Electric wrench

Abstract

The utility model belongs to the field of portable motor tools for screwing or loosening screws or nuts, and particularly relates to an electric wrench. The electric wrench comprises a driving motor, an output shaft of the driving motor is connected with a driving gear, the driving gear is meshed with a driven gear with a center hole, and a nut sleeve is in key connection with the interior of the center hole of the driven gear. The nut sleeve is installed in the center hole of the driven gear in a key connection mode, the nut sleeve is arranged on a nut needing to be disassembled and assembled in a sleeved mode in the using process, the operation space of the nut disassembling and assembling position can be saved, the structure is compact, and the disassembling and assembling requirements of various working conditions of an oil field site are met. Besides, the nut sleeve is fixed in the circumferential direction of the center hole of the driven gear in a key connection mode, torque transmission and movement reliability is guaranteed, nuts of different sizes can be disassembled and assembled by replacing the nut sleeves of different specifications, and the applicability of an oil field site is good.

Description

Technical Field

[0001] The utility model belongs to the field of portable motor-driven tools for tightening or loosening screws or nuts, and particularly relates to an electric wrench. Background Art

[0002] In oil fields, especially when installing and removing nuts on wellhead flanges, due to the large size of the nuts, the torque required for nut disassembly is also large. In the past, large and long mechanical wrenches were often used, even with force bars, to complete normal disassembly and assembly. The disassembly and assembly process is not only time-consuming and labor-intensive, but also prone to safety accidents due to tool slippage. Electric wrenches drive the corresponding sleeve to rotate through the work of the motor, thereby realizing the disassembly and assembly of large nuts. The use of electric wrenches can greatly reduce the workload of disassembling and assembling large nuts in oil fields and ensure operational safety.

[0003] A Chinese utility model patent with an authorization announcement date of August 21, 2013 and an authorization announcement number of CN203141396U discloses an electric wrench, which includes a driving gear connected to the output shaft of a driving motor, two transmission gears meshing with the driving gear, and an internal gear meshing with the two transmission gears and located on the outer periphery of the transmission gear, and a sleeve joint is integrally connected to the outer side of the internal gear; the sleeve joint can be used with sleeves of different models, so that nuts or bolts of different specifications can be disassembled and assembled.

[0004] The above electric wrenches with gear transmission are characterized by high transmission accuracy, low torque loss, and are suitable for transmission of large torques and stable operation. The nuts used in oil field well tools have many specifications and different installation positions. The disassembly and assembly space of some nuts is very limited. Although the above electric wrenches have paid attention to the problem of use in small areas, the gear shafts and sleeve joints of the driving gear and driven gear are all located within the upper and lower projection ranges of the internal gear. After the sleeve joint is connected to the sleeve, the space occupied in the disassembly and assembly direction of the nut will be larger.

[0005] In order to solve this problem, the electric wrench involved in CN203141396U is a set of sleeve accessories designed separately, and its sleeve accessories are composed of a vertical rod, a small bevel gear, a large bevel gear, a gear housing and a flat rod. The upper end of the vertical rod has an inner square joint that matches the sleeve joint, the lower end of the vertical rod is connected to the small bevel gear, the small bevel gear is meshed with the large cone gear, the large cone gear is connected to one end of the flat rod, and the other end of the flat rod has an outer square joint that matches the sleeve head for disassembling or tightening the bolt, thereby meeting the problem of disassembling and tightening nuts in a small space. However, the problem brought about by this is that the complexity of the electric wrench structure increases, the torque loss increases, and the stability of operation decreases. Utility Model Content

[0006] The purpose of the present utility model is to provide an electric wrench to solve the problem that the existing electric wrench is difficult to balance the structural simplicity and the use in the narrow space for disassembling and assembling nuts.

[0007] To achieve the above purpose, the technical solution adopted by the present utility model is:

[0008] An electric wrench includes a driving motor, the output shaft of the driving motor is connected with a driving gear, the driving gear meshes with a driven gear having a central hole, and a nut sleeve is key-connected in the central hole of the driven gear.

