A fixed-axis single screw pump and a coal mining machine rocker arm including the pump

Abstract

The present invention relates to a fixed-axis single-screw pump and a coal mining machine rocker arm including the pump, and belongs to the technical field of hydraulic transmission. The fixed-axis single-screw pump comprises a pump casing and a screw located inside the pump casing. The periphery of the pump casing is connected with a driving gear, and the driving gear and the pump casing rotate synchronously. The pump casing drives the screw to rotate around the axis of the screw and to revolve around the axis of the pump casing. The present invention pumps lubricating oil from an excessive concentrated area to an oil-deficient area through the cooperation of a pump casing outer rotor assembly and the screw, thereby improving the lubrication condition of the oil-deficient area and reducing ineffective oil stirring, power consumption and heat generation caused by excessive concentration of lubricating oil. At the same time, it can run idly in a healthy manner in an oil-deficient state, consumes very little power and avoids damage caused by poor self-lubrication.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic transmission, and in particular relates to a fixed-axis single-screw pump and a rocker arm of a coal mining machine comprising the pump. Background Art

[0002] The rocker arm of the underground coal mining machine belongs to a long-arm gear reducer, which is composed of a series of gears such as the reduction gear of the reducer and the transition gear with increased distance. Its two ends can be divided into a high-speed area and a low-speed area. When the rocker arm is working, it has an upward lifting and downward working state. When it is lifted, the lubricating oil flows down and concentrates in the high-speed cavity. The high-speed cavity has too much oil, and the low-speed area lacks oil. When it is downward, the lubricating oil flows down and concentrates in the low-speed cavity. The low-speed cavity has too much oil, and the high-speed area lacks oil. How to improve the lubrication of bearings and gears in the oil-deficient parts and reduce the ineffective oil stirring, power consumption and heat caused by excessive concentration of lubricating oil are problems that technical personnel in this field urgently need to solve. Summary of the invention

[0003] In view of various deficiencies in the prior art and in order to solve the above problems, a fixed-axis single-screw pump and a coal mining machine rocker arm including the pump are proposed.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A fixed-axis single-screw pump comprises a pump casing and a screw located inside the pump casing. The periphery of the pump casing is connected to a driving gear, and the driving gear and the pump casing rotate synchronously. The pump casing drives the screw to rotate around the axis of the screw and revolve around the axis of the pump casing.

[0006] Furthermore, the driving gear is mounted on the gear bearing seat, and the driving gear is meshed with an external power source.

[0007] Furthermore, the pump casing is a split structure, with end covers connected to both ends respectively, and the end covers are fixedly connected to the gear bearing seats to form a pump casing outer rotor assembly.

[0008] Furthermore, the end cover is made of self-lubricating material.

[0009] Furthermore, both ends of the pump casing outer rotor assembly are supported on the end cover bearing seat through first bearings respectively.

[0010] Furthermore, both ends of the screw rod respectively pass through the end cover and are supported on the end cover bearing seat through the second bearing, and an oblong hole is provided on the end cover for the screw rod to slide and rotate.

[0011] Furthermore, the helical surface of the screw is a single-start helix, and the helical surface of the pump casing is a double-start helix.

[0012] Furthermore, the helical lead of the pump housing is twice the helical lead of the screw.

[0013] Furthermore, a cavity exists between different spiral surfaces of the screw and the pump housing to form an oil seal cavity, and an oil inlet channel and an oil outlet channel connected to the oil seal cavity are respectively provided on the end cover bearing seats located at both ends of the screw.

[0014] In addition, the present invention also provides a coal mining machine rocker arm, including the fixed-axis single screw pump, wherein the fixed-axis screw pump is respectively located in the high-speed zone and the low-speed zone of the rocker arm, and the driving gear is respectively meshed with the gear in the high-speed zone and the gear in the low-speed zone.

