JP3354979B2 - Variable capacity hydraulic rotary machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable displacement type hydraulic rotary machine such as an oblique shaft type or swash plate type hydraulic pump / motor which is capable of variably setting a displacement. The present invention relates to a variable displacement hydraulic rotary machine provided with a rotation angle detecting device for detecting an angle.

[0002]

2. Description of the Related Art FIGS. 3 to 6 show a variable displacement oblique shaft type hydraulic pump as an example of a conventional variable displacement hydraulic rotary machine.

[0003] In the drawings, reference numeral 1 denotes a casing constituting a main body of an oblique-axis type hydraulic pump. The casing 1 has a casing main body 1A formed in a substantially cylindrical shape, and one end of the casing main body 1A is closed. And a head casing 1B fixed to one end of the casing body 1A. Reference numeral 2 denotes a rotating shaft whose base end is rotatably provided in the casing body 1A and whose distal end protrudes out of the casing body 1A. The rotating shaft 2 is rotatably supported by the casing body 1A via bearings 3 and 3. A disk-shaped drive disk 2A is integrally formed on the base end side.

[0004] Reference numeral 4 denotes a cylinder block as a rotor rotatably provided in the casing body 1A so as to rotate integrally with the rotating shaft 2. The cylinder block 4 has a plurality of cylinders 5 in its axial direction. Each of the cylinders 5 is provided on a concentric circle which is separated from a center shaft 12 to be described later by a certain dimension in a radial direction. Each piston 6 is slidably inserted into each cylinder 5, and each piston 6 reciprocates in each cylinder 5 when the cylinder block 4 is rotationally driven via the rotary shaft 2. I do. A connecting rod 7 is attached to each piston 6, and each spherical portion 7A formed at the tip of each connecting rod 7 is swingably supported by the drive disk 2A.

[0005] Reference numeral 8 denotes a substantially rectangular valve plate constituting a variable capacity portion.
The other end face is slidably slidably contacted with a concavely curved tilting sliding surface 9 formed around the tilting center O1 described later formed on the head casing 1B. A through hole 8A is formed at the center of the valve plate 8, and a base end of the center shaft 12 and a distal end of a swing pin 17 described later are inserted into the through hole 8A from both sides. . The valve plate 8 is provided with supply / discharge ports 8B, 8C which are intermittently connected to the respective cylinders 5 by the rotation of the cylinder block 4, and the supply / discharge ports 8B, 8C are located at the tilt positions of the valve plate 8. Regardless, the supply / discharge passages 10, 1 that open to the tilting sliding surface 9 of the head casing 1B
It is designed to communicate with 1.

Reference numeral 12 denotes a center shaft which rotatably supports the cylinder block 4 between the drive disk 2A and the valve plate 8. The center shaft 12 has a spherical portion 12A formed at the tip end thereof. Is the center O1 of the spherical portion 12A with respect to the drive disk 2A.
It is supported swingably. The base end of the center shaft 12 is inserted into the through hole 8A of the valve plate 8.

Reference numeral 13 denotes a sector type tilting mechanism for tilting the valve plate 8 as a variable capacity portion along the tilting sliding surface 9;
The tilting mechanism 13 is bored in the head casing 1B,
A cylinder chamber 14 having oil through holes 14A, 14B at both axial ends is slidably inserted into the cylinder chamber 14 to define hydraulic chambers 15A, 15B on both axial sides of the cylinder chamber 14. Servo piston 16 and servo piston 16
And a swing pin 17 having a spherical tip 17A inserted into a through hole 8A of the valve plate 8 so as to be swingable.

Here, the tilting mechanism 13 changes the tilting angle θ of the cylinder block 4 and the valve plate 8 with respect to the rotary shaft 2 by supplying and discharging pressure oil from outside to the hydraulic chambers 15A and 15B. To tilt control. When the tilt angle θ of the cylinder block 4 and the valve plate 8 changes, the stroke amount of each piston 6 reciprocating in each cylinder 5 is variably adjusted in accordance with the tilt angle θ, as described later. The discharge amount (capacity) of the pressure oil discharged from the supply / discharge passage 11 (10) is changed.