[0009] The present utility model belongs to an improved invention. The nut sleeve is installed in the central hole of the driven gear by a key connection method. During use, the nut sleeve is sleeved on the nut to be disassembled and assembled, which can save the operation space at the nut disassembly and assembly position, has a compact structure and meets the disassembly and assembly requirements of various working conditions at the oilfield site. In addition, the key connection method is used to fix the nut sleeve in the circumferential direction of the central hole of the driven gear, which ensures the torque transmission and motion reliability, and different sizes of nuts can be disassembled and assembled by replacing nut sleeves of different specifications, and it has good applicability at the oilfield site.

[0010] Preferably, a key groove with a groove bottom wall is formed on the inner wall of the central hole of the driven gear, and a key block matched with the key groove is arranged on the nut sleeve; threaded holes are correspondingly formed on the groove bottom wall of the key groove and the key block, and a bolt is installed in the threaded hole to fix the key block on the groove bottom wall of the key groove.

[0011] Further preferably, the threaded hole on the groove bottom wall of the key groove is a stepped hole, the nut of the bolt sinks into the stepped hole, and an anti-slip rubber ring is further arranged between the nut of the bolt and the inner wall surface of the corresponding stepped hole.

[0012] Preferably, the driving gear and the driven gear are installed in a base, guiding blocks are arranged on the end faces at the upper and lower ends of the driven gear, guiding annular grooves matched with the guiding blocks are formed on the base, and the guiding blocks are embedded into the corresponding guiding annular grooves to guide the rotation of the driven gear.

[0013] Further preferably, an installation cavity for installing the driving gear and the driven gear is arranged in the base, the base is of an upper and lower split structure, and the installation cavity of the base is formed by splicing the upper and lower split structures.

[0014] Further preferably, a shock-absorbing rubber pad is connected to the bottom end of the base.

[0015] Preferably, anti-slip lines are arranged on the inner wall surface of the nut sleeve.

[0016] Further preferably, a housing for installing a motor and an output shaft is connected to the end of the base corresponding to the driving gear. A driving rod is connected to one side of the housing, a motor switch is arranged on the driving rod, and a connection socket is arranged at the end of the driving rod.

[0017] More preferably, a dust-proof cover is hinged at the connection socket.

[0018] More preferably, a handle is provided on the other side of the housing, and a wavy finger groove is formed on the handle. Description of the Drawings

[0019] Figure 1 is a schematic diagram of the overall structure of Embodiment 1 of the present utility model;

[0020] Figure 2 is a schematic diagram of the overall partial sectional structure of Embodiment 1 of the present utility model;

[0021] Figure 3 is a schematic diagram of the overall bottom-up sectional structure of Embodiment 1 of the present utility model;

[0022] Figure 4 is a schematic diagram of the exploded structure at the driven gear of Embodiment 1 of the present utility model;

[0023] Figure 5 is a schematic diagram of the enlarged partial structure at the key connection of Embodiment 1 of the present utility model;

[0024] Figure 6 is Figure 2 a schematic diagram of the longitudinal section structure in

[0025] Figure 7 is Figure 3 a schematic diagram of the enlarged structure at A in

[0026] Wherein, 1 - driving gear; 2 - driven gear; 3 - base; 4 - housing; 5 - installation cavity; 6 - nut sleeve; 7 - keyway; 8 - key block; 9 - bolt hole; 10 - bolt; 11 - rubber ring; 12 - guide block; 13 - guide ring groove; 14 - motor; 15 - driving rod; 16 - connection socket; 17 - dust-proof assembly, 170 - dust-proof cover, 171 - iron dial block, 172 - magnetic attraction block; 18 - handle; 180 - finger groove; 19 - rubber pad; 20 - silica gel pad; 21 - anti-slip pattern. Detailed Embodiment

