WO2004104448A1

WO2004104448A1 - Hydrostatic stepless speed change device

Info

Publication number: WO2004104448A1
Application number: PCT/JP2004/005833
Authority: WO
Inventors: Takeaki Nozaki
Original assignee: Yanmar Co., Ltd.
Priority date: 2003-05-22
Filing date: 2004-04-30
Publication date: 2004-12-02
Also published as: US20060120884A1; JPWO2004104448A1; JP4324165B2

Abstract

A hydrostatic stepless speed change device (1) constructed in combination of an axial piston hydraulic pump (30) and a hydraulic motor (40). A pump-side plunger block (31) and a motor-side plunger block (41) are opposed to each other with surfaces sliding and rotating against each other (rotary slide surfaces (33, 44)) in between. Communication passages hydraulically communicating between cylinders (31a, 41a) that are formed in both plunger blocks are formed. A separation element is provided in the communication passages. In each of the pump-side and motor-side plunger blocks, the communication passages are partitioned by the element into passages in a suction area and passages in discharge area.

Description

Specification

Hydrostatic continuously variable transmission

Technical field

The present invention relates to a configuration of a hydrostatic continuously variable transmission, and a hydraulic / mechanical continuously variable transmission formed by combining the hydrostatic continuously variable transmission with a planetary gear mechanism.

Background art

[0002] In a conventional hydrostatic continuously variable transmission (HST) including an axial piston pump and a motor, a pump rotation shaft and a motor rotation shaft are formed by a housing and a high-pressure oil passage. The plunger blocks, which are mounted in parallel with bearings provided on both sides of the plate and are rotationally constrained to be mounted on the respective rotating shafts, have their respective rotating sliding surfaces opposed to the high-pressure oil passage plate.

A valve plate for separating into a suction port and a discharge port is interposed between the plunger block and the high-pressure oil passage plate, and the valve plate is fixed to the high-pressure oil passage plate.

Then, the plunger in the plunger block is slid in the direction of the rotation axis by a swash plate arranged on the opposite side of the high-pressure oil passage plate with the plunger block interposed therebetween. The oil supply and discharge are performed between the units (for example, see Japanese Patent Application Laid-Open No. 2003-035276).

In the above-mentioned conventional HST, there is a problem such as oil leakage on the relative rotation sliding surface (joint surface) between the valve plate and the plunger block. Since there are two locations, one on the motor side and the other on the motor side, there are problems such as a decrease in volumetric efficiency due to oil leakage and a large power loss in the charge pump.

In the above-described conventional HST, the rotary sliding surface of the plunger block is slidably contacted with the non-rotatable valve plate fixed to the high-pressure oil passage plate to form a relative rotary sliding surface. Therefore, the relative rotation speed between the two becomes the rotation speed of the plunger block itself, which causes a problem that a large power loss occurs due to friction generated between the valve plate and the plunger block. Also, as with oil leaks, relative rotation Since there are two rolling sliding surfaces on the pump side and the motor side, it can be said that this frictional resistance greatly affects the power port.

Furthermore, in the above-mentioned conventional HST, a radial load is generated on the plunger block due to the inclination of the swash plate. The load in the radial direction gives a rotational moment to the rotary shaft and causes a rotational load on the bearing that supports the rotary shaft, causing a problem of power loss.

On the other hand, a hydraulic / mechanical continuously variable transmission (hereinafter referred to as “HMT”) combining the above HST and a planetary gear mechanism is also known. In the planetary gear mechanism, the rotational power is input to one of the three elements of sun gear, internal gear, and planet carrier (first element), and one of the remaining two elements (second element) ), And output or input to HST from another element (third element).

The HMT is divided into two types depending on whether the output of the HST is linked to the third element or the input to the HST is linked. The latter is of the output split type.

Further, the third element and the HST are interlocked by a power transmission shaft, and the power transmission shaft and the input shaft or the output shaft of the HST are interlocked via gears.

Also, in the HST, the hydraulic pump and the hydraulic motor are arranged in parallel by sliding the rotating sliding surface of the plunger block, which is mounted on the parallel rotating shaft so that they cannot rotate relative to each other, to the high-pressure oil passage plate. (This configuration is referred to as a second conventional configuration in the HMT; see Japanese Patent Application Laid-Open No. 2000-127785). Also known is an HMT in which the hydraulic pump and the hydraulic motor are arranged coaxially. In the case of the split input type, the hydraulic pump is configured as a fixed displacement type and the hydraulic motor is configured as a variable displacement type. On the other hand, the split-output type is one in which the hydraulic pump is configured as a variable displacement type and the hydraulic motor is configured as a fixed displacement type (this configuration is referred to as the third conventional configuration in HMT; 1). In the technique disclosed in this patent document, a split input type is adopted, in which a fixed swash plate of a hydraulic pump is fitted inside a hollow input shaft. ing.

However, in the above-described second conventional configuration of the HMT, it can be said that the transmission efficiency is low due to oil leakage from the HST section and friction loss. Since two relative rotating sliding surfaces (mating surfaces) are formed between the two plunger blocks and the high-pressure oil passage plate, oil leakage at the relative rotating sliding surfaces and friction on the rotating sliding surfaces are caused. This is because resistance greatly affects power loss. Further, in the second conventional configuration, since there are many components such as the power transmission shaft, bearings, and gears, it can be said that power loss is large and the manufacturing cost is high. Furthermore, the fact that a plurality of shafts are arranged in parallel and the presence of bearings and gears are obstacles to the compactness of the device.

On the other hand, in the above-mentioned third conventional configuration of the HMT, the swash plate of the hydraulic pump is fitted inside the hollow input shaft, and the swash plate rotates, so that the hydraulic pump is configured as a variable displacement type. Can not. For this reason, a gear ratio lower than a fixed gear ratio uniquely determined by the angle of the fixed swash plate cannot be realized, that is, a continuously variable speed operation from zero cannot be performed. I have. In addition, since forward and reverse rotation cannot be performed only by operating the swash plate, a mechanism for switching between forward and backward is required. Similarly, even in the case of the output split type, the swash plate on the hydraulic motor side is configured to rotate, so it cannot be said that the hydraulic motor cannot be a variable capacity type, and the shift range cannot be widened. At the same time, if the swash plate is operated to rotate forward and reverse, the capacity of the hydraulic pump must be about twice as large as that of the hydraulic motor. As described above, the third conventional configuration has a problem that the shift range is narrow, and a problem that the manufacturing cost is high due to the presence of the mechanism for switching between forward and backward.

The present invention has been made in view of the problems of the conventional configuration described above, and proposes a new configuration of the HST and an HMT that combines the HST with a planetary gear mechanism. Patent Document 1: JP-A-2000-127785

Disclosure of the invention

The present invention relates to a hydrostatic continuously variable transmission that combines an axial piston type hydraulic pump and a hydraulic motor, wherein a pump-side plunger block and a motor-side plunger block slide and rotate with each other. Faced through both plunges A plurality of communication passages for fluid communication between the cylinders formed in the first block are formed, and a separation element is provided in the plurality of communication passages. The plurality of communication path forces S are divided into a discharge region and a suction region.

As a result, one relative rotation sliding surface (mating surface) is formed, and the relative rotation sliding surface is compared with the conventional configuration in which two relative rotation sliding surfaces are formed on the high-pressure oil passage plate. The amount of leakage from the running surface can be relatively reduced. Then, the required amount of charge oil can be reduced, and power loss and cost can be reduced. Further, since the plunger blocks rotate in the same direction, they rotate relative to each other at a rotational speed determined from a difference between the rotational speeds of the plunger blocks, thereby reducing a power loss generated between the plunger block and the rotational sliding surface. be able to.

Further, the separation element is constituted by a spool valve provided in one of the plunger blocks in the same number as the number of cylinders in one plunger block.

The spool valve is radially disposed so as to be slidable about the rotation axis of the plunger block, and its outer end is provided on the inner peripheral surface of an inner ring of a bearing eccentrically disposed with respect to the rotation axis. The plunger block is slid in the radial direction of the rotating shaft in accordance with the rotation of the plunger block to open or divide an oil passage connecting the cylinders of the plunger blocks. It is assumed that the oil passage is divided and the oil passage of each plunger block is divided into a suction region and a discharge region.

Thus, the rotation axis of the motor-side plunger block and the rotation axis of the pump-side plunger block can be coaxially arranged, and a compact hydrostatic continuously variable transmission can be configured. .

Further, the rotation axis of the motor-side plunger block and the rotation axis of the pump-side plunger block are arranged coaxially, and the rotation axis and the planetary gear mechanism are combined to form an input split type. This is a hydrostatic type continuously variable transmission that can constitute a hydraulic / mechanical continuously variable transmission.

This enables a configuration in which the two rotation shafts of the HST and the sun gear of the planetary gear mechanism are coaxially arranged, and the third element of the planetary gear mechanism and the HST are connected to the power transmission shaft ′. Compared with the conventional configuration in which the gears are interlocked via gears, the gears for the power transmission shaft can be omitted, and a low-cost and compact hydraulic / mechanical continuously variable transmission can be configured.

In addition, the rotation axis of the motor-side plunger block and the rotation axis of the pump-side plunger block are arranged coaxially, and the rotation axis and the planetary gear mechanism are combined to form an output split type. This is a hydrostatic type continuously variable transmission that can constitute a hydraulic / mechanical continuously variable transmission.

This enables a configuration in which the two rotation shafts of the HST and the sun gear of the planetary gear mechanism are coaxially arranged, and the third element of the planetary gear mechanism and the HST are connected to the power transmission shaft gear. As compared with the conventional configuration in which the gears are interlocked via the power transmission shaft, the gear of the power transmission shaft can be omitted, and a low-cost and compact hydraulic / mechanical continuously variable transmission can be configured.

Further, an inner peripheral surface of an inner race of the bearing is inclined with respect to an axial direction of the rotating shaft.

Thus, the contact portion of the distal end portion of the spool valve contacting the inner peripheral surface with respect to the inner peripheral surface can be rotated and slid, and the durability of the distal end portion of the spool valve can be improved. Further, the sliding direction of the spool valve is inclined with respect to the axial direction of the rotating shaft.

Thus, the contact portion of the tip of the spool valve that contacts the inner peripheral surface of the bearing with respect to the inner peripheral surface can be rotated and slid, and the durability of the distal end portion of the spool valve can be improved.

In addition, the separation element supports the pump-side plunger block and the motor-side plunger block on the eccentrically arranged rotating shafts, respectively, so as to face the relative rotation sliding surface between the two plunger blocks. By forming a pump-side port and a motor-side port that individually communicate with a plurality of cylinders formed on the plunger block, the ports of both plunger blocks that are displaced due to the eccentric arrangement of the rotating shaft overlap each other, An oil path is formed to connect the cylinders of both plunger blocks, and there is no overlap between the ports of both plunger blocks on an extension of a line connecting the axes of the two rotating shafts, thereby dividing the oil path. The oil passages of each plunger block are divided into a suction region and a discharge region by the divided oil passages among the oil passages. And

As a result, the separation element can be configured with a simple configuration such as the eccentric arrangement of both rotating shafts, and a hydrostatic continuously variable transmission with a small number of parts can be configured.

Further, an oil passage plate that rotates integrally with one of the plunger blocks is provided, and the oil passage plate and the other plunger block are brought into contact with each other so as to be relatively rotatable and slidable. A plurality of oil passages are formed in the oil passage plate so as to penetrate in the axial direction, and these oil passages are arranged on the side on which the oil passage plate is integrally rotated. And the rotation shaft of the plunger block on the side where the oil passage plate is integrally rotated is supported by the oil passage plate. It shall be.

Thus, the sliding resistance generated between the rotating sliding surfaces of both plunger blocks can be reduced with a simple configuration, and power loss can be reduced. Further, since the rotation shaft is supported by the oil passage plate, it is possible to prevent the rotation shaft from moving.

In addition, a charge oil supply mechanism is provided between a connection point of the hydrostatic type continuously variable transmission with a charge pump provided in a case housing and a hydraulic circuit in a motor-side or pump-side plunger block. It shall be.

For example, an oil passage is formed in a fixed swash plate, a plunger block, and a rotating shaft, and the oil passage is provided inside the fixed swash plate, the plunger block, and the rotating shaft. This makes it possible to reduce the size of the hydrostatic continuously variable transmission. .

A check valve mechanism is provided between a connection point of a charge pump provided in a case housing of the hydrostatic stepless transmission and a hydraulic circuit in a motor-side or pump-side plunger block. .

