JPS58131377A - Swash plate type variable displacement axial piston pump-motor - Google Patents

Abstract

PURPOSE:To reduce the size, weight and cost of a swash plate type variable displacement axial piston pump-motor and also form it in a compact construction by reasonable arrangement of its swash plate control mechanism. CONSTITUTION:A rotating shaft 7 is supported by a front bearing 134 and a rear bearing 20. When the shaft 7 is rotated, a cylinder block 8 coupled by spline with the shaft 7 is rotated so that a plurality of piston 9 may be reciprocated along the inclined surface of a swash plate 5 having an inclination angle alpha within the cylinder chamber 138. As a result, a fluid is drawn through a suction port 92 into the chamber 138 from where it passes through a port plate 15 and is deliverred through a delivery port 93 formed in the rear body 2. The swash plate actuator unit adapted to control the inclination angle of the swash plate 5 and its control unit are separately disposed on the outer periphery of the front bearing 134 which supports the rotating shaft 7.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a swash plate type variable displacement axial piston pump.
The swash plate control mechanism in the motor is rationally arranged and
It is 1% lighter, more compact, lower cost, and has VC% less moldiness.

Conventional swash plate type variable displacement axial piston pump -
As shown in Figure 1, the main body (e) consists of the front body (e) and the casing (GL and rear body TH).
b), the main body (bl vc), the rotating shaft (cl) rotatably mounted by the front pair cylinder (a) and the rear earring (1), the swash plate (fl) rotatably mounted within the casing (g); , the main body @ (bl
olIIIK arranged nine bodies (k) and the body (1
c) in the control section Tl) and the swash plate actuator section (m
A swash plate control section (which can be roughly divided into at,
The swash plate actuator part (-) of the swash plate control part (at) and the control part (11) are disposed close to each other in the body (k), and the casing at the front bearing ((11) and rear bearing (1) It is arranged so as to protrude outward in the radial direction 111 in (g).

However, in the swash plate [machi displacement axial piston pump motor] as described above, the swash plate control section
However, the main body part (the thickest casing around the body of BL (g
), the swash plate actuator section (m
Since the l and control part (1) are arranged together, they protrude greatly outside the casing (g), and the nuclear pump motor is Therefore, it is disadvantageous in terms of handling and installation.

(b) During assembly, the swash plate control section (a) is mounted on the casing (g
It is necessary to make it a detachable OT rudder, and a connecting flange is required between it and the casing, which increases the weight.
It is necessary to apply a gasket (j) between the connecting surfaces of the two for sealing, which may cause oil leakage.

(c) The body (+c) of the swash plate control unit is a part that requires complicated processing and is separate from the main body 1bl, which is disadvantageous in terms of weight and cost.

There are drawbacks such as.

The present invention aims to eliminate the above-mentioned drawbacks of conventional swash plate type variable displacement axial piston pumps and motors, and the swash plate control section is moved from the front, which was previously unused and wasted space. By disposing the space on the outer periphery of the arinder part, the space can be used effectively and the external size can be reduced. A mosquito control part and a swash plate actuator part are formed in the 70/topoday,
By omitting the body of the swash plate control section, it is wider, smaller, lighter, more compact, lower cost, and more reliable than the conventional structure. The actuator piston moves to control the tilt angle of the swash plate, and the sleeve is linked to the swash plate to move and the servo spool inside the sleeve moves to control the servo supply pressure to the actuator chamber of the swash plate actuator. In an axial piston ponzo motor having a swash plate fJ and a control section that performs coal cutting, the swash plate actuator section and the control section are arranged on the outer periphery of a front bearing that supports the rotating shaft of the pump motor. The main feature is that the axes of the swash plate actuator section and the control section are arranged at substantially right angles to the axis of the rotating shaft, sandwiching the front bearing.

The present invention has the above-described configuration, and the pump and bristles.
A swash plate actuator section that controls the inclination angle of the swash plate in the motor, a control section thereof, and a front bearing that supports the rotating shaft. Since the power is distributed almost at right angles across the front bearing, the swash plate actuator section and control section are compactly arranged in a relatively small part of the pump/motor, and their hydraulic oil passages are relatively compact. It is short and can be placed inside the front body, and the overall structure is well-balanced.
It is compact, low cost, and highly reliable.

