CN100357605C - Cycloidal pin gear hydraulic pump - Google Patents

Abstract

The invention provides a needle-toothed cycloid gear hydraulic pump. The pump body is equipped with a transmission shaft, a pump core and a valve. The pump core is driven to rotate by the transmission shaft. The cycloidal gear mechanism is composed of inner rotor, needle teeth and hypocycloid wheel; the inner rotor is set eccentrically with respect to the hypocycloid wheel, meshes with the needle teeth, and the needle teeth meshes with the hypocycloid wheel; the inner rotor, hypocycloid wheel Each adjacent two needle teeth form a pump cavity; the needle teeth are eccentric needle teeth, the position of the rotating shaft is fixed, and the rotating axis is distributed on a cylindrical surface with the rotation axis of the hypocycloid wheel as the axis. The advantages of the hydraulic pump are: there are multiple pumping chambers, the flow does not fluctuate; the liquid pressure impact is small, the noise is small; the pumping chamber has no liquid transport process, and the energy loss is small; When worn out, only the needle teeth need to be replaced, which is convenient for maintenance; easy to process; large liquid discharge volume can reduce the volume of the pump; the requirements for the liquid to be transported are not high.

Description

A needle-tooth cycloidal gear hydraulic pump

Technical field:

The invention relates to a hydraulic pump.

Background technique:

At present, commonly used hydraulic oil pumps include gear pumps, vane pumps, plunger pumps, and cycloid rotor pumps. Each of these pumps has its own disadvantages.

Gear pumps have problems such as "trapped oil", unbalanced radial hydraulic pressure, and large flow pulsation. "Trapped oil" causes a large additional load on the gears and bearings, the bearing life is short, and the oil pump efficiency is low. In addition, "trapped oil" will also increase the oil temperature, which will easily generate air bubbles, and the bursting of air bubbles will cause loud noises. The radial hydraulic pressure is unbalanced, causing the gear shaft to be bent, the radial clearance of the gear in the liquid suction chamber becomes smaller, and the gear and the inner cavity of the pump body are rubbed or stuck, so that the oil pump cannot work normally. After the hydraulic oil is sucked into the oil chamber, it is transported to the pressure oil chamber and then squeezed out as the gear rotates nearly 180°, and the gear tooth body occupies a certain space, so the flow fluctuation and pressure fluctuation are large, causing shock, Vibration and noise are large.

The structure of the vane pump is complex, difficult to manufacture, sensitive to the rotational speed of the shaft, too fast and too slow can not work normally, high oil requirements, easy to jam the blades after oil contamination, resulting in rapid wear. At high speed, the pressure difference between the two ends of the blade will easily cause the blade to separate from the surface of the stator, resulting in the blade being hollow. Under high pressure, the surface of the blade and stator is easy to wear. Compared with gear pumps, it is noisy.

The plunger pump has a complex structure, many parts, difficult manufacturing, high price, and is mostly used as a high-pressure pump. Similar to the vane pump, this pump has high oil requirements, and the plunger is easy to get stuck after the oil is dirty. Due to the reciprocating motion of the plunger, it is not suitable for high speed.

Cycloidal rotor pump, its structure is shown in Figure 6, it is mainly composed of transmission shaft (1), inner rotor (2), outer rotor (14), front end cover, rear end cover and pump body (6), the inner rotor (2) The tooth profile is a short epicycloid, and the tooth profile of the outer rotor (14) is an arc. Its working principle is to form several independent enclosed spaces during the meshing process by means of a pair of eccentrically meshed inner and outer rotors (2, 14). With the meshing rotation of the inner and outer rotors (2, 14), the volume of each closed space changes, and liquid is sucked and discharged; due to the small number of teeth of the inner and outer rotors (2, 14), the working pressure fluctuates greatly under high pressure and low speed conditions. It is mostly used in the occasions of medium and low pressure, and the precision of the rotor is high, and the outer rotor (14) is a ring gear with circular arc teeth, which is difficult to manufacture.

Invention content:

The invention provides a hydraulic pump with large conveying capacity, small flow fluctuation, small pressure fluctuation, high working stability, small volume, less wear on inner and outer rotor tooth surfaces, high mechanical efficiency and long service life.

