JPS6228713Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an interlocking mechanism for synchronously controlling the discharge amount of both pumps in a dual oblique shaft type pump.

In general, a diagonal shaft type piston pump increases or decreases the discharge amount by tilting the cylinder block and port block (diagonal shaft) with respect to the drive shaft, so the structure of the drive part is larger than that of a diagonal plate type piston pump. Controlling the rotation angle of the port block using a servo cylinder also required a complicated mechanism, especially for dual pumps.

The present invention was proposed to solve this problem, and embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG.
Each block constitutes a right side housing 2, a center housing 3, and a left side housing 4, respectively.

These housings 2, 3, and 4 are connected to a center input shaft 5 to which the driving rotational force from the prime mover is transmitted.
, and are integrally connected to each other with bolts 6A and 6B using the central housing 3 as a sandwich bridge.

Inside the housing 1, there are two pump parts 7.
A, 7B are arranged, and these pump parts 7A, 7B
gears 8 and 9A with respect to the center input shaft 5,
It is rotated by drive shafts 10A and 10B that are interlocked via shaft 9B.

The center input shaft 5 passes through the right side housing 2, is rotatably supported by bearings 11 and 12, and has a gear 8 integrally formed therein.

Drive shafts 10A and 10B are arranged symmetrically below the center input shaft 5, and each of these drive shafts 10A and 10B has a tapered roller bearing 14 mounted on a boss portion 13 of the central housing 3.
A, 14B and 15A, 15B.

The pump sections 7A and 7B have completely the same structure, and for convenience of explanation, the structure of one pump section 7A will be mainly described below.

The pump section 7A includes a plurality of pistons 16A connected to a drive shaft 10A, a cylinder block 17A on which these pistons 16A slide, and a cylinder block 1.
7A, a valve plate 18A that rotates and slides, etc.

A head portion 20A with an enlarged diameter is provided on the end surface of the drive shaft 10A.
is formed, and the ball 21A of the piston 16A is ball-jointed with respect to the head portion 20A, so that the piston 1 is aligned with the axis of the drive shaft 10A.
The axes of 6A can freely intersect.

Each piston 16A is arranged at equal intervals on the same radius (circumference) centering on the axis of the drive shaft 10A, and a push rod 22A for pressing the cylinder block 17A against the valve plate 18A is arranged at the center thereof.

The cylinder block 17A has a cylinder 23A corresponding to the piston 16A.
A piston 16A is slidably housed in 3A.

A port 24A communicating with the valve plate 18 is formed at the bottom of each cylinder 23A, and hydraulic oil sucked into the cylinder 23A during the suction stroke when the piston 16A withdraws is discharged while being pressurized during the discharge stroke when the piston 16A is pushed in.

The valve plate 18A is formed into a disc shape with a gentle conical surface 25A having the axis of the cylinder block 17A at its apex, and is rotatable around an axis having a predetermined inclination angle with respect to the drive shaft 10A. It is supported by port block 26A.

As shown in FIG. 2, the semi-circular long groove formed in the valve plate 18A connects the suction port 27A and the discharge port 2.
8A, and the suction port 27A connects to the internal space 30A of the housing 1 filled with low pressure oil on the tank side.
The discharge port 28A communicates with the port block 2.
6A is connected to a high pressure passage 31A that penetrates in the axial direction.

Note that the suction port 27A is formed over almost the entire range (0° to 180°) in which the piston 16A of the cylinder block 17A moves in the direction in which it comes out, and the discharge port 28A, on the contrary, is formed in the range in which the piston 16A of the cylinder block 17A moves in the direction in which it moves out. range (180° to 360°)
becomes.

The port block 26A has a shaft portion formed in multiple stages, and is supported by the left side housing 4 via roller bearings 33A and 34A, respectively, and a mechanical seal 35A is provided on the end face thereof.
The thrust force acting on the port block 26A is
The bearing 33 receives the thrust reaction force generated by applying sealed high-pressure oil to the end face.
The thrust force acting on A and 34A is significantly reduced.

By the way, the extension line of the rotation center of the port block 26A is set to intersect the axial center line of the drive shaft 10A at the center of the ball joint of the push rod 22A.
6A causes the valve plate 18A and the cylinder block 17A to undergo a turning movement (movement along the conical slope) about this block inclination line, and as a result, the axis of the cylinder block 17A becomes the axis of the drive shaft 10A. As this angle of inclination increases, the piston stroke becomes larger and the pump discharge amount increases.

In order to control the rotation angle of the port block 26A, a servo mechanism 36 is provided. Automatically control the rotation angle.

The servo mechanism 36 is located inside the central housing 3 and is located on the lower surface of the cylinder blocks 17A and 17B, and in the present invention, a connecting lever 37 and link pins 38A, 38B shown in FIG.
to the port blocks 26A and 26B via
It is connected at a position eccentric from its axis.

Link pins 38A and 38B are protruded from the shaft end faces 39 of the port blocks 26A and 26B at positions parallel to the rotation axis of the blocks 26A and 26B and eccentric from the shaft center. The arm portions 40A and 40B of the connecting lever 37 are rotatably connected to the connecting lever 37.

Therefore, the connecting lever 37 itself is in a state where it can move in a plane parallel to the shaft end surfaces of the port blocks 26A, 26B.