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

An actual example of the present invention is shown in Figures 2 to 7, and Figure 2 shows a cross section of the swash plate type variable displacement axial piston pump of the present invention. Showing 6th
In the figure, (11 is the front body, 12 + beamer body, (3) is the casing, (5) is the swash plate, (7) is the rotating shaft, (81 is the cylinder block, (91 is the piston, a4 is the pulp plate, ( 151 is a boat plate,
■ is the rear arinda, (134) is the front bearing, and the rotating shaft (7) is the front bearing (
134) and a rear bearing ■, and when the rotating shaft (7) is rotated, the cylinder block (8) spline-coupled to the rotating shaft (71) is rotated.
A plurality of pistons (91) attached to the power distribution tower in the cylinder block (8) reciprocate within the cylinder chamber (138) along the slope of the swash plate (5) with an inclination angle α, and the cylinder block (
The pump operates by sucking fluid into the cylinder chamber (138) of 8) from the suction boat side and discharging it from the discharge boat of rear body turtle 2 through 151 (boat play) (151). (Hereinafter, the pump operation will be mainly explained.) In other words, the stroke amount of the piston (9) can be changed by the inclination angle α of the swash plate (5), and the discharge amount of the pump can be changed by changing the inclination angle α of the swash plate (5). 5) is a swash plate type variable displacement axial piston pump/motor determined by the size of the inclination angle α.

Next, to explain the swash plate actuator section (Ml), the swash plate (5) has spherical bearings (136), (136')
The piston t9+ is attached to the casing (3) via the trunnion shaft αB (11') IC, and is driven by the pressure of the cylinder chamber (138) into which the piston (91) is inserted.
K receives the generated load via the shoe O2, and the swash plate rotation center (140), that is, the trunnion axis αB (11')
It has a structure that allows it to rotate around a line.

On the other hand, the swash plate (5) mainly has an arm (5a) protruding inside the front body (11) as shown in FIGS. 2 and 5, and connecting rods (C) and (43 '
) to connect the actuator pistons υ, (41'
) is further connected to the actuator chamber (2) of the actuator piston @υ and the actuator piston (
The actuator chamber (39') of the actuator chamber (39') K of the swash plate rotation center (14') is
Rotate or stand still around 0). That is, the inclination angle α of the swash plate (5) can be controlled by controlling the pressure in the actuator chambers (39') and (39').

Actuator piston ← 1), (41') K is passage (144), (144'), and connecting rod (c)
, (43') K are provided with passages (145), (145'), respectively, which (actuator chambers (2), (39)
The hydraulic pressure is guided to the spherical joint part (142
), (142') and (143), (143') to prevent seizure and wear of the joint.

Also, Munrotsu F'443. (43') is a halved bass.

(4r) and retaining rings (133), (133')K, actuator piston (4υ, (41') and joint part (142).

(142') is connected to a certain angle swing town a.

That is, the half-split (451, (45')) is a cylindrical ring whose inner diameter is smaller than the bulbs at both ends of the connecting rod eQ3. The actuator piston (4υ, (41')) is a good one, cut in half and divided into two pieces.
The outer diameter of (45') is constrained and becomes the original cylindrical shape before division, and its inner diameter becomes smaller than the spherical diameter, so the connecting rod is old.

(43 is the actuator piston θυ, (41')
This will prevent you from trying to pull it out.

The arm (5a) of the swash plate (5) has four claws (
2). In other words, the nail (goods) is a clip (
127) It has Ke resiliency and the joint part (143), (14) of the old connecting rod (43').
The spherical part of the nail (3') (has healed and opened outwards, and the claw (4')
A clip (127
) is fixed to the top and bottom of the arm (5a) shown in FIG.
43') is connected to the swash plate (51).

Therefore, for the swash plate (5), the connecting rod "1:l, (
If you try to pull off the nail with more than a certain amount of force, your nails -
Because it has elasticity, it will not be destroyed or permanently deformed, and the swash plate (51 to stove)'@3. (+a') can be separated. That is, remove the cap (3g') and make a screw hole (146) in the actuator piston (41').

