JPS5817893B2 - Ball piston displacement axis axis displacement mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic drive device using a ball piston, and its greatest feature is that it is an axial type.

A radial type hydraulic drive device using a ball piston has been known for some time.

In this radial type drive device, it is difficult to provide a large number of ball pistons to achieve multiple strokes, so the device itself has to be large in proportion to the flow rate, and it is difficult to balance the forces in the radial direction. This had the disadvantage of causing uneven wear on bearings, etc.

The object of the present invention is to provide a hydraulic drive device that eliminates the above-mentioned conventional drawbacks.

This will be explained below with reference to the illustrated embodiment, but first, its operation will be outlined based on the circuit diagram shown in FIG.

Pressure oil discharged from the axial variable discharge ball pump P flows into the axial constant displacement ball motor M via either the main passage A or the port and drives it.

Of the main passage A and the opening, for example, if passage A is the discharge side, it will be the return side of the passage, and either one will be the high pressure passage,
The other becomes a low pressure passage.

Relief passages C and 2 are connected to the main passages A and 2, and high pressure relief valves HR1 and HR2 whose discharge ports are in opposite directions are connected to both passages C and 2, respectively.

Therefore, when the pressure on the passage A side exceeds the set value, the high pressure IJ' IJ-F valve HR1 opens and the high pressure oil is guided to the main passage, and similarly, the high pressure oil on the main passage opening side is passed through the high pressure relief valve HR2. It leads to the main passageway A.

On the other hand, the low pressure oil discharged from the boost pump BP is
The pressure is maintained within the set pressure by the action of the JIJ-F valve LR and flows into the boost passage E.

Of these two passages, one passage E is connected to the high pressure IJ IJ-
It joins the relief passage C leading to the discharge port side of the valve HR1, and similarly, the other passage IJ joins the relief passage C leading to the outlet side of the valve HR1.

The above-mentioned boost passages E and E are check valves C1 and C that only allow passage of low pressure oil from the boost pump BP.
2 are connected.

However, when the main passage A side is under high pressure,
The high pressure oil flows into the motor M, flows back into the passage 2, and reaches the outlet side of the check valve C2.

When high pressure oil acts as back pressure on the outlet side of check valve C2,
Even if low pressure oil from the boost pump BP acts on the check valve C2, it will not open.

Therefore, in this case, the low-pressure oil from the boost pump BP opens the check valve C1 and flows into the main passage port on the low-pressure side via the IJ-F passage C.

Note that when the pressure in the main passage A on the high pressure side exceeds the set value, the pressure oil is at high pressure 1. , l It is clear that the IJ-F valve HR1 is opened and the water flows into the main passageway opening on the low pressure side.

Also, when the main passage port side is under high pressure, contrary to the above case, the low pressure oil of the boost pump BP is
2 is opened, and the IJ' flows into the main passage A on the low pressure side via the IJ-F passage 2.

In summary, the low-pressure oil discharged from the boost pump BP always flows into the pump P via the low-pressure side main hole I or mouth, and the boost pressure is maintained at the low pressure IJ.
The IJ-f valve LR controls the discharge pressure from the pump P, and the discharge pressure from the pump P is controlled by the high pressure relief valve HR.

Alternatively, it is controlled by HR2.

Next, a specific configuration in which the respective elements shown in FIG. 10 are integrated will be described.

The hydraulic drive device in this embodiment includes a boost pump case 1, a spacer 2, a pump case 3, a branch block 4, and a motor case 5, which are successively connected to each other to form a case main body X.
is formed.

The inner ends of the pump shaft 6 and motor shaft T protruding from both sides of the case body
, these blanks 8 are attached to each of the motor cylinder blocks 9 (see Figs. 1 and 5) installed inside the motor case 5.
.

Both lever blocks 8 and 9 are provided with a recessed portion that opens at the center thereof and on opposing surfaces thereof, and the bottle portion 10 of the branch path blank 4 is inserted into the recessed portion.

