Rotor shaft supporting structure for electric tool and electric tool

Abstract

The utility model relates to a rotor shaft supporting structure for an electric tool and the electric tool, and the rotor shaft supporting structure comprises a gear box, the rear wall of which is provided with a bearing installation hole; and the first bearing comprises a bearing inner ring and a bearing outer ring, the bearing inner ring is used for being connected to the rotor shaft in a sleeving mode, the bearing outer ring is installed in the bearing installation hole, a limiting protrusion is arranged on the peripheral wall of the bearing outer ring, and the limiting protrusion forwards abuts against the rear end face of the gear box. According to the rotor shaft supporting structure for the electric tool, the limiting protrusion is directly arranged on the peripheral wall of the bearing outer ring and abuts against the rear end face of the gearbox through the limiting protrusion so as to limit the first bearing to move forwards, a boss does not need to be arranged in a bearing installation hole of the gearbox, the axial size of the bearing installation hole can be reduced, and the service life of the bearing installation hole is prolonged. And the axial size of the electric tool can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of electric tools, in particular to a rotor shaft supporting structure for an electric tool and the electric tool. Background Art

[0002] Power tools mainly include a motor, a reduction mechanism, a transmission mechanism and an output shaft. The tool head (such as a screwdriver bit or a drill bit) is installed on the output shaft. The high-speed rotation output by the motor is decelerated by the reduction mechanism and the torque is transmitted to the transmission mechanism. The transmission mechanism drives the output shaft to drive the tool head to rotate to perform the operation.

[0003] The reduction mechanism is housed in a gearbox, and the front of the motor's rotor shaft is mounted in a bearing chamber on the gearbox via a front bearing. The rotor shaft passes through the gearbox and then engages with the reduction mechanism. In order to prevent the rotor shaft from moving forward, a boss is usually provided on the bearing chamber of the gearbox, which presses against the end of the front bearing backward to limit the forward movement of the rotor shaft. For example, patent CN220337424U discloses an oil-leakage-proof electric tool, in which a gearbox (equivalent to the front shell of the gearbox) and an intermediate cover (equivalent to the rear cover of the gearbox) form a complete gearbox structure, and the motor bearing supporting the front of the motor shaft is mounted in the bearing chamber of the intermediate cover, and the front end surface of the motor bearing abuts against the boss of the intermediate cover, and the forward movement of the motor shaft is limited by the boss. The setting of the boss requires axial space, which increases the axial size of the gearbox, and in turn increases the overall axial size of the electric tool. Utility Model Content

[0004] Based on the above-mentioned defects in the prior art, the purpose of the present utility model is to provide a rotor shaft support structure for an electric tool, in which a limiting protrusion is directly provided on the outer peripheral wall of the outer ring of the bearing, and the limiting protrusion is abutted against the rear end face of the gear box to limit the forward movement of the first bearing. There is no need to provide a boss in the bearing mounting hole of the gear box, and the axial dimension of the bearing mounting hole can be reduced, which is beneficial to the reduction of the axial dimension of the electric tool.

[0005] To this end, the present invention provides the following technical solutions.

[0006] The utility model provides a rotor shaft support structure for an electric tool, the rotor shaft support structure comprising:

[0007] A gear box having a bearing mounting hole provided on its rear wall;

[0008] The first bearing includes a bearing inner ring and a bearing outer ring. The bearing inner ring is used to be sleeved on the rotor shaft. The bearing outer ring is installed in the bearing mounting hole. A limiting protrusion is provided on the outer peripheral wall of the bearing outer ring. The limiting protrusion abuts against the rear end face of the gear box forward.

[0009] Optionally, the limiting protrusion is annular, and the central axis of the limiting protrusion coincides with the central axis of the bearing outer ring.

[0010] Optionally, the rear end portion of the bearing outer ring extends radially outward to form the limiting protrusion.

[0011] Optionally, an annular protrusion is provided on the rear wall of the gear box, and the inner peripheral wall of the annular protrusion abuts against the outer peripheral wall of the limiting protrusion.

[0012] The utility model also provides an electric tool, which includes a motor, a reduction mechanism and the rotor shaft support structure as described above; the reduction mechanism is located in the gear box, the motor includes a rotor shaft, and the rotor shaft passes through the bearing mounting hole and is connected to the bearing mounting hole through the first bearing.