[0027] The electric wrench of the present utility model mainly consists of a driving motor, a driving gear connected to the output shaft of the driving motor, a driven gear meshing with the driving gear and having a central hole, and a nut sleeve key-connected in the central hole of the driven gear. When disassembling and assembling nuts, only the driven gear and the nut sleeve extend into the nut disassembly and assembly space, so the use requirements of most narrow nut disassembly and assembly spaces can be met. In addition, the nut sleeve is key-connected in the central hole of the driven gear, ensuring the reliability of circumferential transmission and greatly reducing torque loss; the key connection method also gives the nut sleeve the convenience of disassembly and replacement, which is applicable to the disassembly and assembly requirements of nuts of different sizes and specifications (the nut sleeve with the corresponding inner hole specification needs to be replaced), and is also applicable to quickly replacing the nut sleeve when the inner part of the sleeve is severely worn.

[0028] Furthermore, through the further optimization of structures such as key connection and base, the operating reliability, safety, etc. of the electric wrench can be correspondingly improved, and it has good practicability in the process of disassembling and assembling nuts at the oilfield site.

[0029] The implementation situation of the present utility model will be described in detail below in combination with specific embodiments.

[0030] Embodiment 1

[0031] The electric wrench of this embodiment, as Figures 1 to 3 shown, includes a base 3 provided with a driving gear 1 and a driven gear 2, and a housing 4 connected to one end of the driving gear of the base 3.

[0032] The base 3 has an installation cavity 5 for installing the driving gear 1 and the driven gear 2, and the driven gear 2 meshes with the driving gear 1. A nut sleeve 6 is key-connected in the central hole of the driven gear 2, and the inner hole of the nut sleeve 6 matches the nut to be disassembled and assembled. In this way, when the motor drives the driving gear 1 to rotate, it drives the driven gear 2 and the nut sleeve 6 to rotate, so as to realize the quick and labor-saving disassembly and assembly of the nut.

[0033] See Figure 4 and Figure 5 , a key groove 7 extending along the axial direction of the central hole is formed on the hole wall of the central hole of the driven gear 2, and the upper end of the key groove 7 is open and the lower end is closed. A key block 8 matching the key groove 7 is correspondingly provided on the nut sleeve 6. During use, the key block 8 is inserted into the key groove 7 from the upper end, and the nut sleeve 6 is key-connected to the driven gear 2 to realize the circumferential fixation of the nut sleeve 6 on the central hole of the driven gear 2. In order to further realize the axial fixation of the nut sleeve 6 on the central hole of the driven gear 2 and further improve the stability and safety during the nut disassembly and assembly process, bolt holes 9 are correspondingly formed on the bottom wall of the key groove 7 and the bottom of the key block 8, and bolts 10 are inserted into the bolt holes 9 to realize the axial fixed connection between the nut sleeve 6 and the driven gear 2.

[0034] The bolt hole on the bottom wall of the keyway 7 is a stepped hole. After the bolt 10 is tightened in the bolt hole 9, the nut of the bolt 10 sinks into the stepped hole, and a rubber ring 11 is also provided between the nut of the bolt 10 and the inner wall surface of the stepped hole. The rubber ring 11 increases the friction between the nut of the bolt 10 and the inner wall of the stepped hole, avoiding the loosening of the thread of the bolt 10 and affecting the firm stability of the installation of the nut sleeve 6.

[0035] In this embodiment, three keyways 7 are equally angularly distributed on the inner wall of the central hole of the driven gear 2, and three sets of corresponding key blocks 8, bolts 10 and other components are correspondingly provided, so as to ensure the firm stability of the installation between the nut sleeve 6 and the driven gear 2.

