input side and an output side of a hydraulic continuously variable transmission via a second hydraulic device.
  • Another object of the present invention is to provide an output of the hydraulic continuously variable transmission through a variable displacement differential hydraulic device when the discharge amount of hydraulic oil from the variable displacement hydraulic device is zero.
  • a hydraulic continuously variable transmission includes a first plunger and a plunger contact portion, and a variable plunger that operates the first plunger by the contact portion.
  • a capacity-type first hydraulic device and a second hydraulic device having a second plunger and having an output rotating portion that performs relative or synchronous rotation with respect to input rotation by contact with the second plunger.
  • the continuously variable transmission has a cylinder block,
  • the latch hook is configured to rotate around an axis by input rotation, and stores the first and second plungers, respectively.
  • the cylinder block has a first plunger hole and a second plunger hole.
  • the first plunger chamber is formed by storing the first plunger in the first plunger hole.
  • the second plunger chamber is formed by housing the second plunger in the second plunger hole.
  • the continuously variable transmission has a hydraulic closed circuit, the closed circuit includes a first oil chamber and a second oil chamber, and circulates hydraulic oil between the first plunger chamber and the second plunger chamber. While the cylinder block makes one rotation about the axis, a section in which the first plunger chamber communicates with the first oil chamber and a section in which the first plunger chamber communicates with the second oil chamber are respectively set, and the output rotating section is formed. A section in which the second plunger chamber communicates with the first oil chamber and a section in which it communicates with the second oil chamber during one rotation around the axis with respect to the cylinder block are respectively set.
  • the first plunger chamber refers to a space formed by a plunger of the first hydraulic device and a plunger hole of a cylinder block for storing the plunger.
  • the second plunger chamber refers to a space formed by a plunger of the second hydraulic device and a plunger hole of a cylinder block that houses the plunger.
  • the first oil chamber is an oil chamber that exchanges hydraulic oil with the first and second plunger chambers
  • the second oil chamber is a second oil chamber that exchanges hydraulic oil with the first plunger chamber and the second plunger chamber.
  • One oil chamber is a separate oil chamber.
  • the hydraulic closed circuit includes at least four oil chambers including a first plunger chamber, a first oil chamber, a second plunger chamber, and a second oil chamber, and circulates hydraulic oil formed by these oil chambers and the like.
  • the stroke volume of the first hydraulic device means that the plunger chamber of the first hydraulic device is in the first oil chamber and the second oil chamber during one rotation of the cylinder block around the axis (during one stroke).
  • the stroke volume of the second hydraulic device means that the plunger chamber of the second hydraulic device has the first hydraulic chamber and the second hydraulic chamber during one rotation of the output rotating part around the axis with respect to the cylinder block (during one stroke). The amount of hydraulic oil exchanged with the oil chamber.
  • the plunger contact portion may not act on the first plunger. That is, when the hydraulic oil does not circulate in the hydraulic closed circuit, the plunger of the second hydraulic device is in contact with the output rotary unit without performing a stroke operation. Therefore, the output rotation unit rotates integrally with the cylinder block. At this time, since the rotation (number) of the cylinder block is the same as the input rotation (number), the output rotation unit rotates synchronously with the input rotation. Also, when the plunger contact portion acts on the first plunger of the first hydraulic device, the hydraulic oil in the first plunger chamber circulates in the hydraulic closed circuit while the cylinder block makes one rotation around the axis. I do.
  • the second plunger When hydraulic oil is sucked into the second plunger chamber of the second hydraulic device during this circulation, the second plunger is operated by the hydraulic oil, and imparts rotation to the output rotary unit. Then, in a range where the stroke volume of the first hydraulic device exceeds the stroke volume of the second hydraulic device, the output rotating section is given a rotation speed higher than the input rotation by the second plunger of the second hydraulic device. Therefore, when the rotation given to the output rotation unit is in the same direction as the input rotation, the present device can obtain a rotation exceeding the double speed of the input rotation as the output rotation. Further, when the rotation given to the output rotation unit is in the opposite direction to the input rotation, the present device can obtain a rotation in the opposite direction to the input rotation as the output rotation.
  • the output rotating section has one rotation around the axis with respect to the cylinder block. It is desirable that the section where the second plunger chamber communicates with the first oil chamber during rotation becomes smaller. In this case, the stroke volume of the second hydraulic device becomes smaller than the stroke volume of the first hydraulic device. Accordingly, the amount of hydraulic oil that the second hydraulic device transfers to and from the first oil chamber during one stroke is smaller than the amount of hydraulic oil that the first hydraulic device transfers to and from the first oil chamber during one stroke. Become. As a result, the operation of the second plunger of the second hydraulic device during one stroke becomes faster, and the output rotation unit rotates accordingly.
  • the continuously variable transmission further includes a first distribution valve and a first application member that imparts reciprocating motion to the first distribution valve.
  • the first applying member applies reciprocating motion in the axial direction to the first distribution valve while the cylinder block rotates once around the axis, and performs the first reciprocating motion in accordance with the axial reciprocation of the first distribution valve.
  • One plunger chamber communicates with the first oil chamber and the second oil chamber.
  • the continuously variable transmission preferably further includes a second distribution valve and a second imparting member that imparts reciprocating motion to the second distribution valve.
  • the force S is desirably used.
  • reciprocation in the axial direction is applied to the second distribution valve during one rotation around the axis, and the second plunger chamber becomes the first oil chamber and the second oil chamber according to the reciprocation of the second distribution valve in the axial direction.
  • the first distributing valve is reciprocally supported by the cylinder block along the axial direction of the cylinder block, and the first applying member is arranged so as to face the first end of the cylinder block. It is desirable to include a first cam disposed around the axis of the first cam.
  • the second distribution valve is reciprocally supported by the cylinder block along the axial direction of the cylinder block, and the second applying member is blocked by the cylinder so as to face the second end of the cylinder block.
  • FIG. 1 is a sectional view of a continuously variable transmission according to an embodiment of the present invention.
  • FIG. 2 is a sectional view of a main part of the continuously variable transmission shown in FIG. 1 on the first hydraulic device side.
  • FIG. 3 is a cross-sectional view of a main part of the continuously variable transmission shown in FIG. 1 on the second hydraulic device side.