The invention provides a needle-toothed cycloid gear hydraulic pump. A transmission shaft (1), a pump core and a valve are installed in a pump body (6). The pump core is driven to rotate by the transmission shaft (1). It is connected to the delivery pipeline through a valve, and it is characterized in that:

The pump core is a pin-tooth cycloid gear mechanism, which is composed of an inner rotor (2), pin teeth (3), and a hypocycloid wheel (4); the inner rotor (2) is eccentrically set relative to the hypocycloid wheel (4), and The needle teeth (3) mesh, the needle teeth (3) mesh with the hypocycloid wheel (4), the inner rotor (2), the hypocycloid wheel (4) and every two adjacent needle teeth (3) constitute a Draw cavity (11);

Wherein the needle teeth (3) are eccentric needle teeth (3), the position of the rotating shaft is fixed, and the rotating axis is distributed on the cylindrical surface with the rotation axis of the hypocycloid wheel (4) as the axis;

The pump core has multiple pumping chambers (11), and the number of pumping chambers (11) is equal to the number of pin teeth (3); when the drive shaft (1) drives the pump core, the hypocycloid wheel (4) and the pin teeth ( 3) Both rotate on a fixed axis, the inner rotor (2) rotates and revolves, and the pin teeth (3) are constantly changing between the roots and tops of the opposite teeth of the hypocycloid (4) and the epicycloid, The volume of the pump cavity (11) changes accordingly. During the working process, the line connecting the inner rotor (2) and the hypocycloid wheel (4) divides these pumping chambers (11) into two parts, and the volume of the pumping chamber (11) passing through the connecting line is either the largest or the smallest. , being in the state of trapped oil, the volume of a part (on the side connecting the center line) of the other pumping chambers (11) increases, while the volume of the other part decreases. With the rotation of the connecting line, the increase or decrease of the volume of each pump chamber (11) is always carried out alternately, so that there is liquid suction and liquid discharge at every moment, which ensures the continuity of liquid suction and liquid discharge. Moreover, the liquid absorption and discharge volume at each moment are basically the same, and the flow rate has no fluctuation. For each pumping cavity (11), liquid suction and liquid discharge are constantly switched according to certain rules. Therefore, there must be corresponding valves to control the suction and discharge of each pump chamber (11). Assuming that there are Zb needle teeth (3), the inner rotor (2) rotates once on its own and revolution Zb-1, the change of Zb pump chambers (11) is suction and discharge Zb×(Zb-1) times, the number of discharges High, large liquid discharge.

The drive shaft (1) of the pin-toothed cycloid gear hydraulic pump provided by the invention can drive the inner rotor (2) or the hypocycloid wheel (4) to rotate, and when the drive shaft (1) drives the inner rotor (2), the drive shaft ( 1) When the force is small, when the transmission shaft (1) drives the hypocycloid wheel (4), the pin-toothed cycloid gear hydraulic pump delivers a relatively large amount of fluid.

The inner rotor (2) of the pin-toothed cycloid gear hydraulic pump provided by the present invention can be an epicycloid wheel, which not only increases the sealing performance of the pump chamber (11), but also increases the variation of the volume of the pump chamber (11), which is More than 2 times that of the cycloidal rotor pump.

The inner rotor (2) of the cycloidal gear hydraulic pump provided by the present invention can also be a circular wheel, which is more convenient to manufacture.

The valve of the needle-toothed cycloidal gear hydraulic pump provided by the present invention can be a distribution valve (9) to replace the liquid inlet valve and the liquid outlet valve of each pumping chamber (11) to switch, when the pumping chamber (11) is in the capacity During the increasing stage, the pumping chamber (11) communicates with the liquid inlet pipe, and when the pumping chamber (11) is in the volume reduction stage, the pumping chamber (11) communicates with the liquid outlet pipe, so that the structure is simple.

The flow distribution valve (9) of the needle-toothed cycloidal gear hydraulic pump provided by the present invention can be a flow distribution shaft. The two semi-annular grooves are on the same ring and do not communicate with each other, but respectively connect the pumping cavity (11) of the pump core with one of the two annular grooves, and the flow distribution shaft and the drive shaft (1) are coaxial. The rotation of the distribution shaft is synchronized with the revolution of the inner rotor (2).

The flow distribution valve (9) of the pin-tooth cycloidal gear hydraulic pump provided by the present invention can also be a flow distribution plate, and there are two semi-circular holes with different radii on the flow distribution plate, respectively connecting the suction cavity (11) of the pump core and the liquid inlet The pipe is connected with one of the liquid outlet pipes, the distribution plate is coaxial with the drive shaft (1), and the rotation of the distribution plate is synchronized with the revolution of the inner rotor (2).

