Linear motor for pumping equipment

Abstract

The utility model provides a linear motor for pumping equipment, including casing and setting in the casing along the axial extension of primary assembly and secondary assembly of linear motor, and primary assembly and secondary assembly interval setting, and, the oil pipe is set up in the extension of secondary assembly, and secondary assembly can link together oil pipe and move along the axial movement of primary assembly. And, the both sides end of casing along the axial, primary assembly and secondary assembly surround and form the sealed containing chamber, the grease is arranged in containing chamber, and the grease is fully contacted with primary assembly and secondary assembly, ensures to primary assembly and secondary assembly all has better heat dissipation effect, and, when secondary assembly moves along the axial movement of primary assembly, makes the grease more fully flow, thereby better heat dissipation to primary assembly and secondary assembly, simultaneously, the grease forms the lubricating film on the inner wall surface of containing chamber, can also play the lubricating effect to secondary assembly and primary assembly when linear motor operation.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, and in particular to a linear motor for oil pumping equipment. Background Technology

[0002] As most domestic oilfields enter the mid-to-late stages of development, the geological conditions and engineering status of oil wells are becoming increasingly complex, placing higher demands on stable production, water control, and energy efficiency optimization. Against this backdrop, the petroleum machinery and equipment industry is focusing its R&D efforts on intelligent, efficient, and low-energy-consumption pumping equipment. Among these, linear motor technology, with its compact structure, high transmission efficiency, and precise control, demonstrates unique advantages in downhole oil production. When applied to pumping equipment, linear motors are typically integrated with the pump body, creating a rodless oil production system that significantly improves operational reliability in complex conditions such as deep wells and deviated wells.

[0003] In the integrated design of linear motors and pump bodies, conventional solutions often employ a nested structure: the oil supply pipe is placed between the secondary component of the linear motor and the base shaft, and grease is filled in the gap between the base shaft and the oil supply pipe. The inertial force generated by the linear motion of the secondary component drives the grease circulation, and the flow of grease achieves dynamic heat dissipation of the secondary component. However, because the primary component of the linear motor is fixed to the outside of the secondary component, the cooling effect of the grease on the primary component is extremely limited, resulting in a significantly higher operating temperature rise than that of the secondary component. Long-term operation can easily lead to insulation aging and magnetic performance degradation. At the same time, since there is no relative movement between the base shaft and the oil supply pipe, the grease can only rely on the inertial flow caused by the movement of the secondary component, which can easily form a stagnant layer in some areas, resulting in a decrease in heat absorption efficiency. Utility Model Content

[0004] The purpose of this invention is to solve the technical problem that in the prior art, linear motors used in oil pumping equipment fill the gap between the base shaft and the oil pipe with grease to dissipate heat from the secondary components, but the cooling effect on the primary components is extremely limited, and the grease can only rely on the inertial flow caused by the movement of the secondary components, which easily forms a stagnant layer in some areas, resulting in a decrease in heat absorption efficiency.

[0005] To address the aforementioned technical problems, this utility model discloses a linear motor for an oil pumping device. This linear motor includes a housing, and a primary assembly and a secondary assembly extending axially along the linear motor and disposed within the housing. The primary and secondary assemblies are spaced apart, and an oil delivery pipe extends within the secondary assembly. The secondary assembly is capable of moving axially relative to the primary assembly in conjunction with the oil delivery pipe. Furthermore, the two axially aligned ends of the housing, the primary assembly, and the secondary assembly enclose a sealed receiving cavity. Grease is disposed within the receiving cavity, forming a lubricating film on the inner wall surface of the cavity.

[0006] By employing the above technical solution, this linear motor incorporates grease within the cavity between the primary and secondary components. The grease maintains full contact with both components, ensuring effective heat dissipation for both. Furthermore, as the secondary component moves axially relative to the primary component, the grease flows effectively due to the pumping effect generated by the secondary component's movement. Compared to the grease positioned between the oil pipe and the base shaft in existing technologies, this solution ensures more thorough grease flow, thereby better dissipating heat from both the primary and secondary components and extending the linear motor's service life. Simultaneously, the grease forms a lubricating film on the inner wall of the cavity, further lubricating the primary and secondary components during operation without negatively impacting the motor's normal operation.