  • FIG. 4 is a cross-sectional view taken along the line 414 of FIG.
  • Fig. 5 is a sectional view taken along line 5-5 in Fig. 1.
  • Fig. 6 (a) is a sectional view taken along line 6-6 in Fig. 1
  • Fig. 6 (b) is an explanatory view showing the operation of the contact portion.
  • Fig. 7 is a sectional view taken along the line 7-7 in Fig. 4.
  • Figure 8 is a plan view of the shifter.
  • FIG. 9 is a conceptual diagram of the continuously variable transmission shown in FIG.
  • FIG. 10 is a characteristic diagram showing a relationship between a stroke volume of a hydraulic device and an output rotation speed in the continuously variable transmission of FIG.
  • FIG. 11 is an explanatory view showing the operation of a plurality of cams for operating the distribution valve.
  • FIG. 12 is an explanatory diagram showing the timing at which the motor port is opened by the action of the cam of FIG.
  • FIG. 13 is an explanatory diagram showing a change in the opening area of the motor port with respect to the rotation angle of the cam in FIG. 11.
  • Figure 14 is a conceptual diagram of a conventional continuously variable transmission consisting of HST.
  • FIG. 15 is a characteristic diagram showing the relationship between the pump / motor stroke volume and the output rotation speed of the apparatus in FIG.
  • Figure 16 is a conceptual diagram of another conventional hydraulic continuously variable transmission.
  • FIG. 17 is a characteristic diagram showing the relationship between the pump Z motor stroke volume and the output rotation speed of the apparatus in FIG.
  • Fig. 18 is a characteristic diagram showing the relationship between vehicle speed and overall efficiency of a vehicle equipped with a conventional continuously variable transmission consisting of HST.
  • Figure 19 is a distribution diagram showing the relationship between vehicle speed and load torque of various work vehicles.
  • FIG. 1 is a sectional view of a hydraulic continuously variable transmission (hereinafter referred to as a continuously variable transmission) T.
  • the continuously variable transmission T is housed in a power unit case 11 of an agricultural work vehicle.
  • the continuously variable transmission T includes a first hydraulic device 100 and a second hydraulic device 200 that forms a hydraulic closed circuit together with the first hydraulic device 100.
  • FIG. 1 is a sectional view of a hydraulic continuously variable transmission (hereinafter referred to as a continuously variable transmission) T.
  • the continuously variable transmission T is housed in a power unit case 11 of an agricultural work vehicle.
  • the continuously variable transmission T includes a first hydraulic device 100 and a second hydraulic device 200 that forms a hydraulic closed circuit together with the first hydraulic device 100.
  • FIG. 1 is a sectional view of a hydraulic continuously variable transmission (hereinafter referred to as a continuously variable transmission) T.
  • the continuously variable transmission T is housed in a power unit case 11 of an agricultural work vehicle.
  • the continuously variable transmission T includes a first hydraulic device
  • the input shaft 12 of the continuously variable transmission T is connected to the crankshaft of the engine EG, and the output gear 39 connected to the yoke 37 located on the output side of the device T is It is connected to an input gear 10 connected to a final deceleration device (not shown).
  • the first hydraulic device 100 corresponds to a variable displacement hydraulic device
  • the second hydraulic device 200 corresponds to a differential hydraulic device.
  • the first end of the input shaft 12 of the continuously variable transmission T is rotatably supported via a bearing portion 14 on a support plate 13 provided on the case 11.
  • the second end is rotatably supported by a side wall of the case 11 via a radial bearing 15.
  • This input shaft is also the PTO shaft (power takeoff shaft).
  • a holder 16 is fixed to the inner surface of the support plate 13. Through holes 13 a and 16 a through which the input shaft 12 passes are formed in the support plate 13 and the holder 16, respectively.
  • the bearing receiving hole 18 is formed in the support plate 13 and the holder 16 by enlarging the diameter of the opposite part of the two through holes 13 a and 16 a.
  • the input shaft 12 is supported by a conical roller bearing 19.
  • a sleeve 20 having a large-diameter portion 20a and a small-diameter portion 20b is passed through the input shaft 12 adjacent to the conical roller bearing 19, and the small-diameter portion 20b Is inserted into the inner ring 19 b of the conical roller bearing 19.
  • the nut 21 screwed to the input shaft 12 is tightened from the outside to the inside (the right side in FIG. 1), so that the outer ring 1 of the conical roller bearing 19 is passed through the sleeve 20.
  • 9a is in contact with the enlarged bottom surface and the peripheral surface of the through hole 16a of the through hole 16a in the bearing housing hole 18 and the inner peripheral surface of the enlarged diameter portion of the through hole 13a.
  • the end surface of the small-diameter portion 20 b of the sleeve 20 is locked in a state of contact with the locking ring 22 engaged with the peripheral surface of the input shaft 12.
  • a seal member 23 is disposed in the small diameter portion of the through hole 13a.
  • the bearing portion 14 includes a conical roller bearing 19, a sleeve 20, and a nut 21.
  • the first hydraulic device 100 is slidably disposed on a cylinder block 24 and a cylinder block 24 which are integrally connected to the input shaft 12 and the input shaft 12 by press-fitting.
  • a cradle 27 including a plurality of first plungers 34 and a swash plate surface 26 abutting on the first plunger 34 is provided.
  • the cradle 27 is supported in contact with the holder 16 on the back side thereof, and the input shaft 12 passes through the cradle 27.
  • FIGS. 1 and 2 the cradle 27 and the holder 16 are shown separated for convenience of explanation.
  • the swash plate surface 26 corresponds to the plunger contact portion of the first variable displacement hydraulic device of the present invention.
  • the opposing surfaces E 1 and E 2 where the cradle 27 and the holder 16 abut each other are centered on the trunnion axis TR 1 orthogonal to the axis O of the cylinder block 24. It has a semi-cylindrical surface.
  • the cradle 27 can be tilted about the trunnion axis TR1.
  • a plurality of lines ⁇ , ⁇ , ⁇ that are orthogonal to the swash plate surface 26 and pass through the trunnion axis TR1 are assumed.
  • the position of the cradle 27, that is, the position of the swash plate surface 26 is distinguished by the lines ⁇ and y.
