KR20060125011A - Inclined board structure for oil hydraulic pump - Google Patents

Abstract

A structure of an inclined board of a hydraulic pump is provided to modify the shape of the inclined board to a conical shape for applying thrust to a surface of the inclined board approximately perpendicularly, thereby improving operation efficiency of the hydraulic pump and reinforcing supporting strength and durability of the inclined board. In a structure of an inclined board of a hydraulic pump, the inclined board(4') is formed in the conical shape, so that a bottom surface of the inclined board is perpendicular to a direction, in which thrust of a piston(8) of a cylinder block(9) is applied. Therefore, surface contact is realized between the inclined board and the piston as well as a shoe(6), resolving problems caused by inclination of the piston and the shoe.

Description

Inclined Board Structure for Oil Hydraulic Pump

1 is a cross-sectional view showing the structure of a conventional hydraulic pump.

Figure 2 is a view showing a cross section of the hydraulic pump according to the present invention.

3 is a conceptual view comparing the inclination plate structure according to the present invention with a conventional inclination plate.

Figure 4 is a view showing the operating state of the hydraulic pump having an inclined plate according to the present invention.

5 is a view showing a cylinder block structure of a hydraulic pump in which the inclined angle is given to the cylinder block so that the hydraulic access hole of the cylinder block of the hydraulic pump and the hydraulic access hole of the valve plate are aligned.

♣ Description of the main parts of the drawing ♣

1: drive shaft 2: oil seal

3: roller bearing 4, 4 ': sloped plate

5: shoe retainer 6: shoe

7: drain bolt 8: piston

9: cylinder block 10: valve plate

11: needle bearing 12: rear housing

13: middle housing 14: coil spring

15: cup spring 16: spherical ring

17: bolt 18: front housing

25: Spline

The present invention relates to an inclined plate structure of a hydraulic pump, and more particularly, to improve the conventional flat inclined plate into a conical shape so that the thrust generated during discharge acts perpendicular to the inclined surface of the inclined plate to prevent problems that may occur with thrust and thrust It relates to an inclined plate structure of a hydraulic pump with enhanced bearing capacity by.

In general, a hydraulic pump (hydraulic pump) is a device for converting the mechanical energy supplied from the outside to the pressure energy of the working oil of the hydraulic system.

Since hydraulic pumps require high pressure, a positive displacement type is mainly used. The hydraulic pump is a gear type that presses by using a gap between two rotating gear teeth, a vane type that pushes and compresses hydraulic fluid by using a vane installed on a rotating shaft, and a rotating shaft Rotary piston type compresses by making the volume in several cylinders installed vertically or parallel to the cylinder smaller in accordance with the rotational direction of the cylinder, and the reciprocating piston which presses the working oil in the cylinder immediately by converting the rotational motion into a reciprocating motion. Or reciprocating piston type.

In addition, the hydraulic pump can be divided into a fixed delivery type (fixed delivery type) with a constant pushing volume, and a variable delivery type that can change the volume during operation.

On the other hand, such a common hydraulic pump has a cavitation in the hydraulic access hole formed in the cylinder block and the hydraulic access hole formed in the cylinder block is the hydraulic force generated when the piston inserted in the cylinder block reciprocates by the rotational movement of the drive shaft (空洞 現象; In order to solve this problem, the present applicant has developed a hydraulic pump that prevents the cavitation from occurring in each hydraulic access hole, and has applied for a patent application No. 10-2004-0099069. .

1 is a cross-sectional view showing the structure of Patent Application No. 10-2004-0099069, which is a hydraulic pump that prevents the cavitation developed and filed by the present applicant.

The hydraulic pump of FIG. 1 gives an inclined angle to the cylinder block coupled to the drive shaft and the spline which rotates so that the diameter of the piston inlet cylinder block reciprocating is larger than the diameter of the cylinder outlet cylinder block. The hydraulic access holes of the ball and the valve plate are formed in a straight line so that the cavitation does not occur in each hydraulic access hole.

However, in the hydraulic pump shown in FIG. 1, as the cylinder block is inclined, the piston and the shoe are inclined outward of the axis, and therefore, the thrust F applied to the piston at the time of discharge of the pump is inclined outward from the rotational axis. Due to this, there is a problem that the operating efficiency of the hydraulic pump is lowered and the bearing capacity and durability may be weakened.

The present invention has been made in order to solve the above problems, by forming the inclined plate in the conical shape so as to be perpendicular to the thrust during the discharge of the hydraulic pump so that the thrust F generated during the discharge acts substantially perpendicular to the surface of the conical inclined plate. The purpose is to increase the operating efficiency of the hydraulic pump and to enhance durability.