Reference numeral 18 denotes a turning angle detecting device for detecting the tilt angle θ of the valve plate 8. The turning angle detecting device 18 projects radially from the casing body 1A as shown in FIGS. The cylindrical case 19 provided and the case 1
9, a rotary shaft 20 rotatably mounted via a seal member 21 and bearings 22 and 22, which will be described later, and a tip end side of which is projected to the outside of the case 19, and an angle detection sensor 28 and the like which will be described later. ing.

[0010] Here, as shown in FIG.
The rotating shaft 20A is substantially constituted by a cylindrical outer rotating cylinder 20A and a shaft 20B fitted inside the rotating cylinder 20A. The shaft 20B is together with the rotating cylinder 20A in the case 19 in the seal member 21, the bearing 22, It is configured to rotate through the connection 22. The outer ring side of each bearing 22 is positioned on the inner peripheral surface of the case 19 via a cylindrical positioning ring 23, and supports the shaft 20B in the case 19 rotatably together with the rotating cylinder 20A.

The shaft 20B has a base end on the side of a positioning screw 2 via a flexible coupling 27 to be described later.
The input shaft 28A of the angle detection sensor 28 is connected to the input shaft 28A by the reference numerals 4 and 24, and a swing lever 29 described later is attached to the distal end of the input shaft 28A via a fixing screw 25. Further, an O-ring 26 is provided at an intermediate position in the axial direction of the shaft 20B to seal between the shaft 20B and the rotary cylinder 20A. Prevents intrusion.

Reference numeral 27 denotes a flexible coupling as a rotation transmitting mechanism connecting the base end side of the rotation shaft 20 to the shaft 20B and the input shaft 28A of the angle detection sensor 28. The flexible coupling 27 is connected to the shaft 20B by an input. The displacement of the shaft center from the shaft 28A is absorbed, and the rotation of the shaft 20B is transmitted to the input shaft 28A of the angle detection sensor 28.

Reference numeral 28 denotes an angle detection sensor fixed to the case 19 so as to close one end of the case 19, and the angle detection sensor 28 fits a fitting portion 28B to one end of the case 19. Installed by The angle detection sensor 28 is configured by, for example, a potentiometer or the like, and detects the rotation angle of the input shaft 28A as a change in the amount of electricity.

Reference numeral 29 denotes an oscillating lever which extends inside the casing 1 of the oblique shaft type hydraulic pump along the side surface of the cylinder block 4 and rotates the rotary shaft 20 in accordance with the tilt of the valve plate 8. The swing lever 29 is formed by press-forming a flat plate-shaped material as shown in FIG. 6, and has an insertion hole 29A which is inserted into the shaft 20B of the rotating shaft 20 at one end thereof and the other end thereof. An engagement recess 29B that engages with a transmission pin 30 described later is formed on the side. And the swing lever 2
9 is inserted into a shaft 20B of the rotating shaft 20 through an insertion hole 29A, and a fixing screw 25 is attached to the shaft 20B.
Is fixed through.

Reference numeral 30 denotes a transmission pin that is implanted on the side surface of the valve plate 8 and protrudes in the radial direction of the casing 1. The protruding end of the transmission pin 30 slides in the engagement recess 29 B of the swing lever 29. When the valve plate 8 is tilted along the tilt slide surface 9, the tilt is transmitted to the rotation shaft 20 of the rotation angle detection device 18 via the swing lever 29, The rotation shaft 20 is rotated by an angle corresponding to the tilt angle θ of the valve plate 8.

Here, the axis of the rotary shaft 2 is AA, the vertical axis passing through the tilt center O1 of the spherical portion 12A of the center shaft 12 and orthogonal to the axis AA is BB, and the tilt center O
The horizontal axis passing through 1 and orthogonal to the axis AA is B'-B '
As shown in FIG. 4, the case 19 and the rotation shaft 20 of the rotation angle detecting device 18 are provided on the horizontal axis B'-B '. The tilt angle θ is shown as a tilt angle of the cylinder block 4 and the valve plate 8 with respect to the axis AA.

The conventional variable displacement oblique shaft type hydraulic pump having the above-described configuration will be described below.

First, when the valve plate 8 is tilted together with the cylinder block 4 by the tilting mechanism 13 to a required tilting position, for example, external pressure oil is supplied to the cylinder chamber 14 through a control valve (not shown). It is supplied as a control pressure to one hydraulic chamber 15A (15B) on one side, and the servo piston 16 is displaced.
When the servo piston 16 is displaced together with the swing pin 17, the valve plate 8 is tilted up and down while sliding on the tilt slide surface 9. Both tilt, the axis AA of the rotating shaft 2
When the tilt angle θ is large, the stroke amount of each piston 6 is large and the hydraulic pump is set to a large capacity, and when the tilt angle θ is small, the stroke amount of each piston 6 is small and small. Set to capacity.
FIG. 3 shows a maximum tilt state.

Next, when the rotary shaft 2 is driven to rotate from the outside by a drive source (not shown) such as an engine or an electric motor, the rotation is transmitted via the drive disk 2A and the connecting rod 7 of each piston 6 to the cylinder block 4. When the cylinder block 4 rotates together with the rotating shaft 2, each piston 6 repeats reciprocating motion in each cylinder 5 of the cylinder block 4. When each piston 6 is slidably displaced from top dead center to bottom dead center in each cylinder 5, each piston 5 is moved from the supply / discharge passage 10 (11) through the supply / discharge port 8B (8C). When each piston 6 is slidably displaced from bottom dead center to top dead center in each cylinder 5, the hydraulic oil in each cylinder 5 is pressurized. Supply / discharge port 8C
This is the discharge stroke of discharging from the supply / discharge passage 11 (10) via (8B).

In this case, for example, when the discharge pressure of the pressure oil discharged from the supply / discharge passage 11 (10) is increased, an overload is applied to the drive source, so that the tilt mechanism 13 tilts the cylinder block 4. By controlling the tilting of the valve plate 8 so that the angle θ becomes small, and by operating the valve plate 8 as a small-capacity pump by reducing the discharge amount of pressure oil, an overload is prevented from acting on the drive source. Further, when the discharge pressure of the pressure oil is low, the overload does not act on the drive source.
Numeral 3 controls the tilting of the valve plate 8 so that the tilt angle θ of the cylinder block 4 increases, and increases the discharge amount of the pressure oil to operate as a large capacity pump.

When the valve plate 8 is tilted together with the cylinder block 4 by the tilting mechanism 13, the valve plate 8 slides on the tilt sliding surface 9 about the tilt center O1. With the movement of the transmission pin 30 provided on the side surface of FIG.
Swing in the D direction. Thereby, the rotation angle detecting device 18 converts the swing of the swing lever 29 into the rotation of the rotation shaft 20, and the rotation of the rotation shaft 20 absorbs the shift of the axis by the flexible coupling 27. Input shaft 2 of the angle detection sensor 28
8A, and the rotation angle at this time is electrically detected as a tilt angle θ.

[0022]

In the above-mentioned prior art, the swing lever 29 is formed by press-forming a flat plate material, and one end of the swing lever 29 is fixed to the insertion hole 29A. The other end of the swing lever 29 is slidably engaged with the transmission pin 30 via the engagement concave portion 29B by being fixed to the shaft 20B of the rotation shaft 20 via the screw 25, whereby the valve plate 8 Since the tilt is transmitted to the rotation shaft 20 of the rotation angle detection device 18, for example, the supply / discharge passage 1
The displacement of the valve plate 8 is controlled so that the discharge pressure of the pressure oil discharged from 1 (10) repeatedly fluctuates, and the tilting mechanism 13 increases or decreases the tilt angle θ of the cylinder block 4. When the upward and downward tilt of the valve plate 8 is transmitted to the swing lever 29 via the transmission pin 30, the engagement recess 29 </ b> B of the swing lever 29 The sliding of the swing lever 2
No. 9 has a problem that the periphery of the engagement concave portion 29B is easily worn out early.

The engagement recess 29 of the swing lever 29
When a gap S is formed between the engagement recess 29B and the transmission pin 30 as shown in FIG. 6 due to wear of the periphery B or a dimensional error at the time of manufacture, the valve plate 8 moves upward and downward. When the tilting is repeated, the swinging lever 29 rattles in the directions indicated by the arrows C and D with respect to the transmission pin 30 by the gap S, so that the tilting angle θ of the cylinder block 4 is determined by the rotation angle detecting device. Therefore, the tilt angle θ of the cylinder block 4 cannot be stably detected by the angle detection sensor 28 of the rotation angle detection device 18.

Further, since the swing lever 29 is formed with relatively high rigidity by press-forming a flat plate material, when the valve plate 8 tilts up and down and repeats vibration, This vibration is directly transmitted to the rotation shaft 20 of the rotation angle detection device 18 via the swing lever 29, and there is a problem that the angle detection sensor 28 including, for example, a potentiometer is damaged at an early stage.

The present invention has been made in view of the above-mentioned problems of the prior art, and the present invention can surely transmit the tilt of a variable capacity portion to a rotation shaft of a rotation angle detecting device via a swing lever. A variable displacement hydraulic rotation that can stably detect the tilt angle at this time by the rotation angle detection device and effectively solve problems such as damage to the rotation angle detection device early. The purpose is to provide a machine.

[0026]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a casing, a rotating shaft having a base end rotatably provided in the casing and a distal end protruding outside the casing. A rotor provided with a plurality of cylinders and provided in the casing so as to rotate integrally with a rotation shaft, and is slidably inserted into each cylinder of the rotor and reciprocates in each cylinder. Multiple pistons,
A variable displacement portion provided in the casing so as to be tiltable so as to variably adjust the stroke amount of each piston; and a transmission provided in the variable displacement portion and protruding from the variable capacity portion in a radial direction of the casing. A rotation angle detection device provided on the casing and spaced apart from the transmission pin in the axial direction of the casing and detecting a rotation angle of a rotation shaft protruding into the casing; and the rotation angle detection device. And a swing lever disposed between the rotating shaft and the transmission pin for rotating the rotating shaft of the rotating angle detecting device in response to the tilting of the variable capacity portion. in the rotating machine, the swing lever has an elongated plate-shaped spring member by bending a substantially U-shape one end side arc shaped bent portion and the other end of the pair
Formed as a holding portion and located at one end of the swing lever .
The arc-shaped bent portion is fixed to the rotation shaft of the rotation angle detecting device in a retaining state, and a pair of holding portions located on the other end side.
Is Ru Tei characterized in that the arrangement for clamping with a spring characteristic of the transmission pin in the radial direction outside.

[0027]

According to the above construction, the swing lever formed by bending the elongated plate-like spring material into a substantially U-shape,
For example, even in the case where the variable capacity portion tilts up and down and repeats vibration, the vibration can be transmitted to the rotation shaft of the rotation angle detecting device with a spring property, and the vibration at that time is buffered and rotated. Vibration can be prevented from being directly transmitted to the angle detection device. The swing lever has an arc-shaped bent portion located at one end side.
The other end side is fixed to the rotation shaft of the moving angle detection device so as not to come off.
, The transmission pin is pinched from the outside in the radial direction with a spring property, so that no gap is formed between the pinch of the rocking lever and the transmission pin, and the variable capacity portion is moved upward and downward . When tilting downward and repeating vibration , the swing lever can be reliably prevented from rattling with respect to the transmission pin.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the embodiment, the same components as those in the prior art shown in FIGS. 3 to 6 are denoted by the same reference numerals, and description thereof will be omitted.

In the figure, reference numeral 41 denotes a swing lever for transmitting the tilt of the valve plate 8 serving as a variable capacity portion to the rotation shaft 20 of the rotation angle detecting device 18, and the swing lever 41 is an elongated plate-shaped metal. By bending the spring material into a substantially U-shape as shown in FIG.
For example, it is formed in a hairpin shape, and one end side thereof is a rotating shaft 2.
Arc-shaped bent portion 41 attached to the shaft 20B
A. The other end of the swing lever 41 is a pair of holding portions 41B, 41B, and the holding portions 41B abut against each other with a required spring force in a free state.