  • the swash plate surface 26 is orthogonal to the axis O, and the swash plate surface 26 is arranged at an upright position (not shown).
  • the position of the swash plate surface 26 specified by the lines ⁇ and ⁇ is positive or negative with respect to the time when the swash plate surface 26 is placed in the upright position (clockwise in FIGS.
  • the direction is defined as positive, and the counterclockwise direction is defined as negative). Accordingly, the swash plate surface 26 shown in FIG. 1 and FIG. 2 shows a state where the swash plate surface 26 is arranged at the position specified by the line, and the tilt angle is the maximum.
  • the cradle 27 tilts to the negative side as shown in FIGS. 1 and 2 when Nout> NE with the output rotational speed Nout2 NE shown in FIG. Cradle 27 tilts to the positive side.
  • the positions Q ;, ⁇ , and ⁇ used in the following description indicate a negative maximum tilt angle position, an upright position, and a positive maximum tilt angle position on the swash plate surface 26, respectively.
  • first cylinder holes 33 are arranged in a ring around the center of rotation, and extend in parallel with the axis ⁇ .
  • the first cylinder hole 33 is open to the holder 16 side.
  • a first plunger 34 is slidably disposed in each first cylinder hole 33.
  • the space formed by the first plunger 34 accommodated in each first cylinder hole 33 and the first cylinder hole 33 corresponds to the first plunger chamber R1.
  • a steel ball 34 a is rotatably fitted to the tip of each first plunger 34, and each first plunger 34 is provided with a steel ball 34 a and a steel ball 34 a attached thereto. It is in contact with the swash plate surface 26 through 35.
  • the swash plate surface 26 in the inclined state reciprocates each first plunger 34 with the rotation of the cylinder block 24, and gives each first plunger 34 an action of a suction and discharge stroke.
  • Each of the first cylinder holes 33 corresponds to a first plunger hole.
  • the second hydraulic device 200 is a cylindrical yoke having a plurality of plungers 44 slidably disposed on the cylinder block 24 and a rotary swash plate surface 36 abutting against each plunger 44. 3 and 7 are provided.
  • a boss plate 40 is rotatably supported at an end of the input shaft 12 on the second hydraulic device 200 side via a bearing 38.
  • the boss plate 40 is formed in a substantially disk shape.
  • An output gear 39 is fixed to the boss portion 40a of the boss plate 40.
  • Each of the plungers 44 corresponds to a second plunger
  • the yoke 37 corresponds to an output rotating unit.
  • the yoke 37 is fixed to the boss plate 40 by bolts 41.
  • rotation The swash plate surface 36 is provided on the side surface of the yoke 37 facing the cylinder block 24.
  • the rotary swash plate surface 36 is aligned with the axis O around the trunnion axis TR 2. It is formed so as to be parallel to the virtual plane inclined at a constant angle with respect to the virtual plane.
  • An enlarged diameter portion 37a is formed on the inner peripheral surface of the yoke 37 on the output gear 39 side.
  • the input shaft 12 is provided with a conical roller bearing 29. Supported by Then, the nut 31 screwed to the input shaft 12 is tightened from the output gear 39 side to the cylinder block 24 side so that the outer ring 29 a of the conical roller bearing 29 becomes the enlarged portion 3. It is in contact with the step bottom of 7a. Further, the inner ring 29 b of the conical roller bearing 29 is locked in a state of contact with the locking ring 32 engaged with the circumferential groove 12 a of the input shaft 12.
  • the same number of the second plunger holes 43 as the first plunger holes 33 are arranged in an annular shape around the center of rotation, and extend in parallel with the axis O. .
  • the second plunger hole 43 corresponds to the second plunger hole.
  • the second plunger hole 43 is arranged concentrically with the pitch circle of the first plunger hole 33 and on a pitch circle having a diameter larger than the pitch circle.
  • each second plunger hole 43 is shifted from the first plunger hole 33 by 1 Z2 pitch in the circumferential direction of the cylinder block 24 so that the second plunger hole 43 is located between the first plunger holes 33 adjacent to each other. (See Figures 4 and 5).
  • the second plunger hole 43 is arranged so as to overlap with the first plunger hole 33 in the longitudinal direction (the direction of the axis O of the cylinder block 24) as shown in FIG. , And open to the yoke 37 side.
  • a plunger 44 is rotatably disposed in each second plunger hole 43, and a steel ball 44a is rotatably fitted at the tip thereof.
  • the space formed by the plunger 44 housed in the second plunger hole 43 and the second plunger hole 43 corresponds to the second plunger chamber R2.
  • Each plunger 44 is in contact with the rotating swash plate surface 36 via a steel ball 44 4a and a shoe 45 to which the steel ball 44a is attached. With the relative rotation between the rotating swash plate surface 36 and the cylinder block 24
  • a first inner oil chamber 51 and a second inner oil chamber 52 are formed on inner circumferential surfaces at both axial ends of the cylinder block 24. Also, annular first outer oil chambers 53 and second outer oil chambers 54 are formed at predetermined intervals near both ends in the axial direction of the cylinder block 24, near the outer peripheral side.
  • the first inner oil chamber 51 and the first outer oil chamber 53 are communicated with each other via a plurality of radially extending oil passages 55, and the second inner oil chamber 52 and the second outer oil chamber 5 are connected to each other. 4 is communicated with a plurality of radially extending oil passages 56.
  • the first outer oil chamber 53 corresponds to a first oil chamber
  • the second outer oil chamber 54 corresponds to a second oil chamber.
  • the cylinder block 24 has the same number of first valve holes 57 communicating with the first outer oil chamber 53 and the second outer oil chamber 54 as the first plunger hole 33, and the number of cylinder blocks 24. It extends along the axial direction. Also, the cylinder block 24 has the same number of second valve holes 58 communicating with the first outer oil chamber 53 and the second outer oil chamber 54 as the second plunger hole 43, and The block 24 extends along the axial direction of the block 24.
  • Each of the first valve holes 57 and each of the second valve holes 58 are arranged so as to be adjacent to each other as shown in FIGS. In each first valve hole 57, a port U of an oil passage 59 communicating with the corresponding first plunger hole 33 is formed between the first outer oil chamber 53 and the second outer oil chamber 54.