[0007] Furthermore, since the grease is placed between the primary and secondary components, the assembly between the secondary components and the pipeline is more compact. Moreover, the secondary components separate the grease containment cavity from the pipeline, preventing well fluid from the pipeline from entering the containment cavity and causing grease emulsification. This provides a more reliable working environment for the grease.

[0008] This utility model also discloses a linear motor for an oil pumping device, wherein an inwardly recessed oil pumping section is formed on the wall of the receiving cavity. The secondary assembly moves axially toward the output end relative to the primary assembly, and the oil pumping section squeezes the grease in the receiving cavity and reduces the thickness of the lubricating film on the inner wall of the receiving cavity; conversely, the secondary assembly moves axially away from the output end relative to the primary assembly, and the oil pumping section squeezes the grease in the receiving cavity and increases the thickness of the lubricating film on the inner wall of the receiving cavity.

[0009] Using the above technical solution, when the secondary component moves axially relative to the primary component, the oil pumping section formed on the wall of the receiving cavity can function as an oil pump, allowing the grease in the receiving cavity to flow axially, thereby providing sufficient lubrication and heat dissipation for both the secondary and primary components. Furthermore, when the secondary component of the linear motor moves axially towards the output end relative to the primary component, the oil pumping section is recessed inward, squeezing the grease in the receiving cavity into the pumping section. This reduces the thickness of the lubricating film on the inner wall of the receiving cavity, and may even scrape away the lubricating film on the wall of the receiving cavity, thereby increasing the magnetic flux between the primary and secondary components and improving the thrust output of the linear motor. Further, when the secondary component of the linear motor moves axially away from the output end relative to the primary component, the grease squeezed into the pumping section is re-coated onto the wall of the receiving cavity, increasing the thickness of the lubricating film and reducing the frictional resistance of the secondary component's return stroke. Therefore, the linear motor provided by this technical solution, through the pumping of grease by the oil pumping unit, fully meets the motion requirements of the secondary components to increase thrust output on the outward stroke and reduce frictional resistance on the return stroke.

[0010] The present invention also discloses a linear motor for an oil pumping device, wherein pumping sections are provided at axially opposite positions of the primary and secondary components. Furthermore, axially, the distance between the pair of pumping sections gradually and smoothly increases from both sides towards the middle, and the axial cross-section of the receiving cavity at the pair of pumping sections is spindle-shaped.

[0011] By adopting the above technical solution, the spacing between the oil pump sections increases smoothly from both sides to the middle, forming a streamlined flow channel, reducing the resistance to grease flow, ensuring that the thickness of the lubricating film reduced during the outward stroke of the secondary component is the same as the thickness of the lubricating film increased during the return stroke of the secondary component, improving the uniformity of lubricating film distribution, and avoiding uneven heat dissipation caused by local grease retention in the cavity.

[0012] The present invention also discloses a linear motor for an oil pumping device, wherein buffer pads are provided on the inner wall surfaces of both ends of the housing, and the buffer pads, primary components and secondary components on both sides form a receiving cavity.

[0013] The primary component includes an iron core with multiple mounting slots spaced axially. Each mounting slot contains a winding, and each mounting slot has an opening on the side facing the secondary component, where a primary magnetic shielding ring is fitted.

[0014] The secondary assembly includes a magnet, an outer sleeve located on the side of the magnet closer to the primary assembly, and a secondary magnetic isolation ring; the outer sleeve is located on one side of the secondary magnetic isolation ring along the axial direction.

[0015] The secondary magnetic shielding ring, along with the outer casing and the outer wall of the magnet located on both sides of the secondary magnetic shielding ring, forms the oil pumping section on the secondary assembly; the primary magnetic shielding ring, opposite to the secondary magnetic shielding ring, and the inner wall of the iron core located on both sides of the primary magnetic shielding ring form the oil pumping section on the primary assembly.