[0013] Optionally, the gearbox includes a front shell and a rear cover sequentially distributed along the front-to-rear direction, and the bearing mounting hole is provided on the rear cover.

[0014] Optionally, the rotor shaft and the bearing inner ring are interference fit.

[0015] Optionally, the electric tool further includes a second bearing located at the rear of the motor for supporting the rear of the rotor shaft.

[0016] Optionally, the reduction mechanism includes a planetary carrier and an inner ring gear, a planetary gear and a sun gear that are meshed in sequence, the sun gear is coaxially connected to the rotor shaft, the planetary gear is mounted on the planetary carrier, and the planetary carrier is connected to the inner wall of the gearbox through a third bearing.

[0017] Optionally, the electric tool further includes a transmission mechanism, which includes a main shaft; the planetary carrier is integrally formed at the rear end of the main shaft, and the sun gear is integrally formed at the front end of the rotor shaft.

[0018] The utility model has the following technical effects:

[0019] The utility model provides a rotor shaft support structure for an electric tool, wherein a limiting protrusion is directly provided on the outer peripheral wall of the outer ring of the bearing, and the limiting protrusion is abutted against the rear end face of the gear box to limit the forward movement of the first bearing, thereby limiting the forward movement of the rotor shaft. In addition, the setting of the limiting protrusion does not affect the axial dimension of the first bearing. In this solution, there is no need to provide a boss in the bearing mounting hole of the gear box to prevent the first bearing from moving forward, and the axial dimension of the bearing mounting hole can be reduced, which is conducive to reducing the axial dimension of the electric tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a cross-sectional view of the structure of the power tool of the present utility model;

[0021] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0022] Figure 3 This is an exploded view of the assembly structure of the rear cover, the first bearing, the motor and the second bearing of the utility model;

[0023] Figure 4 It is a schematic diagram of the three-dimensional structure of the first bearing of the present invention.

[0024] Description of Reference Numerals

[0025] 100. Power tools;

[0026] 1. Gearbox; 11. Front housing; 12. Rear cover; 121. Bearing mounting hole; 122. Annular protrusion; 123. Protrusion structure;

[0027] 2. First bearing; 21. Bearing inner ring; 22. Bearing outer ring; 221. Limiting protrusion;

[0028] 3. Motor; 31. Rotor shaft;

[0029] 4. Speed ​​reduction mechanism; 41. Planet carrier; 42. Ring gear; 43. Planet gear; 44. Sun gear;

[0030] 5. Second bearing;

[0031] 6. The third bearing;

[0032] 7. Transmission mechanism; 71. Main shaft; 72. Striking block; 73. Spring; 74. Ball bearing;

[0033] 8. Motor housing;

[0034] 9. Output shaft. DETAILED DESCRIPTION

[0035] To make the technical solutions and beneficial effects of the present invention more clearly understood, the following describes the present invention in detail by listing specific embodiments. Unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which this application belongs.

[0036] In the description of the present invention, unless otherwise expressly defined, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "height", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of simplifying the description of the present invention, and do not indicate that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and should not be understood as a limitation to the present invention.

[0037] In this utility model, the terms "first" and "second" are used solely for descriptive clarity and should not be construed as indicating the relative importance of the features indicated or the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly include at least one such feature. In the description of this utility model, "plurality" means at least two, and "several" means at least one, unless expressly specified otherwise.

[0038] In this utility model, unless otherwise expressly defined, the terms "install," "connect," "connect," "fix," "dispose," etc. should be understood broadly. For example, "connect" can mean fixed connection, detachable connection, or integral molding; it can be mechanical or electrical; it can be direct or indirect through an intermediary; it can also refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of these terms in this utility model based on the specific circumstances.

[0039] In the present invention, unless otherwise clearly defined, when a first feature is “on,” “above,” “above,” “above,” “below,” “below,” or “below” a second feature, the first feature and the second feature may be in direct contact, or the first feature and the second feature may be in indirect contact via an intermediate medium. Moreover, when a first feature is “on,” “above,” or “above” a second feature, it may mean that the first feature is directly above or obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than the horizontal height of the second feature. When a first feature is “below,” “below,” or “below” a second feature, it may mean that the first feature is directly below or obliquely below the second feature, or simply means that the horizontal height of the first feature is lower than the horizontal height of the second feature.