Here, as shown in FIG. 2, an insertion hole 42 for a retaining pin 44, which will be described later, is formed in the shaft 20B of the rotating shaft 20 so that a bending portion 41A of the swing lever 41 is formed.
Also, a pair of insertion holes 43, 43 are formed corresponding to the insertion holes. The bending portion 4 of the swing lever 41
1A is fitted to the outer periphery of the shaft 20B with a tight allowance, and is fixed to the shaft 20B by inserting a retaining pin 44 into each of the insertion holes 42 and 43. Further, when each of the holding portions 41B holds the transmission pin 30 from outside in the radial direction with a spring property, and the valve plate 8 is tilted together with the transmission pin 30, the swing lever 41 is in the directions indicated by arrows C and D in FIG. To rotate the rotation shaft 20.

Further, reference numeral 44 denotes a bent portion 4 of the swing lever 41.
1A shows a retaining pin for fixing the rotating shaft 1A to the shaft 20B of the rotating shaft 20 in a retaining state. The retaining pin 44 is formed of a split pin or the like, and the bent portion 41A of the swing lever 41 is connected to the rotating shaft 20.
Each of the insertion holes 42, 4 when attached to the shaft 20B of
3 is inserted as shown in FIG. 2 to rotate the swing lever 41 integrally with the rotation shaft 20.

The variable displacement oblique shaft type hydraulic pump according to the present embodiment has the above-described configuration, and its basic operation is not particularly different from that of the prior art.

In this embodiment, however, the swing lever 41 for transmitting the tilt of the valve plate 8 to the rotation shaft 20 of the rotation angle detector 18 is used.
Is formed in a substantially U-shape from an elongated plate-shaped metal spring material,
The bent portion 41A on one end side is connected to the shaft 20 of the rotating shaft 20.
B through a retaining pin 44, and the transmission pin 30 is clamped from outside in the radial direction with spring properties by each clamping portion 41B on the other end side. Thus, the vibration can be transmitted to the rotation shaft 20 of the rotation angle detecting device 18 with a spring property, and even when the valve plate 8 tilts up and down and repeats the vibration, the vibration at this time is transmitted to the swing lever 41. Accordingly, the vibration can be effectively reduced, and the vibration transmitted to the rotation shaft 20 of the rotation angle detection device 18 can be reliably reduced.

Further, since each holding portion 41B of the swing lever 41 continues to hold the transmission pin 30 from outside in the radial direction with a spring property, the valve plate 8 is tilted together with the transmission pin 30 and the swing lever 41 is moved to the position shown in FIG. When swinging in the directions of arrows C and D,
It is possible to prevent rattling between the transmission pin 30 and each of the holding portions 41B, and to accurately transmit the tilt of the valve plate 8 to the rotation shaft 20 of the rotation angle detection device 18.

Therefore, according to the present embodiment, the tilt of the valve plate 8 can be reliably transmitted to the rotation shaft 20 of the rotation angle detecting device 18 via the swing lever 41, and the rotation angle of the rotation angle detecting device 18 The tilt angle θ at this time can be stably detected by the angle detection sensor 28, and even when the valve plate 8 tilts up and down and repeats the vibration, the vibration at this time is detected by the rotation angle detection. Vibration can be prevented from being directly transmitted to the rotation shaft 20 of the device 18, and problems such as, for example, the angle detection sensor 28 including a potentiometer being damaged early can be effectively solved.

The swing lever 41 is formed, for example, in a hairpin shape by bending an elongated plate-like metal spring material into a substantially U-shape as shown in FIG. 2, so that the swing lever 41 can be reduced in weight. Various effects can be obtained, for example, an extra load can be reliably prevented from acting on the valve plate 8 and the like via the transmission pin 30.

In the above embodiment, the rotation angle detecting device 1
The case 19 of FIG.
However, the present invention is not limited to this. For example, the case 19 of the rotation angle detecting device 18 is moved closer to the transmission pin 30 than the position of the horizontal axis B'-B '.
Alternatively, the rotating shaft 20 and the like may be provided on the casing 1. In this case, the swing lever 41 can be formed to be short.