(146') By screwing in the VC bolt and pulling out this bolt, connect rods (43, (43'), actuator piston @υ, (41 pieces, 4 half-split sweeteners,
(45'), retaining rings (133), and (133') can be taken out from the swash plate (5) in the assembled state as a connecting rod assembly.

On the contrary, the joint part (143) of the connecting rod assembly
), (143') spherical part clip (127) claw -
Push the claw (2) open by aligning it with the opening of the K.
The spherical part of the joint part of the connecting rod (43, (43')) is attached to the concave spherical part of the arm (5a) K of the swash plate (5) and connected to the swash plate.

Thereby, the swash plate (5) and the connecting rod assembly move without being separated, and the swash plate (5) and the connecting rod assembly can be disassembled and assembled while remaining in the assembled state.

On the other hand, the front bearing (1
34) For K, the swash plate actuator section (goods) and the actuator chamber (2) of the swash plate actuator section (3)
A control unit (6) that controls the inclination angle α of the swash plate (51) by controlling the pressure of the front bearing (134)
) are placed opposite 11 so as to sandwich them. No. 4B4 is a cross-sectional view cut along a plane perpendicular to the axis including the front bearing (134), along with a cross section of the swash plate actuator part (goods).
On the other hand, the control unit located on the opposite side 1111 is shown.

Furthermore, to explain the control section, especially in Figure 4, (2) is a servo spool, 6υ is a sleeve, and the sleeve 611 is linked to the swash plate (51) by a foot 9 link. (see figure), constitutes a so-called servo that feeds back the movement of the swash plate (5) to the sleeve 6υ.

The supply pressure of the servo is guided to the passage and communicates with the chamber. Now, if the servo spool Q4 is moved to the left by a predetermined amount from the balanced state, the chamber - is moved in the path σ.
Connects to 0. Therefore, the supply pressure led to the chamber from the passage Iη is led to the passage σQ, and the passage σ1 is the passage ff3.
, 6J to communicate with the actuator chamber (2).

On the other hand, chamber 1 and the passage are blocked, and the passage communicates with the chamber συ, and since the chamber συ communicates with the pump case and is connected to the tank, the passage communicates with the tank. Also,
The actuator chamber (
39').

Therefore, as the servo spool C24) moves to the left, servo supply pressure is guided to the actuator chamber @.
The actuator chamber (39') is communicated with the tank, and the force that moves the swash plate actuator to the left in FIG. 4 increases, rotating the swash plate (5) in a direction that reduces the tilt angle α. can.

Figure 6 shows the phytoback link (c), swash plate (51,
This shows the relationship with the sleeve 6υ, and when the swash plate (5) rotates in the direction where the inclination angle α becomes smaller, the feedback link (rotation) is caused by the rotation of the pin group fixed to the swash plate (51). Rotate downward in Figure 6 with the center at .

Feet 9) 2 links (461 ni has a protrusion, and the crease protrusion is perpendicular to the axis of the sleeve 6υ 11c)
(9 slits provided) [Since the sleeve is recessed, the feed mech link and the sleeve 6υ are interlocked.

When the foot chimney link rotates downward, the protrusion also moves downward, that is, in Figure 4, the protrusion moves to the left and the sleeve 6υ also moves to the left.

Then, when the sleeve 6υ moves to the left by an amount equivalent to the amount of movement of the servo spool (2), the actuator chamber 01° (
39') is balanced and returned to the original equilibrium state, and the swash plate (5) is held.

Conversely, if the servo spool is moved to the right by a predetermined amount from the balanced state, the chamber and the passage communicate with each other and with the actuator chamber (39').

Therefore, the servo supply pressure is guided to the actuator chamber (39'), while the chamber branch and the passage σ1 are blocked and the passage σ
I communicates with room 4. Since the chamber - communicates with the pump case and is connected to the tank, the passage ff1) communicates with the tank, and the passage σO communicates with the actuator chamber, so the actuator chamber (to) communicates with the tank. Therefore, the swash plate actuator moves to the right in FIG. 4, and the swash plate (5) rotates in a direction that increases the inclination angle α. That is,
Swash plate (5) in the opposite direction to the above,
The trowel and the sleeve 61) move, and at the position where the sleeve 61) has moved by a predetermined amount of movement from su to sp to ka, a balanced state is reached, and the swash plate (5) is held at position 7.゛As mentioned above, servo spool c! 41 is associated with the inclination angle α of the swash plate, and by controlling the position of the servo spool Q4, the inclination of the swash plate can be controlled.

Next, a specific example of the control unit that controls the swash plate actuator unit described above will be further described.

In devices powered by a diesel engine, a system that performs constant horse power control is often adopted, and the commonly used method is to control the force generated by two springs and a pump discharge force led to a pressure sensor dubin. Balance (therefore the 8th
There is a method to control the characteristics like the A-B-C-D-IC shown in Fig.

In Figure 4, - is the pressure sensing pin, CI is the pressure chamber where the pump discharge force is guided from six types of passages, 6 is the plunger, (to) is the cap, 6υ is the maximum flow rate adjustment screw, (121) is The lock nut (-) is the spring holder, the member (E) is the minimum sediment amount adjustment hole, (129) is the lock nut, (E) is the 17th ζ hole, and the (X) is the 2nd hole.

When the pump discharge pressure is small, the preset value of the first menu (E) is stronger than the force that tries to move the servo spool Q4 to the left by pushing the pressure sensing pin sister due to the pressure on the pressure chamber surface. Due to its large size, servo spool & 4)
is located to the right until the plunger 6 is stopped by the maximum flow rate adjustment screw Iυ. This position is the maximum fit point and corresponds to the point between input and 8 in FIG.

When the ejection force increases and reaches pB, the force acting on the pressure sensing pin 53 becomes exactly equal to the first spring preset load. When the discharge force exceeds pB, the force acting on the pressure sensing pin is proportional to the discharge pressure, so the first spring (E) moves the deflection servo spool (2) to the left according to its spring constant.

As a result, by the above-mentioned operation, the inclination angle α of the swash plate is changed to change the linear Kfi amount ζ between B-0.

The second spring is in a free state until the servo spool @ and the menet receiver (b) move a certain amount to the left, and a certain t
Only when it moves does it begin to compress and generate force. The discharge pressure is P
When reaching c, the second spring is set to start compression, so it acts as the sum of the two springs, so the composite spring constant acts as the sum of the spring constants of both springs. Then, it changes as shown between G and D in Fig. 8, and PxQ, t=
It is possible to approach a constant horsepower curve.

Furthermore, when the discharge pressure rises and reaches PDAK, the servo spool (2) comes into contact with the lowest flow adjustment screw and cannot move to the left even if the discharge pressure rises above PD. It cannot move to the left; it becomes like D- in FIG. 8 and can approach the curve.

For applications with different horsepower, the curves are different, so either replace the first spring (E) and the second spring with two springs with different spring constants or set loads, or adjust the preset load. This can be dealt with by doing the following. In this way, the horse's power can be controlled to a certain degree.

On the other hand, in addition to constant power control using the pump discharge pressure, there are cases where it is necessary to control the pump flow rate using a control pressure that is completely different from the discharge force. It shows.

In Figure 9, (2) is the spring, the ring is the retainer, - is the piston, the ring is the spring receiver, C37) is the adapter, (3
6a) is the cap, σ field is the signal pressure joint port, (6
1a) is a maximum flow adjustment screw, 1a is a shim, and 1a is a signal pressure chamber, and the other components are the same as the above-mentioned constant force control.

Therefore, when the pump discharge pressure is lower than pB, the servo spool 4 receives force to the right by the first spring e#, the plunger pushes the retainer I7J and the piston to the right, and the piston adjusts the maximum flow rate. It is secured by screw (61a) Ic. At this time, the flow rate is maximum QA/.

The control pressure for controlling the flow rate by external pressure, the signal pressure Pal, is led to the signal pressure chamber from the signal pressure joint port (c). The signal pressure P81 acts on the piston to generate a force in the direction of moving the servo spool to the left via the piston, the retainer I4, and the plunger.

