Rotary impact tool

Abstract

The utility model relates to an electric tool, in particular to a rotary impact tool. The rotary impact tool comprises a driving part, an impact part and an output shaft, the driving part comprises a driving motor and a main shaft in transmission connection with the driving motor, the impact part comprises an impact mechanism, a base and an impact shell containing the impact mechanism and an anvil block, and the impact mechanism is in transmission connection with the main shaft; the impact mechanism can rotate around the main shaft and can do reciprocating motion in the axis direction of the main shaft, the anvil block and the main shaft are coaxially arranged, the anvil block is in transmission connection with the main shaft, the anvil block is supported on the impact shell in a rotatable mode, and the anvil block does reciprocating motion under the striking action of the impact mechanism in the axis direction of the main shaft. The output shaft is in transmission connection with the anvil block. The anvil block is supported by the ball bearing, and sliding friction is converted into rolling friction, so that the problem of friction heating under high-frequency impact is reduced, the service life of the tool is prolonged, and the influence of overheating on the performance of the tool is reduced.

Description

Technical Field

[0001] The utility model relates to an electric tool, in particular to a rotary impact tool. Background Art

[0002] Current electric rotary impact tools on the market face several practical challenges, particularly at high speeds and high power. Existing rotary impact tools, particularly those using sliding friction bearings, often generate significant friction during anvil rotation, leading to overheating after prolonged and frequent use. Overheating not only reduces the tool's service life but also causes the output shaft to vibrate, further deforming the tool's head. Utility Model Content

[0003] The purpose of the present invention is to at least solve the problem of overheating of the anvil of a rotary impact tool during operation. This purpose is achieved through the following technical solutions:

[0004] A first aspect of the present invention provides a rotary impact tool, characterized in that it comprises:

[0005] A driving unit, comprising a driving motor and a main shaft drivingly connected to the driving motor;

[0006] an impact portion, the impact portion comprising an impact mechanism, an anvil, and an impact housing for accommodating the impact mechanism and the anvil, the impact mechanism being transmission-connected to the main shaft in a manner that rotates about the main shaft and can reciprocate along the axis of the main shaft, the anvil being coaxially arranged with the main shaft and transmission-connected thereto, the anvil being rotatably supported by the impact housing, and reciprocating along the axis under the action of the impact mechanism;

[0007] An output shaft is transmission-connected to the anvil.

[0008] According to the rotary impact tool of the present invention, first, the driving motor provides rotational power through the main shaft to drive the operation of the entire tool. Then, the impact mechanism is connected to the main shaft by transmission. While the impact mechanism rotates around the main shaft, it can also make reciprocating motion along the axis of the main shaft, and the impact mechanism transmits the impact force to the anvil by striking the anvil. The anvil is coaxially arranged with the main shaft and is supported in the impact housing in a rotatable manner, so that the anvil can rotate stably and reciprocate in the axis direction. This arrangement reduces friction and enables the anvil to maintain good movement stability under high-frequency impact. Finally, the output shaft is connected to the anvil by transmission, and the rotation and impact motion of the anvil are further transmitted to the component that needs to perform the work, thereby realizing the rotary impact function of the tool. The utility model adopts a rotatable support for the anvil, replacing the traditional sliding bearing structure, converting sliding friction into rolling friction, thereby significantly reducing the friction heating problem under high-frequency impact, extending the service life of the tool, and reducing the impact of overheating on the tool performance. At the same time, by setting the anvil coaxially with the main shaft, the rotation and axial reciprocating motion of the anvil are smoother, effectively reducing the torsional instability problem caused by vibration, thereby improving the overall output accuracy of the tool.

[0009] In addition, the rotary impact tool according to the present invention may also have the following additional technical features:

[0010] In some embodiments of the present invention, the anvil includes a shaft and a striking arm, the shaft is coaxially arranged with the main shaft, the shaft is rotatably supported on the impact shell through a rolling bearing, the striking arm extends radially along the circumference of the shaft, the striking arm can be struck by the impact mechanism, a gasket is sandwiched between the striking arm and the impact shell, and the inner diameter of the gasket is smaller than the outer diameter of the rolling bearing.

[0011] In some embodiments of the present invention, an annular boss is provided on the side of the impact shell facing the anvil, and the outer circumferential surface of the gasket abuts against the inner circumferential surface of the annular boss.

[0012] In some embodiments of the present invention, a chamfer is provided at a connection between the shaft portion and the struck arm on a side of the shaft portion facing the output shaft.