[0015] The beneficial effects of the present invention are:

[0016] Through the cooperation of the outer rotor assembly of the pump casing and the screw, the lubricating oil is pumped from the excessive concentrated area to the oil-deficient area, thereby improving the lubrication condition of the oil-deficient area and reducing the ineffective oil stirring, power consumption and heat generation caused by excessive concentration of lubricating oil. At the same time, it can run idly in a healthy manner in the oil-deficient state, consuming very little power and avoiding damage caused by poor lubrication. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a longitudinal cross-sectional schematic diagram of a fixed-axis single-screw pump;

[0018] Figure 2 It is a schematic diagram of the assembly of a fixed-axis single-screw pump and a coal mining machine rocker arm.

[0019] In the attached figure: 1-screw, 2-pump housing, 3-end cover, 4-first bearing, 5-second bearing, 6-sealing ring, 7-end cover, 8-gear bearing seat, 9-end cover bearing seat, 10-end cover bearing seat, 11-oil inlet channel, 12-oil outlet channel, 13-rocker arm housing, 14-rocker arm gear. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings of the present invention. Based on the embodiments in this application, other similar embodiments obtained by ordinary technicians in this field without making creative work should all fall within the scope of protection of this application. In addition, the directional words mentioned in the following embodiments, such as "up", "down", "left", "right", etc., are only reference to the directions of the accompanying drawings. Therefore, the directional words used are used to illustrate rather than limit the invention.

[0021] Embodiment 1:

[0022] like Figure 1As shown, a fixed-axis single-screw pump includes a pump casing 2 and a screw 1 located inside the pump casing 2. The pump casing 2 is a split structure. In this embodiment, the pump casing 2 is divided into two parts with completely identical structures. It can be precisely processed by CNC to improve the accuracy and achieve precise transmission. There is no need to compensate for insufficient processing accuracy through a rubber layer. In other words, the pump casing 2 does not contain a rubber layer.

[0023] The periphery of the pump casing 2 is connected with a driving gear. Specifically, the two ends of the pump casing 2 are respectively connected with an end cover 3 and an end cover 7. Preferably, the pump casing 2 is respectively connected with the end cover 3 and the end cover 7 by bolts, and the end cover 3 and the end cover 7 are made of self-lubricating materials and do not need oil lubrication. The periphery of the end cover 7 is fixedly connected with the gear bearing seat 8 to form a pump casing outer rotor assembly. Preferably, the end cover 7 is connected with the gear bearing seat 8 by bolts. At the same time, the gear bearing seat 8 is fixedly connected with the driving gear, and the driving gear is meshed with an external power source. In other words, under the driving action of the external power source, the driving gear and the pump casing 2 rotate synchronously, that is, the pump casing outer rotor assembly realizes rotation. In addition, one end of the pump casing outer rotor assembly is supported on the end cover bearing seat 9 through the first bearing 4, and the other end is supported on the end cover bearing seat 10 through the first bearing, that is, the pump casing outer rotor assembly can rotate relative to the end cover bearing seat 10 and the end cover bearing seat 9. At the same time, a sealing ring 6 is provided between the end cover 3 and the end cover bearing seat 9 and on the outer side of the first bearing 4 to play a sealing and protective role. The outer side is the side away from the pump housing 2.