  • a spool-type first switching valve 60 is slidably disposed in each first valve hole 57. As shown in FIGS. 1 and 2, the first end of the first switching valve 60 is formed on the outer periphery of the holder 16 by the biasing force of the coil spring 63 wound around the first end. It is always in contact with the cam surface 62 of the cam 61.
  • the first switching valve 60 corresponds to a first distribution valve, and the first cam 61 corresponds to a first applying member.
  • FIG. 11 shows a cam profile of the first cam 61. As shown in the figure, the cam surface 62 of the first cam 61 communicates the first switching valve 60 with the port U and the first outer oil chamber 53 around the port closing position n0.
  • the position for positioning the first switching valve 60 at the first opening position n1 and the second opening position n2 is the stroke of the first switching valve 60 in that region.
  • the cylinder blocks 24 are located on a pair of virtual planes perpendicular to the axis O of the cylinder block 24 so as not to change.
  • a slope is formed on the cam surface 62. Then, by the operation of the first cam 61, a region H and a region I are set in the first hydraulic device 100 as shown in FIG.
  • the first switching valve 60 is moved to the first opening position n1, and the first plunger hole 33, that is, the first plunger chamber R1 Is a section communicating with the first outer oil chamber 53 via the port U.
  • the first switching valve 60 is moved to the second opening position n2 with the rotation of the cylinder block 24, and the first plunger hole 33, that is, the first plunger chamber R 1 is This section communicates with the second outer oil chamber 54 via the port U.
  • the first hydraulic device 100 is configured such that the output rotation speed Nout (the rotation speed of the output gear 39) when the input rotation speed of the input shaft 12 is NE is increased from NE to 2NE.
  • the discharge amount of hydraulic oil on the side is set.
  • the rotation angle around the axis of the cylinder block 24 shown in FIG. 11 is 0 ° to 180 °. In the range, the hydraulic oil is sucked into the first plunger hole 33, that is, the first plunger chamber R1 via the port U.
  • the hydraulic oil is discharged from the first plunger hole 33 through the port U from the first plunger chamber R1. Conversely, 0 if the swash plate surface 26 tilts forward. In the range of up to 180 °, the operating oil is discharged from the first plunger hole 33, ie, from the first plunger chamber R1 via the port U. In the range of 180 ° to 360 ° (0 °), hydraulic oil is sucked into the first plunger hole 33, that is, the first plunger chamber R1 via the port U.
  • the oil chamber to be discharged and the oil chamber to be suctioned are determined by regions H and I corresponding to the rotation angle range of the cylinder block 24.
  • each second valve hole 58 a port W of an oil passage 69 communicating with the corresponding second plunger hole 43 is formed between the first outside oil chamber 53 and the second outside oil chamber 54.
  • a spool type second switching valve 70 is slidably disposed so as to be parallel to the plunger 44.
  • the second switching valve 70 corresponds to a second distribution valve. As shown in FIGS. 1 and 2, the first end of the second switching valve 70 is pressed by a coil spring 73 wound around the second switching valve 70, and a second cylindrical valve provided on the outer periphery of the yoke 37. It is always in contact with the cam surface 72 of the cam 71.
  • the second cam 71 corresponds to a second applying member.
  • the second switching valve 70 corresponds to a second distribution valve.
  • the second cam 71 is slidably fitted to the outer peripheral surface of the yoke 37 in the direction of the axis O of the cylinder block 24.
  • a pair of keys 74 is integrally fixed to the yoke 37 at positions opposed to each other by 180 degrees so as to be along the axis O direction of the cylinder block 24.
  • a pair of guide grooves 75 provided on the inner peripheral surface of the second cam 71 is fitted to the key 74 so that the second cam 71 is moved in the direction of the axis ⁇ of the cylinder block 24. , And is prevented from rotating relative to the yoke 37 in the circumferential direction.
  • the second cam 71 can rotate integrally with the yoke 37 about the axis O.
  • the inner diameter of the second cam 71 is set smaller than the outer diameter of the boss plate 40, and the second cam 71 can be locked to the boss plate 40. That is, when the second cam 71 is locked to the boss plate 40 and further movement to the output gear 39 side (movement to the right in FIG. 3) is restricted, the second cam 71 Is located at the locking position, and the locking position is the first displacement position Q1 of the second cam 71.
  • a displacement imparting member 76 is rotatably supported on the output gear side end surface of the second cam 71 with respect to the case 11.
  • the displacement applying member 76 includes a contact member 77 that can contact the output gear side end surface of the second cam 71, and a worm gear 78 that is integrally connected to the contact member 77 via a shaft 78a. It is composed of As shown in FIG. 6 (b), the abutment body 77 is composed of a pair of arms 79, 80 extending on both sides of the shaft 78a of the worm gear 78, and the clockwise direction of the worm gear 78. Alternatively, one of the arms 79 and 80 abuts on the output gear side end face of the second cam 71 by the counterclockwise rotation. In this embodiment, when the worm gear 78 rotates clockwise in FIG.
  • the arm 80 comes into contact with the end face on the output gear side of the second cam 71 and is positioned at the reference position Q 0.
  • the second cam 71 to the second displacement position Q2.
  • the arm 79 rotates counterclockwise, the second cam 71 is moved from the reference position Q0 to the first displacement position Q.
  • Move to 1 A worm shaft 81 rotatably supported by the case 11 is combined with the worm gear 78.
  • the worm shaft 81 is operatively connected to a not-shown actuator. When the actuator is in the neutral position and is not operated, the contact body 77 contacts the second cam 71 to position the second cam 71 at the reference position Q0.
  • the holding mechanism is constituted by the worm gear 78 and the worm shaft 81.
  • the actuator, the worm shaft 81, the worm gear 78, and the contact member 77 constitute a variable mechanism.
  • FIG. 11 shows a cam blower nozzle of the second cam 71.
  • the relative position between the cam surface 62 and the cam surface 72 changes because the second cam 71 rotates together with the yoke 37, but for convenience of explanation, they are combined into one. Is shown. Then, based on the relative rotation of the yoke 37 with respect to the cylinder block 24, an area J and an area K are set in the second hydraulic device 200 by the action of the second cam 71.
  • the region J is a section in which the second plunger hole 43 communicates with the second outside oil chamber 54 via the port W by the second switching valve 70 displaced by the cam surface 72.
