Easily-assembled semi-direct-drive permanent magnet synchronous motor for oil pumping unit

Abstract

An easily-assembled semi-direct-drive permanent magnet synchronous motor for an oil pumping unit comprises a shell, a stator and a rotor, the stator and the rotor are arranged in the shell, and the shell comprises a middle shell, a front end cover and a rear end cover, and the front end cover and the rear end cover are arranged at the two ends of the middle shell; the middle shell is in transition fit with the stator, a limiting ring is arranged on the inner wall of the middle shell in the circumferential direction, and one end of the stator abuts against the limiting ring and is fixedly connected with the limiting ring through a locking piece. Compared with the prior art, the utility model has the following advantages: the middle shell and the stator are in transition fit, the smoothness of the process of inserting the stator into the middle shell is ensured, the product processing precision is high, the stator is inserted into the middle shell without adopting sudden hammering to avoid damage or hidden damage of the stator, hidden dangers are buried for later use, the product yield is high, and the production cost is low. Therefore, the production cost can be reduced; meanwhile, the stator and the limiting ring are locked together through the locking piece, fixation is firm and convenient, the overall assembly efficiency is high, and later maintenance of the stator is facilitated.

Description

Technical Field

[0001] The utility model relates to the field of electric motors, in particular to an easy-to-assemble semi-direct-drive permanent-magnet synchronous motor for an oil pumping unit. Background Art

[0002] The traditional beam pumping unit reduction gearbox is connected by an induction motor through a belt. During production, the gearbox needs to be lubricated regularly, which can easily cause environmental pollution such as oil seepage and oil leakage over time. In addition, the motor belt is very easy to slip and wear, and usually needs to be replaced with a new belt every one or two months. Over time, as the degree of wear increases, the transmission efficiency of the pumping unit will also decrease.

[0003] In the past two years, in order to tap the potential of energy saving and consumption reduction, effectively reduce the unit consumption of liquid production in pumping wells, and form new energy-saving technologies, permanent magnet semi-direct drive synchronous motors are installed on the pumping units, which can eliminate the belt drive system and directly drive the input shaft of the pumping unit. Through field tests such as testing, energy saving effect comparison, motor selection calculation, and noise testing, an average active power saving rate of 16.05% and a system efficiency improvement of 2.96% are achieved, with very obvious energy-saving and environmental protection effects.

[0004] At present, this type of permanent magnet semi-direct drive synchronous motor is relatively large, with a generally oblate structure of about 0.5-2 meters in diameter. The outer shell adopts a split splicing and welding structure. It is difficult to control the precision of the inner diameter of the outer shell. When the stator is installed, two unfavorable conditions will occur: one is that the gap between the stator and the outer shell is large after installation, and the motor stability is poor; the other is that the stator and the outer shell have an interference fit, and violent installation such as violent impact and hammering is required to enter the outer shell. Violent press-fitting is prone to quality defects, and the structure causes stress concentration in related components. There is a risk of fatigue failure under long-term high-load work. In addition, excessive interference will cause local performance distortion of the stator core, resulting in increased AC loss and stray loss of the motor. In either case, the stator is finally connected and fixed to the outer shell by welding, which makes the later maintenance of the motor difficult and costly. Utility Model Content

[0005] The utility model aims to overcome the deficiencies of the prior art and provide an easy-to-assemble semi-direct-drive permanent magnet synchronous motor for an oil pumping unit.

[0006] The main technical solution adopted by the easy-to-assemble semi-direct-drive permanent magnet synchronous motor for oil pumping units provided by the utility model is: it includes a shell, a stator and a rotor arranged in the shell, the shell includes a middle shell, a front cover and a rear cover arranged at both ends of the middle shell; the middle shell and the stator are transitionally matched, and a limiting ring is provided on the inner wall of the middle shell along the circumferential direction, one end of the stator is against the limiting ring, and is fixedly connected to the limiting ring through a locking member.

[0007] The semi-direct drive permanent magnet synchronous motor for oil pumping units provided by the utility model, which is easy to assemble, also adopts the following auxiliary technical solutions:

[0008] Preferably, a pressure plate is provided at the other end of the stator, and the locking member passes through the pressure plate and the stator in sequence and is fixed to the limiting ring.