In addition, the present invention is designed so that the thickness of the swash plate in the direction in which the thrust is applied in the hydraulic pump is the largest to strengthen the support strength of the inclined plate against the thrust and to reduce the horizontal length of the inclined plate, thereby improving the durability of the hydraulic pump It aims to achieve material and cost savings.

In order to achieve the above object, the inclined plate structure of the hydraulic pump according to the present invention, in the inclined plate structure of the hydraulic pump, so that the lower surface of the inclined plate is perpendicular to the direction in which the thrust of the piston reciprocating in the cylinder block acts. It is characterized in that formed in a conical shape.

In addition, the inclined plate structure of the hydraulic pump according to the present invention has an inclination angle such that the diameter of the piston inlet cylinder block reciprocating the piston in the cylinder block coupled to the drive shaft and the spline for rotational movement is larger than the diameter of the cylinder outlet side cylinder block. The inclined plate is fixed to the front housing of the hydraulic pump and the drive shaft connected to the piston connected to the piston so that the hydraulic access hole of the cylinder block and the hydraulic access hole of the valve plate are formed in a straight line so that no cavitation occurs in each hydraulic access hole. In the structure, the lower surface of the inclined plate is characterized in that it is formed in a conical shape to be perpendicular to the direction in which the thrust of the piston reciprocating in the cylinder block acting.

Hereinafter, the inclined plate structure of the hydraulic pump according to the present invention with reference to the accompanying drawings will be described in detail.

1 is a view showing a cross-sectional view of the hydraulic pump to prevent the cavitation from occurring in the hydraulic opening of the patent application No. 10-2004-0099069 of the present applicant, Figure 2 is a cross-sectional view of the hydraulic pump according to the present invention further improved The figure shown.

3 is a conceptual view comparing the structure of the conventional flat inclined plate and the inclined plate according to the present invention, and FIG. 4 is a view for explaining a state in which a conical inclined plate is assembled to a hydraulic pump and its operation according to the present invention.

In the present specification, the same reference numerals are used for the same components.

1 and 2, the drive shaft 1 of the hydraulic pump 100 according to the present invention is a rotational motion by receiving a rotational force from an engine or a motor, the drive shaft (1) connected to the hydraulic pump 100 The spline has a spline, and the cylinder block 9 is coupled to the spline, and the cylinder block 9 also rotates with the rotation of the drive shaft 1.

The drive shaft 1 is then rotated by the support of the needle bearing 11 in the rear housing 12 and the roller bearing 3 in the front housing 18.

In addition, in the front end of the front housing 18, the drive shaft 1 is kept airtight by the oil seal 2. The middle housing 13 is coupled between the front housing 18 and the rear housing 12, and the cylinder block 9 is axially coupled to the inside of the middle housing 13.

A plurality of (usually seven or nine) pistons 8 are provided inside the cylinder block 9, one end of the piston 8 is connected to the shoe 6, and the shoe 6 is a shoe retainer 5. ) Is combined. The shoe retainer 5 serves to fix the shoe 6 so as not to be separated from the inclined plate 4, and the shoe 6 has an inclined plate having a predetermined inclination angle fixed to the front housing 18 and the drive shaft 1. It is in surface contact with (4), and the shoe retainer 5 is rotated in surface contact with the inclined plate (4).

3 shows a schematic shape of a conventional swash plate and an improved swash plate according to the invention.

As shown in Figure 3 (a), the inclined plate 4 of the conventional hydraulic pump 100 has a flat surface. That is, the inclined plate 4 of the conventional hydraulic pump 100 has a form in which the cylinder is obliquely cut.

In the case of the conventional flat inclined plate 4, since the cylinder block 9 is inclined, the piston 8 and the shoe 6 are inclined in the outward direction of the shaft. Therefore, the thrust F applied to the piston 8 at the time of discharge of the pump is applied to be inclined outwardly from the rotational axis, which causes the operating efficiency of the hydraulic pump 100 to be lowered and the durability is weakened, which may cause a failure. This can happen.

On the other hand, the inclined plate 4 'of the hydraulic pump 100' according to the present invention as shown in Fig. 3 (b) is a conventional inclined plate 4 of the form in which the cylinder is obliquely cut back from its lower surface It has a conical cut shape. That is, in the hydraulic pump 100 'according to the present invention, the inclined plate 4' is formed in a conical shape so that the thrust F generated during discharge of the pump acts as perpendicular to the surface of the inclined plate 4 'as possible.