[0013] In some embodiments of the present invention, the anvil is provided with a groove, and the main shaft is provided with a protrusion, and the protrusion is inserted into the groove to drive the anvil to rotate.

[0014] In some embodiments of the present invention, two rolling bearings are arranged side by side along the axis direction.

[0015] In some embodiments of the present invention, an O-ring is sandwiched between the inner ring of the rolling bearing and the outer peripheral wall of the anvil.

[0016] In some embodiments of the present invention, a retaining spring is provided on one side of the outer ring of the rolling bearing, and the other side of the outer ring of the rolling bearing abuts against the impact housing.

[0017] In some embodiments of the present invention, the driving portion includes a planetary gear, and the output end of the driving motor is transmission-connected to the main shaft via the planetary gear.

[0018] In some embodiments of the present invention, a cam groove is provided on the outer circumference of the main shaft, and an inclination angle is formed between the cam groove and the axis of the main shaft. The inner circumference of the impact mechanism is provided with a snap-fitting groove that cooperates with the cam groove, and a steel ball is sandwiched between the cam groove and the snap-fitting groove. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference numerals are used throughout the accompanying drawings to denote the same components. In the accompanying drawings:

[0020] Figure 1 Schematically shows a structural diagram of a rotary impact tool according to an embodiment of the present utility model;

[0021] Figure 2 Schematically shows a front view of a rotary impact tool according to an embodiment of the present invention;

[0022] Figure 3 for Figure 2 Sectional view of the AA plane;

[0023] Figure 4 for Figure 3 A partial enlarged view of point B in the middle.

[0024] The reference numerals are as follows:

[0025] 100. Rotary impact tool;

[0026] 10. Driving unit; 11. Driving motor; 12. Main shaft; 121. Protrusion; 13. Planetary gear;

[0027] 20. Impact part; 21. Impact mechanism; 22. Anvil; 221. Shaft; 222. Impact arm; 223. Groove; 224. Chamfer; 23. Impact housing; 231. Annular boss; 24. Ball bearing;

[0028] 30. Output shaft; 40. Gasket; 50. Circlip. DETAILED DESCRIPTION

[0029] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0030] It should be understood that the terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "comprise", "include", "contain" and "have" are inclusive and therefore specify the presence of stated features, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring them to be performed in the specific order described or illustrated, unless the order of execution is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0031] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates otherwise, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0032] For ease of description, spatially relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figures, such as "inside," "outside," "inside," "outside," "below," "beneath," "above," and the like. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is flipped over, an element described as "below" or "beneath" another element or feature would then be oriented "above" or "above" the other element or feature. Thus, the example term "below" can encompass both above and below orientations.

[0033] like Figures 1 to 4 As shown, according to an embodiment of the present invention, a rotary impact tool 100 is provided. The rotary impact tool 100 includes a drive unit 10, an impact unit 20, and an output shaft 30. The drive unit 10 includes a drive motor 11 and a spindle 12 transmission-connected to the drive motor 11. The impact unit 20 includes an impact mechanism 21, a seat, and an impact housing 23 that accommodates the impact mechanism 21 and an anvil 22. The impact mechanism 21 is transmission-connected to the spindle 12 and is capable of rotating about the spindle 12 and reciprocating along the axis of the spindle 12. The anvil 22 is coaxially arranged with the spindle 12 and transmission-connected thereto. The anvil 22 is rotatably supported on the impact housing 23. Along the axis of the spindle 12, the anvil 22 can reciprocate under the impact of the impact mechanism 21. The output shaft 30 is transmission-connected to the anvil 22. Specifically, a rolling bearing of the anvil 22 is rotatably supported on the impact housing 23.

[0034] According to the rotary impact tool 100 of the present invention, first, the driving motor 11 provides rotational power through the main shaft 12 to drive the operation of the entire tool. Then, the impact mechanism 21 is connected to the main shaft 12 by transmission. While the impact mechanism 21 rotates around the main shaft 12, it can also make reciprocating motion along the axis direction of the main shaft 12, and the impact mechanism 21 transmits the impact force to the anvil 22 by striking the anvil 22. The anvil 22 is coaxially arranged with the main shaft 12 and supported in the impact housing 23 by rolling bearings, so that the anvil 22 can rotate stably and reciprocate in the axis direction. The rolling bearings reduce friction, so that the anvil 22 can maintain good movement stability under high-frequency impact. Finally, the output shaft 30 is connected to the anvil 22 by transmission, and the rotation and impact motion of the anvil 22 are further transmitted to the parts that need to perform the work, thereby realizing the rotary impact function of the tool. This utility model utilizes rolling bearings to support the anvil 22, replacing the traditional sliding bearing structure. This converts sliding friction into rolling friction, significantly reducing frictional heating under high-frequency impacts, extending the tool's service life, and mitigating the impact of overheating on tool performance. Furthermore, by coaxially positioning the anvil 22 with the spindle 12 and supporting it via rolling bearings, the anvil 22's rotation and axial reciprocating motion are more stable, effectively reducing torsional instability caused by oscillation, thereby improving the tool's overall output precision.