The advantages of the cycloidal gear hydraulic pump provided by the present invention are:

There are multiple pump chambers (11), one part is a liquid suction chamber, and the other part is a liquid discharge chamber. The liquid suction and discharge are carried out at the same time. The process of the chamber (11) changing from suction to discharge (or discharge to suction) is continuous and gradual, and each time a pump chamber (11) is transferred from suction to discharge, at the same time, it will There is another pumping cavity (11) which is transferred from liquid discharge to liquid suction, and the whole process is carried out continuously and alternately, so the flow rate has no fluctuation;

Since the flow does not fluctuate, the influence of flow fluctuation on the stability of oil pressure is eliminated, which is beneficial to reduce the impact of oil pressure and reduce noise;

Each pump chamber (11) is both a liquid suction chamber and a liquid pressure chamber. After the liquid is sucked in, it is squeezed out on the spot, and there is no transportation process, which reduces energy loss;

The needle teeth (3) also rotate, making the contact surfaces between it and the inner and outer rotors (14) close to pure rolling, with little friction and wear, little loss of mechanical efficiency, and long service life;

When the tooth surface of the pump core is worn, there is no need to replace the inner rotor (2) and the hypocycloid wheel (4), only the needle teeth (3) need to be replaced, which is convenient for use and maintenance;

The ring gear of the short hypocycloidal wheel (4) is easier to process than the ring gear of the arc-toothed outer rotor (14) of the cycloidal rotor pump;

The discharge volume is large. When the inner rotor (2) is an outer cycloidal wheel, the inner and outer cycloidal wheels mesh with the pin teeth (3) at the same time. During the rotation, the volume change of the pump chamber (11) Large, so the displacement per revolution is more than 2 times that of the cycloid rotor pump with only the hypocycloid wheel (4) meshing with the needle wheel;

Due to the increased displacement, the volume of the pump can be reduced;

The requirements for the liquid being transported are not high.

Description of drawings:

Fig. 1 is a structural schematic diagram of a pin-toothed cycloidal gear hydraulic pump with a distribution shaft;

Fig. 2 is a schematic diagram of the pump core structure of the needle cycloid gear hydraulic pump;

Fig. 3 is a structural schematic diagram of a needle-toothed cycloidal gear hydraulic pump with a flow plate;

Fig. 4 is a structural schematic diagram of another needle-toothed cycloidal gear hydraulic pump with a distribution shaft;

Fig. 5 is a structural schematic diagram of another needle-toothed cycloidal gear hydraulic pump with a flow plate;

Figure 6 is a schematic diagram of the working principle of the cycloid rotor pump.

Detailed ways:

Example 1:

A needle-toothed cycloid gear hydraulic pump, the structure of which is shown in Figure 1. The hydraulic pump is mainly composed of a transmission shaft (1), an inner rotor (2), a needle tooth (3), a hypocycloid wheel (4), a front end cover (5), a pump body (6), a rear end cover (7), Liquid inlet (8), liquid outlet (10), flow distribution shaft (9) and other components. The transmission shaft (1) is an eccentric shaft, which drives the inner rotor (2) to rotate; the inner rotor (2) is a short epicycloid wheel or a circular wheel; the pin teeth (3) are eccentric pin teeth (3), and rotate eccentrically, The position of the rotation axis is fixed, and the rotation axis of the needle teeth (3) is distributed on a cylindrical surface with the rotation axis of the hypocycloid wheel (4) as the axis; the hypocycloid wheel (4) is a short hypocycloid ring gear, and the inner rotor (2) Set eccentrically with respect to the hypocycloid wheel (4); the inner rotor (2), the needle teeth (3), and the hypocycloid wheel (4) form a plurality of independent closed pump chambers (11) (as shown in Figure 2 shown), these closed pumping chambers (11) are both suction chambers and pressure chambers; there are Wear plate (12). When working, the transmission shaft (1) rotates to drive the inner rotor (2) for planetary motion, the needle teeth (3) and the hypocycloid wheel (4) both rotate on a fixed axis, and the transmission shaft (1) and the hypocycloid wheel ( 4) The axis of rotation coincides. With the rotation of the inner rotor (2), the hypocycloid wheel (4) and the pin teeth (3), the volume of each closed pumping cavity (11) changes, and liquid suction and liquid discharge are performed. On the one hand, the distribution shaft (9) connects each independent pump cavity (11) with the liquid inlet (8) and the liquid outlet (10), and on the other hand controls the flow rate of each pump cavity (11) into and out of liquid. switch.