As shown in FIG. 4, the hydraulic pump 100 ′ according to the present invention rotates while being in surface contact with the inclined plate 4 ′ of the shoe retainer 5. At this time, the piston 8 and the shoe 6 are rotated in the inclined plate 4. The angle between the plane of ') is almost perpendicular. That is, when the inclined plate 4 'according to the present invention is applied, the angle at which the piston 8 and the shoe 6 deviate from the perpendicular to the plane of the inclined plate 4' is much smaller than that of the conventional flat inclined plate 4. will be.

Thus, by forming the surface of the inclined plate 4 'in which the shoe 6 is in surface contact in a conical shape, the piston 8 and the shoe 6 are brought into surface contact with the inclined plate 4' almost vertically. It completely solves the problems caused by the inclination of the piston and the shoe.

4, the inclined plate 4 'of the hydraulic pump 100' according to the present invention is formed so that the thickness of the portion to which the thrust F is applied becomes thicker than the other portion. The support strength of 4 'is further enhanced, and the length of the inclined plate 4' in the transverse direction can be reduced.

On the other hand, Figure 5 shows the cylinder block structure of the hydraulic pump in which the inclined angle to the cylinder block so that the hydraulic access hole of the cylinder block of the hydraulic pump and the hydraulic access hole of the valve plate is in a straight line so that no cavitation occurs.

At one end of the cylinder block 9 through which the piston 8 reciprocates, a hydraulic access hole 9a through which hydraulic fluid is sucked and discharged is formed, and the cylinder block 9 having the hydraulic access hole 9a is formed with a valve plate 10. ) Is in surface contact. The valve plate 10 is fixed to the rear housing 12.

Referring to the valve plate 10 coupled to the cylinder block 9 in surface contact, a plurality of hydraulic access holes 10a are formed, and the hydraulic access holes 10a of the valve plate 10 are illustrated in FIG. 5. And the hydraulic access holes 9a of the cylinder block 9 are located on the same rotation shaft. In other words, the cylinder block 9 is rotated to coincide with the hydraulic access hole 10a of the valve plate 10. The timing at which the hydraulic access holes 9a of the cylinder block 9 and the hydraulic access holes 10a of the valve plate 10 coincide may be controlled according to the rotational speed of the drive shaft 1.

In addition, the diameter (b) of the cylinder block (9) in the portion where the piston (8) is inserted into and coupled to the cylinder block (9) of the present invention is the diameter (b) of the cylinder block in the portion in surface contact with the valve plate (10). (A> b) to give an inclination angle, so that the hydraulic access holes 9a of the cylinder block 9 and the hydraulic access holes 10a of the valve plate 10 are formed in a straight line. By cavitation (cavitation) that can occur in the holes (9a, 10a) it can improve the hydraulic operating force and durability of the hydraulic pump (100).

The present invention improves the operating efficiency of the hydraulic pump and improves the operating efficiency of the hydraulic pump by improving the shape of the inclined plate into a conical shape so as to be perpendicular to the thrust during discharge of the hydraulic pump so that the thrust F generated during discharge acts almost perpendicular to the surface of the conical inclined plate. There is an effect that can strengthen the support strength and durability.

In addition, the present invention is designed so that the thickness of the swash plate in the direction in which the thrust of the hydraulic pump is applied is the largest to increase the support strength against the thrust to improve durability, and to reduce the cost by reducing the horizontal length of the inclined plate There is.

As described above, the present invention is a conical shape of the inclined plate to be perpendicular to the thrust at the time of discharge of the hydraulic pump, and is not limited to the above-described embodiment, it is easy for those skilled in the art within the scope and spirit of the present invention. May be changed or substituted.

Claims (2)

In the inclined plate structure of the hydraulic pump, The inclined plate structure of the hydraulic pump, characterized in that the lower surface of the inclined plate is formed in a conical shape perpendicular to the direction in which the thrust of the piston reciprocating in the cylinder block acting. The cylinder block coupled to the drive shaft and the spline which rotates, and the inlet angle of the piston inlet cylinder block in which the piston reciprocates is larger than the diameter of the cylinder block on the piston outlet side, give the hydraulic inlet and the hydraulic plate in the valve plate. In the inclined plate structure in which the ball is formed in a straight line and fixed to the front housing and the drive shaft of the hydraulic pump to prevent the cavitation from occurring in each hydraulic entrance hole, the surface contact with the shoe connected to the piston, The inclined plate structure of the hydraulic pump, characterized in that the lower surface of the inclined plate is formed in a conical shape perpendicular to the direction in which the thrust of the piston reciprocating in the cylinder block acting.

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