Electric tool

Abstract

The utility model discloses an electric tool which comprises the following components: a housing which is provided with an output shaft hole which comprises a bearing chamber; the bearing is arranged in the bearing chamber; the output shaft penetrates through the output shaft hole and the bearing; the output shaft hole further comprises a clamp spring chamber, and the clamp spring chamber comprises a clamp spring abutting face facing the bearing. The elastic clamping spring is arranged in the clamping spring chamber and is in a non-closed circular ring shape, the outer edge of the first side surface of the elastic clamping spring is matched with the clamping spring abutting face in an abutting mode, the inner edge of the opposite second side surface of the elastic clamping spring is matched with the bearing in an abutting mode, and the distance between the outer edge of the second side surface and the bearing is larger than that between the inner edge of the second side surface and the bearing; and the elastic clamp spring generates elastic deformation in response to the axial acting force of the bearing so as to apply elastic counter-acting force to the bearing to hinder the axial movement of the bearing. Axial movement of the bearing can be restrained, the bearing is kept at a proper installation distance position, and the service life of a tool is guaranteed.

Description

Technical Field

[0001] The utility model belongs to the technical field of power tools, and particularly relates to a power tool with a reliable bearing positioning structure. Background Art

[0002] The output shaft of a power tool is positioned by a bearing, and the end of the output shaft is connected to a working head to drive the working head to perform an operation task. Taking an angle grinder as an example, in the prior art, the bearing at the output end is positioned by a circlip, and the circlip adopts a flat circlip structure. This circlip structure cannot reliably position the bearing when the output shaft is subjected to a heavy load, resulting in the bearing moving upwards, causing the offset of the gear meshing installation distance, and seriously shaving the teeth, greatly reducing the service life of the whole machine.

[0003] Therefore, it is necessary to improve the prior art to overcome the defects in the prior art. Summary of the Utility Model

[0004] Therefore, the technical problem to be solved by the utility model is that the bearing positioning of the output shaft of the power tool in the prior art is unreliable, and it is easy to axially move to cause the offset of the gear meshing installation distance.

[0005] To solve the above technical problem, the utility model provides a power tool, comprising:

[0006] A housing provided with an output shaft hole, and the output shaft hole includes a bearing chamber;

[0007] A bearing disposed in the bearing chamber, and an end face of the bearing close to the power output side abuts against a step face of the bearing chamber;

[0008] An output shaft passing through the output shaft hole and the bearing, and a power output section of the output shaft extends out of the housing to connect a load;

[0009] The output shaft hole further includes a circlip chamber located on a side of the bearing chamber close to the power input, and the circlip chamber includes a circlip abutting surface facing the bearing;

[0010] An elastic circlip disposed in the circlip chamber, the elastic circlip is in a non-closed circular ring shape, the elastic circlip includes opposite first and second side surfaces, an outer edge of the first side surface abuts and cooperates with the circlip abutting surface, an inner edge of the second side surface abuts and cooperates with the bearing, a distance between an outer edge of the second side surface and the bearing is greater than a distance between an inner edge of the second side surface and the bearing, and the elastic circlip generates elastic deformation in response to an axial force of the bearing and applies an elastic reaction force to the bearing to prevent axial movement of the bearing.

[0011] In one embodiment, the elastic retaining spring includes a C-shaped retaining ring and a plurality of retaining flanges. The retaining flanges are arranged at intervals on the radial inner side of the C-shaped retaining ring, and the retaining flanges are in abutting cooperation with the bearing.

[0012] In one embodiment, the C-shaped retaining ring is arranged with a gap from the bearing.

[0013] In one embodiment, the retaining flanges include two first retaining flanges and at least two second retaining flanges. The two first retaining flanges are respectively arranged at both ends of the C-shaped retaining ring, and the second retaining flanges are arranged between the two first retaining flanges.

[0014] In one embodiment, the second retaining flange is semi-cylindrical.

[0015] In one embodiment, the distances between two adjacent second retaining flanges and between the first retaining flange and the adjacent second retaining flange are the same.

[0016] In one embodiment, the C-shaped retaining ring has a uniform thickness everywhere, and the C-shaped retaining ring extends substantially on a conical surface.