[0009] Preferably, the pressing plate is an arc-shaped structure, there are multiple pressing plates and they are evenly attached to the edge of the stator, and a gap is formed between two adjacent pressing plates.

[0010] Preferably, a flat key is provided on the inner wall of the middle shell, a key slot is provided on the outer wall of the stator, and the flat key and the key slot are limitedly matched.

[0011] Preferably, a key slot is provided on the inner wall of the middle shell, the bottom end of the flat key is inserted into the key slot and fixed to the middle shell, and the top end of the flat key is exposed outside and protrudes from the key slot.

[0012] Preferably, the flat key is arranged on the inner wall of the middle shell near the bottom, a water collection groove is arranged at the position corresponding to the flat key on the limiting ring, a drainage hole is arranged at the position of the front cover or the rear cover opposite to the water collection groove, and a removable blocking bolt is arranged in the drainage hole.

[0013] Preferably, the middle shell is an integrally formed structure.

[0014] Preferably, the middle shell and the limiting ring are an integrally formed structure.

[0015] Preferably, the middle shell is a structure that penetrates from left to right.

[0016] Preferably, the shell further comprises a mounting seat, and the bottom of the middle shell is provided with mounting feet, which are fixedly connected to the mounting seat.

[0017] Compared with the prior art, the semi-direct drive permanent magnet synchronous motor for oil pumping units provided by the utility model has the following advantages: the scheme sets the middle shell and the stator as a transition fit, which ensures the smoothness of the stator insertion process into the middle shell, and the product processing precision is high. When the stator is inserted into the middle shell, there is no need to use a critical hammer to avoid stator damage or invisible damage, which will bury hidden dangers for later use. The product yield is high, which helps to reduce production costs; because the middle shell adopts an integrated molding structure, even if there is interference between the two, the interference is much smaller than the interference fit commonly adopted in the industry, and a smaller pressing force can be used to complete the stator assembly into the shell process, ensuring a smooth process and a high yield. At the same time, a locking piece is used to lock the stator and the limit ring together. The setting of the limit ring also helps the stator to be quickly installed in place in the middle shell, eliminating the process of angle adjustment. It only needs to ensure that one end of the stator is against the limit ring and locked with a locking piece. The fixation is reliable and convenient, the overall assembly efficiency is high, and the stator maintenance is convenient in the later stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural exploded view of the utility model.

[0019] Figure 2 This is a structural diagram of the utility model without the rear end cover.

[0020] Description of Figure Numbers:

[0021] 1 middle shell, 11 limiting ring, 12 keyway, 13 water storage tank, 14 mounting foot;

[0022] 2 front end cover;

[0023] 3 rear end cover, 31 drainage hole;

[0024] 4 stator, 41, keyway;

[0025] 5 rotors;

[0026] 6. Pressing plate;

[0027] 7 flat keys;

[0028] 8 plugging bolts;

[0029] 9 Mounting Seat. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0031] See also Figure 1 and Figure 2According to an embodiment of the semi-direct-drive permanent magnet synchronous motor for an oil pumping unit that is easy to assemble provided by the utility model, the motor comprises a housing, a stator 4 and a rotor 5 arranged in the housing, wherein the housing comprises a middle housing 1, a front end cover 2 and a rear end cover 3 arranged at both ends of the middle housing 1; the middle housing 1 and the stator 4 are transitionally matched, and a limiting ring 11 is provided on the inner wall of the middle housing 1 along the circumferential direction, and one end of the stator 4 rests on the limiting ring 11 and is fixedly connected to the limiting ring 11 through a locking member. The locking piece is a bolt. The above scheme sets the middle shell 1 and the stator 4 as a transition fit. The selection principle of the transition fit is that the limit deviation of the outer diameter of the stator 4 is designed according to p8, and the limit deviation of the inner diameter of the matching surface of the middle shell 1 is designed according to H8, so that the maximum clearance and maximum interference of the generated transition fit are guaranteed to be within a reasonable range; the smoothness of the process of inserting the stator 4 into the middle shell 1 is guaranteed, and the product processing accuracy is high. When the stator 4 is inserted into the middle shell 1, there is no need to use a critical hammer to avoid damage to the stator 4 or invisible damage, which will bury hidden dangers for later use. The product yield is high, which helps to reduce production costs; at the same time, the stator 4 is locked together with the limit ring 11 by a locking piece. The setting of the limit ring 11 also helps the stator 4 to be quickly installed in place in the middle shell 1, eliminating the process of axial adjustment of the stator. It is only necessary to ensure that one end of the stator 4 is against the limit ring 11 and locked with a locking piece. The fixation is reliable and convenient, the overall assembly efficiency is high, and the maintenance of the stator 4 is convenient in the later stage.