A pin boss 41 is integrally protruded from the base end of the connecting lever 37, and this pin boss 41 is connected to the drive shaft 10.
It has an axis parallel to A and is connected at right angles to the mounting surface of the servo mechanism 36 (in other words, the axis of the servo piston).

Therefore, when the pin boss 41 is inserted into the servo piston connecting hole 42 of the servo mechanism 36, the movement of the servo mechanism 36 in the direction perpendicular to the plane of the paper in FIG. 26B can be rotated uniformly around its axis.

Next, the overall operation will be explained.

Due to the rotation of the center input shaft 5 (constant rotation), the drive shafts 10A, 10B rotate together, and both pump parts 7A, 7
B is driven. Since both pumps perform similar actions, only the pump section 7A will be described below.

As the drive shaft 10A rotates, the piston 16A
At the same time, the cylinder block 17A rotates, and due to the inclination of the axes of the cylinder block 17A and the drive shaft 10A, the piston 16A is periodically pulled out or pushed in from the cylinder 23A in synchronization with this rotation. At this time, the phases of each piston are sequentially shifted.

In the suction stroke when the piston 16A comes out, the suction port 27 formed in the port 24A and the valve plate 18A
A is in communication with the cylinder 23A, and the low pressure oil on the tank side filling the internal space 30A of the housing 1 is sucked into the cylinder 23A by the movement of the piston 16A.

In the discharge stroke in which the piston 16A is pushed,
The port 24A and a discharge port 28A formed in the valve plate 18A communicate with each other, and the low-pressure hydraulic oil sucked in by the movement of the piston 16A is pressurized and discharged to the high-pressure passage 31A.

As a result of the combined motion of each piston out of phase, low pressure oil is continuously drawn into the pump, and this low pressure hydraulic oil is pressurized and continuously discharged from the high pressure passage 31A.

At this time, as mentioned above, cylinder block 1
By varying the rotation angle of the port block 26A that regulates the inclination between the axis of the pump 7A and the axis of the drive shaft 10A, the piston stroke can be increased and the pump discharge amount can be increased.

In this embodiment, the rotation angle of the port block 26A is automatically adjusted by the servo mechanism 36 while sensing the pump discharge pressure so that the maximum value of the product of the pump discharge pressure and the discharge amount is constant, that is, the horsepower is constant. control the feedback.

That is, when the piston of the servo mechanism 36 is displaced in accordance with the combined pressure of both pump discharge pressures P ₁ and P ₂ and, for example, the combined pressure increases, the piston is displaced via the connecting lever 37 connected to the piston, the arm parts 40A, 40B, etc. Then, both port blocks 26A, 26B rotate in a direction to return the rotation angle to the zero side, thereby reducing the pump discharge flow rate.

When the combined pressure decreases, both port blocks 26A and 26B conversely rotate in the direction of increasing the rotation angle, and the pump discharge flow rate increases.

As a result of such operation, the maximum value of the product of pump discharge pressure and discharge amount is always kept constant.

In this way, according to the present invention, the two piston pumps are connected to the servo mechanism 36 by the connecting lever 3.
7 and the arm portions 40A and 40B, it is possible to increase and decrease the discharge amount of both pumps accurately and in the same manner.

Furthermore, since the pin boss 41 is provided to protrude from the connecting lever 37 parallel to the end faces of the port blocks 26A, 26B so as to be parallel to the drive shaft 10A, the ease of mounting the servo mechanism 36 to the housing 3 is not impaired. , the port block 2 makes the movement smooth.
6A, 26B.

Note that when the servo mechanism 36 operates, the pin boss 41
Since the screw moves forward and backward relative to the connecting hole 42 in the axial direction, a margin for the absolute amount thereof is set in advance for the insertion depth into the connecting hole 42.

[Brief explanation of the drawing]

FIG. 1 is an overall cross-sectional view showing an embodiment of the present invention, FIG. 2 is a vertical cross-sectional view, and FIG. 3 is a front view of a connecting portion. 1... Pump housing, 2... Right side housing, 3... Center housing, 4... Left side housing, 5... Center input shaft, 7A, 7B...
Pump part, 10A, 10B... Drive shaft, 16A...
...Piston, 17A...Cylinder block, 18
A...Valve plate, 23A...Cylinder, 26A, 26
B... Port block, 36... Servo mechanism, 3
7... Connection lever, 38A, 38... Link pin, 40A, 40B... Arm portion, 41... Pin boss, 42... Connection hole.

Claims (1)

[Scope of utility model registration request] a piston pump unit universally connected to the drive shaft;
A dual diagonal shaft type pump in which two sets of pumps are housed in parallel in a housing, each consisting of a port block whose rotating shaft intersects with the drive shaft at a predetermined angle of inclination, Connecting lever 2 is placed eccentrically from the shaft center on the shaft end surface of both port blocks.
While the two arm parts are connected with pins, a pin boss is provided to protrude from the base end of the connecting lever so as to be parallel to the drive shaft, and this pin boss is inserted into the connecting hole of the servo mechanism housed in the space under the rotation of the piston pump part. An interlocking mechanism for a dual diagonal shaft pump characterized by being inserted freely in the axial direction.