[0017] In one embodiment, the distance between the second side surface and the bearing gradually increases along the radial direction of the output shaft.

[0018] In one embodiment, the distance between the first side surface and the bearing gradually increases along the radial direction of the output shaft.

[0019] In one embodiment, it further includes an output gear sleeved on the output shaft. One end of the output gear is in abutting cooperation with the inner ring of the bearing, and the elastic retaining spring is in abutting cooperation with the outer ring of the bearing.

[0020] The technical solution provided by the present utility model has the following advantages:

[0021] For the electric tool provided by the present utility model, the bearing of the output shaft is positioned by an elastic retaining spring. The elastic retaining spring itself has the function of automatically adjusting the up-and-down gap. Under the condition of receiving a major load, the bearing has a tendency to move upward, and the elastic retaining spring will exert an elastic reaction force on the bearing to prevent its axial movement. It can ensure that the bearing is always at a proper installation distance position, realize more reliable positioning of the bearing, reduce the risk of shaving caused by axial movement, and significantly improve the product life. Description of the Drawings

[0022] To more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for description in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0023] Figure 1 Partial three-dimensional schematic diagram of the structure of the power tool provided by the embodiment of the present utility model;

[0024] Figure 2 Second housing cross-sectional structure schematic diagram of the power tool provided by the embodiment of the present utility model;

[0025] Figure 3 For Figure 1 Partial cross-sectional schematic diagram of the power tool shown passing through the axis of the output shaft;

[0026] Figure 4 Three-dimensional structure schematic diagram of the elastic circlip provided by the embodiment of the present utility model;

[0027] Figure 5 For Figure 4 Side view structure schematic diagram of the elastic circlip shown. Specific embodiments

[0028] The following will clearly and completely describe the technical solutions of the present utility model in conjunction with the drawings. Obviously, the described embodiments are some embodiments of the present utility model, rather than all embodiments. In the following, the present utility model will be described in detail with reference to the drawings and in conjunction with the embodiments. It should be noted that, without conflict, the embodiments in the present utility model and the features in the embodiments can be combined with each other.

[0029] It should be noted that the terms "first", "second", etc. in the specification and claims of the present utility model and the above drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence.

[0030] In the present utility model, unless otherwise stated, the orientation words such as "upper, lower, top, bottom" are usually in the direction shown in the drawings, or in the vertical, perpendicular or gravitational direction of the component itself; similarly, for the convenience of understanding and description, "inner, outer" refer to the inner and outer of the contour of each component itself, but the above orientation words do not limit the present utility model.

[0031] Embodiment 1

[0032] This embodiment provides a power tool. Figure 1A partial three-dimensional structure schematic diagram of the power tool provided by the embodiment of the present utility model. Figure 2 A second housing cross-sectional structure schematic diagram of the power tool provided by the embodiment of the present utility model. Figure 3 For Figure 1 A partial cross-sectional schematic diagram of the power tool shown passing through the axis of the output shaft. Please refer to Figure 1 、 Figure 2 And Figure 3 ,The power tool includes a housing 10, an output shaft 20, a bearing 30, and an elastic snap ring 50.

[0033] Among them, the housing 10 includes a first housing 11 and a second housing 12. The first housing 11 and the second housing 12 are fixedly connected to each other to form a gear cavity for accommodating a transmission gear inside. Specifically, the first housing 11 and the second housing 12 are fastened and connected by bolts. An input shaft hole (not shown) is also provided on the first housing 11 for a power shaft to pass through it to drive the transmission gear to rotate.

[0034] The output shaft 20 penetrates through the second housing 12 and is connected to the transmission gear at one end and extends out of the housing 10 at the other end for connecting a load. Specifically, an output shaft hole 120 is provided on the second housing 12, and the output shaft 20 passes through it. The part of the output shaft 20 located inside the gear cavity serves as a power input section to connect the transmission gear, and the power output section of the output shaft 20 extends out of the second housing 12 for connecting a working head to drive the working head to perform an operation task. Among them, the working head matches the type of the power tool. Taking the power tool as an angle grinder as an example, the working head can specifically be a grinding disc.