On the other hand, the servo spool receives a load from the first spring (and the second spring) via the spring receiver 64f, and pushes the piston to the right via the plunger 63 and the retainer. Further, the spring also pushes the piston to the right via the retainer.

When the signal pressure P81 is smaller than PSI, these spring forces are greater than the force generated by the signal pressure, so the flow rate is QA' between A' and B' at the maximum.

When Pal reaches Pa1B', piston I due to PSl
The force generated by IK is exactly equal to the sum of the loads of the 1st spring (E) and the No. z spring. *When PSl becomes larger than p81B', the 1st and t springs (E) and the spring (To) are deflected by the servo spool. Q moves to the left, so the inclination angle α of the swash plate (5) decreases, and the flow rate decreases as shown in B'-G'.

When sPa1 further increases and reaches Pslc', the second spring starts to act, so when it rises above PSIC',
Three springs, the first spring, the second spring, and the spring act, and the 0'-
It changes like F'. Then, when pBl rises to Pstp', the retainer reaches the end of the adapter r37), and even if vCPBl rises, the retainer cannot move to the left, resulting in F'-G'. At this time, Qr can be set by adjusting the weight of the shim.

In addition, if the spring does not have this, it will be necessary to change the f7A1 nomination, the second spring constant, the rounding that determines the preset load, and the characteristics shown in Figure 10 in accordance with the constant horsepower control custom order. However, it is not easy to change the cross-sectional area or diameter of the piston each time. However, by providing a spring and changing the springiness, the flow rate characteristics can be easily changed. In addition, the spring (
(e), the spring characteristics of the 17th ζ (e) and the second spring appear as flow characteristics, so the first
If the nominal constant of the second (e) screw is larger than that of the spring (G), there will be an inconvenience that the area between B"-C" and G"-F" will be bent significantly as shown in FIG. However, installing the spring is the first step)
If the spring constant is sufficiently larger than No. 2 (E) and 27th ζ (E), it is possible to obtain a characteristic close to a straight line as between B'-C' and C/-F' in Fig. 10. There are advantages.

Further, FIG. 12 shows another embodiment in which the pump flow rate is controlled by a control pressure completely different from the discharge pressure, and FIG. 15 shows the seven percentage points.

In Fig. 12, (52b) is a plunger, υ is a spring, ■ is a cap, (61b) is a maximum flow rate adjustment screw,
The ring is a signal pressure chamber, the rut is a joint boat for signal pressure,
Other details are the same as in Figure 4.

The plunger (52b) receives a force to the left by the spring @i)K, and a force to the right by the pressure of the signal pressure chamber. Moreover, the first spring (E) and the J12 spring are;
-, servo spool c! 41 to the right, the plunger (52b) receives force to the right.

When the signal pressure pst is greater than P81B'', the force acting on the plunger (52b) K is large due to the signal pressure, so the spring υ゛ is bent and the sylanger (52b) is stopped and positioned by the maximum flow rate adjustment screw (61b)K. There is.

At this time, the pump flow rate is maximum. When the signal pressure Ps1 decreases to PslB'', the signal pressure changes to the syranger (
The sum of the force pushing the plunger (52b) to the right and the force of the first spring (e) pushing the plunger (52b) to the right is balanced by the force of the spring υ pushing the silanger (52b) to the left. , and further P
81# decreases, the rightward pushing force becomes smaller and the plunger (52b) and servo spool move to the left. Therefore, the pump flow rate decreases and changes between B'# - G''. When pst reaches ps t c///, the second spring starts to act, so the percentage changes and C'' - E
It changes between itH. Furthermore, when P9m decreases,
Since the spring retainer is stopped at the adjustment position of the lowest flow rate adjustment screw, the vcR amount is constant like F///G/#.

As in the previous embodiment, the front body (11, servo spool c!4, and sleeve 6υ are all common, and the control section is made up of small parts that can be easily removed from both ends of the front body (1). , allowing various types of control to be done easily.

On the other hand, the control unit and the swash plate actuator are disposed on opposite sides of the front body (11), sandwiching the front earring (134).