For example, a check mechanism is provided inside a fixed swash plate, a plunger block, and a rotating shaft, whereby the compactness of the hydrostatic continuously variable transmission can be achieved. The case housing of the continuously variable transmission is located near the separation element. Harm 1J.

Thus, a hydraulic pump and a hydraulic motor can be separately arranged in each case housing, and a configuration that is easy to operate can be achieved.

Further, the case housing of the hydrostatic continuously variable transmission is configured to be divided, and a hydraulic motor and a hydraulic pump are housed in a first housing, and a first housing is formed by other housings. Is closed.

Thereby, the rigidity of the housing can be improved as compared with a mode in which the motor'pumps are individually housed in separate housings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a side sectional view showing a first configuration example of an HST.

Garden 2] FIG. 1 is a partial sectional view taken along the line Π-Π in FIG.

Garden 3] FIG. 2 is a partial cross-sectional view taken along the line ΠΙ-ΠΙ in FIG. 1.

[Garden 4] is a diagram showing a state where an oil passage formed between both plunger blocks is divided. Garden 5] (a) is a diagram showing an oil passage formed in a first section, and (b) is a diagram showing an oil passage formed in a second section. .

FIG. 6 is a view showing a rotary sliding surface of a pump-side plunger block.

FIG. 7 is a view showing a rotary sliding surface of a motor-side plunger block.

FIG. 8 is a view showing a rotary sliding surface of an oil passage plate.

[Garden 9] is a partial cross-sectional side view showing a series of oil passages formed by a road board and the like.

Garden 10] is a side sectional view showing a configuration example in which the spool valve is inclined in the first configuration example.

[Garden 11] is a view showing the configuration of the inclined surface of the constant swash plate.

Garden 12] is a plan sectional view showing the configuration of a charge oil supply mechanism and a check relief mechanism.

FIG. 13 is a view showing a configuration of a valve plate.

Garden 14] is a side sectional view of the HST to which the second configuration example of the charge oil supply mechanism and the check 'relief mechanism is applied.

Garden 15] HST applying the third configuration example of charge oil supply mechanism and check 'relief mechanism' FIG.

[FIG. 16] (a) is a diagram showing a case housing configured to be split at the front side of the separation element, (b) is a diagram illustrating a case housing configured to be split at the rear side of the separation element, (C) is a diagram showing a case housing configured to house a hydraulic motor and a hydraulic pump in a first housing.

FIG. 17 is a diagram showing a configuration of an HST in which a hydraulic motor and a hydraulic pump are housed in a first housing.

FIG. 18 is an overall configuration diagram of an input split type HMT.

Garden 19] is a side sectional view showing the configuration of the HST section in the same configuration.

Garden 20] is a side sectional view showing a configuration example in which a spool vanoleb is inclined.

Garden 21] is a side sectional view showing the configuration of the charge oil supply mechanism and the check relief mechanism.

FIG. 22 is an overall configuration diagram of an output split type HMT.

Garden 23] is a side sectional view showing the configuration of the HST section in the same configuration.

Garden 24] is a side sectional view showing a configuration example of the HST in which the rotation shaft is eccentrically arranged.

FIG. 25 is a partial cross-sectional view taken along the line XXV-XXV shown in FIG. 24.

FIG. 26 is a diagram showing a configuration of a rotary sliding surface of a pump-side plunger block.

FIG. 27 is a diagram showing a configuration of a rotary sliding surface of a motor-side plunger block.

FIG. 28 is a view showing a configuration of an oil passage plate.

FIG. 29 is a diagram showing a configuration of an oil passage communicating the cylinders of the plunger block.

FIG. 30 is a view showing a relative rotation sliding surface formed when the oil passage plate is integrated with the plunger block in the same configuration.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments will be described with reference to the drawings.

The hydrostatic continuously variable transmission 1 (hereinafter referred to as “HST1”) as shown in FIGS. 1 and 2 has the following configuration.

That is, the axial piston pump 30 (hereinafter referred to as “hydraulic pump 30”) and the axial pump 30 An HST1 equipped with a hydraulic piston motor 40 (hereinafter referred to as a “hydraulic motor 40”), and the pump-side plunger block 31 and the motor-side plan supported respectively by two concentrically arranged rotating shafts 30a'40a. The jar blocks 41 are disposed to face each other, and the same number of spool valves 50, 50 as the number of cylinders 41a '41a (or 31a' 31a) of the plunger blocks are provided in the motor-side plunger block 41 (or 31). The rotation shaft 40a (or 31a) is slidably arranged radially around the center. The outer ends of the spool valves 50, 50 are in contact with the inner peripheral surface 61 of the inner ring 60a of the bearing 60 eccentrically arranged with respect to the rotating shaft 30a'40a, and are radially moved according to the rotation of the motor-side plunger block 41. The oil passages 6a'6b for connecting the cylinders 31a'41a of the plunger blocks 31 and 41 to each other are opened or divided by the spool valves 50 and 50.

The HST 1 having the above configuration has a configuration in which the side on which the rotary shaft 30a is disposed in the axial direction of the rotary shaft 30a'40a is the front side, the hydraulic pump 30 is disposed on the front side, and the hydraulic motor 40 is disposed on the rear side. It is housed in the case housing 2a '2b which is a front and rear split type.

More specifically, bearings 30b'40b are fitted on the front side of the case housing 2a and the rear side of the case housing 2b, respectively. The two rotation shafts 30a'40a are arranged concentrically with the front end surfaces of the rotation shafts 40a facing each other. The rotating shaft 30a supports a pump-side plunger block 31 force and the rotating shaft 40a supports a motor-side plunger block 41 so that they cannot rotate relative to each other, and the rotating sliding surfaces 34 and 44 face each other. . Thus, one relative rotational sliding surface (the mating surface 5c; see FIG. 1) is formed.

In the case housing 2a, a movable swash plate 33M is arranged between the bearing 30b and the pump-side plunger block 31, and is formed at equal intervals on the pump-side plunger block 31 and in the axial direction of the rotary shaft 30a. The variable displacement hydraulic pump 30 is configured so that plungers 32 and 32 in the provided 31a '31a are slid back and forth.

In the case housing 2b, a fixed swash plate 43F is disposed between the bearing 40b and the motor-side plunger block 41, and is formed at equal intervals on the motor-side plunger block 41 and in the axial direction of the rotary shaft 40a. The fixed displacement hydraulic motor 40 has a configuration in which plungers 42 and 42 in the provided 41a'41a are slid back and forth. Further, the swash plate tilt shaft 33a of the movable swash plate 33M of the hydraulic pump 30 and the swash plate tilt shaft 43a of the fixed swash plate 43F of the hydraulic motor 40 are parallel to each other. The swash plate tilting shafts 33a and 43a have a relationship perpendicular to the paper surface in FIG.

Further, as shown in FIG. 1, the sum of the bottom area 32t 'and 32t of the rotation sliding surface 34 of the cylinder 31a' 31a of the pump-side plunger block 31 and the rotation of the cylinder 41a'41a of the motor-side plunger block 41 are shown. The sum of the bottom areas 42t'42t on the sliding surface 44 side is designed to be almost the same, and the total pressure receiving area of each cylinder 31a'41a of the pump side plunger block 31 and the motor side plunger block 41 is calculated. They are almost the same.

As shown in FIG. 1, at a position where the end surfaces of the rotating shafts 30a and 40a face each other, a bearing 7 is fitted to the front end of the rotating shaft 40a so as to be relatively non-rotatable, and is rotated by the bearing 7. The rear ends of the shafts 30a are inserted so as to be relatively rotatable, so that the end surfaces of the two rotating shafts 30a and 40a are arranged close to and opposed to each other.

As shown in FIG. 1, the motor-side plunger block 41 has its outer peripheral surface supported by a bearing 160 fitted to the case housing 2b.

As shown in FIGS. 1 and 6, a pump-side port 34a'34a for individually communicating with the inside of each cylinder 31a'31a is opened on the rotary sliding surface 34 of the pump-side plunger block 31. The sliding of the plungers 32 allows oil to pass through the pump-side port 34a'34a.

In addition, as shown in FIGS. 1 and 7, on the rotary sliding surface 44 of the motor-side plunger block 41, a motor-side port 44a'44a for individually communicating with each cylinder 41a'41a has one motor-side port 44a'44a. Two openings are provided for the cylinders 41a'41a, and the sliding of the plungers 42 and 42 allows oil to pass through the motor-side ports 44a'44a. In addition, as shown in FIGS. 1, 8, and 9, one of the rotational sliding surfaces 34 of the pump-side plunger block 31 and the rotational sliding surface 44 of the motor-side plunger block 41 is provided. The plunger blocks 31 and 41 have the same shape as the ports 34a'44a of the rotation sliding surfaces 34 and 44 of the plunger blocks 31 and 41 on the side where the rotation is restricted. An oil passage plate 5 to be opened is sandwiched. In this embodiment, the arrangement is such that the rotation is restricted with respect to the motor-side plunger block 41, and the arrangement of the communication ports 5a 'and 5a is shown in FIG. The motor side port 44a of the motor side plunger block 41 shown in FIG. Then, as shown in FIG. 1 and FIG. 9, the rotation sliding surface 34 of the pump side plunger block 31 is brought into contact with the rotation sliding surface 55 of the A series of oil passages 6 are formed densely.

That is, in this embodiment, the relative rotation sliding surface (the mating surface 5c) between the two plunger blocks 31 and 41 of the pump motor is changed to the rotation sliding surface 55 of the oil passage plate 5 and the pump-side plunger block. 31 is a contact surface with the rotary sliding surface 34.

This oil passage plate 5 is intended, in particular, to reduce sliding resistance generated between the two rotating sliding surfaces 34 and 44 and to prevent seizure. It is covered with a material. If there is no problem of seizure between the plunger blocks 31 and 41, the configuration may be such that the oil passage plate 5 is not provided and the rotary sliding surfaces 34 and 44 are directly contacted. Good.

In the motor-side plunger block 41 as shown in FIGS. 1, 2 and 9, between the respective cylinders 41a and the ports 44a of the rotary sliding surface 44, the cylinders are arranged with the rotary shaft 40a as a center. 51a'51a is formed radially, and column-shaped spool valves 50 are slidably disposed in the cylinder 51a'51a in the radial direction.

As shown in FIG. 2, a series of annular oil passages 54 are formed in the circumferential direction of the rotary shaft 40a between the bottom of the cylinders 51a '51a' and the outer peripheral surface of the bearing 7 as shown in FIG. A series of oil chambers 51b are formed so as to communicate with each other in the cylinders 51a '51a' ''.

As shown in FIG. 2, the same number of the spool valves 50 as the number of the cylinders 41a and 41a are arranged radially around the rotation shaft 40a, and are formed in a hemispherical shape. The distal end portion 50a'50a 'projects radially outward from the motor-side plunger block 41, and is eccentrically arranged on the rotation shaft 40a to form a bearing 60 for the outer ring of the motor-side plunger block 41. The inner ring 60a is configured to be in contact with the inner peripheral surface 61 of the inner ring 60a. The direction of eccentricity of the bearing 60 with respect to the rotating shaft 40a is the axial direction of the swash plate tilting shafts 33a'43a (FIG. 1) which are in parallel with each other. A straight line 4h connecting the axis 60d of the rotating shaft 40a and the axis 40d of the rotating shaft 40a is parallel to the swash plate tilting axis 33a'43a. Also, as shown in FIG. 1, the inner diameter of the inner peripheral surface 61 of the bearing 60 (the inner ring 60a) is gradually reduced from the axial front side to the rear side of the rotary shaft 40a, so that the inner peripheral surface 61 is The rotary shaft 40a is tilted with respect to the axial direction.