[0016] Using the above technical solution, the buffer pads located at both ends of the shell can absorb the impact energy generated by the reciprocating motion of the secondary components, reducing the amplitude of mechanical vibration. In high-frequency reciprocating oil pumping scenarios, this can reduce the vibration amplitude of the pumping equipment, reduce fatigue damage to bearings and connecting parts, and extend component life. The primary magnetic isolation ring is installed at the opening of the iron core mounting slot, blocking the diffusion of magnetic lines of force generated by the windings to non-working areas, reducing magnetic saturation at the iron core ends. For example, in low-permeability oilfield pumping, reduced magnetic leakage can improve motor efficiency and avoid power waste caused by magnetic losses. A secondary magnetic isolation ring is wrapped around the outside of the magnets to block the diffusion of magnetic lines of force to the axial ends, reducing magnetic leakage losses. For example, in deep well pumping scenarios, reduced magnetic leakage can improve the effective magnetic field utilization rate of the motor, increase output power, and simultaneously reduce eddy current heating caused by magnetic leakage, preventing grease deterioration due to high temperatures.

[0017] In addition, oil pumping units are provided on both the primary and secondary components to better pump the grease flow during linear motor operation.

[0018] The present invention also discloses a linear motor for an oil pumping device, wherein an elastic seal is provided between the opening of each mounting slot and the corresponding primary magnetic isolation ring.

[0019] By adopting the above technical solution, the elastic seal prevents the grease in the cavity from leaking into the mounting groove, thus providing a more reliable working environment for the winding in the mounting groove.

[0020] The present invention also discloses a linear motor for an oil pumping device, wherein the secondary magnetic isolation ring forms an inwardly recessed groove on the outer wall surface near the primary magnetic isolation ring.

[0021] By adopting the above technical solution, the grooves on the secondary magnetic shielding ring collect the dust and debris mixed in the grease in the receiving cavity, thus preventing the receiving cavity from being blocked.

[0022] The present invention also discloses a linear motor for an oil extraction device, wherein the ratio of the volume of the grease to the volume of the receiving cavity is in the range of 1:3 to 8.

[0023] By adopting the above technical solution, it is ensured that the grease in the receiving cavity can fully lubricate and dissipate heat for the primary and secondary components of the linear motor during operation, and that excessive grease filling the receiving cavity is avoided, thus avoiding waste.

[0024] The present invention also discloses a linear motor for an oil pumping device, wherein the grease is formed by mixing base oil, thickener, extreme pressure additive, high temperature resistant additive and magnetic additive.

[0025] Using the above technical solution, this grease can not only absorb the heat generated by the secondary and primary components during operation, but also adapt to pressure changes within the cavity. Furthermore, the thickener gives the grease semi-solid properties, making it particularly suitable for unidirectional lubrication conditions. Specifically, during the output stroke (moving axially towards the output end) of the secondary component, the thickness of the lubricating film on the inner wall of the cavity may decrease, or even be scraped off. However, this semi-solid grease has high adhesion, effectively preventing excessive grease buildup on the side of the cavity near the output end. Then, during the return stroke (moving axially away from the output end) of the secondary component, it ensures that the grease is recoated onto the cavity wall, thus uniformly increasing the thickness of the lubricating film on the inner wall of the cavity, preparing for the next output movement. In addition, because the grease includes magnetic additives, it can ensure a large magnetic flux between the primary and secondary components.

[0026] The present invention also discloses a linear motor for an oil pumping device. The secondary component includes a base shaft located on the side opposite to the primary component. One end of the oil delivery pipe is nested outside the base shaft, and a heat-conducting layer is provided between the outer wall of the base shaft and the inner wall of the oil delivery pipe.

[0027] By adopting the above technical solution, a heat-conducting layer is set between the base shaft and the oil pipeline, so that some of the heat on the base shaft can be transferred to the heat-conducting layer, thereby further improving the heat dissipation of the secondary components.

[0028] The present invention also discloses a linear motor for an oil pumping device, wherein the heat-conducting layer is a film layer in which heat-conducting silicone grease is uniformly distributed between the outer wall surface of the base shaft and the inner wall surface of the oil delivery pipe.

[0029] By employing the above technical solution, a film layer of thermally conductive silicone grease is uniformly applied between the outer wall of the base shaft and the inner wall of the oil pipeline, thereby improving the heat transfer performance between the base shaft and the oil pipeline and better reducing the temperature on the base shaft without increasing the assembly gap between them.