[0035] Please pay special attention to Figure 2 ,The output shaft hole 120 includes a bearing chamber 123 and a snap ring chamber 121. The bearing chamber 123 is used for accommodating and positioning the bearing 30, and the snap ring chamber 121 is used for accommodating and positioning the elastic snap ring 50. The snap ring chamber 121 and the bearing chamber 123 are adjacent to each other. In the power transmission direction, the snap ring chamber 121 is located on the side of the bearing chamber 123 close to the power input. The output shaft 20 sequentially passes through the elastic snap ring 50 and the bearing 30 and finally extends out of the housing 10. Specifically, a limiting step is provided at one end of the bearing chamber 123 away from the snap ring chamber 121, and the end face of the bearing 30 axially abuts against the step surface of the limiting step to axially limit the bearing 30. The inner diameter of the snap ring chamber 121 is larger than the inner diameter of the bearing chamber 123. A snap ring abutting surface 121a is formed at one end of the snap ring chamber 121 away from the bearing chamber 123. The snap ring abutting surface 121a faces the bearing 30 and is used for abutting against the elastic snap ring 50 to limit the elastic snap ring 50.

[0036] Please combine Figure 3 、 4 And Figure 5As shown, the elastic snap ring 50 is in the shape of a non-closed circular ring. In the axial direction, the elastic snap ring 50 includes opposite first side surface 54 and second side surface 55. The outer edge of the first side surface 54 abuts and cooperates with the snap ring abutting surface 121a, and the inner edge of the second side surface 55 abuts and cooperates with the bearing 30. In this embodiment, the second side surface 55 is inclined relative to the output shaft 20. The distance between the outer edge of the second side surface 55 and the bearing 30 is greater than the distance between the inner edge of the second side surface 55 and the bearing 30. This distance refers to the distance in the axial direction. That is to say, the second side surface 55 is not a planar setting, is inclined relative to the output shaft 20, the inner edge of the second side surface 55 abuts against the bearing 30, and the outer edge of the second side surface 55 is set farther away from the bearing 30 relative to the inner edge. When the bearing 30 applies an axial pressure to the elastic snap ring 50 under the action of the working head, since the inner and outer edges of the second side surface are not on the same plane but are relatively inclined, the elastic snap ring 50 is compressed axially to generate an elastic reaction force, and this elastic reaction force cancels out the pressure of the bearing, which can prevent the axial movement of the bearing 30. That is to say, when subjected to the axial force of the bearing 30, the elastic snap ring 50 elastically deforms axially to generate a reaction force on the bearing 30.

[0037] The electric tool provided in this embodiment, by setting an elastic snap ring that abuts against the bearing, when subjected to the axial pressure of the bearing, the elastic snap ring is compressed axially to generate an elastic reaction force, and this elastic reaction force can prevent the axial movement of the bearing, so that the bearing is maintained at a proper installation distance position, reducing the shaving risk caused by the installation distance deviation and ensuring the service life of the whole machine. Moreover, the installation process and internal structure of the electric tool do not need to be adjusted, achieving simplicity and reliability.

[0038] In order to ensure the reliable limit of the elastic snap ring on the bearing. In a specific implementation, please refer to Figure 4 , the elastic snap ring 50 includes a C-shaped clamping ring 51 and a plurality of clamping flanges 53. The clamping flanges 53 are arranged at intervals on the radial inner side of the C-shaped clamping ring 51, and the plurality of clamping flanges 53 axially abut and cooperate with the bearing 30. On the one hand, using the spaced clamping flanges to abut against the bearing can ensure that the elastic snap ring provides a greater elastic force. On the other hand, since the clamping flanges are configured as radially inwardly protruding extensions, the force-bearing area between the elastic snap ring and the bearing can be increased, so as to press the bearing more reliably.

[0039] Further, in a specific embodiment, the C-shaped clamping ring is arranged with a gap from the bearing 30. That is to say, the C-shaped clamping ring does not contact the bearing 30, and only the clamping flanges 53 abut and cooperate with the bearing 30. This can ensure that the elastic snap ring provides a greater elastic force, presses the bearing more reliably, and avoids the problem of insufficient elastic force caused by too large rigidity of the elastic snap ring due to the continuous annular inner edge of the C-shaped clamping ring pressing against the bearing.