[0024] One end of the screw 1 passes through the end cover 3 and is supported on the end cover bearing seat 9 through the second bearing 5, and the other end passes through the end cover 7 and is supported on the end cover bearing seat 10 through the second bearing, that is, the screw 1 can also rotate relative to the end cover bearing seat 10 and the end cover bearing seat 9. At the same time, oblong holes are provided on the end covers 3 and 7 for the screw 1 to slide and rotate relatively in the oblong holes, forming end transmission. The pump housing 2 drives the screw 1 to rotate around the axis of the screw 1 and the axis of the pump housing 2 (the axis of the pump housing 2 coincides with the axis of the pump housing outer rotor assembly), forming a middle transmission, that is, the rotation axis of the pump housing 2 and the rotation axis of the screw 1 are both fixed, and no universal joint coupling shaft is required, which greatly shortens the length of the fixed-axis single-screw pump. The spiral surface of the screw 1 is a single-head spiral, and the spiral surface of the pump housing 2 is a double-head spiral, and the spiral lead of the pump housing 2 is twice the spiral lead of the screw 1. There is a cavity between the different spiral surfaces of the screw 1 and the pump housing 2 to form an oil seal cavity. The end cover bearing seats at both ends of the screw 1 (i.e., the end cover bearing seat 10 and the end cover bearing seat 9) are respectively provided with an oil inlet channel 11 and an oil outlet channel 12 connected to the oil seal cavity, and the structure is compact.

[0025] In summary, the fixed-axis single-screw pump described in the present invention has two sets of transmission mechanisms, namely, end transmission and middle transmission. The end transmission mainly focuses on dry working conditions (i.e., low-oil working conditions). In dry working conditions, only the two ends have low-power transmission, and there are cavities and gaps in the middle relative sliding and rolling parts, which are essentially non-contact. In full working conditions, the ends are fully mechanically transmitted, and the middle part is dynamic pressure oil film transmitted. The design of dry working conditions ensures that the fixed-axis single-screw pump runs idle in the absence of oil, consumes very little power, and avoids damage due to idling due to lack of oil.

[0026] During operation, the external power source inputs power, the rotor assembly outside the pump housing and the screw 1 rotate, and the screw 1 performs a rotary motion in the pump housing 2. The volume of the oil seal chamber in the middle remains unchanged, and only spiral conveying is performed. However, the volume of the oil seal chamber near the oil inlet channel 11 and the oil outlet channel 12 changes periodically, and the lubricating oil is sucked in and discharged periodically. In other words, under the action of the external power source, the volume of the oil seal chamber near the oil inlet channel 11 and the oil outlet channel 12 increases and decreases periodically to achieve the suction and discharge of the lubricating oil, and the oil seal chamber in the middle transfers the lubricating oil, and then pumps the lubricating oil to the destination. Compared with the oil pump used in the prior art, which uses a spiral surface transmission to deliver oil, the lubricating oil is directly connected to the oil pool, and the oil is delivered purely by spiral power, which is very inefficient and cannot effectively supply oil. The fixed-axis single-screw pump of the present invention is a positive displacement pump, which compresses oil by volume changes and has high efficiency.

[0027] Embodiment 2:

[0028] like Figure 1 and Figure 2 As shown, a rocker arm of a coal mining machine includes the fixed-axis single screw pump, which is respectively located in the high-speed zone and the low-speed zone of the rocker arm, and the driving gear is respectively meshed with the rocker arm gear 14, and the rocker arm gear is a gear in the high-speed zone or a gear in the low-speed zone. In other words, the high-speed zone and the low-speed zone of the rocker arm are installed at the same time, and the working state is selected intelligently and automatically. A part of the lubricating oil in the excessive concentrated part is pumped to another oil-deficient part, so as to improve the lubrication of the bearing gears in the oil-deficient part and reduce the ineffective stirring of oil, power consumption and heat generation caused by the excessive concentration of the original lubricating oil. The oil inlet channel leads directly to the oil pool, and the oil outlet channel leads to the parts of the coal mining machine rocker arm such as the bearings and gears that need lubrication through the processed oil channel on the rocker arm housing 13. The oil output of the fixed-axis single screw pump in the high-speed zone eventually flows to the parts that need lubrication in the low-speed zone, and the oil output of the fixed-axis single screw pump in the low-speed zone eventually flows to the parts that need lubrication in the high-speed zone.

