CN216477705U - Plunger pump - Google Patents

Abstract

A plunger pump comprising: a pump housing; a main rotating shaft installed in the pump housing; and a plunger assembly mounted in the pump housing and driven by the main rotating shaft; the plunger pump further comprises: an input shaft at least a body portion of which is disposed in the pump housing; and a speed increasing mechanism disposed between the input shaft and the main rotating shaft in the pump housing, configured to transmit a rotational speed increase of the input shaft to the main rotating shaft. The plunger pump is suitable for various low-speed driving sources such as a diesel engine and the like, and can save installation space and cost.

Description

Plunger pump

Technical Field

The present application relates to a plunger pump integrated with a speed increasing mechanism.

Background

In the field of engineering equipment, such as excavators, drilling rigs, etc., a diesel engine driven pump is often used as a main power source of the equipment. When the diesel engine is operated at a high speed, the amount of pollutants in the exhaust gas is large. In order to meet emission standards for diesel engines, diesel engines are increasingly designed to operate at low speeds to reduce the pollutant content of the exhaust gases. Further, the fuel efficiency of the diesel engine is higher at the low speed than at the high speed. Therefore, it is likely to become mainstream to design and produce a low-speed diesel engine.

For diesel engine driven pumps, if the diesel engine speed is reduced, a larger size pump may be required to meet the same output flow requirement, which results in wasted pump performance. Alternatively, it is conceivable to add a speed increasing device between the diesel engine and the pump. However, the addition of the outboard type speed increasing device requires an additional installation space.

SUMMERY OF THE UTILITY MODEL

An object of the present application is to provide a plunger pump which is itself integrated with a speed increasing mechanism, and thus is suitable for various low-speed drive sources such as a diesel engine.

To this end, the present application provides in one of its aspects a plunger pump comprising: a pump housing; a main rotating shaft installed in the pump housing; and a plunger assembly mounted in the pump housing and driven by the main rotating shaft; the plunger pump further comprises: an input shaft at least a body portion of which is disposed in the pump housing; and a speed increasing mechanism disposed between the input shaft and the main rotating shaft in the pump housing, configured to transmit a rotational speed increase of the input shaft to the main rotating shaft.

In one embodiment, the speed increasing mechanism is a gear mechanism.

In one embodiment, the gear mechanism includes a first gear mounted on the input shaft and a second gear mounted on the main shaft and meshing with the first gear, the first gear having a greater number of teeth than the second gear.

In one embodiment, the first and second gears are spur gears.

In one embodiment, the first and second gears are helical gears and are configured to generate an axial thrust on the main shaft in operation through meshing between the teeth, the axial thrust being in a direction opposite to the axial thrust generated on the main shaft by the plunger assembly.

In one embodiment, the first gear is a ring gear and the second gear is arranged inside the ring gear and meshes with the ring gear.

In one embodiment, the second gear is directly engaged with the ring gear, and the input shaft is arranged in parallel with the main rotation shaft.

In one embodiment, an intermediate gear is arranged between the second gear and the ring gear, and the input shaft is arranged coaxially with the main rotation shaft.

In one embodiment, the pump housing includes: the pump shell comprises a pump shell body, a first end cover and a second end cover, wherein the first end cover and the second end cover are assembled at two axial ends of the pump shell body; the two ends of the main rotating shaft are respectively supported by the first end cover and the second end cover through bearings.

In one embodiment, the outer end of the input shaft is configured to be connected to an output shaft of a diesel engine by a shaft connecting element.

According to the application, the speed increasing mechanism is integrated in the plunger pump, so that the plunger pump can be driven by the low-speed driving source to run at a high speed, an additional external speed increasing device is not required to be added, and the installation space and the cost can be saved.

Drawings

The foregoing and other aspects of the present application will be more fully understood from the following detailed description, taken with reference to the accompanying drawings, in which:

fig. 1 illustrates a schematic layout of a plunger pump according to one possible embodiment of the present application;

fig. 2 illustrates a schematic layout of a plunger pump according to another possible embodiment of the present application;

fig. 3 is a schematic cross-sectional view of a possible structure of the plunger pump in fig. 1.

Detailed Description

The present application relates generally to a plunger pump suitable for use with a low speed drive source, such as a low speed diesel engine, an exemplary layout of which is shown schematically in fig. 1.

As shown in fig. 1, an exemplary plunger pump 1 according to the present application is adapted to be driven by a low speed diesel engine 2.

The low speed here means that the rotational speed of the drive source, for example, a diesel engine, is lower than the rated rotational speed of the associated plunger pump, for example, by 30% or more.