[0035] Specifically, the rolling bearing may be a ball bearing 24 or a tapered roller bearing. The following embodiments are described using the ball bearing 24 as an example.

[0036] In some embodiments, the anvil 22 includes a shaft 221 and a striking arm 222. The shaft 221 is coaxial with the main shaft 12 and rotatably supported in the impact housing 23 via a ball bearing 24. The striking arm 222 extends radially from the shaft 221 and is capable of receiving impacts from the impact mechanism 21. A gasket 40 is interposed between the striking arm 222 and the impact housing 23. The inner diameter of the gasket 40 is smaller than the outer diameter of the ball bearing 24. The gasket 40 is positioned between the striking arm 222 and the impact housing 23, forming a sealing barrier. Due to the intense vibration and impact forces generated during the operation of the impact tool, the gasket 40 effectively seals the gaps around the bearing, preventing oil from leaking through these gaps. The inner diameter of the gasket 40 is smaller than the outer diameter of the ball bearing 24 because this design allows the gasket 40 to fit more tightly between the striking arm 222 and the impact housing 23, effectively improving sealing performance. Even under high-frequency impact and rotational motion, the gasket 40 can maintain a good sealing effect, thereby preventing the oil from leaking to the outside of the tool.

[0037] It will be appreciated that the shaft portion 221 of the anvil 22 is coaxially disposed with the main shaft 12. The shaft portion 221 is configured to withstand the rotational force from the impact mechanism 21 and transmit this rotational force to the output shaft 30. One or more impact arms 222 are circumferentially disposed around the anvil 22. These impact arms 222 extend radially from the shaft portion 221 and are designed to directly withstand the impact of the impact mechanism 21. When the impact mechanism 21 moves to a certain position, it strikes the impact arms 222 at high speed, causing the anvil 22 to rotate and impact on its axis.

[0038] In a specific embodiment, two impact arms 222 are disposed at positions bisecting the circumference of the shaft portion 221. These two impact arms 222 extend radially from the shaft portion 221 and are arranged opposite each other. Each impact arm 222 can receive an impact from the impact mechanism 21 during tool operation. Because the impact arms 222 are located at positions bisecting the circumference of the shaft portion 221, this arrangement balances the impact force distribution, reduces vibration caused by asymmetric force, and improves the stability of the rotary impact tool 100.

[0039] Furthermore, on the side of the impact shell 23 facing the anvil 22, an annular boss 231 is provided on the impact shell 23, and the outer peripheral surface of the gasket 40 abuts against the inner peripheral surface of the annular boss 231, so that the gasket 40 can be stably embedded between the impact shell 23 and the anvil 22, thereby enhancing the positioning effect of the gasket 40 and further improving the sealing performance.

[0040] Furthermore, a chamfer 224 is provided at the connection between the shaft portion 221 and the impact arm 222 on the side of the shaft portion 221 facing the output shaft 30. Providing the chamfer 224 at the connection between the shaft portion 221 and the impact arm 222 effectively reduces stress concentration and enhances the mechanical strength of the connection. This design reduces the risk of structural fatigue and fracture of the anvil 22 when subjected to high-frequency impact forces, thereby improving the overall durability of the tool. Furthermore, the chamfer 224 is relatively simple and easy to machine, allowing it to be completed without increasing the complexity of the process. This helps improve production efficiency and reduce manufacturing costs, particularly in large-scale production, where it can significantly save time and money.

[0041] In some embodiments, the anvil 22 is provided with a groove 223, and the spindle 12 is provided with a protrusion 121. The protrusion 121 is inserted into the groove 223 to drive the rotation of the anvil 22. The protrusion 121 on the spindle 12 is inserted into the groove 223 of the anvil 22. When the spindle 12 rotates, the protrusion 121 drives the groove 223 to rotate together, thereby driving the entire anvil 22 to rotate along the axis of the spindle 12. During the impact process, the impact mechanism 21 strikes the impact arm 222. While the anvil 22 is subjected to the impact force, the rotation of the spindle 12 causes the groove 223 of the anvil 22 to cooperate with the protrusion 121 of the spindle 12 to enable the anvil 22 to continue to maintain a stable rotation state, thereby effectively transmitting the impact force to the output shaft 30, realizing the striking function of the tool.

[0042] In some embodiments, two ball bearings 24 are arranged side by side along the axis of the spindle 12. These two ball bearings 24 respectively support the shaft portion 221 of the anvil 22, ensuring its stability during rotation. The support of the shaft portion 221 of the anvil 22 by these two side-by-side ball bearings 24 enables the anvil 22 to maintain a stable rotational state during the rotation of the spindle 12. Because both ball bearings 24 simultaneously bear the load from the anvil 22, this side-by-side arrangement significantly enhances the support strength of the anvil 22 compared to the case of using a single ball bearing 24.

[0043] In some embodiments, an O-ring is sandwiched between the inner ring of the ball bearing 24 and the outer peripheral wall of the anvil 22. The outer peripheral wall of the anvil 22 is provided with an annular groove for accommodating the O-ring. The O-ring, filled in the annular groove, effectively prevents lubricating oil or other liquids from leaking from the ball bearing 24. Furthermore, the O-ring forms a buffer layer between the anvil 22 and the ball bearing 24, reducing wear caused by direct contact. This not only extends the service life of the ball bearing 24 and the anvil 22, but also ensures the stability of the rotary impact tool 100 under high-frequency impacts.

[0044] In some embodiments, a retaining spring 50 is provided on one side of the outer ring of the ball bearing 24, while the other side of the outer ring of the ball bearing 24 abuts against the impact housing 23. The outer ring of the ball bearing 24 is secured by the retaining spring 50 and the impact housing 23, while the inner ring of the ball bearing 24 is not secured and is subjected to the impact of the impact mechanism 21. The fixed structure of the retaining spring 50 and the impact housing 23 ensures that the ball bearing 24 remains stable during high-frequency impacts and rotation, reducing the risk of wear and failure caused by axial movement.

[0045] In some embodiments, the drive unit 10 further includes a planetary gear 13, through which the output end of the drive motor 11 is connected to the main shaft 12 for power transmission and reduction. Specifically, a pinion is fixedly mounted on the output end of the drive motor 11. The gear portion of the pinion is coaxial with the motor shaft and arranged in the front-to-back direction to receive the rotational power output by the drive motor 11. An internal gear is fixedly mounted on the inner circumference of the impact housing 23. The internal gear and the pinion are aligned in the front-to-back direction and mesh with the pinion. The planetary gear 13 meshes between the internal gear and the pinion. The planetary gear 13 revolves around the pinion and is pivotally fixed to a planetary carrier, which enables the planetary gear 13 to rotate about its own axis. The front portion of the planetary carrier is integrally connected to the main shaft 12, allowing the main shaft 12 to be coaxial with the motor shaft and rotated by the planetary gear 13 mechanism. When the drive motor 11 is operating, the drive motor 11 drives the pinion to rotate. The rotation of the pinion is transmitted to the planetary gear 13 through the planetary gear mechanism, causing it to revolve on the internal gear, while also driving the planetary carrier and main shaft 12 to rotate. The high speed of the motor is reduced by the deceleration effect of the planetary gear mechanism 13, while outputting a strong torque to drive the tool to work.

[0046] It can be understood that one end of the main shaft 12 is supported by the planetary gear 13 and the other end is supported by the anvil 22, so that the main shaft 12 can rotate around the same axis as the output shaft 30 of the drive motor 11, ensuring that the main shaft 12 remains stable during rotation and effectively reducing friction and wear.

[0047] It is understandable that the existing impact mechanism 21 includes a drop body, a striking block and a spring, and the hammer is the core component of the impact mechanism 21 that generates the impact force. It is usually arranged coaxially with the main shaft 12 and can rotate around the main shaft 12 and move along the axial direction. The outer peripheral surface of the hammer body is provided with a cam or groove structure for transmitting the impact force. When the main shaft 12 rotates, the hammer body, under the action of the cam or other structure, will contact the struck arm 222 at a specific position and generate an impact force, and the rotation and axial movement of the hammer body are usually assisted by a spring or other reset mechanism. The striking part is usually located at the front end or periphery of the hammer body, and is used to directly strike the struck arm 222. The spring is usually arranged between the hammer body and the tool housing to reset the hammer body to its initial position. The reset mechanism can be a compression spring, a torsion spring or other forms of elastic elements.

[0048] Specifically, the outer circumference of the spindle 12 is provided with a cam groove, which is tilted at an angle to the axis of the spindle 12. The inner circumference of the impact mechanism 21 is provided with a snap-fitting groove that mates with the cam groove, with a steel ball sandwiched between the cam groove and the snap-fitting groove. Furthermore, one or more cam grooves are provided on the outer circumference of the spindle 12, each of which has a specific tilt angle to the axis of the spindle 12. This tilt angle ensures that when the spindle 12 rotates, the cam grooves drive the steel balls sandwiched therein to move along the cam groove's trajectory. The tilt angle of the cam grooves is designed so that when the spindle 12 rotates, the movement of the steel balls within the cam grooves generates an axial force, driving the impact mechanism 21 to reciprocate along the axis of the spindle 12. The inner circumference of the impact mechanism 21 is provided with a snap-fitting groove that corresponds to the cam groove on the spindle 12. The shape and size of the snap-fitting grooves match the cam grooves, effectively sandwiching the steel balls therein. As the spindle 12 rotates, the steel ball rolls between the cam groove and the engagement groove, causing the impact mechanism 21 to simultaneously rotate and generate axial motion, completing the impact action. The steel ball, sandwiched between the cam groove and the engagement groove, acts as a medium for power transmission. Through the rolling motion of the steel ball, the rotational force of the cam groove is converted into axial reciprocating motion of the impact mechanism 21.

[0049] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A rotary impact tool, characterized in that: include: A driving unit, comprising a driving motor and a main shaft drivingly connected to the driving motor; an impact portion, the impact portion comprising an impact mechanism, an anvil, and an impact housing for accommodating the impact mechanism and the anvil, the impact mechanism being transmission-connected to the main shaft in a manner that rotates about the main shaft and can reciprocate along the axis of the main shaft, the anvil being coaxially arranged with the main shaft and transmission-connected thereto, the anvil being rotatably supported by the impact housing, and reciprocating along the axis under the action of the impact mechanism; An output shaft is transmission-connected to the anvil.

2. The rotary impact tool according to claim 1, wherein The anvil includes a shaft and a striking arm, the shaft being coaxially arranged with the main shaft, the shaft being rotatably supported on the impact shell via a rolling bearing, the striking arm extending radially along the circumference of the shaft, the striking arm being capable of being struck by the impact mechanism, a gasket being sandwiched between the striking arm and the impact shell, the inner diameter of the gasket being smaller than the outer diameter of the rolling bearing.

3. The rotary impact tool according to claim 2, wherein An annular boss is provided on a side of the impact housing facing the anvil, and an outer peripheral surface of the gasket abuts against an inner peripheral surface of the annular boss.

4. The rotary impact tool according to claim 2, wherein A chamfer is provided at a connection between the shaft portion and the struck arm on a side of the shaft portion facing the output shaft.

5. The rotary impact tool according to any one of claims 1 to 4, characterized in that The anvil is provided with a groove, and the main shaft is provided with a protrusion, and the protrusion is inserted into the groove to drive the anvil to rotate.

6. The rotary impact tool according to any one of claims 2 to 4, characterized in that Two rolling bearings are arranged side by side along the axial direction.

7. The rotary impact tool according to any one of claims 2 to 4, characterized in that An O-type sealing ring is sandwiched between the inner ring of the rolling bearing and the outer peripheral wall of the anvil.

8. The rotary impact tool according to any one of claims 2 to 4, characterized in that A retaining spring is provided on one side of the outer ring of the rolling bearing, and the other side of the outer ring of the rolling bearing abuts against the impact housing.

9. The rotary impact tool according to any one of claims 1 to 4, characterized in that The driving part includes a planetary gear, and the output end of the driving motor is transmission-connected to the main shaft through the planetary gear.

10. The rotary impact tool according to any one of claims 1 to 4, characterized in that The outer peripheral surface of the main shaft is provided with a cam groove, and an inclination angle is formed between the cam groove and the axis of the main shaft. The inner peripheral surface of the impact mechanism is provided with a clamping groove that cooperates with the cam groove, and a steel ball is sandwiched between the cam groove and the clamping groove.

Images