The pump cylinder block 8, which rotates integrally with the pump shaft 6 as described above, has shafts arranged at regular intervals on a perfect circle, as is clear from FIG. , 1 are formed, and a pair of ball pistons 12, 13 having a diameter that is snugly inserted into each of the cylindrical holes 11 is movably housed in each of the cylindrical holes 11.

A pair of disc-shaped cam plates 14 and 15 are arranged on both sides of the cylindrical hole 11.

The cam plates 14, 15 form a wave-shaped cam curve in the circumferential direction on their opposite side surfaces.

As is clear from FIG. 11, which is a developed view of this cam curve, the rotation angle of the cam plate 14°15 is 180°.
It forms a sine wave curve with a period of one cycle within the range of degrees.

Projections are provided on the cam plates 14 and 15 having such cam curves, and ranks 16.1.gamma. are formed on opposing surfaces of these projections.

And between these ranks 16 and 11, both ranks 1
A pinion 18 that meshes with both of the pins 6 and 1γ is interposed, and the operating rod 19 of this pinion 18 is made to protrude outward from the case body X.

Therefore, when the operating rod 19 is rotated, the cam plate 14 .
The cam plates 14 and 15 rotate in opposite directions, in other words rotate relative to each other, and the phases of the cam curves of both cam plates 14 and 15 are adjusted.

Regarding the phases of the cam curves of both cam plates 14.15, when the peaks of the cam curve of one cam plate and the valleys of the cam curve of the other cam plate are opposed to each other, both dam plates 14.
The cam curves No. 15 are defined to be in phase.

As is clear from FIG. 4, around the bottle part 10 of the branch block 4 facing the four parts of the pump cylinder block 8, there are four holes facing each other on the diameter line. Concave grooves 20, 20' are formed, and each of these concave grooves 20, 20' communicates with four oil passage holes 21, 21' formed in the pintle portion 10.

Of these oil passage holes 21 and 21', oil passage holes that are diametrically opposed to each other communicate with each other via communication holes 22 and 22'.

Further, as is clear from FIG. 59, which is a cross-sectional view taken along line b-b in FIG. Ball pistons 24 and 25 are housed inside so that they can be moved freely, and cam plates 26 and 27 having cam curves similar to those described above are arranged on the sides thereof.

However, the cam plates 26 and 27 on this motor side are
8.29 is fixed to the branch road block 4 and the motor case 5, and the two cam plates do not rotate relative to each other like on the pump side, and the phase of the cam curves of both is set in advance as shown in Fig. 14. It is shifted.

Around the bottle part 10 of the branch road block 4, which faces the concave part of the motor cylinder block 9,
Similarly to the pump side, grooves 30 and 30'□ are formed, and these grooves 30 and 30' are connected to the oil passage hole 21, respectively.
, 21', and also in this portion, the oil passage holes 21 communicate with each other via a communication hole 31.

However, the cam curves of both cam plates 14 and 15 on the pump side are set to have opposite phases as shown in FIG.
As shown in Figure 3, the troughs of the cam curves of both cam plates are set to face each other at the 0 degree rotational angle position of the cam plate, and the cam curves of both cam plates 26 and 27 on the motor side are set as shown in Figure 14. The phases are shifted as shown in , and the distance between the opposing cam curves is set to be the minimum at the 0 degree rotation angle position of the cam plate.

In this state, when the pump cylinder block 8 is rotated clockwise in FIG. 4 by the pump shaft 6.

The ball piston 12.13 has a rotation angle of 0 degrees and 180 degrees.
Both maximum at degree position? □ Separate, ゛Also rotation angle 9
The two move back and forth so that they are closest to each other at the 0 degree and 270 degree positions.

When the ball pistons 12.13 are maximally separated, the hydraulic oil from the oil passage holes 21.21 is sucked in through the recessed grooves 20.20 and the holes 32 formed in each cylindrical hole 11, and when the two are closest to each other. When the hydraulic oil passes through the oil holes 21', 21
'Discharge to.