  • the area K is a section in which the second plunger hole 43 force, that is, the second plunger chamber R 2 communicates with the first outer oil chamber 53 via the port W.
  • the second cam 71 shown in the reference position Q 0 shown in FIG. Hydraulic oil is sucked into the second plunger hole 43, ie, the second plunger chamber R2, through the port W in the range of 0 ° to 180 ° in the relative rotation angle around the axis.
  • the second plunger hole 43 is provided when the relative rotation angle is in the range of 180 ° to 360 ° (0 °). That is, hydraulic oil is discharged from the second plunger chamber R2 through the port W.
  • FIG. 12 shows the second cam 71 and the second cam 71 when the second switching valve 70 is switched by the action of the second cam 71 and the port W communicates with the first outer oil chamber 53 and the second outer oil chamber 54, respectively.
  • the relative rotation angle range of the cylinder block 24 is shown.
  • FIG. 13 shows the relative rotation angle between the second cam 71 and the cylinder block 24 and the opening by the second switching valve 70 when communicating with the first outer oil chamber 53 or the second outer oil chamber 54.
  • FIG. 4 is a characteristic diagram of the present embodiment showing a relationship with an opening area of a port W.
  • the plus (+) side indicates the opening area when the port W communicates with the first outside oil chamber 53
  • the minus (1) side indicates the opening area when the port W communicates with the second outside oil chamber 54. .
  • the port W When the second cam 71 is located at the reference position Q0, that is, when 0 ⁇ Nout ⁇ 2NE in FIG. 10, the port W is in the range from 0 ° to 180 ° as shown in FIGS. In the range from 180 ° to 360 ° (0 °), it is communicated with the first outer oil chamber 53. In the present embodiment, when the second cam 71 is located at the reference position Q 0, the port W is opened when the port W communicates with the first outer oil chamber 53 and when the port W communicates with the second outer oil chamber 54. Sections are the same as each other So that the cam surface 72 is set.
  • the second plunger chamber R2 communicates with the second outer oil chamber 54 up to a predetermined angle (for example, about 3 degrees) to 150 °, and the second plunger chamber R2 has a second angle from 150 ° to the predetermined angle.
  • a predetermined angle for example, about 3 degrees
  • the second plunger chamber R2 has a second angle from 150 ° to the predetermined angle. 1Communicated with the outer oil chamber 53. That is, the area J is set such that the area (opening section) becomes narrower than when the second cam 71 is located at the reference position Q0, and conversely, the area of the second cam 71 becomes wider so that the area K becomes wider.
  • Surface 72 is set.
  • the communication section (region) with the second outer oil chamber 54 in one stroke of the second hydraulic device 200 (force) is applied to the first hydraulic device 100. It is smaller than the communication section (area I) with the second outer oil chamber 54 in one stroke. That is, the yoke 37 is compared with the region I (section) where the first plunger chamber R1 communicates with the second outer oil chamber 54 while the cylinder hook 24 makes one rotation around the axis. During one rotation around the axis with respect to the cylinder block 24, the area J (section) where the second plunger chamber R2 communicates with the second outer oil chamber 54 becomes smaller.
  • the second hydraulic device 200 compared to the amount of hydraulic oil that the first hydraulic device 100 transfers to and from the second outer oil chamber 54 during one stroke, the second hydraulic device 200
  • the distribution of the areas J and K is set so that the amount of hydraulic oil transferred to and from the chamber 54 decreases, and finally the stroke volume at the first displacement position Q1 decreases to 0.5 VMmax.
  • the port W that is, the second plunger chamber R2 is communicated with the second outer oil chamber 54 from about 240 degrees to about 240 degrees, and from about 240 degrees to about 34 degrees. Up to 0 degrees, it is communicated with the first outer oil chamber 53.
  • the communication section (area ⁇ ) with the first outer oil chamber 53 in one stroke of the second hydraulic apparatus 200 (the area ⁇ ) force The first hydraulic apparatus 1 It becomes smaller than the communication section (area ⁇ ) with the first outer oil chamber 53 in one stroke of 00.
  • the yoke 37 is The section (area I) where the second plunger chamber R2 communicates with the first outer oil chamber 53 during one rotation around the axis with respect to the cylinder block 24 becomes smaller. Therefore, compared to the amount of hydraulic oil that the first hydraulic device 100 sends and receives to and from the first outer oil chamber 53 during one stroke, the first hydraulic device 200 The distribution of the areas J and K is set so that the amount of hydraulic oil transferred to and from the chamber 53 decreases, and finally decreases to 0.5 VMmax at the second displacement position Q2.
  • the oil passage 59, the oil passage 69, the port U and the port W constitute a hydraulic closed circuit.
  • a communication passage 8 is provided between the first outer oil chamber 53 and the second outer oil chamber 54 so as to be along the axis O of the cylinder block 24. 2, 8 3 are formed.
  • a relief valve 85 for opening and closing a valve seat 84 provided on the first outer oil chamber 53 side is provided, and by the action of a coil spring 86 built in the communication passage 82, The valve seat 84 is closed.
  • the relief valve 85 opens the valve seat 84 and the first outer oil chamber 53 is opened.
  • the communication between the second outer oil chambers 54 is established.
  • a relief valve 88 for opening and closing a valve seat 87 provided in the second outer oil chamber 54 is provided in the communication passage 83.
  • Valve seats 8 and 7 are closed.
  • the hydraulic pressure of the hydraulic oil in the second outer oil chamber 54 is When the panel pressure is higher than the panel pressure of 89, the relief valve 88 opens the valve seat 87 to allow communication between the second outer oil chamber 54 and the first outer oil chamber 53.
  • the shaft hole 90 is formed in the input shaft 12 along the axis O in order to charge the hydraulic closed circuit with hydraulic oil.
  • the shaft hole 90 has an introduction oil passage 91 in the radial direction corresponding to the large diameter portion 20a of the sleeve 20, and the introduction oil passage 91 has a radius in the large diameter portion 20a.
  • the oil passage 92 and the large-diameter portion 20a are formed in a circumferential groove 93 formed on the outer peripheral surface of the large-diameter portion 20a.
  • the support plate 13 is provided with an oil passage 94 communicating with the circumferential groove 93.