[0032] See also Figure 1 and Figure 2 According to the above-mentioned embodiment of the utility model, a pressure plate 6 is provided at the other end of the stator 4, and the locking member passes through the pressure plate 6 and the stator 4 in sequence and is fixed to the limit ring 11. The arrangement of the pressure plate 6 makes the edge of the other end of the stator 4 more evenly stressed, thus preventing the bolts from causing extrusion damage to the stator 4.

[0033] See also Figure 1 and Figure 2 According to the above-mentioned embodiment of the utility model, the pressing plate 6 is an arc-shaped structure, and there are multiple pressing plates 6 that are evenly attached to the edge of the stator 4, and a gap is formed between two adjacent pressing plates 6. The pressing plate 6 is set as an arc-shaped split structure, and the assembly process is more flexible and simple; it helps to reduce the production cost of the pressing plate 6, avoid a large amount of waste of material plates, and further reduce the production cost. Bolt holes are provided on the pressing plate 6, the stator 4, and the limit ring 11.

[0034] See also Figure 1 and Figure 2 According to the above-mentioned embodiment of the utility model, the inner wall of the middle shell 1 is provided with a flat key 7, and the outer wall of the stator 4 is provided with a key slot 41, and the flat key 7 is limitedly matched with the key slot 41. The provision of the flat key 7 assists the connection strength between the middle shell 1 and the stator 4, reduces the force strength of the locking member, improves the reliability and stability of the product, and at the same time improves the installation accuracy of the product.

[0035] See also Figure 1 and Figure 2 According to the above-mentioned embodiment of the utility model, the inner wall of the middle shell 1 is provided with a key groove 12, the bottom end of the flat key 7 is inserted into the key groove 12 and fixed to the middle shell 1, and the top end of the flat key 7 is exposed and protrudes from the key groove 12. The flat key 7 is fixed in the key groove 12 by bolts. The flat key 7 is arranged on the middle shell 1 in this split structure, which facilitates the processing and casting of the middle shell 1, and the installation is more flexible, and the size and height of the flat key 7 can be flexibly adjusted and replaced according to actual conditions.

[0036] See also Figure 1 and Figure 2 According to the above-mentioned embodiment of the utility model, the flat key 7 is arranged on the inner wall of the middle shell 1 near the bottom, the position corresponding to the flat key 7 on the limit ring 11 is provided with a water accumulation groove 13, and the position opposite to the water accumulation groove is provided with a drainage hole 31 on the front cover 2 or the rear cover 3. The drainage hole 31 in this embodiment is arranged on the rear cover 3, and a removable plugging bolt 8 is arranged in the drainage hole 31. Since the product mainly provides power for outdoor oil pumping units, it is inevitable that rainwater and fog will enter the shell from the shaft gap to form water accumulation in the harsh outdoor environment for a long time. The design of the water accumulation groove 13 can make the water vapor entering the shell accumulate at the bottom of the shell, effectively avoiding the contact between the accumulated water and the stator 4 coil, and improving the stability of the product operation; at the same time, the setting of the drainage hole 31 and the plugging bolt 8 facilitates the discharge of the accumulated water, and the drainage process is simple and convenient; the water accumulation groove 13 is arranged opposite to the flat key 7, so that the water accumulation groove 13 is adjacent to the key slot 12, which facilitates the slotting process, avoids the frequent displacement of the large middle shell 1, and improves the safety of the production process.

[0037] See also Figure 1 and Figure 2 According to the above-mentioned embodiment of the utility model, the middle shell 1 is an integrally formed structure. Compared with the structure of the shell in the prior art that is a split splicing and welding structure, the accuracy of the inner diameter of the shell is easy to control, which can effectively avoid the problem that the gap between the middle shell 1 and the stator 4 is too large, or too small and requires violent installation, or poor reliability.