The high pressure oil discharged into the oil passage holes 21' and 21' flows through the concave groove 30'.
, 30' and the openings 33 provided in each cylindrical hole 23, and are press-fitted into the cylindrical hole 23 concerned.

The cam plate 26' is in this position. Since the cam curve No. 27 is in a direction in which the opposing interval gradually increases as the rotation angle approaches 90 degrees or 270 degrees, the cylindrical hole □2
The ball pistons 24, 25 within the ball pistons 24, 25 move in the direction of the arrow in FIG. 14 while being separated according to their cam curves.

In other words, the motor cylinder block 9 is rotated in the same direction as the pump cylinder block 8, and the motor shaft 7 that is integral therewith is rotated.

During this rotation process, when passing through rotation angles of 0 degrees and 180 degrees, the ball pistons 24 and 25 come closest to each other, and the hydraulic oil that has been press-fitted into the cylindrical hole 23 passes through the oil passage holes 21.
21 and returns it to the pump side.

As is clear from this, the axial type constant displacement ball motor M is constituted by the cylinder block 9, the ball pistons 24, 25, and the cam plates 26, 27.

Also, the operation land 19 is rotated in a predetermined direction, and the cam plate 14 is
．． 15 within a relative rotation angle of 90 degrees as shown by the arrow in Figure 11, i
By gradually moving the cam in this direction, the maximum separation becomes smaller, and eventually both cam curves become in phase.

When both cam curves are in phase, the ball piston 12.13
simply reciprocate in the same direction, and the amount of hydraulic oil discharged and sucked becomes zero.

As is clear from this, the discharge amount can be adjusted by rotating the cam plates 14 and 15 relative to each other as described above.
2.13 and the cam plate 14.15 constitute the axial variable discharge ball pump P.

In other words, if the cam plates 14 and 15 of the pump P are moved from a state where their cam curves are in the same phase in the direction of the arrow in FIG. 14 within a relative rotation angle of 90 degrees, contrary to the above, the operation When the rod 19 is rotated in the opposite direction, the cam plate 14. The cam curve of j5 has a minimum spacing between the two at the rotation angle of 0 degrees and 180 degrees,
Maximum at 90° and 270° positions (12th
(see figure).

This ultimately means that the motor M and the motor shaft 7 are rotated in the opposite direction to the rotation direction of the pump shaft 6 and the pump P.

That is, by rotating the operating rod 19, the discharge amount of the pump P can be adjusted, and the rotation of the motor M can be switched to either normal rotation or reverse rotation.

As is clear from FIG. 2, which is shown as a C-c cross section in FIG. The boost pove BP consisting of a rotating driven gear 35 is installed inside.

The pump wall 36 is brought into close contact with approximately half the circumference of the drive gear 34, and a partition wall 37 is provided on the outside of the pump wall 36 to form the passage grooves 3B and 39. 44 is formed.

Furthermore, point holes 45 to 50 are formed in the through grooves 3B and 39 and at both ends of the partition wall 31.
0 can be inserted with a required pin to close the passage, but the conditions for selecting the point holes 45 to 50 into which the pins are inserted will be described later. The explanation will be based on the assumption that it is inserted.

The spacer 2 that is in close contact with the boost pump case 1 has circular holes 51 to 55 at positions corresponding to the circular holes 40 to 44, as is clear from FIG. At the same time, a connection port 56 is formed at a position corresponding to the passage groove 38 between the point holes 47 and 48 of the boost pump case 1.

As is clear from FIG. 1, one end of the boost pump suction hole 57 provided in the pump case 3 communicates with the passage groove 38 via the connection port 56.

Therefore, when the pump shaft 6 rotates counterclockwise in FIG. 2, the hydraulic oil sucked from the suction hole 57 flows into the passage groove 38 through the connection port 56.

The hydraulic oil that has flowed into the passage groove 38 flows in the direction of the arrow in FIG. 2 and is discharged into the passage groove 39 because the pin is inserted into the point hole 47. Ru.