Further, as shown in FIG. 2, the spool valve 50 is a columnar body having a small-diameter portion 50d disposed between two large-diameter portions 50b '50c. The outer peripheral surface of the cylinder 51a is slid on the inner peripheral surface of the cylinder 51a, and an oil passage 56 is formed between the small-diameter portion 50d and the inner peripheral surface of the cylinder 51a as shown in FIG. The oil passage 56 constitutes a part of the series of oil passages 6 that communicate the cylinder 41a of the motor-side plunger block 41 with the cylinder 31a of the pump-side plunger block 31. The oil passage 56 is closed by the large diameter portion 50c of the spool valve 50 at a position where the motor-side plunger block 41 has a predetermined rotation angle. That is, at the position of the rotation angle 4v'4w, which is 90 degrees out of phase with respect to the straight line 4h parallel to the swash plate tilting shaft 33a '43a as shown in FIGS. The large diameter portion 50c of the valve 50 is configured to reach the position of the port 44a of the rotary sliding surface 44, and the opening height of the port 44a in the radial direction about the rotation axis 40a and the large diameter The oil passages 56 are closed by the spool valve 50 at the rotation angle 4v'4w with the shaft length of the portion 50c being substantially the same. In the configuration shown in FIG. 2, the bearing 60 is eccentric in the vertical direction with respect to the rotating shaft 40a, and as shown in FIG. 1, the spool valve 50 is at the uppermost position (rotation angle 4 V) and the lowermost position (rotation angle 4 V). When the rotation angle becomes 4w), the oil passage 56 is closed as shown in FIG.

Then, as shown in FIG. 3, two sections 11 and 12 which are separated based on the position of the rotation angle 4v ′ 4w are formed, and in the first section 11, as shown in FIG. By arranging the small diameter portion 50d of the spool valve 50 so as to overlap the position of the port 44a, a series of oil passages 6a including the oil passage 56 is opened, while in the second section 12, FIG. As shown in b), the spool valve 50 protrudes outward, and the large diameter portion 50c is arranged radially outward from the position of the port 44a, so that the spool valve 50 is formed via the oil chamber 51b (cylinder 51a). A series of oil passages 6b are opened. In this way, the oil passages 6a 'and 6b that connect the cylinders 31a' and 41a of the plunger blocks 31 and 41 are opened or divided by the spool valve 50. It is configured to be disconnected.

As described above, in the first section 11, the discharge area (or suction area) of the hydraulic pump 30 is formed as the suction area (or discharge area) of the hydraulic motor 40, and in the second section 12, The hydraulic pump 30 has a suction area (or discharge area), and a hydraulic motor 40 has a discharge area (suction area) formed therein. In each of the hydraulic pump 30 and the motor 40, a suction area and a discharge area Is separated by a spool valve 50 that closes the oil passage 56.

Further, as described above, the pump-side plunger block and the motor-side plunger block face each other via the surfaces that slide and rotate with each other (rotary sliding surfaces 33 and 44). A communication passage (oil passages 6a and 6b) for fluid communication between the formed cylinders is formed, and a separation element (a spool valve 50, a bearing 60, and the like) is provided in the communication passage. A passage (oil passage 6a) communicating the suction area of one plunger block and the discharge area of the other plunger block; a discharge area of the one plunger block; and the other plunger block. And a passage (oil passage 6b) that communicates with the suction area. That is, the oil passage group in each plunger block 31 · 41 is divided into a suction area and a discharge area (one of them is oil path 6a and the other is 6b) by the separation element. .

Further, as described above, the separation element is configured by the spool valve 50 provided in the one of the plunger blocks in the same number as the number of cylinders of the plunger block. Numeral 50 is radially disposed so as to be slidable about the rotation axis of the plunger block, and its outer end is in contact with the inner peripheral surface of an inner ring 60a of a bearing 60 eccentrically arranged with respect to the rotation axis. The plunger block is slid in the radial direction of the rotating shaft in accordance with the rotation of the plunger block, and opens or separates an oil passage communicating the cylinders of the plunger blocks. The oil passage is divided, and the oil passage of each plunger block is divided into a suction area and a discharge area.

With the above configuration, in the first section 11, the high pressure oil path (or the low pressure oil path) is formed by the oil paths 6 a ′ 6 a ′ ′ ′, and in the second section 12, the oil paths 6 b ′ 6 b By By forming the low-pressure oil passage (or high-pressure oil passage), the HST1 is configured to supply pressure oil to the hydraulic motor 40 from the hydraulic pump 30 using the rotating shaft 30a as an input shaft and drive the rotating shaft 40a as an output shaft. Is done.

Further, according to the above configuration, as shown in FIG. 1, the swash plate tilt shaft 33a of the movable swash plate 33M of the hydraulic pump 30 and the swash plate tilt shaft 43a of the fixed swash plate 43F of the hydraulic motor 40 are parallel. Therefore, by setting the inclination directions of the two swash plates 33M and 43F in the main drive direction (for example, the direction in which the vehicle body equipped with the HST1 is moved forward) to the same direction, the plunger 32 of the hydraulic pump 30 can be set. Uses a smaller bearing 160 that can cancel out the thrust and radial loads with respect to the rotating shaft 30a '40a generated by the sliding of the plunger 32 of the hydraulic motor 40 and the plunger 42 of the hydraulic motor 40. As a result, the motor-side plunger block 41 can be supported, and power loss and cost can be reduced.

Further, according to the above configuration, as shown in FIG. 1, the total pressure receiving areas of the cylinders 31a and 41a of the pump-side plunger block 31 and the motor-side plunger block 41 are substantially the same. The thrust direction and the radial load can cancel each other more reliably. In addition, as long as the total pressure receiving area is substantially the same, the number of cylinders 31a and 41a is not particularly limited, and the degree of freedom in designing the plunger block is wide.

Further, according to the above configuration, the rotating shaft 40a of the motor-side plunger block 41 and the rotating shaft 30a of the pump-side plunger block 31 can be arranged coaxially, so that a compact hydrostatic A continuously variable transmission 1 can be configured.

In addition, according to the above configuration, the pump-side plunger block 31 and the motor-side plunger block 41 rotate in the same direction as shown in FIG. As a result, it is possible to reduce the power loss generated between the rotary sliding surfaces 34 and 44 (55).

Further, according to the above configuration, as shown in FIG. 1, the rotary sliding surfaces 34 and 44 (55) face each other to form one relative rotary sliding surface (the mating surface 5c). It is possible to relatively reduce the amount of leakage from the relative rotation sliding surface (the mating surface 5c) as compared with the configuration in which two relative rotation sliding surfaces are formed with respect to the high pressure oil passage plate. it can. From this, The required amount of charge oil can be reduced, and power loss and cost can be reduced.

Further, according to the above configuration, as shown in FIG. 1, since the high pressure oil passage plate required for the conventional configuration is not provided, the mass of the HST 1 as a whole can be reduced and the cost can be reduced.

Further, according to the above configuration, as shown in FIG. 1, the rotating shaft 30a'40a is configured to be supported by the bearings 30b'40b, and the rear end surface of the rotating shaft 30a and the front end surface of the rotating shaft 40a are close to each other. As a result, the entire length of the HST1 can be made more compact than in a conventional configuration in which bearings are arranged on a high-pressure oil passage plate to support a rotary shaft.

Further, according to the above configuration, by providing the oil passage plate 5 as shown in FIG. 1, the sliding resistance generated between the two rotating sliding surfaces 34 and 44 can be reduced with a simple configuration. . Thus, power loss can be reduced.

Further, according to the above configuration, since the inner peripheral surface 61 of the inner ring 60a of the bearing 60 as shown in FIG. 1 is inclined with respect to the axial direction of the rotating shaft 40a, the inner peripheral surface 61 contacts the inner peripheral surface 61. The hemispherical tip portions 50a '50a' · · of the spool valves 50 · 50 rotate about the sliding direction of the spool valves 50 · 50 as the motor-side plunger block 41 rotates. Thus, the distal end portion 50a '50 _a - an abutment against the inner peripheral surface 61 can be rotated sliding, it is possible to improve the durability of the spool valve 50 tip.

As another configuration for improving the durability of the spool valve 50, as shown in FIG. 10, in the motor-side plunger block 41, a cylinder 51a ′ 51a on which the spool valve 50 slides is attached to the rotation shaft 40a. It can be formed so as to be inclined with respect to the axial direction, the sliding direction of the spool valve is inclined with respect to the radial direction of the rotating shaft 40a, and the inner peripheral surface 61 of the inner ring 60a of the bearing 60 can be configured to be flat. . According to this configuration, similarly to the configuration in which the inner peripheral surface 61 is inclined, the effect of improving the durability of the spool valve 50 by rotating the spool valve 50 in the sliding direction can be obtained. A general-purpose bearing that makes the inner peripheral surface 61 flat can be used.

Next, the charge oil supply mechanism and the check リ The structure will be described.

The configuration described below is based on the configuration of the charge oil supply mechanism between the connection point (charge oil passage 2f) with the charge pump provided in the case housing 2b of the HST1 and the hydraulic circuit in the motor or pump side plunger block. This is a specific example of a configuration including a relief mechanism, which is installed inside a fixed swash plate, a plunger block, and a rotating shaft, respectively, to achieve the compactness of the HST1. Things.

In the first configuration example, a charge oil supply mechanism and a chuck relief mechanism are provided in the fixed swash plate 43f of the hydraulic motor 40.

In the second configuration example, a charge oil supply mechanism and a check relief mechanism are provided in the motor-side plunger block 41 of the hydraulic motor 40.

In the third configuration example, a charge oil supply mechanism and a check relief mechanism are provided in the rotating shaft 40a of the hydraulic motor 40.

Hereinafter, each configuration example will be described in detail.

The configurations shown in FIGS. 1, 11 to 13 show a first configuration example relating to the charge oil supply mechanism and the check-relief mechanism.

As shown in FIG. 1 and FIG. 12, in this configuration, in a hydraulic motor 40 of a type in which plungers 42 and 42 are provided with showers 46 and 46, a charge oil is formed on a fixed swash plate 43F of the hydraulic motor 40. The passage 47 and the cylinder 41a'41a of the motor-side plunger block 41 are connected to the connecting oil passage 46a'46a formed in the bush 46,46 and the connecting oil formed in the plunger 42,42. A structure in which a check oil relief valve 48 having a function of a check valve and a relief valve is provided in the charge oil passage 47 in the fixed swash plate 43F (FIG. 12). Is what you do.

More specifically, as shown in FIGS. 11 and 12, a series of through holes 43c forming the charge oil passage 47 are formed in the fixed swash plate 43F as shown in FIGS. 11 and 12, and the left and right openings of the through holes 43c are formed. The mouth is closed by the check 'relief valve 48L.48R'. A charge oil passage 43d is formed rearward from a substantially central portion of the through hole 43c, and is illustrated via a charge oil passage 2f formed in the case housing 2b as shown in FIG. Nuyaichi It is connected to the dipump.

As shown in FIGS. 11 and 12, a pair of kidney ports 43L'43R is formed on the inclined surface 43f of the fixed swash plate 43F as shown in FIGS. 11 and 12, and the kidney one port 43L'43R and the check relief relief are provided. Connect the relief drain chambers 48a-48a of 48L-48R with the oil passages 43b-43b.

A valve plate 49 is fixed to the inclined surface 43f of the fixed swash plate 43F as shown in FIG. 1 and FIG. 13, and the kidney plate is formed on the valve plate 49 by being divided into four parts in the circumferential direction. The one port 49a'49a '' forms a series of oil passages with the kidney one port 43L-43R of the inclined surface 43f. Bridges 49b'49c '' formed between the kidney ports 49a'49a '' are provided to disconnect the kidney ports 43L.43R from the bridges 49b'49b located above and below. The left and right bridges 49c'49c are provided to maintain the strength of the valve plate 49. The valve plate 49 is intended to reduce sliding resistance generated between the fixed swash plate 43F and the intermediate plates 146 and 146 described below, and to prevent image sticking. For example, it is coated with a seizure-resistant material. If no seizure problem occurs between the fixed swash plate 43F and the intermediate plate 146, the valve plate 49 may not be provided.

As shown in FIG. 1, a fixed swash plate-side cylindrical portion 46b'46b of the shoe 46 is inserted between the valve plate 49 and the shoe 46, thereby connecting the rotating shaft 40a. Intermediate plates 146, 146 that rotate integrally with each shoe 46, 46 are sandwiched at the center. A flat bottom insertion hole 146b '146b is formed in the intermediate plate 1 46, 146 on the side opposite to the valve plate 49, and the fixed swash plate side cylindrical portion 46 of the shoe 46' 46 is formed in the insertion hole 146 146). No. 46) is inserted, and the end surface of the fixed swash plate side cylindrical portion 46b '46b is abutted on a flat bottom. In the intermediate plates 146, 146, connecting oil passages 146a '146a are formed obliquely in a side view, and the kidney ports 49a' 49a 'of the valve plate 49 and the connecting oil passages 46 of the showers 46, 46 are formed. a'46a.