Further, in the above-described embodiment, the description has been made by taking the inclined shaft type hydraulic pump as an example. However, the present invention is not limited to this, and various types such as an inclined axis type hydraulic motor or a swash plate type The present invention can also be applied to a variable displacement hydraulic rotating machine.

[0039]

As described above in detail, according to the present invention, the swing lever is formed by bending an elongated plate-like spring material into a substantially U-shape, and one end of the swing lever becomes an arc-shaped bent portion. is fixed by retaining state to the rotation shaft of the rotation angle detecting device, the other end side is configured for clamping with a spring characteristic of the transmission pin in the radial direction outside becomes a pair of holding portions, for example, variable capacity part Even in the case of repeating the vibration by tilting up and down, the vibration can be transmitted to the rotation shaft of the rotation angle detecting device with a spring property by the swing lever , and the vibration at this time is buffered and the rotation angle is reduced. Vibration can be prevented from being directly transmitted to the detection device, rattling can be prevented between the holding portion of the swing lever and the transmission pin, and the tilt of the variable capacity portion can be reliably transmitted to the rotation angle detection device. . Accordingly, various effects are exhibited, such as being able to stably detect the tilt angle of the variable capacity portion and the like by the rotation angle detection device and effectively preventing the rotation angle detection device from being damaged early. .

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a swing lever, a rotation angle detecting device, and the like according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken in the direction of arrows II-II in FIG.

FIG. 3 is a longitudinal sectional view showing a variable displacement oblique shaft type hydraulic pump according to the related art.

FIG. 4 is a sectional view taken in the direction of arrows IV-IV in FIG. 3;

FIG. 5 is an enlarged longitudinal sectional view of the swing lever, the rotation angle detection device, and the like shown in FIG.

FIG. 6 is an enlarged sectional view taken in the direction of arrows VI-VI in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 2 Rotating shaft 4 Cylinder block (rotor) 5 Cylinder 6 Piston 8 Valve plate (variable capacity part) 10, 11 Supply / discharge passage 13 Tilting mechanism 18 Rotation angle detecting device 19 Case 20 Rotation shaft 30 Transmission pin 41 Swing Moving lever 41A Bending part 41B Nipping part 44 Locking pin

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsuya Sakairi 650, Kandate-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. Inside the Tsuchiura Plant (56) References JP-A-3-258972 (JP, A) Jiko 62-12273 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) F04B 1/24 F03C 1/253 G01B 7/30

Claims (1)

(57) [Claims] 1. A casing, a base end side of which is rotatably provided in the casing, a distal end side of which is provided in the casing so as to rotate integrally with the rotating shaft protruding out of the casing and the rotating shaft. A rotor having a plurality of cylinders formed therein, a plurality of pistons slidably inserted into respective cylinders of the rotor and reciprocating in the respective cylinders, and variably adjusting a stroke amount of the respective pistons. A variable capacity portion tiltably provided in the casing, a transmission pin provided on the variable capacity portion and protruding from the variable capacity portion in a radial direction of the casing, and an axial direction of the casing from the transmission pin. Provided in the casing at a distance from each other,
A rotation angle detection device that detects a rotation angle of a rotation shaft protruding into the casing; and a rotation angle detection device that is disposed between the rotation shaft of the rotation angle detection device and the transmission pin, and tilts the variable capacitance portion. the variable displacement hydraulic rotary machine comprising a swing lever to rotate the rotation axis of the pivoting angle detection apparatus in accordance with the rolling, prior KiYurado lever, substantially U-elongated plate-like spring member One end is bent into an arc shape by bending it into a shape
Sides are formed as a pair of holding portions, and the arc-shaped bent portion located at one end side of the swing lever
Is fixed to the rotation shaft of the rotation angle detection device in a retaining state.
And, a pair of clamping portions located on the other end, a variable displacement hydraulic rotary machine, characterized in that it has a structure for clamping with a spring characteristic of the transmission pin in the radial direction outside.