As is clear from the above, point holes 45-5
0, which position the pin should be inserted into depends on whether the pump shaft 6 is rotated in the forward direction or in the reverse direction.

That is, when rotating the pump shaft 6 counterclockwise in Figure 2, as described above, it is clear that when rotating it clockwise in Figure 2, the point holes 46 and 48 must be closed. It is.

Note that the point holes 45 and 50 are used when the hydraulic fluid is to be cooled.

That is, in this case, the four parts 5 provided at the ends of the passage groove 39
B, 59 and the holes 60 and 61 provided in the spacer 2 are made to correspond to each other, and the holes 60 and 61 are communicated with each other via a required cooling mechanism (not shown), and the pump shaft is 6 in the counterclockwise direction in FIG. It passes through the cooling mechanism and is discharged into the passage groove 39 from the hole 61 on the opposite side.

It is clear that when rotating the pump shaft 6 clockwise in FIG. 2, it is sufficient to insert pins into the point holes 46, 48 and 50 to close off the corresponding portions.

As is clear from FIG. 1, the low pressure IJ valve LR is housed inside the circular hole 42 and the circular hole 53.

This low pressure IJ IJ-F valve LR is connected to the boost pump BP.
When the discharge pressure of the boost pump, that is, the pressure inside the passage groove 39, exceeds the set value, the valve opens and the hydraulic oil is transferred to the boost pump suction hole 5.
7 side to maintain this boost pressure within the set value.

A to pump case 3, Fig. 4 and branch block 4
As is clear from Figure 7, which shows the side surface of the circular hole 5.
1. Passage hole 62 ~ whose center is the same as 52, 54, 55
65 are provided parallel to the axis.

Among these passage holes, the passage holes 62 and 65 are the interlocking holes 66 and 67 provided in the branch passage blank 4, and the oil passage hole 21'.
, 21' and a communication hole 22'.

Further, the passage holes 63 and 64 communicate with each other via the communication holes 68, 69 and the oil passage hole 21.

Furthermore, the passage holes 62 and 63 communicate with each other via a communication passage 10 formed in the pump case 3, and the passage holes 64 and 65 communicate with each other via a communication passage 71 (see FIG. 4).

The passage holes 63 and 65 are provided with check valves ρ1 as shown in FIG. C2 is installed inside.

These check valves C1 and C2 are connected from the passage groove 39 to the passage hole 63.
The relationship is such that the hydraulic oil is allowed to pass only through 65.

Furthermore, the passage holes 62 and 64 are equipped with high-pressure IJ valves HR and HR2, as shown in FIG.

The high pressure IJ valves HR1 and HR2 open when the pressure in the passage holes 63, 65 exceeds a set value to allow the high pressure oil to flow into the communication passage 70.71.

If the cam plates 14 and 15 on the pump side are set in the relationship shown in FIG. 11 and the pump shaft 6 is rotated, the oil passage hole 2L
21 has return oil, and the oil passage hole 21. As mentioned above, the discharge oil passes through the oil passage holes 21.
21 denotes the main passage opening in FIG. 10, and the oil passage hole 2.
1' and 21' constitute the main passage A.

The high pressure oil in the oil passage holes 21', 21' flows into the communication hole '67 and the passage hole 65, and acts as a back pressure on the check valve C2.

Therefore, the low pressure oil maintained at the set pressure by the low pressure IJ valve LR opens the check valve C1 corresponding to the circular hole 4i and flows into the passage hole 63.

The low-pressure oil that has flowed into the passage hole 63 enters the oil passage holes 21, 21 via the communication hole 68, and further flows into the oil passage holes 21, 21.
The oil flows into the cylindrical hole 1'1' communicating with the ball piston 1' to replenish the hydraulic oil.

13 against the cam plate 14.15.

As is clear from this, the passage hole 65 and the communication hole 6T form a connection to the boost passage shown in FIG. 10, and the passage holes 63 and 68 constitute a boost passage E.