Example 2:

A needle cycloid gear hydraulic pump, the structure of which is shown in Figure 3. The hydraulic pump is mainly composed of transmission shaft (1), inner rotor (2), needle teeth (3), hypocycloid wheel (4), front end cover, pump body (6), rear end cover (7), liquid inlet (8), liquid outlet (10), distribution plate (9) and other components. The transmission shaft (1) is an eccentric shaft, which drives the inner rotor (2) to rotate; the inner rotor (2) is a circular wheel or a short epicycloidal wheel; the pin teeth (3) are eccentric pin teeth (3), and rotate eccentrically, The position of the rotation axis is fixed, and the rotation axis of the needle teeth (3) is distributed on a cylindrical surface with the rotation axis of the hypocycloid wheel (4) as the axis; the hypocycloid wheel (4) is a short hypocycloid ring gear, and the inner rotor (2) Set eccentrically with respect to the hypocycloid wheel (4); the inner rotor (2), the needle teeth (3), and the hypocycloid wheel (4) form a plurality of independent closed pump chambers (11) (as shown in Figure 2 Shown), these closed drawing chambers (11) are both suction chambers and hydraulic pressure chambers. When working, the transmission shaft (1) rotates to drive the inner rotor (2) for planetary motion, the needle teeth (3) and the hypocycloid wheel (4) both rotate on a fixed axis, and the transmission shaft (1) and the hypocycloid wheel ( 4) The axis of rotation coincides. With the rotation of the inner rotor (2), the hypocycloid wheel (4) and the pin teeth (3), the volume of each closed pumping cavity (11) changes, and liquid suction and liquid discharge are performed. On the one hand, the distribution plate (9) connects each independent pumping cavity (11) with the liquid inlet (8) and the liquid outlet (10), and on the other hand controls the flow rate of each pumping cavity (11) into and out of liquid. switch.

Example 3:

A needle-toothed cycloid gear hydraulic pump, the structure of which is shown in Figure 4. The hydraulic pump is mainly composed of transmission shaft (1), inner rotor (2), needle teeth (3), hypocycloid wheel (4), front end cover, pump body (6), rear end cover (7), liquid inlet (8), liquid outlet (10), flow distribution shaft (9) and other components. The transmission shaft (1) is fixedly connected with the hypocycloid wheel (4); the inner rotor (2) is a short epicycloid wheel or a disc; the pin teeth (3) are eccentric pin teeth (3), and rotate eccentrically, The axial position is fixed, and the rotation axis of the needle teeth (3) is distributed on the cylindrical surface with the rotation axis of the hypocycloid wheel (4) as the axis; the hypocycloid wheel (4) is a short hypocycloid ring gear, and the inner rotor ( 2) It is arranged eccentrically with respect to the hypocycloid wheel (4); the inner rotor (2), the needle teeth (3), and the hypocycloid wheel (4) form a plurality of independent closed pump chambers (11) (as shown in Figure 2 ), these closed drawing chambers (11) are both suction chambers and hydraulic pressure chambers. When working, the transmission shaft (1) rotates, driving the hypocycloid wheel (4) to rotate, the pin tooth (3) rotates as a fixed axis, the inner rotor (2) performs planetary motion, and drives the flow distribution shaft (9) to rotate through the eccentric shaft . With the rotation of the hypocycloidal wheel (4), the inner rotor (2) and the pin teeth (3), the volume of each closed pumping chamber (11) changes to perform liquid suction and liquid discharge. On the one hand, the distribution shaft (9) connects each independent pump cavity (11) with the liquid inlet (8) and the liquid outlet (10), and on the other hand controls the flow rate of each pump cavity (11) into and out of liquid. switch.

Example 4:

A needle-toothed cycloid gear hydraulic pump, the structure of which is shown in Figure 5. The hydraulic pump is mainly composed of transmission shaft (1), inner rotor (2), needle teeth (3), hypocycloid wheel (4), front end cover, pump body (6), rear end cover (7), liquid inlet (8), oil outlet (10), distribution plate (9) and other components. The transmission shaft (1) is fixedly connected with the hypocycloid wheel (4); the inner rotor (2) is a disk or a short epicycloid wheel; the pin teeth (3) are eccentric pin teeth (3), and rotate eccentrically, The axial position is fixed, and the rotation axis of the needle teeth (3) is distributed on the cylindrical surface with the rotation axis of the hypocycloid wheel (4) as the axis; the hypocycloid wheel (4) is a short hypocycloid ring gear, and the inner rotor ( 2) It is arranged eccentrically with respect to the hypocycloid wheel (4); the inner rotor (2), the needle teeth (3), and the hypocycloid wheel (4) form a plurality of independent closed pump chambers (11) (as shown in Figure 2 ), these closed pump chambers (11) are not only liquid suction chambers but also pressure liquid chambers; both sides of the distribution plate (9) are provided with wear-resistant plates (12). When working, the transmission shaft (1) rotates, driving the hypocycloid wheel (4) to rotate, the pin tooth (3) rotates as a fixed axis, the inner rotor (2) performs planetary motion, and drives the distribution plate (9) to rotate through the eccentric shaft . With the rotation of the hypocycloidal wheel (4), the inner rotor (2) and the pin teeth (3), the volume of each closed pumping chamber (11) changes to perform liquid suction and liquid discharge. On the one hand, the distribution plate connects each independent pumping cavity (11) with the liquid inlet (8) and the liquid outlet (10), and on the other hand controls the switching of each pumping cavity (11) into and out of liquid.