[0030] The beneficial effects of this utility model are:

[0031] This utility model provides a linear motor for an oil pumping device, including a housing, and a primary component and a secondary component extending axially along the linear motor and disposed within the housing. The primary and secondary components are spaced apart, and an oil delivery pipe extends within the secondary component. The secondary component can move axially relative to the primary component in conjunction with the oil delivery pipe. Furthermore, the two axial ends of the housing, the primary component, and the secondary component form a sealed receiving cavity. Grease is disposed within the receiving cavity, ensuring sufficient contact between the grease and the primary and secondary components, thus providing good heat dissipation for both. When the secondary component moves axially relative to the primary component, the grease flows more fully, further enhancing heat dissipation for both components. Simultaneously, the grease forms a lubricating film on the inner wall of the receiving cavity, which also lubricates the primary and secondary components during linear motor operation.

[0032] To better pump the grease within the receiving cavity, an inwardly recessed pumping section is formed on the cavity wall. When the secondary component of the linear motor moves axially towards the output end relative to the primary component, the grease within the receiving cavity is squeezed into the pumping section, thereby reducing the thickness of the lubricating film on the inner wall of the receiving cavity, or even scraping the lubricating film on the cavity wall. This increases the magnetic flux between the primary and secondary components, improving the thrust output of the linear motor. Furthermore, when the secondary component of the linear motor moves axially away from the output end relative to the primary component, the grease squeezed into the pumping section is re-coated onto the cavity wall, further increasing the lubricating film thickness and reducing the frictional resistance of the secondary component during the return stroke. Thus, the linear motor provided by this invention, through the pumping of grease by the pumping section, fully satisfies the motion requirements of the secondary component to increase thrust output on the outward stroke and reduce frictional resistance on the return stroke. Attached Figure Description

[0033] Figure 1 A schematic cross-sectional view of a linear motor for an oil pumping device provided in an embodiment of this utility model;

[0034] Figure 2 for Figure 1 A magnified view of a portion of point A in the middle.

[0035] Explanation of reference numerals in the attached figures:

[0036] 10. Linear motor;

[0037] 100. Shell;

[0038] 200. Primary component; 210. Iron core; 220. Winding; 230. Primary magnetic shielding ring;

[0039] 300. Secondary component; 310. Magnet; 320. Outer casing; 330. Secondary magnetic shielding ring; 331. Groove; 340. Base shaft;

[0040] 400. Oil pump section;

[0041] 20. Oil pipeline;

[0042] Y-axis, axial direction. Detailed Implementation

[0043] As mentioned in the background section, in the prior art, the linear motor used in oil pumping equipment fills the gap between the base shaft and the oil delivery pipe with grease to dissipate heat from the secondary components. However, the cooling effect on the primary components is extremely limited, and the grease can only rely on the inertial flow caused by the movement of the secondary components, which easily forms a stagnant layer in some areas, resulting in a decrease in heat absorption efficiency.

[0044] Therefore, this utility model provides a linear motor for an oil pumping device. This linear motor includes a housing, and a primary component and a secondary component extending axially along the linear motor and disposed within the housing. The primary and secondary components are spaced apart, and an oil delivery pipe extends within the secondary component. The secondary component can move axially relative to the primary component in conjunction with the oil delivery pipe. Furthermore, the two axially aligned ends of the housing, the primary component, and the secondary component enclose a sealed receiving cavity. Grease is disposed within the receiving cavity, and the grease forms a lubricating film on the inner wall surface of the receiving cavity.

[0045] This linear motor incorporates grease within a cavity between the primary and secondary components. The grease ensures thorough contact with both components, guaranteeing effective heat dissipation. Furthermore, as the secondary component moves axially relative to the primary component, the grease flows effectively via a pumping effect generated by the secondary component's movement. Compared to existing grease placement between the oil pipe and the base shaft, this linear motor ensures more complete grease flow, thus better dissipating heat from both components. Simultaneously, the grease forms a lubricating film on the inner wall of the cavity, further lubricating the primary and secondary components during linear motor operation without negatively impacting its normal operation.