Further, as shown in FIG. 1, a retainer plate 246 is slidably held by a spherical portion 41b provided at the rear end of the plunger block 41 in order to prevent the shoe 46 from separating from the intermediate plate 146. . As shown in FIG. 1, a communication oil passage 42a'42a for communicating the cylinder 41a * 41a with the communication oil passage 46a * 46a of the shoe 46 is formed in the sliding direction of the plungers 42. It is set up.

The cylinder 41a'41a of the motor-side plunger block 41 and the fixed swash plate are provided by the above-described communication oil passage 42a, communication oil passage 46a, communication oil passage 146a, kidney port 49a, and kidney port 43L'43R. A series of connecting oil passages communicating with the charge oil passage 47 on the 43F is formed.

With the above configuration, the cylinders 41a and 41a of the motor-side plunger block 41 and the check oil passage 47 are communicated via the check relief valves 48L and 48R, and the hydraulic pump 30 and the hydraulic motor 40 And a relief oil supply circuit for a closed hydraulic circuit (the oil passages 6a'6b) formed between them.

According to the above configuration, the charge oil supply mechanism and the check 'relief valve 48L' 48R as a relief mechanism are provided inside the fixed swash plate 43F of the hydraulic motor 40, so that the charge oil is supplied. The space required for installing the supply mechanism and relief mechanism is not required. The HST1 can be made more compact as a whole, and both mechanisms have high pressure resistance and excellent oil-tightness.

In addition, in addition to the above configuration, a configuration may be adopted in which two through holes 43c are provided, and a check valve and a relief valve are independently disposed in each of the through holes 43c.

The configuration shown in FIG. 14 shows a second configuration example related to the charge oil supply mechanism and the check relief mechanism.

This configuration includes a motor-side plunger block 41, a first annular oil passage 41r communicating with an oil passage 56 formed by the small diameter portion 5Od of the spool valve 50, and a cylinder 51a of the spool valve SO-SO. In addition to providing a second annular oil passage 41s communicating with the '51a to form an oil chamber 51b, a connecting oil passage 40ιι40ν40w40x communicating with a charge pump (not shown) is provided on the rotating shaft 40a. The first and second annular oil passages 41r * 41s and the communication oil passages 40ιι ・ 40ν ・ 40 w'40x are connected via two communication oil passages 41e'4 If installed inside the motor side plunger block 41. While communicating, check valve 48c'48c to one set of connecting oil passages 41e'41f And a relief valve is arranged in another set of connecting oil passages (not shown).

More specifically, a charge oil passage 2f formed in the case housing 2b as shown in FIG. 14 is communicated with a charge pump (not shown).

The charge oil passage 2f communicates with a communication oil passage 40x • 40w formed inside the rotary shaft 40a via a swivel joint 23 formed on the inner peripheral surface of the shaft hole 2u in the case housing 2b. Have been.

In the rotating shaft 40a, an annular communication oil passage 40u is formed between the inner peripheral surface of the motor-side plunger block 41 and the communication oil passage 40u is connected to the connection oil passage 40v via the communication oil passage 40v. Communicate with 40w.

The outer peripheral surface of the motor-side plunger block 41 is supported by a bearing 160. A first annular member is provided between the outer peripheral surface of the motor-side plunger block 41 and the inner peripheral surface of the inner ring 160 a of the bearing 160. An oil passage 41r is formed. The first annular oil passage 41r communicates with an oil passage 56 formed by the small diameter portion 50d of the spool valve 50 via a communication oil passage 41h.

Further, between the inner peripheral surface of the motor-side plunger block 41 and the outer peripheral surface of the bearing 7, a second annular member that communicates the cylinders 51a '51a of the spool valves 50 and 50 to form an oil chamber 51b is formed. An oil passage 41s is formed.

In addition, the motor side plunger block 41 is provided with two connecting oil passages 41e and 41f for connecting the first and second annular oil passages 41r '41s and the communication oil passage 40u, each of which has two paths, and is connected to the rotating shaft 40a. Two sets of connecting oil passages 41e 'and 41f are formed by shifting the phase around the axis. Of these, one set of connecting oil passages 41e'41f is provided with check valves 48c'48c, while the other set of connecting oil passages 41e'41f (not shown) is provided with a relief valve. is there.

With the above-described configuration, the cylinders 51a and 51a of the spool valve 50 of the motor-side plunger block 41 and the charge oil passage 2f are communicated with each other via the check valve and the relief valve. A charge oil supply circuit and a relief circuit of a hydraulic closed circuit (the oil passages 6a and 6b) formed with the motor 40 are configured. According to the above configuration, the charge oil supply mechanism, the check valves 48c and 48c as the check relief mechanism, and the relief valve (not shown) are provided inside the motor-side plunger block 41 of the hydraulic motor 40. The HST1 requires a space to provide a charge oil supply mechanism and a check and relief mechanism, and the HST1 as a whole can be made more compact, and both mechanisms have high pressure resistance and oil tightness. It becomes.

Further, according to the above configuration, it is not necessary to provide an oil passage in the swash plate in the hydraulic motor 40. The hydraulic motor 40 as shown in FIG. Can be configured. It goes without saying that the same applies to adopting a fixed displacement type by employing a fixed swash plate for the hydraulic motor 40.

Third configuration example of charge oil supply mechanism and pick-up relief mechanism>

The configuration shown in FIG. 15 shows a third configuration example related to the charge oil supply mechanism and the check relief mechanism.

This configuration includes a motor-side plunger block 41, a first annular oil passage 71r communicating with an oil passage 56 formed by the small diameter portion 5Od of the spool valve 50, and a cylinder 51a of the spool valve 50, 50. A first annular oil passage 71s communicating with the oil pump 51a and forming an oil chamber 51b is provided, and a connecting oil passage 70w '70x communicating with a charge pump (not shown) is provided on the rotating shaft 40a. The second annular oil passage 71r * 71s and the communication oil passage 70w 70x communicate with each other through two sets of communication oil passages 71e '71f formed inside the rotary shaft 40a, and a pair of communication oil passages. Check valves 78c and 78c are provided in 71e and 71f, and a relief valve is arranged in another set of connecting oil passages (not shown).

More specifically, as shown in FIG. 15, a charge oil passage 2f formed in the case housing 2b is communicated with a charge pump (not shown).

The charge oil passage 2f communicates with a communication oil passage 70x • 70w formed inside the rotary shaft 40a via a swivel joint 23 formed on the inner peripheral surface of the shaft hole 2u in the case housing 2b. Have been.

In the rotating shaft 40a, the communication oil passage 70w is formed in the axial direction, and the communication oil passage 70w is formed radially toward the inner peripheral surface of the motor-side plunger block 41. Is formed. The connecting oil passages 71e and 71f are configured in two sets, that is, A total of four connecting oil passages 71e'71f are formed, two of which are provided with check valves 78c'78c, and two connecting oil passages (not shown) are provided with relief valves. Configuration.

The outer peripheral surface of the motor-side plunger block 41 is supported by a bearing 160. A first annular member is provided between the outer peripheral surface of the motor-side plunger block 41 and the inner peripheral surface of the inner ring 160 a of the bearing 160. An oil passage 71r is formed. The first annular oil passage 71r communicates with the oil passage 56 formed by the small diameter portion 50d of the spool valve 50 via a communication oil passage 71h.

Further, a second oil chamber 51b is formed between the inner peripheral surface of the motor side plunger block 41 and the outer peripheral surface of the rotary shaft 40a by communicating the cylinders 51a '51a of the spool valves 50, 50. An annular oil passage 71s is formed.

The motor-side plunger block 41 has a communication oil passage 71m connecting the first annular oil passage 71r and the communication oil passage 71e of the rotating shaft 40a. As described above, two communication oil passages 71e are formed so as to be out of phase about the axis of the rotary shaft 40a, and two communication oil passages 71m are also formed.

Further, the second annular oil passage 71s is communicated with a communication oil passage 71f of the rotating shaft 40a. A check valve 78c '78c is provided in one set of communication oil passages 71e' 71f, while a relief valve (not shown) is provided in another set of communication oil passages 71e '71f (not shown). It has a configuration.

With the above-described configuration, the cylinders 51a and 51a of the spool valve 50 of the motor-side plunger block 41 and the charge oil passage 2f are communicated with each other via the check valve and the relief valve. A charge oil supply circuit and a relief circuit of a hydraulic closed circuit (the oil passages 6a and 6b) formed with the motor 40 are configured.

According to the above configuration, the charge oil supply mechanism, the check valves 78c to 78c as the chuck relief mechanism, and the relief valve (not shown) are provided inside the rotary shaft 40a. The space required for providing the oil supply mechanism and the check-relief mechanism is required, and the HST1 as a whole can be compacted, and both mechanisms have excellent high-pressure resistance and oil-tightness. Further, according to the above configuration, it is not necessary to provide an oil passage in the swash plate in the hydraulic motor 40. The hydraulic motor 40 as shown in FIG. Can be configured. It goes without saying that the same applies to adopting a fixed displacement type by employing a fixed swash plate for the hydraulic motor 40.

Next, the configuration of the case housing in the HST1 having the above configuration will be described. As a configuration of the case housing as shown in FIG. 16, three configuration examples are proposed. In the first configuration example, in the case where the HST1 case housing is divided near the spool valve 50 as a high / low pressure separation element for hydraulic oil, the HST1 is divided at the front side of the spool valve 50 as the separation element. Configuration.

The second configuration example is a configuration in which the HST1 case housing is divided near the spool valve 50 as a high / low pressure separating element for hydraulic oil, and is divided on the rear side of the spool valve 50 as the separating element. Configuration.

In a third configuration example, the case housing of the HST1 is configured to be divided, and the hydraulic motor 40 and the hydraulic pump 30 are housed in the first housing, and the first housing is housed in another housing. Are closed.

Hereinafter, each configuration example will be described in detail.

The first configuration example has a configuration in which the spool valve 50 is divided in the vicinity of a spool valve 50 as a high / low pressure separation element for hydraulic oil as shown in FIG. 1 and FIG. Is divided at the front side of

As shown in FIG. 1, the case housing is of a front-rear split type, and a bearing hole 20a in which the bearing 60 eccentrically arranged on the rotating shaft 40a is fitted in a case housing 2b in which the hydraulic motor 40 is arranged, and A bearing hole 20b into which the bearing 160 of the motor-side plunger block 41 is fitted is formed.

According to this configuration, for example, in processing the case housing 2b, after the bearing hole 20b is added, the processing of the bearing hole 20a can be performed while the case housing 2b is fixed. It is possible to realize the design value of 160 relative relationships. As for the ball, the machining accuracy of the eccentricity of the bearing 60 relative to the axis of the rotating shaft 30a'40a can be improved.

As shown in FIGS. 1 and 14, the case housing is of a front-rear split type, and the case housing 2a on the hydraulic pump 30 side has a half bearing guide 21 of a movable swash plate 33M and a rotating shaft 30a as an input shaft. The bearing hole 22 of the bearing 30b is integrally formed, while the case housing 2b on the hydraulic motor 40 side is provided with a swivel joint 23 (only in the case of the configuration shown in FIG. 14: the charge oil supply mechanism, check The relief mechanism is the second configuration example), the half bearing guide 27 of the movable swash plate 43M (only when the configuration is the same as in Fig. 14), the bearing hole 20a of the bearing 60 for the spool valves 50 and 50, The bearing hole 24 of the rotating shaft 40a as the output shaft is integrally formed.

According to this configuration, since the case housing is formed by die casting, machining can be reduced and cost can be reduced.

Further, in the above configuration example, the hydraulic pump 30 is of a variable displacement type, and the hydraulic motor 40 is of a fixed displacement or variable displacement type. Is also applicable.

In the above-described configuration example, the force S is a configuration in which the spool valves 50, 50 are slidably disposed on the motor-side plunger block 41, and the reverse configuration, that is, the pump-side plunger The present invention is also applicable to a configuration in which the spool valves 50 and 50 are slidably disposed in the block 31. In this case, the charge oil supply mechanism and the check relief mechanism are provided on the hydraulic pump 30 side. is there.

In the case where the hydraulic pump 30 is of a fixed displacement type, the hydraulic motor 40 is of a fixed displacement type or a variable displacement type, and a spool vano-lev 50, a charge oil supply mechanism, and a check relief mechanism are provided on the hydraulic pump 30 side. Although not shown, the case housing is divided into front and rear, and the case housing 2a on the hydraulic pump 30 side has a swivel joint 23, a bearing hole 20a for a bearing 60 for a spool valve 50, and an input shaft. While the bearing holes 22 of all the rotating shafts 30a are integrally formed, the case housing 2b on the hydraulic motor 40 side has a half bearing guide 21 of a movable swash plate 43M and a bearing of a bearing 30b of the rotating shaft 40a as an output shaft. The hole 24 is integrally formed. As described above, in addition to the above-described configuration example, in the case of a configuration in which the hydraulic pump 30 is a fixed displacement type and the hydraulic motor 40 is a variable displacement type, even if the case housing is formed by die casting, Machining can be reduced, and costs can be reduced.