[0040] The "front" and "back" mentioned in this utility model are Figure 1 The markings in the table shall prevail.

[0041] The following is based on Figures 1 to 4 The electric tool of the present utility model is described in detail.

[0042] In this embodiment, if Figures 1 to 4 As shown, the power tool 100 includes a motor 3, a reduction mechanism 4, and a rotor shaft support structure. The rotor shaft support structure includes a gearbox 1 and a first bearing 2. A bearing mounting hole 121 is provided on the rear wall of the gearbox 1. The reduction mechanism 4 is located within the gearbox 1. The motor 3 includes a rotor shaft 31, which passes through the bearing mounting hole 121. The first bearing 2 includes an inner bearing ring 21 and an outer bearing ring 22. The inner bearing ring 21 is sleeved onto the rotor shaft 31, and the outer bearing ring 22 is mounted in the bearing mounting hole 121. The rotor shaft 31 is connected to the bearing mounting hole 121 via the first bearing 2, and the front portion of the rotor shaft 31 is supported by the rotor shaft support structure. A stopper protrusion 221 is provided on the outer circumferential wall of the bearing outer ring 22, which abuts forward against the rear end surface of the gearbox 1.

[0043] In the above scheme, a limiting protrusion 221 is directly provided on the outer peripheral wall of the bearing outer ring 22, and the limiting protrusion 221 is abutted against the rear end face of the gear box 1 to limit the forward movement of the first bearing 2, thereby limiting the forward movement of the rotor shaft 31. In addition, the setting of the limiting protrusion 221 does not affect the axial dimension of the first bearing 2. In this scheme, there is no need to provide a boss in the bearing mounting hole 121 of the gear box 1 to prevent the first bearing 2 from moving forward. Since the boss is omitted, the axial dimension of the bearing mounting hole 121 can be reduced, which is beneficial to reducing the axial dimension of the power tool 100.

[0044] In one embodiment, if Figure 3 and Figure 4 As shown, the limiting protrusion 221 is annular, and the central axis of the limiting protrusion 221 coincides with the central axis of the bearing outer ring 22. In this embodiment, the limiting protrusion 221 is configured as an annular shape, which can increase the contact area between the limiting protrusion 221 and the rear end surface of the gearbox 1, thereby facilitating the balanced force on the rear end surface of the gearbox 1 and avoiding deformation caused by localized force.

[0045] In one embodiment, if Figures 2 to 4 As shown, the rear end of the bearing outer ring 22 extends radially outward to form a limiting protrusion 221. This limiting protrusion 221 is located at the rear end of the bearing outer ring 22. The longitudinal cross-section of the first bearing 2 is roughly T-shaped, with a simple structure. After the first bearing 2 is assembled with the bearing mounting hole 121, the limiting protrusion 221 of the first bearing 2 is located outside the bearing mounting hole 121, while the rest of the first bearing 2 is located entirely within the bearing mounting hole 121.

[0046] Furthermore, if Figure 2 and Figure 3As shown, the rear wall of the gearbox 1 is provided with an annular protrusion 122, and the inner peripheral wall of the annular protrusion 122 abuts against the outer peripheral wall of the limiting protrusion 221 to increase the contact area between the outer peripheral wall of the bearing outer ring 22 and the gearbox 1, so as to improve the assembly stability between the first bearing 2 and the gearbox 1.

[0047] In one embodiment, if Figure 1 and Figure 3 As shown, the gearbox 1 includes a front housing 11 and a rear cover 12, arranged in sequence along the front-to-back direction. Bearing mounting holes 121 are provided on the rear cover 12, providing the gearbox 1 with a split structure to facilitate assembly of the corresponding components into the gearbox 1. The power tool 100 also includes a motor housing 8 for accommodating the motor 3. A protrusion 123 is provided on the outer wall of the rear cover 12. The rear end surface of the front housing 11 and the front end surface of the motor housing 8 jointly clamp the protrusion 123, and the three are fixed together by screws.

[0048] In one embodiment, if Figure 2 As shown, the rotor shaft 31 is interference fit with the bearing inner ring 21 to stably transmit torque.

[0049] In one embodiment, if Figure 1 and Figure 3 As shown, the electric tool 100 further includes a second bearing 5 , which is located at the rear of the motor 3 to support the rear of the rotor shaft 31 . The first bearing 2 cooperates with the second bearing 5 to support the rotor shaft 31 .