The plunger pump 1 has a pump housing 3 and various functional elements mounted in the pump housing 3 or carried by the pump housing 3. These functional elements are described in turn below.

First, a main rotating shaft 4 is arranged in the pump housing 3, which is located completely within the housing 3. The main shaft 4 drives the plunger assembly. The plunger assembly comprises a cylinder body 5 and a circle of uniformly distributed plungers 6. The cylinder 5 is disposed around the main rotating shaft 4 and is rotatable together with the main rotating shaft 4. The front end of each plunger 6 faces an oil distribution pan 7 mounted on the front side of the cylinder block 5, and the rear end slidably pushes against a swash plate 8.

The swash plate 8 is mounted around the main rotating shaft 4, but does not rotate with the main rotating shaft 4. The swash plate 8 may have a fixed inclination angle with respect to the main rotary shaft 4 so that the plunger pump 1 has a constant displacement. Alternatively, the inclination angle of the swash plate 8 with respect to the main rotary shaft 4 is adjustable, for example by means of a variable head, so that the piston pump 1 has a variable displacement.

The plunger pump 1 further comprises an input shaft 9 which is arranged parallel to the main rotational axis 4 and the body is located in the pump housing 3 with the outer end extending through the pump housing 3 to the outside of the pump housing 3. The input shaft 9 is provided with a first gear 10, and the main rotating shaft 4 is provided with a second gear 11 meshed with the first gear 10. The first gear 10 has a larger diameter (number of teeth) than the second gear 11, so that the first gear 10 and the second gear 11 constitute a speed increasing mechanism between the input shaft 9 and the main rotating shaft 4, that is, the rotational motion of the input shaft 9 can be transmitted to the main rotating shaft 4 through the first gear 10 and the second gear 11, and the rotational speed of the main rotating shaft 4 is larger than that of the input shaft 9.

The first gear 10 and the second gear 11 may be spur gears, such as spur gears. The first gear 10 and the second gear 11 may also be helical gears, so that when they are operated, they can generate an axial thrust on the main rotating shaft 4 toward the oil distribution disc 7 by meshing between the teeth, which helps to prevent or reduce the leakage of the working fluid between the cylinder 5 and the oil distribution disc 7.

The outer end of the input shaft 9 is configured to be able to couple with an output shaft 12 of the diesel engine 2, for example by means of a clutch 13, a coupling, a spline housing, or other type of shaft connecting element.

Of course, it is also possible to arrange the outer end of the input shaft 9 inside the pump housing 3.

Note that, in the traveling construction machine, the diesel engine 2 also serves as a traveling power source of the entire machine.

For some mobile work machines, the travel mechanisms (e.g., tracks, wheels, etc.) are also hydraulically driven, and thus the plunger pump 1 may be used to drive various actuators and travel mechanisms of the work machine.

For other types of mobile work machines, the travel mechanism is directly driven by the diesel engine 2. In this case, the output shaft 12 of the diesel engine 2 may be connected to a transfer case (not shown) having an output shaft for driving the running gear and an output shaft for driving the plunger pump 1. The outer end of the input shaft 9 of the plunger pump 1 is then configured to be able to couple with the output shaft of the transfer case for driving the plunger pump 1.

As a modification (not shown) to the arrangement shown in fig. 1, the first gear takes the form of a toothed ring, and the second gear is arranged inside and in mesh with the toothed ring. Other aspects of this modification are similar to the arrangement shown in fig. 1 and will not be described in detail. The advantage of this modification is that the distance between the main rotating shaft and the input shaft, and thus the radial dimension of the pump casing, can be reduced relative to the arrangement shown in figure 1.

As a further variant of the arrangement shown in fig. 1, the input shaft 9 is arranged coaxially with the main shaft 4, as shown in fig. 2, the input shaft 9 being provided with a first gear in the form of a toothed ring 14, the main shaft 4 being provided with a second gear 11, and an intermediate gear 15 being arranged between the toothed ring 14 and the second gear 11. The rotation shaft of the intermediate gear 15 is immovable, so the intermediate gear 15 can transmit the rotation of the ring gear 14 to the second gear 11.

The ring gear 14, the second gear 11, and the intermediate gear 15 actually constitute one planetary gear mechanism. The number of intermediate gears 15 may be one or a plurality of gears evenly distributed around the second gear 11. The rotating shaft of the intermediate gear 15 may be directly mounted in the pump housing 3, or may be mounted on a carrier (not shown) fixed in the pump housing 3.

Other types of speed increasing mechanisms suitable for integration in the plunger pump 1 may also be designed.