[0046] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0047] like Figure 1 As shown, this embodiment provides a linear motor 10, which converts electrical energy into linear motion through electromagnetic induction. When using oil pumping equipment, it can achieve precise motion control based on the stepping principle. The structure of the linear motor 10 will be described in detail below.

[0048] This linear motor 10 includes a housing 100, and a primary component 200 and a secondary component 300 disposed within the housing 100. The housing 100 may be a cylindrical structure made of stainless steel to protect the components of the primary component 200 and the secondary component 300 from damage by other external parts. The output end of the linear motor 10 is connected to one end of the secondary component 300 in the axial direction Y and can extend out from the housing 100. When this linear motor 10 is used in an oil pumping device, the oil delivery pipe 20 for transporting crude oil extends along the axial direction Y and is located within the secondary component 300. When the secondary component 300 moves relative to the primary component 200 in the axial direction Y, it can move the oil delivery pipe 20 in the axial direction Y and pump crude oil.

[0049] Specifically, such as Figure 1 and Figure 2As shown, this linear motor 10 has buffer pads on the inner wall surfaces of both ends of the housing 100. The buffer pads on both sides, the primary component 200, and the secondary component 300 surround and form a receiving cavity. The buffer pads located at both ends of the housing 100 can be made of a high-damping material (such as rubber) to absorb the impact energy generated by the reciprocating motion of the secondary component 300, reduce the mechanical vibration amplitude, and in high-frequency reciprocating oil pumping scenarios, reduce the vibration amplitude of the oil pumping equipment, reduce fatigue damage to bearings and connecting parts, and extend the service life of components.

[0050] More specifically, the primary component 200 includes an iron core 210, which has multiple mounting slots spaced along the axial direction Y. Each mounting slot is provided with a winding 220. Furthermore, each mounting slot has an opening on the side facing the secondary component 300, and a primary magnetic isolation ring 230 is fitted into the opening to block the diffusion of magnetic lines of force generated by the winding 220 to the non-working area and reduce the magnetic saturation phenomenon at the end of the iron core 210. For example, in oil pumping in low-permeability oil fields, the reduction of magnetic leakage can improve the efficiency of the motor and avoid power waste caused by magnetic loss.

[0051] In this embodiment, multiple iron cores 210 are spliced ​​together along the axial direction Y inside the housing 100. For example, ten, twenty, or other numbers of iron cores 210 can be spliced ​​together along the axial direction Y inside the housing 100, and an installation groove is formed between two adjacent iron cores 210.

[0052] The secondary component 300 includes a magnet 310, an outer sleeve 320 located on the side of the magnet 310 closer to the primary component 200, and a secondary magnetic isolation ring 330. The outer sleeve 320 is located on the side of the secondary magnetic isolation ring 330 along the axial direction Y. The secondary magnetic isolation ring 330 wraps around the magnet 310 to block the diffusion of magnetic lines of force to the axial Y end, reducing leakage magnetic loss. For example, in deep well oil pumping scenarios, reduced leakage magnetic field can improve the effective magnetic field utilization rate of the motor, increase the output power, and at the same time reduce eddy current heating caused by leakage magnetic field, preventing grease from deteriorating due to high temperature.

[0053] Furthermore, the secondary component 300 also includes a base shaft 340 on the side of the magnet 310 facing away from the primary component 200. The base shaft 340 is used to assemble the oil pipeline 20. The two can be connected by welding or interference fit. This embodiment does not specifically limit this.

[0054] It should be noted that the linear motor 10 may be provided with multiple primary components 200 and secondary components 300 along the axial direction Y. Two adjacent primary components 200 are connected by sliding bearings, while two adjacent secondary components 300 are connected by spherical bearings. This embodiment does not make specific limitations on this.

[0055] Furthermore, in order to fully achieve heat dissipation for the primary component 200 and the secondary component 300, in this embodiment, the housing 100, the primary component 200, and the secondary component 300 form a sealed receiving cavity along the two ends of the housing 100 along the axial direction Y, and the receiving cavity is filled with grease, which forms a lubricating film on the inner wall surface of the receiving cavity.

[0056] When the secondary component 300 moves axially Y relative to the primary component 200, the grease can flow due to the effective pumping effect generated by the movement of the secondary component 300. Compared with the grease disposed between the oil pipe 20 and the base shaft 340 in the prior art, the linear motor 10 provided in this embodiment can ensure more sufficient grease flow, thereby better dissipating heat from the primary component 200 and the secondary component 300 and extending the service life of the linear motor 10. At the same time, the grease forms a lubricating film on the inner wall of the receiving cavity, which can also lubricate the secondary component 300 and the primary component 200 when the linear motor 10 is operating, without negatively affecting the normal operation of the linear motor 10.

[0057] Furthermore, since the grease is placed between the primary component 200 and the secondary component 300, the assembly between the secondary component 300 and the oil delivery pipe 20 is more compact. Moreover, the secondary component 300 separates the grease's receiving cavity from the oil delivery pipe 20, preventing the well fluid in the oil delivery pipe 20 from seeping into the receiving cavity and causing the grease to emulsify, thus providing a more reliable working environment for the grease.

[0058] Furthermore, such as Figure 1 As shown, in this embodiment, an inwardly recessed oil pumping section 400 is formed on the wall surface of the receiving cavity. The secondary component 300 moves relative to the primary component 200 along the axial direction Y towards the output end. The oil pumping section 400 squeezes the grease within the receiving cavity, allowing the grease to flow along the axial direction Y. The grease is squeezed into the oil pumping section 400, thereby reducing the thickness of the lubricating film on the inner wall surface of the receiving cavity, and even scraping away the lubricating film on the wall surface of the receiving cavity. This increases the magnetic flux between the primary component 200 and the secondary component 300, improving the thrust output of the linear motor 10. Furthermore, when the secondary component 300 moves relative to the primary component 200 along the axial direction Y away from the output end, the oil pumping section 400 squeezes the grease within the receiving cavity. At this time, the grease squeezed into the oil pumping section 400 is reapplied to the wall surface of the receiving cavity, thereby increasing the thickness of the lubricating film and reducing the frictional resistance of the secondary component 300 during its return stroke. Therefore, the linear motor 10 provided in this embodiment, through the pumping of grease by the oil pumping unit 400, fully meets the motion requirements of the secondary component 300 to increase thrust output on the outward stroke and reduce frictional resistance on the return stroke.

[0059] In this embodiment, both the primary component 200 and the secondary component 300 are provided with oil pumping sections 400 at relative positions in the axial Y direction. Furthermore, in the axial Y direction, the distance between the pair of oil pumping sections 400 gradually and smoothly increases from both sides towards the middle. The axial cross-section of the receiving cavity at the pair of oil pumping sections 400 is spindle-shaped. This receiving cavity can reduce the resistance to grease flow, ensuring that the thickness of the lubricating film reduced during the forward stroke of the secondary component 300 is the same as the thickness of the lubricating film increased during the return stroke of the secondary component 300, thereby improving the uniformity of lubricating film distribution and avoiding uneven heat dissipation caused by local grease retention in the receiving cavity.

[0060] Of course, the oil pumping section 400 can also be provided on one side of the primary component 200 or the secondary component 300 on the wall of the receiving cavity. In this case, the axial cross-section of the receiving cavity at the oil pumping section 400 is trapezoidal. Alternatively, the primary component 200 and the secondary component 300 can both be provided with oil pumping sections 400 at relative positions in the axial Y direction. However, the distance between a pair of oil pumping sections 400 gradually and smoothly increases from both sides to the middle, and the pair of oil pumping sections 400 extend at equal intervals in the middle. The axial cross-section of the receiving cavity at a pair of oil pumping sections 400 is hexagonal. That is to say, the variation in the distance between the oil pumping sections 400 in the axial Y direction forms an irregular receiving cavity, which can improve the pumping effect of grease. This embodiment does not limit the specific structure of the oil pumping section 400.

[0061] The oil pump section 400 on the secondary component 300 will be described in detail below.