[0040] In a specific embodiment, please continue to refer to Figure 4 , the clamping flanges include two first clamping flanges 531 and at least two second clamping flanges 532. The shapes of the first clamping flanges 531 and the second clamping flanges 532 are different. The two first clamping flanges 531 are respectively arranged at both ends of the C-shaped clamping ring, and the second clamping flanges 532 are arranged between the two first clamping flanges 531. The shape design of the second clamping flanges located in the middle mainly takes into account the structural strength and ensures sufficient pressure. The shapes of the first clamping flanges at both ends should not only ensure the structural strength but also match the shapes of the two end parts of the C-shaped clamping ring, so as to further ensure the structural reliability of the elastic clamping spring itself. Preferably, the size of the first clamping flanges 531 is slightly larger than that of the second clamping flanges 532, which can ensure a larger pressing area at the end of the C-shaped clamping ring.

[0041] Specifically, the second clamping flange 531 is semi-cylindrical, and the outer contour of the contact surface between the second clamping flange 531 and the bearing is arc-shaped. The cylindrical structure can ensure that there are no angular regions on the pressing surface between the second clamping flange and the bearing, which can disperse the pressing force on the bearing and reduce the structural damage caused by stress concentration.

[0042] In order to ensure the uniform distribution of the axial pressing force of the elastic clamping spring on the bearing and keep the bearing at a proper installation distance position. In a specific embodiment, the distances between two adjacent second clamping flanges 532 and between the first clamping flange 531 and the adjacent second clamping flange 532 are the same. Since each clamping flange acts as a stress-bearing surface to press against the bearing, and the distances between adjacent clamping flanges are the same, it can ensure that the pressure received by the bearing is evenly distributed in the circumferential direction, and the bearing can be more reliably held in a proper position, reducing the risk of the bearing tilting. Preferably, the distance between the two first clamping flanges 531 is the same as the distance between the two first clamping flanges 531 and the adjacent second clamping flanges 532. The clamping flanges are strictly uniform in the circumferential direction, further ensuring the reliable positioning of the bearing.

[0043] In order to ensure the reliable positioning of the elastic clamping spring on the bearing, in a specific embodiment, the distance between the second side surface 55 and the bearing 30 gradually increases along the radial direction of the output shaft 30. The second side surface gradually moves away from the bearing along the radial direction from the inside to the outside, which can ensure that the pressing area between the elastic clamping spring and the bearing is positively correlated with the bearing pressure it receives. The greater the pressure, the larger the contact surface between the second side surface and the bearing, so as to provide a greater low pressure and ensure the reliable positioning of the bearing.

[0044] Furthermore, the first side surface 54 and the second side surface 55 are substantially inclined in the same direction relative to the output shaft 30, and the distance between the first side surface 54 and the bearing 30 gradually increases from the inside to the outside along the radial direction of the output shaft 30. The outer edge of the first side surface is higher than the inner edge of the first side surface, and when the elastic retaining spring is subjected to axial pressure, the first and second side surfaces are deformed in the axial direction, which can ensure the elastic force and structural strength of the elastic retaining spring.

[0045] In a specific embodiment, the thickness of the C-shaped retaining ring 51 is uniform at all locations, and the C-shaped retaining ring 51 extends approximately on the conical surface. The distances between the first side surface 54 and the second side surface 55 formed on the C-shaped retaining ring 51 are approximately the same, and the thickness of the C-shaped retaining ring is uniform, which can further ensure the uniform elastic distribution and structural strength of the elastic retaining ring.

[0046] For specific embodiments, see Figure 3 As shown, the electric tool further includes an output gear 60 sleeved on the output shaft 20, one end of the output gear 60 is abutted against the inner ring of the bearing 30, and the elastic retaining spring 50 is abutted against the outer ring of the bearing 30. Specifically, the output gear 60 is a first bevel gear, and the transmission gear further includes a second bevel gear meshing with the first bevel gear. The second bevel gear is smaller than the first bevel gear, so the second bevel gear is also called a small bevel gear, and the first bevel gear is called a large bevel gear.