  • the oil passage 94 is filled with hydraulic oil from a charge pump (not shown).
  • a portion facing the first inner oil chamber 51 and the second inner oil chamber 52 is provided with a pair of charge valves 95 (inverted) that open and close a valve seat that can communicate with the shaft hole 90. Stop valve) is located.
  • the charge valve 95 opens until the hydraulic pressure of the hydraulic closed circuit reaches the charge pressure in the shaft hole 90, and supplies the hydraulic oil in the shaft hole 90 to the hydraulic closed circuit.
  • the charge valve 95 prevents the hydraulic oil from flowing back to the shaft hole 90.
  • each first plunger 34 of the first hydraulic device 100 is not reciprocated by the swash plate surface 26, and in this state, the operating oil does not circulate in the hydraulic closed circuit.
  • the protruding end of each plunger 44 abuts and engages with the rotary swash plate surface 36 via the shoe 45 in a state where the plunger 44 cannot perform a stroke movement. Therefore, the cylinder block 24 and the rotary swash plate surface 36 are directly connected to each other, and rotate together. That is, in this state, the input shaft 12 and the output gear 39 are directly connected.
  • the forward rotation imparted to the rotating swash plate surface 36 in this manner is transmitted to the final reduction gear via the yoke 37, the POS plate 40, the output gear 39, and the input gear 10.
  • the stroke volume of the first hydraulic device 100 becomes zero as shown in FIG. 10, and the output rotation speed Nout (the rotation of the output gear 39) Is equal to the input speed NE.
  • the case where the output rotation speed Nout (the rotation speed of the output gear 39) is the same as the input rotation speed NE is included, that is, the input shaft 12 of the continuously variable transmission T and the output gear are included.
  • the range before and after, including when the vehicle is directly connected to the vehicle 39, is set as the main working speed range of the agricultural work vehicle.
  • the running speed is assumed to be 3 km / h to 8 kmZh in the main working speed range.
  • the direct connection state is established and the output rotation speed Nout (the rotation speed of the output gear 39) is set to be NE.
  • the main working speed range is 3 kmZh to 8 kmZh.
  • the hydraulic oil is sucked from the first outer oil chamber 53 through the port U into the first plunger hole 33.
  • the amount of hydraulic oil circulating in the hydraulic closed circuit increases as the tilt angle of the swash plate surface 26 in the negative direction increases.
  • the hydraulic oil discharged into the second outer oil chamber 54 is sucked into the second plunger hole 43 in the range of 0 ° to 180 ° through the port W. Meanwhile, 180. Hydraulic oil is discharged (discharged) from the second plunger hole 43 in the range of about 360 ° (0 °).
  • the number of rotations NE at which the cylinder block 24 is driven via the input shaft 12 and the forward direction of the plunger 44 of the second hydraulic device 200 with respect to the rotation swash plate surface 36 of the plunger 44 are increased.
  • the rotation swash plate surface 36 is rotated by the sum with the rotation speed.
  • the forward rotation applied to the rotating swash plate surface 36 is transmitted as a forward rotation to the final reduction gear via the yoke 37, the boss plate 40, the output gear 39, and the human power gear 10. And performs a speed increasing action.
  • the stroke volume of the first hydraulic device 100 in FIG. 10 increases from zero to VMmax (maximum stroke volume).
  • the output speed Nout increases from NE to 2 NE.
  • the cradle 27 When moving the vehicle forward and at high speed, that is, by operating the shift lever 97 shown in FIG. 8 in the F region further to the distal side (upward in FIG. 8) than the N position, the cradle 27 is moved. The swash plate surface 26 is located at the maximum negative tilt angle position. At this time, the stroke volume of the first hydraulic device 100 remains at the maximum stroke volume VMmax. Then, when the displacement applying member 76 is operated, the second cam 71 located at the reference position Q0 is It moves between the quasi position Q 0 and the first displacement position Q 1. For example, when the second cam 71 is located at the first change position Q1, as shown in FIGS. 12 and 13, the port W is in the range of about 3 degrees to 150 degrees.
  • the outer oil chamber (54) is communicated with the first outer oil chamber (53) in a range of 150 ° to about 3 degrees. That is, the area J is narrower than when the second cam 71 is located at the reference position Q0. Therefore, compared to the section in which the first hydraulic device 100 communicates with the second outer oil chamber 54 during one stroke, the second hydraulic device 200 performs the second outer oil chamber during one stroke. The section communicating with 54 becomes smaller. Accordingly, compared with the amount of hydraulic oil that the first hydraulic device 100 transfers to and from the second outer oil chamber 54 during one stroke, the second hydraulic device 200 The amount of hydraulic oil exchanged with the outer oil chamber 54 is reduced.
  • the second hydraulic device 200 gives the rotation swash plate surface 36 a rotation speed higher than that of NE. Therefore, the output rotation speed Nout is larger than 2 NE due to the rotation speed NE of the cylinder block 24 ⁇ the sum of the rotation speeds applied by the second hydraulic device 200.
  • the stroke volume of the first hydraulic device 100 is a fixed amount of VMraax (maximum stroke volume) as described above, while the stroke volume of the second hydraulic device 200 is Changes from VMmax to 0.5 VMmax.
  • the output rotation speed Nout increases from 2 NE to 3 NE.
  • the swash plate surface 26 tilts forward through the cradle 27. It is located in the area between the positive maximum tilt angle position and the upright position. In this case, the swash plate surface 26 tilts in the forward direction. Therefore, when the cylinder block 24 is rotated via the input shaft 12 by the driving force of the engine EG, the first plunger hole in the region H shown in FIG. From 33, the hydraulic oil is discharged to the first outer oil chamber 53 via the oil passage 59 and the port U. In the region I, the hydraulic oil is sucked into the first plunger hole 33 through the second outer oil chamber 54, the port U and the oil passage 59. The amount of hydraulic oil circulating in the hydraulic closed circuit increases as the tilt angle of the swash plate surface 26 in the forward direction increases.
  • the hydraulic oil discharged to the first outer oil chamber 53 is sucked into the second plunger hole 43 through the port W.
  • the hydraulic oil from the second plunger hole 43 in the range of 0 ° to 180 ° is discharged to the second outer oil chamber 54.