[0062] In this embodiment, the inner wall surfaces of the primary magnetic shielding ring 230 and the iron core 210 located on both sides of the primary magnetic shielding ring 230 form the oil pumping part 400 on the primary assembly 200. Furthermore, an elastic seal is provided between the opening of each mounting groove and the corresponding primary magnetic shielding ring 230. The elastic seal prevents the grease in the receiving cavity from leaking into the mounting groove, thus providing a more reliable working environment for the winding 220 in the mounting groove.

[0063] The oil pump section 400 on the primary component 200 will be described in detail below.

[0064] In this embodiment, the secondary magnetic shielding ring 330, and the outer wall surfaces of the outer jacket 320 and the magnet 310 located on both sides of the secondary magnetic shielding ring 330 form the oil pumping part 400 on the secondary assembly 300. Furthermore, the secondary magnetic shielding ring 330 forms an inwardly recessed groove 331 near the outer wall surface of the primary magnetic shielding ring 230. The groove 331 on the secondary magnetic shielding ring 330 collects dust and debris mixed in the grease in the receiving cavity, thus preventing the receiving cavity from being blocked.

[0065] It should be noted that in this embodiment, the oil pumping section 400 on the primary component 200 and the secondary component 300 is formed on its own magnetic shielding ring and the connected component, respectively. Of course, other sleeves can also be added to the primary component 200 and the secondary component 300 to form the oil pumping section 400.

[0066] The following is a detailed description of the grease inside the cavity.

[0067] In this embodiment, the grease is formed by mixing base oil, thickener, extreme pressure additive, high temperature resistant additive, and magnetic additive. This grease can not only absorb the heat generated by the secondary component 300 and the primary component 200 during operation, but also adapt to pressure changes within the cavity. Furthermore, the thickener gives this grease semi-solid properties, making it particularly suitable for unidirectional lubrication conditions. Specifically, during the output stroke (moving along the Y-axis towards the output end) of the secondary component 300, the thickness of the lubricating film on the inner wall of the cavity is reduced, or even scraped off. This semi-solid grease has high adhesion, effectively preventing excessive grease buildup on the side of the cavity near the output end. Then, during the return stroke (moving along the Y-axis away from the output end) of the secondary component 300, it ensures that the grease can be recoated onto the wall of the cavity, thereby uniformly increasing the thickness of the lubricating film on the inner wall of the cavity, preparing for the next round of output movement. Furthermore, since the grease contains magnetically conductive additives, it can ensure a large magnetic flux between the primary component 200 and the secondary component 300 as much as possible.

[0068] Furthermore, the ratio of the grease volume to the volume of the receiving cavity is in the range of 1:3 to 8, for example, the ratio of the grease volume to the volume of the receiving cavity is 1:3, 1:5, 1:6, 1:8 or other ratios within the above range, to ensure that the grease in the receiving cavity can fully lubricate and dissipate heat on the primary component 200 and the secondary component 300 of the linear motor 10 during operation, and to avoid waste caused by filling the receiving cavity with too much grease.

[0069] Furthermore, in this embodiment of the linear motor 10, since no grease is required between the base shaft 340 and the oil supply pipe 20, one end of the oil supply pipe 20 can be nested outside the base shaft 340, and a heat-conducting layer can be provided between the outer wall surface of the base shaft 340 and the inner wall surface of the oil supply pipe 20. By providing a heat-conducting layer between the base shaft 340 and the oil supply pipe 20, some of the heat on the base shaft 340 can be transferred to the heat-conducting layer, further improving the heat dissipation of the secondary component 300.

[0070] Specifically, the thermal conductive layer is a film layer in which thermally conductive silicone grease is evenly distributed between the outer wall surface of the base shaft 340 and the inner wall surface of the oil pipeline 20. Without increasing the assembly gap between the base shaft 340 and the oil pipeline 20, it improves the heat transfer performance between the base shaft 340 and the oil pipeline 20 and better reduces the temperature on the base shaft 340.

[0071] It should be noted that, in addition to the specific embodiments described above, those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. Although the description of this utility model is presented in conjunction with preferred embodiments, this does not mean that the features of this utility model are limited to that embodiment. On the contrary, the purpose of describing the utility model in conjunction with the embodiments is to cover other options or modifications that may be derived based on the claims of this utility model. In order to provide a deep understanding of this utility model, many specific details are included in the above description, and this utility model may also be implemented without using these details. In addition, in order to avoid confusion or obscuring the focus of this utility model, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0072] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0073] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the utility model.