[0029] In the prior art, most single screw pumps have universal joints. At the same time, the power of the single screw pump is driven by its own motor, and the axial direction is very long, which is not suitable for the narrow space of the rocker arm. In addition, the screw rotates in an unfixed axis, has an eccentric dynamic load, and works poorly. The pump housing cannot be finely processed. Generally, a rubber inner sleeve is added, which has great resistance and is easy to damage. The fixed-axis single screw pump of the present invention is driven by the internal gears of the rocker arm (gears in the high-speed zone and gears in the low-speed zone), and a small part of the power is used to drive the fixed-axis single screw pump, without the need for a special motor. At the same time, the pump housing is a split structure, which can be finely processed with high precision. The outer rotor assembly of the pump housing and the screw are meshed and driven, thereby realizing liquid film transmission near the meshing line. The pump housing and the screw have no contact wear and can effectively seal oil. In addition, the general single screw pump cannot run empty with less oil, while the fixed-axis single screw pump of the present invention can run empty in a healthy state in the absence of oil because there are cavities and gaps between the different spiral surfaces of the screw 1 and the pump housing 2, consuming very little power and avoiding damage due to poor lubrication.

[0030] The present invention has been described in detail above. The above description is only a preferred embodiment of the present invention and should not limit the scope of implementation of the present invention. That is, all equivalent changes and modifications made within the scope of this application should still fall within the scope of the present invention.

Claims

1. A fixed-axis single-screw pump, comprising a pump casing and a screw located inside the pump casing, characterized in that: The periphery of the pump casing is connected to a driving gear, and the driving gear and the pump casing rotate synchronously. The two ends of the pump casing are respectively connected to end covers, and oblong holes are provided on the end covers for the screw to slide and rotate relatively in the oblong holes, forming end transmission; the pump casing drives the screw to rotate around the axis of the screw and revolve around the axis of the pump casing, forming a middle transmission; under low-oil working conditions, only the two ends have low-power transmission, and there are cavities and gaps in the relatively sliding and rolling part in the middle, which is essentially non-contact; under full working conditions, the ends are fully mechanically driven, and the middle is driven by dynamic pressure oil film.

2. The fixed-axis single-screw pump according to claim 1, characterized in that: The driving gear is mounted on the gear bearing seat, and the driving gear is meshed with an external power source.

3. The fixed-axis single-screw pump according to claim 2, characterized in that: The pump casing is a split structure, with end covers connected to both ends respectively, and the end covers are fixedly connected to the gear bearing seat to form a pump casing outer rotor assembly.

4. The fixed-axis single-screw pump according to claim 3, characterized in that: The end cover is made of self-lubricating material.

5. The fixed-axis single-screw pump according to claim 3 or 4, characterized in that: Both ends of the pump casing outer rotor assembly are supported on the end cover bearing seat through first bearings respectively.

6. The fixed-axis single-screw pump according to claim 5, characterized in that: The two ends of the screw rod respectively penetrate the end cover and are supported on the end cover bearing seat through the second bearing, and the end cover is provided with an oblong hole for the screw rod to slide and rotate.

7. The fixed-axis single-screw pump according to claim 6, characterized in that: The helical surface of the screw is a single-start helix, and the helical surface of the pump housing is a double-start helix.

8. The fixed-axis single-screw pump according to claim 7, characterized in that: The helical lead of the pump housing is twice the helical lead of the screw.

9. The fixed-axis single-screw pump according to claim 8, characterized in that: There is a cavity between the screw and different spiral surfaces of the pump housing to form an oil seal cavity, and the end cover bearing seats located at both ends of the screw are respectively provided with an oil inlet channel and an oil outlet channel connected to the oil seal cavity.

10. A rocker arm of a coal mining machine, characterized in that: It comprises the fixed-axis single-screw pump as described in any one of claims 1 to 9, wherein the fixed-axis screw pump is respectively located in the high-speed zone and the low-speed zone of the rocker arm, and the driving gear is respectively meshed with the gear in the high-speed zone and the gear in the low-speed zone.

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