An exemplary internal structure of the plunger pump layout shown in fig. 1 is schematically illustrated in fig. 2. It should be noted that the plunger pump is shown schematically in fig. 2 rather than drawn to scale and that certain elements and details have been omitted from the drawing in order to clearly illustrate the principles of the present application.

Referring to fig. 2, the pump casing 3 includes a pump casing body 31 and a first end cover 32 and a second end cover 33 assembled at both axial ends of the pump casing body 31. Both ends of the main rotating shaft 4 are supported by a first end cap 32 and a second end cap 33 through bearings, respectively. The input shaft 9 is supported by the first end cover 32 through a bearing, and the outer end of the input shaft 9 is exposed through the first end cover 32 to facilitate diesel engine connection. The first gear 10 and the second gear 11 are arranged in the pump housing body 31 near the first end cover 32.

The second end cover 33 has formed therein oil passages and ports 34, 35 communicating with an oil inlet groove and an oil outlet groove in the oil distribution pan 7. One of the ports 34, 35 is an oil inlet and the other is an oil outlet. The front portion of each plunger 6 is inserted into a plunger chamber 16 formed in the cylinder 5 and is axially reciprocally slidable in the corresponding plunger chamber 16. The rear end of each plunger 6 is urged against the swash plate 8 by a shoe 17. Each plunger chamber 16 is alternately communicated with an oil inlet groove and an oil outlet groove in the oil distribution disc 7. Inside the cylinder 5, a spring 18 that urges the cylinder 5 in the direction of the oil distribution pan 7 is disposed around the main rotating shaft 4.

When the input shaft 9 rotates the main shaft 4 via the first gear 10 and the second gear 11, the respective plungers 6 are reciprocated in the axial direction to suck in and discharge the working fluid via the ports 34 and 35.

For other forms of speed increasing mechanism, a specific structure for integrating the speed increasing mechanism into the plunger pump 1 can be designed.

According to the present application, the speed increasing mechanism is integrated in the plunger pump, so that the plunger pump can be driven by a low-speed driving source such as a diesel engine, and the like, thereby realizing high-speed operation of the plunger pump under the condition that the rotating speed of the driving source is low, ensuring high output flow, and avoiding the need of increasing the model of the plunger pump in order to compensate for the low speed of the driving source. In addition, an additional external speed increasing device is not required to be added between the plunger pump and the low-speed driving source, and the installation space and the cost can be saved.

Although the present application has been described herein with reference to particular embodiments, the scope of the present application is not intended to be limited to the details shown. Various modifications may be made to these details without departing from the underlying principles of the application.

Claims (10)

1. A plunger pump comprising:

a pump housing (3);

a main rotating shaft (4) installed in the pump housing; and

a plunger assembly mounted in the pump housing and driven by the main rotating shaft;

characterized in that, the plunger pump still includes:

an input shaft (9) at least a body portion of which is disposed in the pump housing; and

a speed increasing mechanism disposed between the input shaft and the main rotating shaft in the pump housing, configured to transmit a rotational speed increase of the input shaft to the main rotating shaft.

2. The plunger pump of claim 1, wherein said speed increasing mechanism is a gear mechanism.

3. Plunger pump according to claim 2, characterised in that the gear mechanism comprises a first gear wheel (10) mounted on the input shaft and a second gear wheel (11) mounted on the main shaft and meshing with the first gear wheel, the number of teeth of the first gear wheel being greater than the number of teeth of the second gear wheel.

4. The plunger pump of claim 3 wherein said first and second gears are spur gears.

5. The plunger pump of claim 3, wherein the first and second gears are helical gears and are configured to generate an axial thrust on the main shaft through inter-tooth engagement in a direction opposite to the axial thrust generated on the main shaft by the plunger assembly.

6. The plunger pump according to claim 3, wherein the first gear is a ring gear, and the second gear is disposed inside the ring gear and is meshed with the ring gear.

7. The plunger pump according to claim 6, wherein the second gear is directly engaged with the ring gear, and the input shaft is arranged in parallel with the main rotating shaft.

8. The plunger pump according to claim 6, wherein an intermediate gear is disposed between the second gear and the ring gear, and the input shaft is disposed coaxially with the main rotating shaft.

9. The plunger pump according to any one of claims 1-8, wherein the pump housing comprises: a pump case body (31), and a first end cover (32) and a second end cover (33) assembled at both ends of the pump case body in the axial direction; two ends of the main rotating shaft are respectively supported by the first end cover and the second end cover through bearings.

10. The plunger pump as claimed in any one of claims 1 to 8, characterized in that the outer end of the input shaft is configured and adapted to be connected to an output shaft of a diesel engine by means of a shaft connecting element.

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