  • the “when the output rotation speed Nout exceeds the range between NE and 2 NE and exceeds 2 NE” due to the protrusion and pressing action of the second hydraulic device 200 on the rotating swash plate surface 36 of the plunger 44.
  • the rotation in the opposite direction is applied to the yoke 37.
  • the yoke 37, the boss plate 40, and the output gear 39 are rotated by the sum of the rotation speed in the reverse direction and the rotation speed in the forward direction of the cylinder block 24. Since the sum of the rotation speeds at this time is the rotation speed in the forward direction reduced by the rotation speed in the reverse direction, the output rotation speed Nout is smaller than “when the output rotation speed Nout is NE”. In this embodiment, at this time, when the swash plate surface 26 is displaced from the upright position to the positive maximum tilt angle position side, the stroke volume of the first hydraulic device 100 in FIG.
  • the swash plate surface 26 is disposed at the maximum positive tilt angle position via the cradle 27.
  • the stroke volume of the first hydraulic device 100 is fixed to one VMmax.
  • the rotational speed in the opposite direction is balanced with the rotational speed NE at which the cylinder block 24 is driven via the input shaft 12. That is, the sum of the rotational speeds is zero (the output rotational speed Nout is zero). ) And the output gear 39 stops.
  • the swash plate surface 26 is disposed at the positive maximum tilt angle position via the cradle 27.
  • the stroke volume of the first hydraulic device 100 is fixed to one VMmax.
  • the second cam 71 located at the reference position Q0 is moved between the reference position Q0 and the second displacement position Q2.
  • the port W is in the range of about 340 degrees to about 240 degrees.
  • the second outer oil chamber 54 is communicated with the first outer oil chamber 53 in a range of about 240 degrees to about 340 degrees.
  • the output rotation speed Nout exceeds 2 NE
  • the area J is expanded and the area K is narrowed compared to when the second cam 71 is located at the reference position Q0.
  • the first outer hydraulic chamber 200 compared with the section in which the first hydraulic device 100 communicates with the first outer oil chamber 53 during one stroke, the first outer hydraulic chamber 200 during the one stroke. 53 The section communicating with 3 becomes smaller. Accordingly, compared with the amount of hydraulic oil that the first hydraulic device 100 sends and receives with the first outer oil chamber 53 during one stroke, the first hydraulic device 200 The amount of hydraulic oil exchanged with the outer oil chamber 53 decreases.
  • the amount of hydraulic oil discharged from the first hydraulic device 100 to the first outer oil chamber 53 during one stroke and the amount of the hydraulic oil discharged from the second hydraulic device 200 to the first outer oil chamber 53 during one stroke are reduced.
  • the number of strokes of the second hydraulic device 200 increases until the first hydraulic device 100 completes one stroke, corresponding to the ratio of the amount of hydraulic oil sucked from 53.
  • the second hydraulic device 200 gives the rotating swash plate surface 36 a rotational speed whose absolute value is larger than one NE. Therefore, the output rotation speed Nout is smaller than zero due to the sum of the rotation speed NE of the cylinder block 24 and the applied rotation speed of the second hydraulic device 200.
  • the stroke volume of the first hydraulic device 100 in FIG. 10 is one VMmax of a fixed amount as described above, while the stroke volume of the second hydraulic device 200 is Is set to change from 1 VMmax to 10.5 VMmax.
  • the output speed Nout increases from zero in the reverse direction. According to the present embodiment, the following effects can be obtained.
  • the continuously variable transmission shares a cylinder hook 24 of the first hydraulic device 100 and the second hydraulic device 200 and has the first hydraulic device 100 in the cylinder block 24.
  • a hydraulic closed circuit in which hydraulic oil circulates between the second hydraulic device 200 and the second hydraulic device 200 is formed, and the rotation is driven by the engine EG.
  • the driving force from the engine EG is transmitted to the rotary swash plate surface 36 of the second hydraulic device 200 even when the hydraulic oil does not circulate in the hydraulic closed circuit. That is, the input shaft 12 (input side) of the continuously variable transmission T and the output gear 39 (output side) are directly connected.
  • a wide range of continuously variable transmissions including both the low speed side and the deceleration side can be obtained centering on such a direct connection state.
  • the second hydraulic device 200 By making the second hydraulic device 200 a variable displacement type, the speed change range is expanded to a forward high-speed range and a reverse range, and a gear mechanism (reverser) for switching between forward and backward can be omitted.
  • the first hydraulic device 100 operates according to the displacement of the tilt angle of the swash plate surface 26. Also, when the swash plate surface 26 is at the maximum positive / negative tilt angle position, the second hydraulic device 200, as shown in FIGS. The section communicating with the second outer oil chamber 54 can be narrowed.
  • the stroke volume of the second hydraulic device 200 can be made relatively smaller than the stroke volume of the first hydraulic device 100.
  • the stroke volume of the second hydraulic device 200 is smaller than the stroke volume of the first hydraulic device 100, the reciprocating speed of the plunger 44 increases.
  • the rotation speed greater than NE or one NE is applied to the rotating swash plate surface 36 by the projecting and pressing action of the plunger 44 of the second hydraulic device 200. Therefore, the continuously variable transmission T can obtain a forward high-speed region exceeding 2 NE and a reverse traveling region below the opening.
  • the continuously variable transmission is a continuously variable transmission used for traveling of agricultural work vehicle. As a result, the above-described operational effects can be obtained when the agricultural work machine vehicle travels.
  • the shift range when the hydraulic oil discharge amount of the first hydraulic device 100 is zero is set within the main working speed range of the work machine. That is, when the output rotation speed Nout (the rotation speed of the output gear 39) is the same as the input rotation speed NE, that is, when the input shaft 12 and the output gear 39 of the continuously variable transmission are connected.
  • the range before and after, including the direct connection state, was set as the main working speed range of this agricultural machine vehicle. As shown in Fig. 19, when the agricultural work vehicle of the present embodiment is a cultivator, the traveling speed is assumed to be approximately 2 km / h to 8 km / h as the traveling speed range of the main working speed range.
  • the rotation speed Nout (the rotation speed of the output gear 39) was set to be NE.
  • the rotation speed Nout (the rotation speed of the output gear 39) was set to be NE.