[0074] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0075] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0076] Although the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the present invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the present invention to these descriptions. Those skilled in the art can make various changes in form and detail, including some simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A linear motor for an oil pumping device, characterized in that, The linear motor includes a housing, and a primary component and a secondary component extending axially along the linear motor and disposed within the housing. The primary component and the secondary component are spaced apart, and an oil supply pipe extends within the secondary component. The secondary component is capable of moving the oil supply pipe relative to the primary component along the axial direction. The housing, along its two ends along the axial direction, the primary component, and the secondary component form a sealed receiving cavity. Grease is disposed within the receiving cavity, and the grease forms a lubricating film on the inner wall surface of the receiving cavity.

2. The linear motor for oil pumping equipment as described in claim 1, characterized in that, An inwardly recessed oil pumping section is formed on the wall surface of the receiving cavity; wherein The secondary component moves relative to the primary component along the axial direction toward the output end, the oil pumping section squeezes the grease in the receiving cavity and reduces the thickness of the lubricating film on the inner wall surface of the receiving cavity; and the secondary component moves relative to the primary component along the axial direction away from the output end, the oil pumping section squeezes the grease in the receiving cavity and increases the thickness of the lubricating film on the inner wall surface of the receiving cavity.

3. The linear motor for oil pumping equipment as described in claim 2, characterized in that, The primary component and the secondary component are both provided with the oil pump section at relative axial positions; and... In the axial direction, the distance between the pair of pump parts gradually increases smoothly from both sides to the middle, and the axial cross-section of the receiving cavity at the pair of pump parts is spindle-shaped.

4. The linear motor for oil pumping equipment as described in claim 3, characterized in that, in, The inner wall surfaces at both ends of the housing are provided with buffer pads, and the buffer pads, the primary component, and the secondary component on both sides surround and form the receiving cavity; The primary component includes an iron core, which has multiple mounting slots spaced along the axial direction. Each mounting slot is provided with a winding, and each mounting slot has an opening on the side facing the secondary component, where a primary magnetic shielding ring is fitted. The secondary component includes a magnet, an outer sleeve and a secondary magnetic isolation ring located on the side of the magnet closer to the primary component; the outer sleeve is located on one side of the secondary magnetic isolation ring along the axial direction; The secondary magnetic shielding ring, and the outer walls of the outer jacket and the magnet located on both sides of the secondary magnetic shielding ring, form the oil pumping section on the secondary assembly; the primary magnetic shielding ring opposite to the secondary magnetic shielding ring, and the inner walls of the iron core located on both sides of the primary magnetic shielding ring, form the oil pumping section on the primary assembly.

5. The linear motor for oil pumping equipment as described in claim 4, characterized in that, An elastic seal is provided between the opening of each mounting slot and the corresponding primary magnetic shielding ring.

6. The linear motor for oil pumping equipment as described in claim 4, characterized in that, The secondary magnetic shielding ring forms an inwardly recessed groove on the outer wall surface near the primary magnetic shielding ring.

7. The linear motor for an oil pumping device as described in any one of claims 1 to 6, characterized in that, The ratio of the volume of the grease to the volume of the receiving cavity is in the range of 1:3 to 8.

8. The linear motor for an oil pumping device as described in any one of claims 1 to 6, characterized in that, The grease is formed by mixing base oil, thickener, extreme pressure additive, high temperature resistant additive and magnetic additive.

9. The linear motor for an oil pumping device as described in any one of claims 1-6, characterized in that, The secondary component also includes a base shaft located on the side opposite to the primary component, one end of the oil pipe is nested outside the base shaft, and a heat-conducting layer is provided between the outer wall of the base shaft and the inner wall of the oil pipe.

10. The linear motor for an oil pumping device as described in claim 9, characterized in that, The thermally conductive layer is a film layer in which thermally conductive silicone grease is uniformly distributed between the outer wall surface of the base shaft and the inner wall surface of the oil pipeline.

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