Claims (10)

1. A needle-toothed cycloid gear hydraulic pump. The pump body (6) is equipped with a transmission shaft (1), a pump core and a valve. The pump core is driven by the transmission shaft (1) to rotate, and the pump core (11) passes through the The valve is connected to the conveying pipeline, which is characterized by: The pump core is a pin-tooth cycloid gear mechanism, which is composed of an inner rotor (2), pin teeth (3), and a hypocycloid wheel (4); the inner rotor (2) is eccentrically set relative to the hypocycloid wheel (4), and The needle teeth (3) mesh, the needle teeth (3) mesh with the hypocycloid wheel (4), the inner rotor (2), the hypocycloid wheel (4) and every two adjacent needle teeth (3) constitute a Draw cavity (11); Wherein the needle teeth (3) are eccentric needle teeth (3), the position of the rotating shaft is fixed, and the axis of the rotating shaft is distributed on the cylindrical surface with the rotation axis of the hypocycloid wheel (4) as the axis. 2. The pin-toothed cycloid gear hydraulic pump according to claim 1, characterized in that: the transmission shaft (1) drives the inner rotor (2) or the hypocycloid wheel (4) to rotate. 3. The pin cycloid gear hydraulic pump according to claim 1 or 2, characterized in that the inner rotor (2) is an epicycloid wheel. 4. The cycloidal gear hydraulic pump according to claim 3, characterized in that: said valve is a distribution valve (9). 5. The needle-toothed cycloidal gear hydraulic pump according to claim 4, characterized in that: the distribution valve (9) is a distribution shaft, and there are two annular grooves and two semi-annular grooves on the distribution shaft, two The ring grooves communicate with the liquid inlet pipe and the liquid outlet pipe respectively. The two half ring grooves are on the same ring and do not communicate with each other, but respectively connect the pumping chamber (11) of the pump core with one of the two ring grooves. The shaft is coaxial with the transmission shaft (1), and the rotation of the flow distribution shaft is synchronized with the revolution of the inner rotor (2). 6. The needle-toothed cycloidal gear hydraulic pump according to claim 4, characterized in that: the distribution valve (9) is a distribution plate, and there are two semi-circular holes with different radii on the distribution plate, respectively connecting the pump The pump cavity (11) of the core is connected with one of the liquid inlet pipe and the liquid outlet pipe, the distribution plate is coaxial with the transmission shaft (1), and the rotation of the distribution plate is synchronous with the revolution of the inner rotor (2). 7. The cycloidal gear hydraulic pump according to claim 1 or 2, characterized in that the inner rotor (2) is a circular wheel. 8. The cycloidal gear hydraulic pump according to claim 7, characterized in that: said valve is a distribution valve (9). 9. The needle-toothed cycloidal gear hydraulic pump according to claim 8, characterized in that: the distribution valve (9) is a distribution shaft, and there are two annular grooves and two semi-annular grooves on the distribution shaft, two The ring grooves communicate with the liquid inlet pipe and the liquid outlet pipe respectively. The two half ring grooves are on the same ring and do not communicate with each other, but respectively connect the pumping chamber (11) of the pump core with one of the two ring grooves. The shaft is coaxial with the transmission shaft (1), and the rotation of the flow distribution shaft is synchronized with the revolution of the inner rotor (2). 10. The needle-tooth cycloidal gear hydraulic pump according to claim 8, characterized in that: the valve distribution is a distribution plate, and there are two semi-circular holes with different radii on the distribution plate, respectively connecting the pump core The cavity (11) communicates with one of the liquid inlet pipe and the liquid outlet pipe, the distribution plate is coaxial with the transmission shaft (1), and the rotation of the distribution plate is synchronized with the revolution of the inner rotor (2).

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