  • the hydraulic oil does not flow through the hydraulic closed circuit, and oil leakage in the hydraulic closed circuit is suppressed.
  • transmission efficiency is enhanced, energy loss in the main working speed range can be reduced, and highly efficient farming can be performed.
  • (5) in FIG. 18 shows the characteristics of the relationship between the total efficiency (total transmission efficiency) and the vehicle speed in the present embodiment. As shown in the figure, in the present embodiment, it can be seen that an extremely high overall efficiency can be obtained as compared with other conventional HST sub-shifts, sub-seconds, and sub-three shifts.
  • the second hydraulic device 200 is actuated by a plunger group 44 and a plunger group 44 inserted into the plurality of second plunger holes 43 in the cylinder block 24.
  • a rotary swash plate surface 36 that rotates relative to or synchronously with the cylinder block 24, a second switching valve 70 group that controls the suction and discharge of hydraulic oil to and from each second plunger hole 43,
  • the 2 switching valve 70 group is constituted by a second cam 71 (valve operating mechanism) that operates according to the rotation of the cylinder block 24.
  • the second cam 71 is provided with a worm shaft 81, a worm gear 78, and an abutting member 77 (variable mechanism).
  • the operation of the variable mechanism causes the second hydraulic device 200 to perform one stroke.
  • the section communicating with the first outer oil chamber 53 or the second outer oil chamber 54 is changed.
  • the stroke capacity of the second hydraulic device 200 can be changed, and the capacity can be varied.
  • the second switching valve 70 is constituted by a timing spool provided in parallel with each plunger 44, and the second cam 71 is rotated integrally with the rotary swash plate surface 36.
  • a timing cam is provided so as to be displaceable along the axis of the cylinder block 24.
  • the second cam 71 rotates integrally with the rotary swash plate surface 36 and is displaced along the axis of the cylinder block 24.
  • the suction / discharge timing of the second switching valve 70 can be changed.
  • the second cam 71 is provided with a base in the axial direction of the cylinder block 24.
  • the worm gear 78 and the worm shaft 81 are provided so as to be displaceable between the quasi position QO, the first displacement position Ql, and the second displacement position Q2, and hold the second cam 71 at the displaced position. Holding mechanism).
  • the second cam 71 can be held at each position, and a stable action can be given to the second switching valve # 0 at each position.
  • the boss plate 40 functions as a stopper. Therefore, a stable cam action can be provided to the second switching valve 70.
  • the traveling speed in the main working speed range is about 2 kmZl! It is not limited to ⁇ 8 kmZh.
  • there is a main working speed range according to the work equipment vehicle so the input side and output side of the continuously variable transmission are directly connected. If the condition is set according to the main working speed range, work can be performed with high efficiency.
  • a configuration in which the stroke volume of the first hydraulic device 100 exceeds the maximum stroke volume VMmax of the second hydraulic device 200 may be adopted.
  • the second The stroke volume of the first hydraulic device 100 may be changed to a range exceeding VMmax while the stroke volume of the hydraulic device 200 is maintained at VMmax-constant.
  • the tilt angle of the swash plate surface 26 of the first hydraulic device 100 is larger than the tilt angle of the rotary swash plate surface 36 of the second hydraulic device 200.
  • the second hydraulic device 200 does not require a variable mechanism and a holding mechanism for the second cam 71.
  • the stroke volume of the second hydraulic device can be made smaller than the stroke volume of the first hydraulic device 100.
  • the plunger 4 4 may be protruded and immersed in the radial direction.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
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Abstract

Cette invention a trait à une transmission hydraulique à variation continue. Un premier dispositif hydraulique, du type à cylindrée variable, fait fonctionner une première série de pistons au moyen d'un élément de contact, l'élément de sortie rotatif d'un second dispositif hydraulique se mettant en rotation relative ou synchrone relativement à une rotation d'entrée, du fait de son entrée en contact avec une seconde série de pistons. Un bloc-cylindres tourne autour de son axe. La première et la seconde chambre à pistons du bloc-cylindres sont formées par stockage des premiers et seconds pistons dans leurs orifices respectifs. Un circuit hydraulique fermé comportant une première et une seconde chambre à huile fait circuler de l'huile hydraulique entre les deux chambres à pistons. Ce dispositif comporte des zones où la première chambre à piston communique avec la première et la seconde chambre à huile, pendant la rotation d'un tour du bloc-cylindres autour de son axe, ainsi que des zones où la seconde chambre à piston communique avec la première et la seconde chambre à huile, pendant la rotation d'un tour de l'élément de sortie rotatif relativement à la rotation du bloc-cylindres autour de son axe. La cylindrée unitaire du premier dispositif hydraulique a une plage supérieure à celle du second.
PCT/JP2001/005215 2000-07-14 2001-06-19 Transmission hydraulique a variation continue et vehicule machine de chantier WO2002006704A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2001274547A AU2001274547A1 (en) 2000-07-14 2001-06-19 Hydraulic continuously variable transmission and working machine vehicle

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2000/214949 2000-07-14
JP2000214949 2000-07-14

Publications (1)

Publication Number Publication Date
WO2002006704A1 true WO2002006704A1 (fr) 2002-01-24

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PCT/JP2001/005215 WO2002006704A1 (fr) 2000-07-14 2001-06-19 Transmission hydraulique a variation continue et vehicule machine de chantier

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WO (1) WO2002006704A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6978572B1 (en) 1998-11-06 2005-12-27 Colorado State University Research Foundation Method and device for attracting insects

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5054289A (en) * 1987-12-15 1991-10-08 Nagatomo Fluid Machinery Laboratory Limited Hydraulic transmission
EP0902212A2 (fr) * 1997-09-11 1999-03-17 Honda Giken Kogyo Kabushiki Kaisha Transmission à variation continue du rapport de transmission avec plateau oscillant

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5054289A (en) * 1987-12-15 1991-10-08 Nagatomo Fluid Machinery Laboratory Limited Hydraulic transmission
EP0902212A2 (fr) * 1997-09-11 1999-03-17 Honda Giken Kogyo Kabushiki Kaisha Transmission à variation continue du rapport de transmission avec plateau oscillant

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6978572B1 (en) 1998-11-06 2005-12-27 Colorado State University Research Foundation Method and device for attracting insects

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