[0036] To realize the rotational assembly of the driven gear 2 in the base 3, guide blocks 12 are provided at intervals along the circumferential direction on the upper and lower end faces of the driven gear 2. The installation cavity 5 of the base 3 is surrounded by an upper cavity wall, a lower cavity wall and a side cavity wall. Guide ring grooves 13 corresponding to the guide blocks 12 on the upper and lower end faces of the driven gear 2 are opened on the upper cavity wall and the lower cavity wall. The guide blocks 12 are embedded in the guide ring grooves 13 to realize the rotational assembly of the driven gear 2 in the installation cavity 5 of the base. In this embodiment, there are five guide blocks 12 on each of the upper and lower end faces of the driven gear 2, and they are equally angularly arranged in the circumferential direction. By using the sliding of the guide blocks 12 inside the guide ring grooves 13, the rotation of the driven gear 2 is made more stable.

[0037] See Figure 2 , the base is designed with an upper and lower split structure, consisting of an upper seat body and a lower seat body. The installation cavity 5 of the base 3 is formed by the upper seat body and the lower seat body being joined together. The above split structure design facilitates the installation of the driving gear 1 and the driven gear 2 in the installation cavity 5. After the relevant components are installed, the upper seat body and the lower seat body are locked and fixed together by bolts.

[0038] Figure 2 and Figure 6 In, a housing 4 is installed at one end of the driving gear 1 of the base 3. A motor 14 is fixedly connected inside the housing 4. The motor 14 drives and connects the driving gear 1 through a connecting shaft. One side of the housing 4 is connected with a driving rod 15. A motor switch (not shown in the figure) is arranged on the driving rod 15. A connecting socket 16 is arranged at the end of the driving rod 15. After the external power cord is plugged into the connecting socket 16 and powered on, the motor 14 can be controlled to work through the motor switch, and then the disassembly and assembly operation of the nut can be realized.

[0039] Embodiment 2

[0040] The electric wrench of this embodiment includes a base and a housing. The designs of the driving gear and the driven gear in the base and the design of the motor in the housing are the same as those in Embodiment 1. As Figure 1 , Figure 6 and Figure 7As shown, a drive rod 15 is connected to one side of the housing 4. To prevent dust and other impurities from entering the inside when the connection socket 16 is not in use and achieve dust protection, a dust-proof component 17 is also provided at the connection socket 16. The dust-proof component 17 includes a dust-proof cover 170 hinged to the connection socket 16 at one end, an iron block 171 provided at the other end of the dust-proof cover 170, and a magnetic block 172 provided on the connection socket 16 and cooperating with the iron block 171. By using the magnetic attraction fixation between the magnetic block 172 and the iron block 171, the dust-proof cover 170 is fixed after deflection, and thus one side of the connection socket 16 can be completely blocked and sealed to prevent dust and other impurities from entering the inside of the connection socket 16.

[0041] Figure 1 In [description], on the other side of the housing 4 opposite to the drive rod 15, a handle 18 is provided. A wavy finger groove 180 is formed on the inner wall of the handle 18, which can improve the comfort of the user holding the handle 18.

[0042] As Figure 2 shown, a rubber pad 19 is fixedly connected to the bottom end of the base 3. The rubber pad 19 is provided with a corresponding notch at one end corresponding to the driven gear 2 to avoid affecting the nut from being sleeved into the nut sleeve 6. The rubber pad 19 realizes the flexible contact between the bottom of the base 3 and the contact surface, and thus can achieve simple buffering and shock absorption between the two.

[0043] The front end of the base 3 is arc-shaped and is provided with an arc-shaped silica gel pad 20. By using the arc-shaped silica gel pad 20, when the base 3 is carried, a hard collision at its front end can be avoided.

[0044] In addition, as Figure 2 shown, anti-slip lines 21 are provided inside the nut sleeve 6 to increase the contact friction between the inner wall of the nut sleeve 6 and the surface of the nut. The anti-slip lines 21 are arranged in two rows up and down on the inner wall of the nut sleeve 6, and the distance between adjacent anti-slip lines in each row is equal. The cross-sectional shape of the anti-slip lines 21 is rectangular to facilitate processing and enhance the contact friction.