[0047] To prevent foreign matter from entering the gear cavity, see Figure 3 As shown, the electric tool further includes a dust cover 40, the output shaft hole 120 further includes a dust chamber 125 adjacent to the bearing chamber 123, the dust cover 40 is arranged in the dust chamber 125, the output shaft 20 is inserted through the dust cover 40, and the dust cover 40 rotates synchronously with the output shaft 20. A gap is set between the dust cover 40 and the inner wall of the dust chamber 125, and a labyrinth gap is formed between them to prevent foreign matter from entering the gear cavity through the output shaft hole.

[0048] In summary, the electric tool provided in this embodiment uses an elastic retaining spring to press against the bearing. When subjected to axial pressure from the bearing, the elastic retaining spring is compressed in the axial direction to generate an elastic reaction force, which can hinder the axial movement of the bearing, thereby keeping the bearing at a suitable installation distance, reducing the risk of tooth shaving caused by installation distance deviation, and ensuring the service life of the whole machine. Furthermore, a plurality of spaced retaining flanges are arranged on the inner side of the elastic retaining spring, and the plurality of retaining flanges cooperate with the bearing to not only ensure that the pressure on the bearing is evenly distributed in the circumferential direction, but also ensure the elastic force of the elastic retaining spring, and more reliably press the bearing.

[0049] Obviously, the above-described embodiments are only a part of the embodiments of the present utility model, rather than all embodiments. Based on the embodiments of the present utility model, those of ordinary skill in the art can make other different forms of changes or modifications without creative efforts, and all of them should fall within the protection scope of the present utility model.

Claims

1. An electric tool, characterized in that: include: A housing is provided with an output shaft hole, wherein the output shaft hole includes a bearing chamber; A bearing is disposed in the bearing chamber, wherein an end surface of the bearing close to the power output side abuts against a step surface of the bearing chamber; An output shaft passes through the output shaft hole and the bearing, and a power output section of the output shaft extends out of the housing to connect with a load; The output shaft hole further comprises a retaining spring chamber, the retaining spring chamber is located on the side of the bearing chamber close to the power input, and the retaining spring chamber comprises a retaining spring abutting surface facing the bearing; An elastic retaining spring is arranged in the retaining spring chamber, and the elastic retaining spring is in a non-closed circular ring shape. The elastic retaining spring includes a first side surface and a second side surface relative to each other, the outer edge of the first side surface is abutted and matched with the retaining spring abutment surface, the inner edge of the second side surface is abutted and matched with the bearing, the distance between the outer edge of the second side surface and the bearing is greater than the distance between the inner edge of the second side surface and the bearing, and the elastic retaining spring is elastically deformed in response to the axial force of the bearing and applies an elastic reaction force to the bearing to hinder the axial movement of the bearing.

2. The electric tool according to claim 1, characterized in that: The elastic retaining spring comprises a C-shaped retaining ring and a plurality of retaining flanges, wherein the retaining flanges are arranged at intervals on the radial inner side of the C-shaped retaining ring, and the retaining flanges are in abutment with the bearing.

3. The electric tool according to claim 2, characterized in that: The C-shaped retaining ring is gap-set with the bearing.

4. The electric tool according to claim 2, characterized in that: The clamping flanges include two first clamping flanges and at least two second clamping flanges, the two first clamping flanges are respectively arranged at two ends of the C-shaped clamping ring, and the second clamping flange is arranged between the two first clamping flanges.

5. The electric tool according to claim 4, characterized in that: The second clamping flange is semi-cylindrical.

6. The electric tool according to claim 4, characterized in that: The distance between two adjacent second clamping flanges and the distance between the first clamping flange and the adjacent second clamping flange are the same.

7. The electric tool according to claim 2, characterized in that: The thickness of the C-shaped clamping ring is uniform at all locations, and the C-shaped clamping ring extends roughly on the conical surface.

8. The electric tool according to claim 1, wherein: The distance between the second side surface and the bearing gradually increases along the radial direction of the output shaft.

9. The electric tool according to claim 8, characterized in that: The distance between the first side surface and the bearing gradually increases along the radial direction of the output shaft.

10. The electric tool according to claim 1, wherein: It also includes an output gear sleeved on the output shaft, one end of the output gear is abutted and matched with the inner ring of the bearing, and the elastic retaining spring is abutted and matched with the outer ring of the bearing.

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