As shown in FIG. 16 (b), the second configuration example is a configuration in which the hydraulic oil is divided in the vicinity of a spool valve 50 as a high / low pressure separating element for the hydraulic oil. It is configured to be divided.

In this case, shaft holes of bearings 60 and 160 are formed in each case housing 2a '2b.

In the third configuration example, as shown in FIGS. 16C and 16, the case housing of the HST1 is configured to be divided, and the hydraulic motor 40 and the hydraulic pump 30 are provided in the first housing 222b. The first housing 222b is closed by another housing (second housing 222a).

In this configuration, the tubular portion of the first housing 222b is configured to be long, and both the hydraulic motor 40 and the hydraulic pump 30 are configured in the tubular portion.

The bearings 60 and 160 are fitted to a stepped portion 89 formed in the first housing 222b. In the present embodiment in which the hydraulic motor 40 and the hydraulic pump 30 are arranged from the left side in the drawing, the bearing 60 A snap ring 88 is fitted to prevent slippage.

The second housing 222a is configured to close the opening of the first housing 222b when the hydraulic motor 40 and the hydraulic pump 30 are assembled into the first housing 222b. The half housing guide 21 of the movable swash plate 33M of the hydraulic pump 30 is formed in the second housing 222a.

In the above configuration example, since the hydraulic motor 40 and the hydraulic pump 30 are arranged in the first housing 222b, the rigidity of the housing is superior to that in the case where the motor pumps are individually housed in separate housings. It will be.

In addition, as described above, the first housing 222b and the second housing 222a are divided into two parts, and for example, both sides in the longitudinal direction of the first housing 222b are opened. Alternatively, the openings may be closed (three divisions).

Next, an example in which an HMT (hydraulic / mechanical continuously variable transmission) is configured using the above HST will be described.

Input split type>

The hydraulic / mechanical continuously variable transmission 300 (hereinafter, referred to as “HMT300”) shown in FIG. 18 is configured as a split input type.

That is, an HMT 300 configured to perform a speed change of an output rotation by combining a hydrostatic continuously variable transmission device 301 (hereinafter, referred to as “HST301”) and a planetary gear mechanism 10, as shown in FIGS. 18, 19 and As shown in Fig. 2, the motor-side plunger block 41 (Fig. 19) of the HST301 is supported on the rotating shaft 130a so as not to rotate relatively, and the pump-side plunger block 31 is supported on the rotating shaft 140a so as not to rotate relatively. The shaft 140a is hollow and arranged coaxially with the rotary shaft 130a, the pump-side plunger block 31 and the motor-side plunger block 41 are arranged to face each other, and the motor-side plunger block 41 is arranged. (Or 31), the spool valves 50, 50 are radially arranged slidably about the rotation shaft 130a, and the outer ends of the spool valves 50, 50 are eccentrically arranged with respect to the rotation shaft 130a. Bearing The inner ring 60 abuts against the inner peripheral surface 61 of the inner ring 60a and slides in the radial direction according to the rotation of the motor-side plunger block 41. The spool valves 50, 50 cause the cylinders 31a 'of the plunger blocks 31, 41 to rotate. The oil passage 6a '6b (FIG. 2) for communicating the 41a is opened or divided, and the input shaft is constituted by the rotary shaft 130a' 140a and the planetary gear mechanism 10.

As shown in FIG. 19, the hydraulic motor 340 is arranged in the t! ST 301 of FIG. 300 with the hydraulic pump 330 disposed on the front side in the axial direction of the rotary driving mechanisms 130a and 140a. Side is the rear side, and these are housed in the case housings 2a and 2b which are divided into front and rear.

More specifically, bearings 30b and 40b are fitted on the front side of the case housing 2a and the rear side of the case housing 2b, respectively, and the rotating shaft 140a is mounted on the bearing 30b, and the rotating shaft is mounted on the bearing 40b. 130a is mounted. A hydraulic pump 330 is provided on the rotating shaft 130a. The outer side is annularly formed by the hollow rotary shaft 140a. A motor-side plunger block 41 is supported on the rotating shaft 130a, and a pump-side plunger block 31 is supported on the rotating shaft 140a such that the respective rotating sliding surfaces 34 and 44 face each other so as not to rotate relatively.

In the case housing 2a, a movable swash plate 33M is disposed between the bearing 30b and the pump-side plunger block 31, and is formed at equal intervals in the pump-side plunger block 31 and in the axial direction of the rotary shaft 140a. The variable displacement hydraulic pump 330 is configured such that the plungers 32 and 32 in the provided 31a '31a are slid forward and backward.

In the case housing 2b, a movable swash plate 43M is disposed between the bearing 40b and the motor-side plunger block 41, and is formed at equal intervals in the motor-side plunger block 41 and in the axial direction of the rotating shaft 130a. A variable displacement hydraulic motor 340 is constructed, in which plungers 42 and 42 in 41a '41a provided are slid forward and backward.

The swash plate tilting shaft 33a of the movable swash plate 33 ° of the hydraulic pump 330 and the swash plate tilting shaft 43a of the movable swash plate 43M of the hydraulic motor 340 are parallel to each other. The swash plate tilt shafts 33a 'and 43a have a relationship perpendicular to the paper surface in FIG.

Further, as shown in FIG. 19, the sum of the bottom area 32t 'and 32t of the rotation sliding surface 34 of the cylinder 31a' 31a of the pump-side plunger block 31 and the rotation of the cylinder 41a'41a of the motor-side plunger block 41. The sum of the bottom areas 42t and 42t on the sliding surface 44 side is designed to be substantially the same, and the total pressure receiving area of each cylinder 31a and 41a of the pump side plunger block 31 and the motor side plunger block 41 They are almost the same.

As shown in FIG. 19, a bearing 7 is fitted in the middle of the rotation shaft 130a in the front and rear direction so as to be relatively non-rotatable, and a rear end of the rotation shaft 140a is rotatable relative to the bearing 7. Has been inserted.

Also, as shown in FIG. 18, the rotary shaft 130a is configured to be longer in the front and rear direction than the case housing 2, and the front end extends forward of the case housing 2a and is connected to the sun gear 13 of the planetary gear mechanism 10. At the same time, the rear end extends to the rear of the case housing 2b and functions as an output shaft for driving wheels, a working machine, and the like (not shown).

Further, as shown in FIG. 18, the front end of the rotary shaft 140a It extends forward and is connected to the internal gear 14 of the planetary gear mechanism 10, and inputs power from a planet carrier 15 driven by a drive source (not shown) to function as an input shaft for driving the hydraulic pump 330.

As shown in FIG. 19, the motor-side plunger block 41 has its outer peripheral surface supported by a bearing 160 fitted to the case housing 2b.

Also, as shown in FIGS. 19 and 6, a pump-side port 34a '34a for individually communicating with the inside of each cylinder 31a' 31a is opened on the rotary sliding surface 34 of the pump-side plunger block 31. The sliding of the plungers 32 allows the oil to pass through the pump-side ports 34a 'and 34a.

In addition, as shown in FIGS. 19 and 7, on the rotating sliding surface 44 of the motor-side plunger block 41, the motor-side port 44a '44 4a force for individually communicating with the inside of each cylinder 41a' 41a has one force. Two openings are provided for the cylinders 41a'41a, and the sliding of the plungers 42, 42 allows oil to pass through the motor-side ports 44a'44a. As shown in FIGS. 19 and 8, one of the plungers is provided between the rotary sliding surface 34 of the pump-side plunger block 31 and the rotary sliding surface 44 of the motor-side plunger block 41. The rotation is restricted by the blocks 31 and 41, and the rotation sliding surfaces 34 and 44 of the plunger blocks 31 and 41 on the side that is restricted by rotation The ports 34a of the 44 and 44 are the same as the ports 44a and 44a.The communication ports 5a and 5a of the same arrangement are opened. Road board 5 is sandwiched. In this embodiment, the motor-side plunger block 41 is configured to be rotationally constrained, and the arrangement of the communication ports 5a '5a is changed to the motor-side ports 44a'44a' of the motor-side plunger block 41 shown in FIG. · It is almost the same as · ·. Then, as shown in FIGS. 19 and 20, the rotary sliding surface 34 of the pump-side plunger block 31 comes into contact with the rotary sliding surface 55 of the oil passage plate 5 so as to be oil-tight. , A series of oil passages 6 is formed. This oil passage plate 5 is intended particularly to reduce sliding resistance generated between the two rotating sliding surfaces 34 and 44 and to prevent seizure. The surfaces of these sliding surfaces are, for example, seizure-resistant. It is covered with a conductive material. If there is no problem of seizure between the plunger blocks 31 and 41, if the oil passage plate 5 is not provided, the rotary sliding surfaces 34 and 44 should be directly contacted. It may be configured to contact.

In addition, in the motor-side plunger block 41 as shown in FIGS. Between each cylinder 41a and the port 44a of the rotary sliding surface 44, a cylinder 51a'51a is formed radially around the rotation shaft 130a'140a. The column-shaped spool valves 50 and 50 are slidably arranged in the radial direction.

As shown in FIG. 2, a series of annular oil passages 54 are formed in the circumferential direction of the rotary shafts 130a '140a between the bottom of the cylinders 51a' 51a 'and the outer peripheral surface of the bearing 7 as shown in FIG. A series of oil chambers 51b are formed by communicating with each other in the cylinders 51a '51a.

Further, as shown in FIG. 2, the same number of the spool valves 50 as the number of the cylinders 41a '41a are arranged radially around the rotation shafts 130a' 140a, and are formed in a hemispherical shape. The inner end of a bearing 60 that projects radially outward from the motor-side plunger block 41 and is eccentrically arranged on the rotation shaft 130a and that externally surrounds the motor-side plunger block 41. It is configured to be in contact with the inner peripheral surface 61 of 60a. The direction in which the bearing 60 is eccentric with respect to the rotating shaft 130a is assumed to be the axial direction of the swash plate tilting shafts 33a'43a (FIG. 19) which are in parallel with each other. As shown in FIG. 2, a straight line 4h connecting the axis 130d of the rotary shaft 130a to the axis 130d is parallel to the swash plate tilting vehicle ground 33a'43a.

As shown in FIG. 19, the inner diameter of the inner peripheral surface 61 of the bearing 60 (the inner ring 60a) is gradually reduced from the axial front side to the rear side of the rotary shaft 130a, so that the inner peripheral surface 61 is The rotating shaft 130a is inclined with respect to the axial direction.

Further, as shown in FIG. 2, the spool valve 50 is a columnar body having a small-diameter portion 50d disposed between two large-diameter portions 50b '50c. The outer peripheral surface of the cylinder 51a is brought into sliding contact with the inner peripheral surface of the cylinder 51a, and an oil passage 56 is formed between the small-diameter portion 50d and the inner peripheral surface of the cylinder 51a as shown in FIG. The oil passage 56 constitutes a part of the series of oil passages 6 that communicate the cylinder 41 a of the motor-side plunger block 41 with the cylinder 31 a of the pump-side plunger block 31. The oil passage 56 is closed by the large diameter portion 50c of the spool valve 50 at a position where the motor-side plunger block 41 has a predetermined rotation angle. That is, at the position of the rotation angle 4v'4w, which is 90 degrees out of phase with respect to the straight line 4h parallel to the swash plate tilting shaft 33a '43a as shown in Figs. 2 and 3, respectively. Large diameter part 50c of valve 50 Is configured to reach the position of the port 44a of the rotary sliding surface 44, and the opening height of the port 44a in the radial direction around the rotary shaft 130a and the axial length of the large-diameter portion 50c are substantially equal to each other. In the same manner, the oil passages 56 are closed by the spool valve 50 at the rotation angle 4v'4w. In the configuration shown in FIG. 2, the bearing 60 is eccentric in the horizontal direction with respect to the rotary shaft 130a on the paper surface, and the spool valve 50 as shown in FIG. The oil passage 56 is configured to be closed as shown in FIG. 4 when the lower position (rotation angle 4w) is reached.