[0045] The working principle and usage process of the electric wrench in the above embodiments are described as follows:

[0046] First, select a nut sleeve 6 of different sizes according to the nut to be disassembled and assembled. Use a tool such as a screwdriver to rotate the bolt 10 until it is completely separated from the inside of the bolt hole 9. Then, push the nut sleeve 6 forcefully so that the key block 8 is completely separated from the inside of the key groove 7 to achieve disassembly. Subsequently, install a suitable nut sleeve 6, snap the key block 8 into the inside of the key groove 7, and then rotate the bolt 10 until it completely enters the bolt hole 9 to achieve a firm snap fit and fixation between the key block 8 and the inside of the key groove 7. Thus, the disassembly and assembly between the nut sleeve 6 and the driven gear 2 can be realized, which is convenient for it to be applicable to nuts of different sizes and specifications. At the same time, it can also quickly replace the nut sleeve 6 when the inside of the nut sleeve 6 is severely worn.

[0047] Afterwards, turn the iron block 171 to deflect and open the dust cover 170. Then, the external power cord can be inserted into the connection socket 16 for power supply. Then, the staff holds the handle 18 with one hand and the driving rod 15 with the other hand, carries the base 3 to a suitable position, and makes the lower opening of the nut sleeve 6 cover the nut. After that, press the switch on the driving rod 15 to start the motor 14 inside the housing 4, thereby driving the driving gear 1 to rotate. By using the meshing of the driving gear 1 and the driven gear 2, the driven gear 2 rotates to drive the nut sleeve 6 to rotate, thereby realizing the disassembly and assembly actions of the nut;

[0048] Meanwhile, when not in use, unplug the power cord, deflect the dust cover 170, and use the magnetic attraction between the magnetic block 172 and the iron block 171 for fixation, so as to fix the deflected dust cover 170, completely cover and seal one side of the connection socket 16, and prevent dust and other impurities from entering the inside of the connection socket 16.

[0049] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An electric wrench, comprising a driving motor, wherein the output shaft of the driving motor is connected to a driving gear, characterized in that: The driving gear is meshed with a driven gear having a center hole, and a nut sleeve is keyed in the center hole of the driven gear; the driving gear and the driven gear are installed in the base, and guide blocks are provided on the end faces at the upper and lower ends of the driven gear. The base is provided with a guide ring groove matching the guide block, and the guide block is embedded in the corresponding guide ring groove to guide the driven gear to rotate.

2. The electric wrench according to claim 1, characterized in that: A keyway with a bottom wall is provided on the wall of the central hole of the driven gear, and a key block matching the keyway is provided on the nut sleeve; threaded holes are correspondingly provided on the bottom wall of the keyway and the key block, and bolts are installed in the threaded holes to fix the key block on the bottom wall of the keyway.

3. The electric wrench according to claim 2, characterized in that: The threaded hole on the bottom wall of the keyway is a stepped hole, the nut of the bolt is sunk into the stepped hole, and an anti-slip rubber ring is arranged between the nut of the bolt and the corresponding inner wall of the stepped hole.

4. The electric wrench according to claim 1, characterized in that: An installation cavity for installing the driving gear and the driven gear is arranged in the base, and the base is an upper and lower split structure, and the installation cavity of the base is formed by splicing the upper and lower split structures.

5. The electric wrench according to claim 1, characterized in that: The bottom end of the base is connected with a shock-absorbing rubber pad.

6. The electric wrench according to claim 1, characterized in that: Anti-slip grooves are arranged on the inner wall surface of the nut sleeve.

7. The electric wrench according to claim 1, characterized in that: A housing for mounting a motor and an output shaft is connected to the end of the base corresponding to the driving gear, a driving rod is connected to one side of the housing, a motor switch is arranged on the driving rod, and a connecting socket is arranged at the end of the driving rod.

8. The electric wrench according to claim 7, characterized in that: A dust cover is hingedly connected to the connection socket.

9. The electric wrench according to claim 7, characterized in that: A handle is provided on the other side of the shell, and a wave-shaped finger groove is provided on the handle.

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