[0038] See also Figure 1 and Figure 2 According to the above-mentioned embodiment of the utility model, the middle shell 1 and the limiting ring 11 are an integrally formed structure. The limiting ring 11 is an intermediate body connecting the middle shell 1 and the stator 4. The integrally formed limiting ring 11 with the middle shell 1 is convenient for processing and has high mechanical strength, thereby ensuring the connection strength between the stator 4 and the middle shell 1.

[0039] See also Figure 1 and Figure 2 According to the above-mentioned embodiment of the utility model, the middle shell 1 is a structure that is through-through on the left and right. For such large motors, the through-through structure of the middle shell 1 is convenient for processing, assembly and maintenance.

[0040] See also Figure 1 and Figure 2 According to the above-mentioned embodiment of the utility model, the front cover 2 and the rear cover 3 are both provided with shaft holes, and the middle part of the rotor 5 is provided with a drive shaft hole, which is opposite to the shaft holes on the front cover 2 and the rear cover 3. The housing also includes a mounting seat 9, and the bottom of the middle housing 1 is provided with a mounting foot 14, which is fixedly connected to the mounting seat 9. It is easy to assemble, has high stability, and has a wide range of adaptability.

[0041] The technical solution provided by the present invention is introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. The words such as front, back, left, right, positive and negative in this solution are all words for clear expression from a certain perspective. At the same time, for general technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. An easy-to-assemble semi-direct drive permanent magnet synchronous motor for an oil pump, comprising a housing, a stator and a rotor arranged in the housing, wherein the housing comprises a middle housing, a front cover and a rear cover arranged at both ends of the middle housing; characterized in that: The middle shell and the stator are in transitional fit, a limiting ring is circumferentially arranged on the inner wall of the middle shell, one end of the stator rests on the limiting ring and is fixedly connected to the limiting ring through a locking member.

2. The easy-to-assemble semi-direct drive permanent magnet synchronous motor for oil pumping unit according to claim 1 is characterized in that: A pressing plate is arranged at the other end of the stator, and the locking piece passes through the pressing plate and the stator in sequence and is fixed with the limiting ring.

3. The easy-to-assemble semi-direct-drive permanent magnet synchronous motor for oil pumping unit according to claim 2 is characterized in that: The pressing plate is an arc-shaped structure, and there are multiple pressing plates that are evenly attached to the edge of the stator, with a gap formed between two adjacent pressing plates.

4. The easy-to-assemble semi-direct-drive permanent magnet synchronous motor for oil pumping unit according to claim 1 is characterized in that: A flat key is arranged on the inner wall of the middle shell, and a key slot is arranged on the outer wall of the stator. The flat key and the key slot are limitedly matched.

5. The easy-to-assemble semi-direct drive permanent magnet synchronous motor for oil pumping unit according to claim 4 is characterized in that: The inner wall of the middle shell is provided with a key slot, the bottom end of the flat key is inserted into the key slot and fixed to the middle shell, and the top end of the flat key is exposed outside and protrudes from the key slot.

6. The easy-to-assemble semi-direct drive permanent magnet synchronous motor for oil pumping unit according to claim 4, characterized in that: The flat key is arranged on the inner wall of the middle shell near the bottom, a water accumulation groove is arranged at the position corresponding to the flat key on the limiting ring, a drainage hole is arranged at the position opposite to the water accumulation groove of the front cover or the rear cover, and a detachable blocking bolt is arranged in the drainage hole.

7. The easy-to-assemble semi-direct drive permanent magnet synchronous motor for oil pumping unit according to any one of claims 1 to 6, characterized in that: The middle shell is an integrally formed structure.

8. The easy-to-assemble semi-direct drive permanent magnet synchronous motor for oil pumping unit according to any one of claims 1 to 6, characterized in that: The middle shell and the limiting ring are an integrally formed structure.

9. The easy-to-assemble semi-direct drive permanent magnet synchronous motor for oil pumping unit according to any one of claims 1 to 6, characterized in that: The middle shell is a structure that penetrates from left to right.

10. The easy-to-assemble semi-direct drive permanent magnet synchronous motor for oil pumping unit according to any one of claims 1 to 6, characterized in that: The shell body also includes a mounting seat, and the bottom of the middle shell is provided with mounting feet, which are fixedly connected to the mounting seat.

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