Then, as shown in FIG. 3, two sections 11 and 12 which are separated based on the position of the rotation angle 4v ′ 4w are formed, and in the first section 11, as shown in FIG. By arranging the small diameter portion 50d of the spool valve 50 so as to overlap the position of the port 44a, a series of oil passages 6a including the oil passage 56 is opened, while in the second section 12, FIG. As shown in b), the spool valve 50 protrudes outward, and the large diameter portion 50c is arranged radially outward from the position of the port 44a, so that the spool valve 50 is formed via the oil chamber 51b (cylinder 51a). A series of oil passages 6b are opened. As described above, the oil passages 6a 'and 6b for connecting the cylinders 31a' and 41a of the plunger blocks 31 and 41 are opened or disconnected by the spool valve 50.

With the above configuration, in the first section 11, the high pressure oil path (or the low pressure oil path) is formed by the oil paths 6a '6a' ···, and in the second section 12, the oil paths 6b '6b' By forming a low-pressure oil passage (or high-pressure oil passage) by '', pressure oil is supplied from the hydraulic pump 330 to the hydraulic motor 340 using the rotating shaft 140a as an input shaft as shown in FIG. An HST 301 driven using 130a as an output shaft is configured.

Then, the input split type HMT 300 shown in FIG. 18 is configured by combining the HST 301 configured as described above and the planetary gear mechanism 10.

That is, the rotating shaft 130a is configured to be longer in the front-rear direction than the case housing 2, and the front end extends forward of the case housing 2a and is connected to the sun gear 13 of the planetary gear mechanism 10, and has a rear end. The portion extends to the rear of the case housing 2b and functions as an output shaft for driving wheels (not shown) and a working machine, etc., while the rotating shaft 140a has a front end extending forward of the case housing 2a and a planetary gear. Connected to internal gear 14 of mechanism 10 A power is input from the planet carrier 15 driven by a drive source (not shown) to function as an input shaft for driving the hydraulic pump 330. Further, the rotary shaft 140a is hollow and coaxial with the rotary shaft 130a. Is arranged.

According to the above configuration, as shown in FIG. 19, the swash plate tilting shaft 33a of the movable swash plate 33M of the hydraulic pump 330 and the swash plate tilting shaft 43a of the movable swash plate 43M of the hydraulic motor 340 are different from each other. Since they are parallel, the inclination direction of both swash plates 33Μ and 43Μ in the main drive direction (for example, the direction in which the vehicle equipped with HMT300 moves forward) is set to the same direction, so that the plunger 32 of hydraulic pump 330 The load in the thrust direction and the radial direction based on the rotating shaft 130a '140a generated by the sliding of the plunger 42 of the hydraulic motor 340 and the plunger 42 of the hydraulic motor 340 can cancel each other out. It can be used to support the motor-side plunger block 41, which can reduce power loss and cost.

Further, according to the above configuration, as shown in FIG. 19, the total pressure receiving area of each of the cylinders 31a and 41a of the pump-side plunger block 31 and the motor-side plunger block 41 is substantially the same. Directional and radial loads can more reliably cancel each other out. In addition, as long as the total pressure receiving area is substantially the same, the number of cylinders 31a and 41a is not particularly limited, and the degree of freedom in designing the plunger block is wide.

Further, according to the above configuration, since the pump-side plunger block 31 and the motor-side plunger block 41 rotate in the same direction as shown in FIG. As a result of the relative rotation, it is possible to reduce the power loss generated between the rotary sliding surfaces 34 and 44 (55).

In addition, according to the above configuration, as shown in FIG. 19, the relative sliding surfaces 34 and 44 (55) face each other to form one relative rotating sliding surface (the mating surface 5c). As compared with a conventional configuration in which two relatively rotating sliding surfaces are formed on a high-pressure oil passage plate, the amount of leakage from the relatively rotating sliding surfaces can be relatively reduced. This makes it possible to reduce the required amount of chilled oil, thereby reducing power loss and cost.

Also, according to the above configuration, as shown in FIG. Since no plate is provided, the mass of the HST301 as a whole can be reduced and the cost can be reduced.

The rotating shaft 140a of the motor-side plunger block 41 and the rotating shaft 130a of the pump-side plunger block 31 are coaxially arranged, and the sun gear 13 of the planetary gear mechanism 310 is connected to the rotating shaft 130a. It is assumed that the rotary shafts 130a '140a and the planetary gear mechanism 310 are combined to constitute a hydraulic-type mechanical continuously variable transmission 300 configured in a split-input type. This enables a configuration in which the two rotation shafts 130a to 140a of t! ST and the sun gear 13 of the planetary gear mechanism 310 are coaxially arranged, and the third element of the planetary gear mechanism and the HST When compared with the conventional configuration in which the power transmission shaft and the gear are interlocked, the power transmission shaft and gear can be omitted, and a low-cost, compact hydraulic and mechanical continuously variable transmission can be configured. Can be.

Further, according to the above configuration, by providing the oil passage plate 5 as shown in FIG. 19, the sliding resistance generated between the two rotating sliding surfaces 34 and 44 can be reduced with a simple configuration. . Thus, power loss can be reduced.

Further, according to the above configuration, as shown in FIG. 19, the inner peripheral surface 61 of the inner ring 60a of the bearing 60 is inclined with respect to the axial direction of the rotating shaft 130a, so that it comes into contact with the inner peripheral surface 61. The hemispherical tips 50a '50a' · · of the spool valves 50 · 50 rotate about the sliding direction of the spool valves 50 · 50 as the motor-side plunger block 41 rotates. Thus, the contact portion of the distal end portion 50a '50a against the inner peripheral surface 61 can be slidably rotated, and the durability of the distal end portion of the spool valve 50 can be improved.

As another configuration for improving the durability of the spool valve 50, in the motor side plunger block 41 as shown in FIG. 20, the cylinders 51a and 51a on which the spool valve 50 slides are connected to the rotary shaft 130a. The inner surface of the inner ring 60a of the bearing 60 must be flat, while the sliding direction of the spool vane levule is inclined with respect to the radial direction of the rotating shaft 130a. You can also. According to this configuration, similarly to the configuration in which the inner peripheral surface 61 is inclined, the effect of improving the durability of the spool valve 50 by rotating the spool valve 50 in the sliding direction can be obtained, and the inner peripheral surface 61 can be obtained. A general-purpose bearing with a flat surface 61 can be used. Further, according to the input split type HMT300 having the above configuration, as compared with the above-described first conventional configuration, a power transmission shaft is not required, and the number of bearings and gears can be reduced. As a result, it is possible to achieve a configuration with less power loss, and to reduce the production cost due to the reduction in the number of these components.

In addition, according to the input split type HMT 300 having the above configuration, the rotating shaft 140a is arranged coaxially with the rotating shaft 130a. A compact dangling can be achieved.

Further, according to the input split type HMT 300 having the above configuration, since the hydraulic pump 330 is configured as a variable displacement type, it is possible to perform a continuously variable shift operation from zero. As compared with the second conventional configuration, a wider shift range can be configured. In particular, when it is not necessary to secure a wide shift range, a configuration using a fixed displacement hydraulic pump 330 and a variable displacement hydraulic motor 340 may be adopted in addition to the above configuration example. In addition, according to the input split type HMT 300 having the above configuration, the hydraulic pump 330 is configured as a variable displacement type, and therefore, compared to the above-described second conventional configuration, a mechanism for switching between forward and backward movement is provided. It is not required, and the manufacturing cost of the mechanism can be reduced. <Charge oil supply mechanism, check 'relief mechanism>

Next, the charge oil supply mechanism and the check-relief mechanism in the HST301 having the above configuration will be described.

In this configuration, the above-described second configuration example of the charge oil supply mechanism and the check and relief mechanism is adopted, but the first and third configuration examples are also applicable.

As shown in FIG. 21, the motor-side plunger block 41 has a first annular oil passage 41r communicating with an oil passage 56 formed by the small-diameter portion 50d of the spool valve 50, and a cylinder of the spool valve 50, 50. A second annular oil passage 41s communicating with 51a '51a to form an oil chamber 51b is provided, and a connecting oil passage 40u'40v 40w 40x communicating with a charge pump (not shown) is provided on the rotating shaft 130a. The first and second annular oil passages 41r'41s and the communication oil passages 40u-40v '40w' 40x are formed via two communication oil passages 41e '41f formed inside the motor-side plunger block 41. In addition to the communication, check valves 48c and 48c are provided in one set of connecting oil passages 41e and 41f, and a relief valve is provided in another set of connecting oil passages (not shown). Things.

More specifically, a charge oil passage 2f formed in the case housing 2b as shown in FIG. 21 is connected to a charge pump (not shown).

Further, the charge oil passage 2f is connected to a communication oil passage 40x'40w formed inside the rotary shaft 130a via a swivel joint 23 formed on the inner peripheral surface of the shaft hole 2u in the case housing 2b. Are in communication.

In addition, on the rotating shaft 130a, an annular communication oil passage 40u is formed between the rotation shaft 130a and the inner peripheral surface of the motor-side plunger block 41, and the communication oil passage 40u is connected via the communication oil passage 40v. Contact Let it communicate with the oil passage 40w.

In addition, the motor side plunger block 41 is provided with two connecting oil passages 41e and 41f for connecting the first and second annular oil passages 41r '41s and the communication oil passage 40u to the rotating shaft 130a. Two sets of connecting oil passages 41e 'and 41f are formed by shifting the phases around the axis. Of these, one set of communication oil passages 41e'41f is provided with a check valve 48c'48c, while the other set of communication oil passages 41e'41f (not shown) is provided with a relief valve. is there.

With the above configuration, the cylinders 51a and 51a of the spool valve 50 of the motor-side plunger block 41 and the charge oil passage 2f are communicated with each other via the check valve and the relief valve. A charge oil supply circuit and a relief circuit of a hydraulic closed circuit (the oil passages 6a and 6b) formed between the motor and the motor 340 are configured. Then, according to the above configuration, the motor-side plunger block 41 of the hydraulic motor 340 The inside is equipped with a charge oil supply mechanism, a check valve 48c as a check 'relief mechanism' 48c, and a relief valve (not shown). The HST301 as a whole requires more space and can be made more compact, and both mechanisms are more resistant to high pressure and oil. In the configuration example described above, the spool valves 50, 50 are slidably disposed on the motor-side plunger block 41. The force is the reverse of the configuration, that is, the pump-side plunger. It is also applicable to a configuration in which the spool valves 50 and 50 are slidably disposed in the block 31. In this case, a configuration in which a charge oil supply mechanism and a check relief mechanism are provided on the hydraulic pump 330 side is adopted. It is.

Next, the configuration of the case housing 2a′2b in the HST301 having the above configuration will be described.

That is, as shown in FIG. 19, the case housing according to the present invention is of a front-rear split type, and the bearing 60, which is eccentrically arranged on the rotating shaft 130a, is fitted to the case housing 2b on which the hydraulic motor 340 is arranged. A bearing hole 20a into which the bearing 160 of the motor-side plunger block 41 is fitted is formed.

According to this configuration, for example, in the processing of the case housing 2b, after the processing of the bearing 160, the processing of the bearing 60 can be performed while the case housing 2b remains fixed. The design value of the relationship can be embodied, that is, the machining accuracy of the eccentricity of the bearing 60 with respect to the axis of the rotating shaft 130a'140a can be improved.

As shown in Fig. 19, the case housing is of a front-rear split type, and the case housing 2a on the hydraulic pump 330 side has a half bearing guide 21 of a movable swash plate 33M, a rotating shaft 130a as an input shaft. While the bearing hole 22 of the bearing 30b is integrally formed, the case housing 2b on the hydraulic motor 340 side has a swivel joint 23, a movable bearing swash plate 43M half bearing guide 27, and a bearing 60 for the spool valves 50 and 50. The bearing hole 20a of the bearing shaft 20a and the bearing hole 24 of the rotating shaft 140a as the output shaft are integrally formed.

According to this configuration, by making the case housing 2 by die casting, it is possible to reduce the mechanical load and to reduce the cost. In addition, as the configuration of the case housing, the configurations (a) to (c) shown in FIG. 16 are applicable.

The hydraulic / mechanical continuously variable transmission 320 (hereinafter, referred to as “HMT320”) shown in FIGS. 22 and 23 is configured as a split output type.