On the other hand, when the pressure inside the oil passage holes 21', 21' reaches or exceeds the set pressure, the hydraulic oil passes through the communication hole 66 and the passage hole 62 and passes through the high pressure I
J IJ-F acts on HR1 to open it and open communication path 7.
0 to the passage hole 63, and reaches the oil passage holes 21, 21 in the same manner as described above.
It constitutes a passageway to the front.

The oil discharged to the oil passage hole 2L21 is the oil passage hole 21'.

When the oil returns to 21' and passes through, the oil passage hole 21°21
The high-pressure oil flows into the communication hole 68 and the passage hole 63 and acts as back pressure on the check valve C1, so that the boost pump BP
The low-pressure oil from there opens the check valve C2 and reaches the oil passage holes 21', 21' via the passage hole 65 and the communication hole 67.

Also, when the high pressure oil in the oil hole 21°21 exceeds the set pressure,
The high-pressure oil passes through the communication hole 69 and the passage hole 64, acts on the high-pressure IJ and IJ-F valve HR2 to open it, flows into the passage hole 65 via the communication passage 71, and flows into the passage hole 21 through the communication passage 71. /
.

21', and the communication hole 69, the passage hole 64, and the communication passage 71 constitute the relief passage 2 shown in FIG.

As is clear from the above description, according to the first drive device of the present invention, since it is an axial type, a large number of ball pistons can be provided to achieve multiple strokes, and the device itself can be made smaller in relation to the flow rate. , □ There is no unbalanced load on the shaft, and the operation is smooth.

In addition, the low pressure oil discharged from the boo/<) pump always flows into the main passage on the return side, improving the followability of the ball piston to the cam plate, and the low pressure oil is controlled by the low pressure relief valve. The pump power, etc., and the discharge pressures are controlled by high pressure IJ valves.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal cross-sectional view, and FIGS. 2 to 5 are cross-sectional views along the line CC, DD, and A-A. Fig. 7 is a rear view of the branch block, Fig. 6 is a developed cross-sectional view taken on e'-''-e line of Fig. 7, and Figs. 8 and 9 are a part of the case body. 10 is a circuit diagram, FIG. 1L12 is a developed view of the cam curve of the pump side force plate, and FIG. 13 is an explanatory diagram showing the relationship between the cam plate and the bottle, Figure 14 is a developed view of the cam curve of the cam plate on the motor side. P is the pump, 8 is the pump block, 12°1
3 is a ball piston, 14.15 is a cam plate, 6 is a pump shaft, M is a motor, 9 is a cylinder block for the motor, 24
, 2sc-i ball piston, 26° 27 is cam plate, T
is the motor shaft, A, mouth is the main passage, C, 2 is the IJ IJ-F passage, HRl, HR2 is the high pressure IJ IJ-F valve, BP is the boost pump, LR is the low pressure relief valve, E, is the boost passage, C1 and C2 are check valves.

Claims (1)

[Claims] 1. A pump block that rotates integrally with the pump shaft is equipped with a pair of ball pistons that can freely move parallel to the axis, and on both sides of the ball pistons,
A pump consisting of a pair of cam plates with wave-shaped cam curves formed in the circumferential direction on opposing sides, and a motor cylinder block that rotates integrally with the motor shaft, and a pair of cam plates that are movable parallel to the axis of the motor cylinder block. The motor is equipped with a ball pitton and a pair of cam plates similar to the pump is connected to the motor, and the pump and motor are connected to each other, and the oil discharged from the pump is supplied to the motor. There are two types of main passages that lead return oil to the pump, and two types of relief passages connected between these main passages, with discharge ports in opposite directions. A pump, a low-pressure relief valve that maintains the discharge pressure from the boost pump at a set value, and a low-pressure relief valve that also supplies the discharge oil from the boost pump to the IJ-F passage and its high-pressure IJ.
Two types of boost passages guided to the discharge port side of the IJ-F valve are provided, and a check valve is provided in each of these boost passages and only allows passage of low-pressure oil discharged from the boost pump. An axial hydraulic drive device using a ball piston that is characterized by: