Power wrench striking unit

Abstract

The utility model provides a striking unit of a power wrench. The striking unit solves the problem that an existing power wrench is short in service life. The power wrench striking unit comprises a machine shell and a wheel carrier horizontally and rotatably arranged in the machine shell, a shaft body is arranged at the front end of the wheel carrier, a power shaft is fixedly connected to the front end of the shaft body, and a through hole allowing the front end of the power shaft to extend out is formed in the front side of the machine shell; the shaft body is sleeved with a striking sleeve, at least two striking blocks are arranged on the front end face of the striking sleeve in the circumferential direction, linkage blocks with the same number as the striking blocks are formed on the outer wall of the power shaft, a spring is arranged between the striking sleeve and the wheel frame, and a driving structure capable of enabling the striking sleeve to overcome the elastic force of the spring to move backwards is arranged between the striking sleeve and the shaft body. At least two outer ring grooves are formed in the inner wall of the through hole and distributed in the axial direction of the power shaft. Inner ring grooves are formed in the outer wall of the power shaft, and an inner ring groove is formed between every two adjacent outer ring grooves. A rubber ring is arranged in the outer ring groove, and the inner ring groove is filled with lubricating grease. The striking unit of the power wrench can prolong the service life of the power wrench.

Description

Technical Field

[0001] The utility model belongs to the field of power tools and relates to a power wrench, in particular to a power wrench striking unit. Background Art

[0002] A power wrench is a wrench tool that is driven by an electric motor, pneumatic motor, etc. It has high torque and speed, and can more easily complete operations that require greater force or frequent reciprocating movements. It is especially suitable for large-scale operations or the disassembly and assembly of larger-sized bolts.

[0003] Existing power wrenches include an air wrench and a striking unit thereof disclosed in the China Patent Library (application number: 201620776184.5), wherein the striking unit includes a wheel frame connected to a torque multiplier, a coupling sleeve is sleeved on the wheel frame, a coupling shaft for outputting torque coaxial with the coupling sleeve is provided outside the coupling sleeve, the coupling sleeve and the coupling shaft are respectively provided with matching striking structures, and a lifting mechanism is provided on the wheel frame, the lifting mechanism includes a reset spring located between the wheel frame and the coupling sleeve, a curved groove located on one side of the wheel frame close to the coupling shaft, and an adjusting steel ball located in the curved groove for promoting the movement of the coupling sleeve.

[0004] In the above-mentioned air wrench, the front end of the coupling shaft extends out of the air wrench housing, and the two are in contact through the sleeve. During operation, the coupling shaft not only rotates, but also receives a forward impact force under the action of the striking structure, which aggravates the relative wear between the sleeve and the coupling shaft and affects the service life. Utility Model Content

[0005] The utility model aims to solve the above problems in the prior art and proposes a power wrench striking unit with a long service life.

[0006] The purpose of the utility model can be achieved through the following technical solutions: a power wrench striking unit, including a housing and a wheel frame horizontally rotatably arranged in the housing, the front end of the wheel frame is a shaft body, the front end of the shaft body is fixedly connected to the power shaft, and the front side of the housing is provided with a through hole for the front end of the power shaft to extend out; a striking sleeve is sleeved on the shaft body, at least two striking blocks are arranged circumferentially on the front end surface of the striking sleeve, and a linkage block is formed on the outer wall of the power shaft, the striking blocks and the linkage blocks are the same in number and the two are alternately distributed along the circumference of the power shaft; a striking sleeve and the wheel frame are provided between them so that the front end surface of the striking sleeve has a pressing force on the linkage block. A spring that blocks the tendency of the block, and a driving structure that can enable the striking sleeve to overcome the spring elastic force and move backward is provided between the striking sleeve and the shaft body, characterized in that the power shaft and the through hole are contacted and matched through a circumferential surface; an outer ring groove coaxially arranged with the through hole is provided on the inner wall of the through hole, and there are at least two outer ring grooves and distributed along the axial direction of the power shaft; an inner ring groove coaxially arranged with the power shaft is provided on the outer wall of the power shaft, and the above-mentioned inner ring groove is provided between two adjacent outer ring grooves; a rubber ring is provided in the outer ring groove, and the inner side wall of the rubber ring is in contact and sealed with the outer wall of the power shaft; and the inner ring groove is filled with lubricating grease.

[0007] The power shaft and the through hole are lubricated by grease filled in the inner ring groove, and rubber rings are provided on both sides of the inner ring groove to prevent leakage of the grease. This not only reduces the relative wear between the power shaft and the casing, but also the rubber ring and the grease cooperate to buffer the impact and vibration of the casing, thereby delaying the aging of the casing and extending the life of the power wrench.

[0008] In the above-mentioned power wrench striking unit, an annular step is provided on the inner wall of the front end of the through hole, a sealing ring is provided in the annular step, the sealing ring is pressed on the bottom surface of the annular step, and the inner and outer side walls of the sealing ring are in contact and sealed with the outer wall of the power shaft and the side of the annular step respectively. The sealing ring is used to block external dust and other impurities and protect the rubber ring, so as to prolong the life of the power wrench by prolonging the life of the rubber ring.

[0009] In the above-mentioned power wrench striking unit, a mounting hole is axially opened at the rear end of the power shaft, and a shaft portion matching the mounting hole is formed on the front end surface of the shaft body. The shaft portion is inserted into the mounting hole and fixedly connected to the power shaft.

[0010] In the above-mentioned power wrench striking unit, a cavity is formed between the front end surface of the shaft body and the inner wall of the mounting hole, and a heat dissipation hole that connects the inner ring groove to the cavity is penetrated on the bottom wall of the inner ring groove farthest from the front end of the through hole. The cooperation between the heat dissipation hole and the cavity is conducive to heat dissipation of the corresponding inner ring groove, delaying the emulsification speed of the lubricating grease there, so that the purpose of increasing the service life of the power wrench is stably achieved.

[0011] In the above-mentioned power wrench striking unit, the mounting hole is a blind hole, and the shaft seals the lower end of the mounting hole, so that the cavity contacts the inner ring groove only through the heat dissipation hole, thereby preventing the lubricating grease from being contaminated.

[0012] In the above-mentioned power wrench striking unit, the outer wall of the shaft portion is in contact and sealed with the wall of the mounting hole, which has the advantages of simple structure and convenient assembly.

[0013] In the above-mentioned power wrench striking unit, the heat dissipation hole is a tapered hole, and the diameter of the heat dissipation hole gradually becomes smaller in the direction of the cavity, so as to prevent the lubricating grease from leaking into the cavity through the heat dissipation hole.

[0014] In the above-mentioned power wrench striking unit, the number of striking blocks and linkage blocks is 3, so as to increase the striking force and thus enhance the performance of the power wrench.

[0015] Compared with the prior art, the power wrench striking unit has the following advantages:

[0016] 1. The power shaft and the through hole are lubricated by the grease filled in the inner ring groove, and rubber rings are arranged on both sides of the inner ring groove to prevent the leakage of the grease. This can not only reduce the relative wear between the power shaft and the casing, but also buffer the impact and vibration of the casing with the cooperation of the rubber ring and the grease, so as to delay the aging speed of the casing and extend the life of the power wrench.

[0017] 2. With the cooperation of the heat dissipation holes and the cavity, it is beneficial to dissipate the heat of the corresponding inner ring groove, delay the emulsification speed of the lubricating grease there, and stably achieve the purpose of increasing the life of the power wrench. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional schematic diagram of a power wrench.

[0019] Figure 2 It is a cross-sectional schematic diagram of a power wrench.

[0020] Figure 3 yes Figure 2 A magnified schematic diagram of center A.

[0021] Figure 4 It is a three-dimensional schematic diagram of the connection between the power shaft and the striking sleeve.

[0022] In the figure, 1, casing; 1a, outer ring groove; 2, wheel frame; 2a, shaft body; 2a1, shaft portion; 2b, curved groove; 3, power shaft; 3a, linkage block; 3b, inner ring groove; 3c, heat dissipation hole; 4, striking sleeve; 4a, striking block; 5, spring; 6, rubber ring; 7, sealing ring; 8, cavity. DETAILED DESCRIPTION

[0023] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0024] like Figure 1 and Figure 2 As shown, the power wrench striking unit includes a casing 1 and a wheel frame 2 horizontally rotatably arranged in the casing 1, wherein the front end of the wheel frame 2 is a shaft body 2a, and the axis of the shaft body 2a extends forward and backward, and the rear end of the wheel frame 2 is rotatably arranged in the casing 1 using a bearing.

[0025] Specifically,

[0026] like Figure 2 and Figure 4As shown, the front end of the shaft body 2a is fixedly connected to the power shaft 3, the power shaft 3 and the shaft body 2a are coaxially arranged, and the front side of the housing 1 is provided with a through hole for the front end of the power shaft 3 to extend out. A striking sleeve 4 is sleeved on the shaft body 2a, and at least two striking blocks 4a are circumferentially arranged on the front end surface of the striking sleeve 4, and the striking blocks 4a and the striking sleeve 4 are an integrated structure. A linkage block 3a is formed on the outer wall of the rear end of the power shaft 3, and the linkage block 3a and the power shaft 3 are an integrated structure. The number of striking blocks 4a and the linkage blocks 3a is the same, and the two are alternately distributed along the circumference of the power shaft 3. A spring 5 is provided between the striking sleeve 4 and the wheel frame 2 to make the front end surface of the striking sleeve 4 have a tendency to press against the linkage block 3a, and a driving structure is provided between the striking sleeve 4 and the shaft body 2a to enable the striking sleeve 4 to overcome the elastic force of the spring 5 and move backward. Among them, the driving structure includes two curved grooves 2b circumferentially arranged on the outer wall of the shaft body 2a, and a steel ball is provided in each curved groove 2b. The driving structure is a prior art. For details, please refer to a pneumatic wrench and its striking unit disclosed in the Chinese Patent Library (application number: 201620776184.5), which will not be elaborated here.

[0027] like Figure 2 and Figure 3 As shown, the power shaft 3 and the through hole are in contact with each other through the circumferential surface; the inner wall of the through hole is provided with an outer ring groove 1a coaxially arranged with the through hole, and there are at least two outer ring grooves 1a and distributed along the axial direction of the power shaft 3; the outer wall of the power shaft 3 is provided with an inner ring groove 3b coaxially arranged with the power shaft 3, and the inner ring groove 3b is provided between two adjacent outer ring grooves 1a; a rubber ring 6 is provided in the outer ring groove 1a, and the inner side wall of the rubber ring 6 is in contact and sealed with the outer wall of the power shaft 3; the inner ring groove 3b is filled with lubricating grease. In the actual product, the number of outer ring grooves 1a is 3, that is, at this time, the number of inner ring grooves 3b is 2.

[0028] The power shaft 3 and the through hole are lubricated by grease filled in the inner ring groove 3b, and rubber rings 6 are provided on both sides of the inner ring groove 3b to prevent leakage of the grease. This not only reduces the relative wear between the power shaft 3 and the casing 1, but also the rubber ring 6 and the grease cooperate to buffer the impact and vibration of the casing 1, thereby delaying the aging speed of the casing 1 and extending the life of the power wrench.

[0029] Further explanation, an annular step is provided on the inner wall of the front end of the through hole, and the annular step is coaxially arranged with the through hole. A sealing ring 7 is provided in the annular step, and the sealing ring 7 is pressed on the bottom surface of the annular step, and the inner and outer side walls of the sealing ring 7 are in contact and sealed with the outer wall of the power shaft 3 and the side of the annular step respectively. The sealing ring 7 is used to block external dust and other impurities and protect the rubber ring 6, so as to increase the life of the power wrench by extending the life of the rubber ring 6.

[0030] In this embodiment,

[0031] The spring 5 is sleeved on the shaft body 2a, and two ends of the spring 5 act on the striking sleeve 4 and the wheel frame 2 respectively.

[0032] The power shaft 3 and the shaft body 2a are connected as follows: a mounting hole is axially opened at the rear end of the power shaft 3, and a shaft portion 2a1 matching the mounting hole is formed on the front end surface of the shaft body 2a. The shaft body 2a is inserted into the mounting hole and fixedly connected to the power shaft 3.

[0033] like Figure 2 and Figure 3 As shown, it is further explained that a cavity 8 is formed between the front end surface of the shaft portion 2a1 and the inner wall of the mounting hole, and a heat dissipation hole 3c is penetrated on the bottom wall of the inner ring groove 3b farthest from the front end of the through hole, which connects the inner ring groove 3b to the cavity 8. With the cooperation of the heat dissipation hole 3c and the cavity 8, it is beneficial to dissipate heat corresponding to the inner ring groove 3b, delay the emulsification speed of the lubricating grease there, and stably achieve the purpose of increasing the service life of the power wrench.

[0034] The mounting hole is a blind hole, and the shaft portion 2a1 closes the lower end of the mounting hole, so that the cavity 8 is in contact with the inner ring groove 3b only through the heat dissipation hole 3c, thereby preventing the lubricating grease from being contaminated.

[0035] In this embodiment, the outer wall of the shaft portion 2a1 is in contact and sealed with the wall of the mounting hole, which has the advantages of simple structure and convenient assembly. The heat dissipation hole 3c is a tapered hole, and the diameter of the heat dissipation hole 3c gradually decreases toward the cavity 8 to prevent lubricating grease from leaking into the cavity 8 through the heat dissipation hole 3c.

[0036] In actual products, the number of striking blocks 4a and linkage blocks 3a is three, so as to increase the striking force and thus enhance the performance of the power wrench.

[0037] The specific embodiments described herein are merely examples of the spirit of the present invention. A person skilled in the art of the present invention may make various modifications or additions to the specific embodiments described or replace them in a similar manner, but this will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A power wrench striking unit, comprising a housing (1) and a wheel frame (2) horizontally rotatably arranged in the housing (1), the front end of the wheel frame (2) being a shaft body (2a), the front end of the shaft body (2a) being fixedly connected to a power shaft (3), and the front side of the housing (1) being provided with a through hole for the front end of the power shaft (3) to extend out; a striking sleeve (4) being sleeved on the shaft body (2a), at least two striking blocks (4a) being circumferentially arranged on the front end surface of the striking sleeve (4), and linkage blocks (3a) being formed on the outer wall of the power shaft (3), the striking blocks (4a) and the linkage blocks (3a) being the same in number and being alternately distributed along the circumference of the power shaft (3); a spring (5) being provided between the striking sleeve (4) and the wheel frame (2) so that the front end surface of the striking sleeve (4) has a tendency to press against the linkage block (3a), and a driving structure being provided between the striking sleeve (4) and the shaft body (2a) so that the striking sleeve (4) can overcome the elastic force of the spring (5) and move backward, characterized in that: The power shaft (3) and the through hole are in contact with each other through a circumferential surface; an outer ring groove (1a) coaxially arranged with the through hole is provided on the inner wall of the through hole, and there are at least two outer ring grooves (1a) distributed along the axial direction of the power shaft (3); an inner ring groove (3b) coaxially arranged with the power shaft (3) is provided on the outer wall of the power shaft (3), and the inner ring groove (3b) is provided between two adjacent outer ring grooves (1a); a rubber ring (6) is provided in the outer ring groove (1a), and the inner side wall of the rubber ring (6) is in contact and sealed with the outer wall of the power shaft (3); and lubricating grease is filled in the inner ring groove (3b).

2. The power wrench striking unit according to claim 1, characterized in that: An annular step is provided on the inner wall of the front end of the through hole, a sealing ring (7) is provided in the annular step, the sealing ring (7) is pressed on the bottom surface of the annular step, and the inner and outer side walls of the sealing ring (7) are in contact and sealed with the outer wall of the power shaft (3) and the side surface of the annular step respectively.

3. The power wrench striking unit according to claim 1 or 2, characterized in that: A mounting hole is axially provided at the rear end of the power shaft (3), and a shaft portion (2a1) matching the mounting hole is formed on the front end surface of the shaft body (2a). The shaft portion (2a1) is inserted into the mounting hole and fixedly connected to the power shaft (3).

4. The power wrench striking unit according to claim 3, characterized in that: A cavity (8) is formed between the front end surface of the shaft body (2a) and the inner wall of the mounting hole, and a heat dissipation hole (3c) is penetrated through the bottom wall of the inner ring groove (3b) farthest from the front end of the through hole so that the inner ring groove (3b) is connected to the cavity (8).

5. The power wrench striking unit according to claim 4, characterized in that: The mounting hole is a blind hole, and the shaft portion (2a1) closes the lower end of the mounting hole.

6. The power wrench striking unit according to claim 5, characterized in that: The outer wall of the shaft portion (2a1) is in contact and sealed with the wall of the mounting hole.

7. The power wrench striking unit according to claim 4, characterized in that: The heat dissipation hole (3c) is a conical hole, and the diameter of the heat dissipation hole (3c) gradually becomes smaller in the direction of the cavity (8).

8. The power wrench striking unit according to claim 1, characterized in that: The number of the striking blocks (4a) and the number of the linkage blocks (3a) are both 3.

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