That is, the HMT 320 is configured to perform the output rotation shift by combining the HST 311 and the planetary gear mechanism 310, and the pump-side plunger block 31 of the HST 311 is supported on the rotation shaft 130a so as to be relatively non-rotatable. The side plunger block 41 is supported so as not to rotate relative to the rotation shaft 140a, the rotation shaft 140a is hollow, and is disposed coaxially with the rotation shaft 13 Oa. The motor-side plunger block 41 is disposed so as to face the plunger block 41, and the motor-side plunger block 41 (or 31) has spool valves 50, 50 radially disposed slidably about the rotary shaft 130a. The outer ends of the spool valves 50, 50 abut against the inner peripheral surface 61 of the inner ring 60a of the bearing 60 eccentrically arranged with respect to the rotary shaft 130a, and the outer ends of the spool valves 50, 50 are rotated in half according to the rotation of the motor-side plunger block 41. It is configured to slide in the radial direction to open or separate the oil passages 6a '6b communicating with the cylinders 31a' 41a of the plunger blocks 31 and 41 by the spool valves 50 and 50. , And a planetary gear mechanism 310 to form an output split type.

Note that the reference numerals given in FIGS. 22 and 23 perform the same configuration and function as the HMT 300 having the input division type described above, and a description thereof will be omitted. In the power split type HMT320 configured as described above, the rotating shaft 130a is configured to be longer in the front-rear direction than the case housing 2, and the front end is extended forward of the case housing 2a and illustrated. The rear end extends to the rear of the case housing 2b and is connected to the sun gear 13 of the planetary gear mechanism 310, while the rotating shaft 140a The rear end portion extends rearward of the case housing 2b and is connected to the internal gear 14 of the planetary gear mechanism 310, and is arranged coaxially with the rotating shaft 130a with the rotating shaft 140a being hollow. Configuration. The rotating shaft 140a of the motor-side plunger block 41 and the rotating shaft 130a of the pump-side plunger block 31 are coaxially arranged, and the sun gear 13 of the planetary gear mechanism 310 is connected to the rotating shaft 130a. By combining these rotary shafts 130a '140a and the planetary gear mechanism 310, a hydraulic' mechanical continuously variable transmission 320 configured as a split-output type is constructed. With the coaxial arrangement, a compact hydraulic / mechanical continuously variable transmission can be configured.

The output split type HMT320 configured as described above has the same effects as the above-described HMT300.

In particular, when it is not necessary to secure a wide shift range, in addition to the above configuration examples, a configuration using a fixed displacement hydraulic pump 330 and a variable displacement hydraulic motor 340, or a variable displacement hydraulic pump A configuration using a 330 and a fixed displacement hydraulic motor 340 may be used. <Hydrostatic type continuously variable transmission>

Next, a description will be given of a hydrostatic stepless transmission in which the separation elements of the suction area and the discharge area of the opposing hydraulic pump 30 and hydraulic motor 40 are constituted by eccentricity of both rotating shafts of the pumps 30 and 40. I do.

The hydrostatic continuously variable transmission 401 (hereinafter, referred to as “HST401”) as shown in FIGS. 24 and 25 has the following configuration.

That is, an HST 401 provided with an axial piston pump 430 (hereinafter referred to as “hydraulic pump 430”) and an axial piston motor 440 (hereinafter referred to as “hydraulic motor 440”). '' The pump-side plunger block 431 and the motor-side plunger block 441, which are respectively supported by the 480a, are opposed to each other. The rotating sliding surfaces 434 and 444 of the plunger blocks 431 and 441 have respective plunger blocks. The pump-side ports 434a and 434a and the motor-side ports 444a and 444a that are individually connected to the plurality of cylinders 431a and 441a that are formed on the 431 and 441 are formed. When viewed in the radial direction around the axis of the rotating shaft 470a, it is located on the same straight line with respect to the pump port 434a '434a at the two opposite positions located on a straight line connecting the axes of the rotating shafts 470a' 480a. The corresponding motor-side ports 444a and 444a are farthest apart (maximum eccentric position) and separated. The motor-side port 444a located other than on this straight line is The radial displacement (amount of eccentricity) with respect to the corresponding pump-side port 434a is reduced, thereby causing an overlap with the corresponding pump-side port 434a, that is, the ports 434a and 444a communicate with each other. . That is, in each oil passage 408 that connects the cylinders 431a '441a of both plunger blocks 431 and 441, the motor side cylinder 441a reaches the maximum eccentric position of the motor side plunger block 441 with respect to the pump side plunger block 431. When the motor-side cylinder 441a is at any other position, it is opened when the motor-side cylinder 441a is in the other position. A hydraulic pump 430 is arranged on the rear side, and a hydraulic motor 440 is arranged on the rear side.

In addition, the separation element supports the pump-side plunger block 431 and the motor-side plunger block 441 on the eccentrically arranged rotating shafts 470a and 480a, respectively, and faces the relative rotational sliding surface between the two plunger blocks 431. As shown in the figure, the rotary sliding surfaces 434 and 444 of the plunger blocks 431 and 441 have pump-side ports 434a'434a and motor-side ports 444a that individually communicate with a plurality of cylinders formed on each plunger block. '444a, and the ports 434a'434a of the plunger blocks 431 and 441, which are displaced by the eccentric arrangement of the rotating shafts 470a and 480a, overlap with each other. Oil passages 408 and 408 are formed to communicate with each other, and there is no overlap between the ports of both plunger blocks on the extension of the line connecting the axes of the rotary shafts 470a and 480a, and the oil passages 408 and 408 are separated. The oil passages of each plunger block are divided into a suction region and a discharge region by the divided oil passages among the oil passages 408 and 408. .

More specifically, bearings 430b′40b are fitted on the front side of the case housing 402a and the rear side of the case housing 402b, respectively.These bearings 430b′40b allow the rear end face of the rotating shaft 470a and the The configuration is such that both rotating shafts 470a'480a are eccentrically arranged with the front end faces of the rotating shafts 480a facing each other. The pump-side plunger block 431 is provided on the rotating shaft 470a, and the motor-side plunger block 441 is provided on the rotating shaft 480a. The respective rotary sliding surfaces 434 and 444 are supported so as not to rotate relative to each other. Further, in the case housing 402a, a movable swash plate 433M is disposed between the bearing 430b and the pump-side plunger block 431, and is arranged at equal intervals on the pump-side plunger block 431 and in the axial direction of the rotating shaft 470a. 431a A variable displacement hydraulic pump 430 configured to slide the plungers 432 in the '431a back and forth is configured. Also, in the case housing 402b, the bearing 440b and the motor-side plunger blower are provided. A fixed swash plate 43F is disposed between the swash plate 441 and the swash plate 43F. The swash plate 43F is formed at regular intervals on the motor-side plunger block 441 and in the axial direction of the rotating shaft 480a. , A fixed displacement hydraulic motor 440 having a configuration in which is moved back and forth. The swash plate tilt axis 433a of the movable swash plate 433M of the hydraulic pump 430 and the swash plate tilt axis 443a of the fixed swash plate 43F of the hydraulic motor 440 are parallel to each other. The swash plate tilting shafts 433a and 443a are perpendicular to the plane of FIG.

Further, as shown in FIG. 24, the sum of the bottom areas 432t and 432t of the rotary sliding surface 434 side of the cylinder 431a'431a of the pump side plunger block 431 and the cylinder 441a of the motor side plunger block 441 · 441a Rotating sliding surface 444t Bottom area on 444t · Total of 442t is designed to be almost the same, and each cylinder 431a '441a of pump side plunger block 431 and motor side plunger block 441 Are almost the same.

Further, as shown in FIG. 24, the motor-side plunger block 441 has its outer peripheral surface supported by a bearing 496 fitted to the case housing 402b. The bearing 407 is sandwiched between the motor-side plunger block 441 and the rotating shaft 480a, so that the front end of the rotating shaft 480a passes through the bearing 407 and the motor-side plunger block 441. It is configured to be supported by 96.

Further, as shown in FIG. 24, the rear end face of the rotating shaft 470a and the front end face of the rotating shaft 480a are arranged close to and opposed to each other.

In addition, as shown in FIGS. 25 and 26, on the rotary sliding surface 434 of the pump-side plunger block 431, the pump-side port for individually communicating with the inside of each cylinder 431a '431a is provided. G is opened so that the oil passes through the pump side port 434a'434a by sliding of the plungers 432a.

In addition, as shown in FIGS. 26 and 27, the motor sliding ports 444a and 444a have an S opening on the rotary sliding surface 444 of the motor-side plunger block 441 for individually communicating with the respective cylinders 441a and 441a. The sliding of the plungers 442 allows the oil to pass through the motor-side ports 444a and 444a.

As shown in FIGS. 24 and 27, an oil passage plate 490 is interposed between the rotary sliding surfaces 433 and 444 of the plunger blocks 431 and 441. The oil passages 490a and 490a are formed to penetrate in the axial direction, and the arrangement of these oil passages 490a and 490a is formed on the rotating sliding surfaces 433 and 444 of one of the plunger blocks 431 and 441. Port 434a Same as port 444a. In this embodiment, the oil passage plate 490 is provided with oil passages 490a and 490a having the same cross-sectional shape and arrangement as the pump-side ports 434a and 434a formed on the rotary sliding surface 433 of the pump-side plunger block 431. And

Further, the oil passage plate 490 and the other plunger block (in this embodiment, the motor-side plunger block 441) are brought into contact with each other so as to be slidable relative to each other so that the plunger block 433 It defines a relative rotating sliding surface (mating surface 5c). The oil passage plate 490 has a disk shape and has a rotary shaft that supports a plunger block (in this embodiment, a pump-side plunger block 431) in which ports having the same arrangement as the oil passages 490a and 490a are formed. It is arranged concentrically with 470a.

The oil passage plate 490 is fitted in a bearing 497 concentrically arranged on the rotating shaft 470a, and rotates relative to the pump-side plunger block 431, the motor-side plunger block 441, and the rotating shaft 470a '480a. It is freely configured. The oil passage plate 490 may be configured so as to be unable to rotate relative to the rotating shaft 470a at an angle at which the position of the oil passage 490a and the position of the pump-side port 434a coincide. Further, the oil passage plate 490 may not be rotatable relative to the pump-side plunger block 431 by a locking member such as a pin, and may be configured to rotate integrally with the pump-side plunger block 431. That is, an oil passage plate 490 that rotates integrally with one of the plunger blocks is interposed between the rotating sliding surfaces of both plunger blocks, and the oil passage plate 490 has a plurality of oil passages 490a. Formed in the axial direction, The arrangement of the oil passage 490a is substantially the same as the port formed on the rotary sliding surface of the plunger block on the side where the oil passage plate 490 is rotated by the body.

Further, the oil passage plate 490 supports the rotating shaft 470a of the plunger block 431 on the side where the oil passage plate 490 is rotated by the body, that is, by the bearing 497 via the oil passage plate 490. According to the configuration supporting the rotating shaft 470a, it is possible to prevent the rotating shaft 470a from being shaken.

Then, as shown in FIGS. 24 and 29, the rotation sliding surface 434 of the pump side plunger block 431 and the rotation of the motor side plunger block 441 with respect to the rotation sliding surface 494a'494b of the oil passage plate 490. A series of oil passages 408 are formed by the contact of the sliding surface 444. The oil passage plate 490 has the purpose of not only indicating the shaft 470a but also reducing the sliding resistance generated between the two rotating sliding surfaces 434 and 444 and preventing seizure. The surface of the moving surface is, for example, coated with a seizure-resistant material. If there is no problem of seizure between the two sliding surfaces 434 and 444 and the oil passage plate 490, the oil passage plate 490 may be configured to omit the coating with a seizure-resistant material. .

As shown in FIGS. 24 and 25, the swash plate tilt shaft 433a of the movable swash plate 433 ° of the hydraulic pump 430 and the swash plate tilt shaft 443a of the fixed swash plate 43F of the hydraulic motor 440 are parallel to each other. The centers of the rotating shafts 470a and 480a are eccentrically arranged in a direction orthogonal to the swash plate tilting shafts 433a and 443a.

The amount of eccentricity 499 of these rotary shafts 470a '480a is the rotational angle at which the maximum amount of eccentricity is reached, that is, the rotational angle 404t which is 90 degrees out of phase with respect to the axial direction of the swash plate tilting shafts 433a' 443a.回転 Position at 404u, and then rotate the sliding surfaces of both plunger blocks 431 and 441 4 Port 434a of 434-444 (490a) By maximizing the amount of displacement of -444a, both ports 434a (490a) The oil passages 408-408 formed by overlapping the '444a are divided, and the eccentric amount 499 through which the oil passages 408-408 communicate with each other at other rotation angles.

As a result, two sections 411 and 412, which are separated from each other with reference to the position of the rotation angle 404t'404u as shown in FIG. 25, are formed. In each section 411 and 412, as shown in FIG. 434a (490a) -444a Force S overlaps to form 408 force S in oil path. With the above configuration, in the first section 411 as shown in FIG. 25, the oil paths 408 and 408 form a high-pressure oil path (or a low-pressure oil path), and in the second section 412, the oil path 40 8 · 408 forms a low-pressure oil passage (or high-pressure oil passage), whereby hydraulic oil is supplied from hydraulic pump 430 to hydraulic motor 440 using rotary shaft 470a as an input shaft, and rotary shaft 480a is used as an output shaft. The HST 401 is configured to be driven.

Also, in the first section 411, a discharge area (or suction area) is formed in the hydraulic pump 430, and in the second section 412, a suction area (or discharge area) is formed in the hydraulic pump 430. Suction area (or discharge area) ヽ Hydraulic motor 440 has a discharge area (suction area) formed separately. These suction area and discharge area shall be configured with eccentric arrangement of rotating shafts 470a and 480a. It is what it is.

Further, as described above, the pump-side plunger block 431, the motor-side plunger block 441, and the force S face each other through the surfaces that slide and rotate (rotary sliding surfaces 433 and 444). A communication passage (oil passage 408) for fluid communication between the cylinders formed in the jar block is formed, and a separation element is interposed in the communication passage. The separation element allows the pump-side motor-side plunger. In each of the blocks, the plurality of communication passages are of the suction area (first section 411 (second section 412)) and the discharge area (second section 412 (second section 411)). It is categorized as That is, the oil passage group in each of the plunger blocks 431 and 441 is divided into a suction area and a discharge area (one of them is a first section 411 and the other is a second section 412) by the separation element. It is.

According to the above configuration, as shown in FIG. 24, the swash plate tilt shaft 433a of the movable swash plate 433433 of the hydraulic pump 430 and the swash plate tilt shaft 443a of the fixed swash plate 43F of the hydraulic motor 440 are different from each other. Because they are parallel, the inclination direction of both swash plates 433M'43F in the main drive direction (for example, the direction in which the vehicle equipped with HST401 is advanced) is set to be parallel, so that the plunger 432.432 of the hydraulic pump 430 and the plunger 432.432 The load in the thrust direction and the radial direction based on the rotating shaft 470a'480a generated by the sliding of the plunger 442.442 of the hydraulic motor 440 can cancel each other, and the motor-side plan can be reduced by using a smaller bearing 496. The jar block 441 can be supported, and power loss and cost can be reduced. In addition, according to the above configuration, as shown in FIG. 24, the total pressure receiving area of each of the cylinders 431a and 441a of the pump-side plunger block 431 and the motor-side plunger block 441 is substantially the same. Directional and radial loads can more reliably cancel each other out. In addition, as long as the total pressure receiving area is substantially the same, the number of cylinders 431a and 441a is not particularly limited, and the design flexibility of the plunger block is wide.

In addition, according to the above configuration, as shown in FIG. 24, the pump-side plunger block 431 and the motor-side plunger block 441 rotate in the same direction. As a result, it is possible to reduce power loss generated between the rotary sliding surfaces 434 ′ and 444 (494a and 494b).

Further, in the above configuration, by forming the oil passage plate 490 integrally with the pump-side plunger block 431 as shown in FIG. 30, the rotary sliding surfaces 494b and 444 face each other, Since two relative rotation sliding surfaces (mating surface 405c) are formed, the relative rotation sliding surface is compared with the conventional configuration in which two relative rotation sliding surfaces are formed on the high-pressure oil passage plate. The amount of leakage from the surface can be relatively reduced. In this way, the required amount of charge oil can be reduced, and power loss and cost can be reduced. Further, according to the above configuration, as shown in FIG. 24, since the high pressure oil passage plate required for the conventional configuration is not provided, the mass of the entire HST 401 can be reduced and the cost can be reduced.

Further, according to the above configuration, as shown in FIG. 24, the rear end face of the rotating shaft 470a and the front end face of the rotating shaft 480a are arranged close to and opposed to each other. As a result, the overall length of the HST401 can be made more compact as compared with a configuration in which a rotary shaft is supported.

Further, according to the above configuration, by providing the oil passage plate 490 as shown in FIG. 24, it is possible to reduce the sliding resistance generated between the two rotating sliding surfaces 434 with a simple configuration. As a result, power loss can be reduced.

Further, according to the above configuration, as shown in FIG. 24, the oil passage plate 490 is fitted inside the bearing 497 so as to be rotatably supported, and the pump side plunger block 431 and the motor side Because it is configured to be rotatable relative to the lancer block 441 and the rotating shafts 470a and 480a, even if there is a large difference between the rotation speeds of the two rotating shafts 470a and 480a, the oil plate 490 can rotate freely. Is allowed, and the oil passage plate 490 does not restrain the rotation of the plunger blocks 431 and 441, so that the rotational sliding generated between the oil passage plate 490 and the plunger blocks 431 and 441 is performed. Resistance can be minimized.

Further, according to the above configuration, the separation element can be configured by a simple configuration such as the eccentric arrangement of the two rotating shafts 470a and 480a, and the force S can be reduced to a hydrostatic continuously variable transmission with a small number of parts. .

Further, the charge oil supply mechanism and the check relief mechanism in the HST 401 having the above configuration have the same configuration as the first configuration example described above, as understood from the configurations shown in FIGS. 11 to 13 and 24. I have. Note that the above-described second and third configuration examples can also be applied.

Next, the configuration of the case housing in the HST 401 having the above configuration will be described. That is, as shown in FIG. 24, the case housing is of a front and rear split type, and the case housing 402a on the hydraulic pump 430 side has a movable swash plate 433M. The half bearing guide 421, the rotary shaft 470a as the input shaft, the bearing hole 422 of the bearing 430a 430b, and the bearing hole 420a of the bearing 497 for the oil passage plate 490 are integrally formed, while the case housing 402b on the hydraulic motor 440 side is formed. In the figure, a bearing hole 424 of a rotating shaft 480a as an output shaft is integrally formed.

According to this configuration, by forming the case housing by die-casting, machining can be reduced and the cost can be reduced.

In the above-described configuration example, the hydraulic pump 430 is of a variable displacement type, and the hydraulic motor 440 is of a fixed displacement type. The present invention is also applicable to a configuration in which the motor 440 is of a variable displacement type. Further, in the above-described configuration example, the force is such that the oil passage plate 490 is arranged on the pump-side plunger block 431. The present invention is also applicable to a configuration in which 490 is provided.

In the configuration example described above, a charge oil supply mechanism and a hydraulic oil supply mechanism are provided on the hydraulic motor 440 side. Force with Provision of Check and Relief Mechanism The reverse configuration may be adopted, that is, a configuration in which a charge oil supply mechanism and a check and relief mechanism are provided on the hydraulic pump 430 side.

As described above, the hydraulic pump 430 is a fixed displacement type, the hydraulic motor 440 is a variable displacement type, the charge oil supply mechanism and the check relief mechanism are provided on the hydraulic pump 430 side, and the hydraulic motor 440 is provided on the hydraulic motor 440 side. In the case where the 440 is provided, although not shown, the case housing is of a front-rear split type, and the case housing 402a on the hydraulic pump 430 side has a bearing hole 422 of a rotary shaft 470a as an input shaft. On the other hand, the half housing guide 421 of the movable swash plate 433M and the bearing hole 424 of the bearing 440b of the rotary shaft 480a as the output shaft are integrally formed in the case housing 402b on the hydraulic motor 440 side. Things.

As described above, in addition to the above-described configuration example, even in a configuration in which the hydraulic pump 430 is a fixed displacement type and the hydraulic motor 440 is a variable displacement type, machining can be reduced by forming the case housing by die casting. Therefore, cost can be reduced.

In addition, as the configuration of the case housing, the configurations (a) to (c) shown in FIG. 16 are applicable.

Industrial applicability

INDUSTRIAL APPLICABILITY The present invention can be used as a substitute for a conventional hydrostatic continuously variable transmission, and is particularly suitable for a place where a space-saving design is required. In addition, since power loss is small, this configuration is suitable for places where high transmission efficiency is required.

Claims

The scope of the claims

[1] A hydrostatic continuously variable transmission that combines an axial piston type hydraulic pump and a hydraulic motor,

The plunger block on the pump side and the plunger block on the motor side are opposed to each other via surfaces that slide and rotate with each other.

A plurality of communication passages for fluid communication between the cylinders formed in both plunger blocks are formed,

A separation element is interposed in the plurality of communication paths,

In each of the pump-side and motor-side plunger blocks, the plurality of communication paths are divided into a suction area and a discharge area by the separation element.

A hydrostatic continuously variable transmission having a configuration.

[2] The separation element includes:

In either one of the plunger blocks,

The plunger block is constituted by the same number of spool valves as the number of cylinders,

The spool valve is

The plunger block is radially arranged slidably about a rotation axis of the plunger block, and an outer end thereof is in contact with an inner peripheral surface of an inner ring of a bearing eccentrically arranged with respect to the rotation axis,

According to the rotation of the plunger block, the plunger block is slid in the radial direction of the rotating shaft, and opens or divides an oil passage communicating the cylinders of the plunger blocks.

The oil passages are divided by the spool vanoleb, and the oil passages in each plunger block are divided into a suction region and a discharge region.

The hydrostatic continuously variable transmission according to claim 1, wherein:

[3] The rotary shaft of the motor-side plunger block and the rotary shaft of the pump-side plunger block are arranged coaxially, and the rotary shaft and the planetary gear mechanism are combined to form a hydraulic system configured in an input split type. '' Claims that made it possible to construct a mechanical continuously variable transmission 3. The hydrostatic stepless transmission according to item 1 or 2.

[4] The rotary shaft of the motor-side plunger block and the rotary shaft of the pump-side plunger block are arranged coaxially, and these rotary shafts and a planetary gear mechanism are combined to form a hydraulic output-split hydraulic system. · The hydrostatic continuously variable transmission according to claim 1 or 2, wherein the mechanically continuously variable transmission can be configured.

[5] The inner peripheral surface of the inner race of the bearing is inclined with respect to the axial direction of the rotating shaft,

3. The hydrostatic continuously variable transmission according to claim 2, wherein:

[6] inclining the sliding direction of the spool valve with respect to the axial direction of the rotating shaft;

[7] The separation element includes:

The pump-side plunger block and the motor-side plunger block are supported on the eccentrically arranged rotating shafts, respectively.

So that it faces the relative rotation sliding surface between both plunger blocks,

Pump-side ports and motor-side ports that individually communicate with multiple cylinders formed in each plunger block are formed.

The ports of both plunger blocks that are displaced due to the eccentric arrangement of the rotating shaft overlap each other to form an oil passage that connects the cylinders of both plunger blocks. The overlap between the ports of both plunger blocks is eliminated, and the oil passage is divided.

Of the oil passages, the oil passages of each plunger block are divided into a suction region and a discharge region by a divided oil passage.

[8] An oil passage plate that rotates integrally with one of the plunger blocks is provided, and the oil passage plate and the other plunger block are brought into contact with each other so as to be slidable relative to each other. Draw a relative rotation sliding surface between the blocks,

The oil passage plate is formed by penetrating a plurality of oil passages in the axial direction,

The arrangement of these oil passages is substantially the same as the port formed on the plunger block on the side where the oil passage plate is integrally rotated, and The rotation shaft of the plunger block on the side on which the oil passage plate is integrally rotated is supported by the oil passage plate.

8. The hydrostatic continuously variable transmission according to claim 7, wherein:

[9] a connection point with a charge pump provided in a case housing of the hydrostatic continuously variable transmission,

A charge oil supply mechanism is provided between the motor and the hydraulic circuit in the pump side plunger block.

[10] A connection point with a charge pump provided in a case housing of the hydrostatic continuously variable transmission,

A check mechanism is provided between the motor and the hydraulic circuit in the plunger block on the pump side.

[11] The case housing of the hydrostatic continuously variable transmission is

Divided near the separation element,

[12] The case housing of the hydrostatic continuously variable transmission includes:

It is a configuration that is divided,

A hydraulic motor and a hydraulic pump are housed in the first housing,

2. The hydrostatic continuously variable transmission according to claim 1, wherein an opening of the first housing is closed by another housing.