The passage of the control part a and υC and the swash plate actuator part (
(b) It is necessary to communicate the actuator chamber (39') and (to). However, if you try to arrange both parts as close to the axis center as possible to create a connosect, a large front bearing will be required between the two parts! (134), and since it is close to this, it is difficult to provide a passage only inside the front body (1) using a straight hole such as a drilled hole to communicate the inside. Therefore, the front bearing (
134) was removed from the outside station.

The oil seal case (4) is equipped with passage care a, n and koji, and the front bearing (
134) is detoured to facilitate communication between the control section and the swash plate actuator section.

As shown in Fig. 7, a bottom with an orifice is installed in the passage between the passage shaft and the actuator chamber (to), and the fluid discharged from the actuator chamber is /-
! The speed of the swash plate actuator is limited, and conversely, the passage f
When supplied from fl to the actuator chamber (to),
A slow-return poppet ■ is installed that lifts the poppet ■ and allows it to operate without resistance and without limiting the speed of the flow swash plate actuator. this is,
This is effective when it is necessary to slow down the rotational speed in a specific rotational direction of the swash plate and cause the flow rate to change gradually.

Furthermore, by attaching screws (102) K and screw plugs with fixed throttle holes, the rotational speed of the swash plate in both rotational directions can be slowed down. In this way, by using a combination of a slow return point and a screw plug with a fixed throttle hole in the middle of the passage connecting the control section and the swash plate actuator section, the swash plate rotation speed can be adjusted in any direction depending on the application. can be set.

As described above, according to the present invention, the swash plate actuator class that controls the inclination angle of the swash plate in the pump motor and its control section are separately mounted on the outer periphery of the front bearing that supports the small rotating shaft around the body. Ninth, the entire pump/motor has been made significantly smaller, lighter, and more compact, and since both are placed so as to sandwich the front bearing, the overall shape is well-balanced, and operation is improved. The oil passages can be placed in a connoct manner within the front body, resulting in superior reliability.Furthermore, the front body serves as the body for the swash plate actuator and control unit, eliminating the need for a dedicated body. It is something that you have.

The present invention has been described above with reference to actual examples, but of course the present invention is not limited to such practical examples, and various modifications of the design may be made without departing from the spirit of the present invention. It is something that can be used.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view showing an outline of a conventional swash plate m variable displacement axial pump/motor, Fig. 2 is a cross-sectional view showing an embodiment of the present invention, and Fig. 6 is a cross-sectional view of the swash plate M variable displacement axial pump/motor. Figure 4 is a sectional view IV-IV in Figure 2, Figure 5 is a sectional view along ■-■ in Figure 2, Figure 6 is a sectional view Vl-Vl in Figure 2, and Figure 7 is a sectional view along 8 is a characteristic diagram of a constant horse power control device, FIG. 9 is a sectional view showing another control device of the present invention,
0 is a characteristic diagram of the device shown in FIG. 9, FIG. 11 is a reference characteristic diagram for nine cases in which the control device in FIG. 9 is changed, and FIG. Figure 15 is the 12th
FIG. 3 is a characteristic diagram of the device shown in the figure. 1: Front body 5: Swash plate 7: Rotating shaft 24: Servo spool 59.3
9': Actuator chamber 41.41' near actuator unit biston 45.45';
Connecting rod 46: Feedback link 51 Nisleaf' 154: Front bearing α: Inclination angle L: Control section M: Swash plate actuator section sub-agent Patent attorney Shige Okamoto 2 foreign names 3 drawings 4 drawings ＼ JLI gu 7 drawings Figure 6 Figure 9 Funeral Figure 12

Claims (1)

[Claims] The actuator piston moves in response to the servo supply pressure in the actuator chamber, and controls the tilt angle of the swash plate.The swash plate actuator section links to the swash plate and moves, and the servo spool inside the sleeve moves to control the swash plate actuator. A swash plate type variable displacement axial piston pump/motor having a control section for controlling the servo supply pressure to an actuator chamber of the section, wherein the swash plate actuator section and the control section support a rotating shaft of the pump/motor. The swash plate actuator part and the control (
1. A slant-shaped variable displacement axial piston pump/motor, characterized in that the axial center of the first part is substantially perpendicular to the axial center of the rotating shaft, and the front part is arranged so as to sandwich the alignment.