[0050] In one embodiment, if Figure 1 and Figure 2 As shown, the reduction mechanism 4 includes a planetary carrier 41 and an inner ring gear 42, a planetary gear 43 and a sun gear 44 that are meshed in sequence. The sun gear 44 is coaxially connected to the rotor shaft 31. The planetary gear 43 is mounted on the planetary carrier 41. The planetary carrier 41 is connected to the inner wall of the gearbox 1 through a third bearing 6.

[0051] Furthermore, if Figure 1 and Figure 2 As shown, the power tool 100 further includes a transmission mechanism 7, which includes a main shaft 71; the planet carrier 41 is integrally formed at the rear end of the main shaft 71, and the sun gear 44 is integrally formed at the front end of the rotor shaft 31 to reduce the number of parts.

[0052] In one embodiment, Figure 1As shown, the transmission mechanism 7 is an impact mechanism, and the transmission mechanism 7 also includes a striking block 72, a spring 73 and a ball 74. The striking block 72 is sleeved on the outer periphery of the main shaft 71, and one end of the spring 73 abuts against the striking block 72, and the other end abuts against the planetary carrier 41 integrally formed on the main shaft 71. The outer wall of the main shaft 71 is provided with a first guide groove (not shown in the figure), and the inner wall of the striking block 72 is provided with a second guide groove (not shown in the figure). The first guide groove and the second guide groove together form a guide ball path, and the ball 74 is movably located in the guide ball path. When the motor 3 drives the main shaft 71 to rotate, the main shaft 71 drives the striking block 72 to move through the ball 74, and the striking block 72 drives the output shaft 9 of the power tool 100 to rotate, and finally drives the tool head to rotate through the output shaft 9 to perform the operation.

[0053] It should be understood that the above embodiments are exemplary and are not intended to encompass all possible implementations of the claims. Various modifications and variations may be made to the above embodiments without departing from the scope of the present disclosure. Similarly, the various technical features of the above embodiments may be arbitrarily combined to form additional embodiments of the present invention that may not be explicitly described. Therefore, the above embodiments merely represent several implementations of the present invention and do not limit the scope of protection of the present utility model patent.

Claims

1. A rotor shaft support structure for an electric tool, characterized in that: The rotor shaft support structure comprises: The gear box (1) has a bearing mounting hole (121) provided on its rear wall; A first bearing (2) includes a bearing inner ring (21) and a bearing outer ring (22), wherein the bearing inner ring (21) is used for sleeve connection with the rotor shaft (31), and the bearing outer ring (22) is installed in the bearing mounting hole (121). A limiting protrusion (221) is provided on the outer peripheral wall of the bearing outer ring (22), and the limiting protrusion (221) abuts against the rear end surface of the gear box (1) in a forward direction.

2. The rotor shaft support structure for an electric tool according to claim 1, wherein: The limiting protrusion (221) is annular, and the central axis of the limiting protrusion (221) coincides with the central axis of the bearing outer ring (22).

3. The rotor shaft support structure for an electric tool according to claim 1 or 2, wherein: The rear end portion of the bearing outer ring (22) extends radially outward to form the limiting protrusion (221).

4. The rotor shaft support structure for an electric tool according to claim 3, wherein: The rear wall of the gear box (1) is provided with an annular protrusion (122), and the inner peripheral wall of the annular protrusion (122) abuts against the outer peripheral wall of the limiting protrusion (221).

5. An electric tool, characterized in that: The electric tool (100) comprises a motor (3), a reduction mechanism (4) and a rotor shaft support structure according to any one of claims 1 to 4; the reduction mechanism (4) is located in the gear box (1); the motor (3) comprises a rotor shaft (31), and the rotor shaft (31) passes through the bearing mounting hole (121) and is connected to the bearing mounting hole (121) through the first bearing (2).

6. The electric tool according to claim 5, wherein: The gear box (1) comprises a front shell (11) and a rear cover (12) sequentially distributed along the front-to-back direction, and the bearing mounting hole (121) is provided on the rear cover (12).

7. The electric tool according to claim 5, wherein: The rotor shaft (31) and the bearing inner ring (21) are interference fit.

8. The electric tool according to claim 5, wherein: The electric tool (100) further comprises a second bearing (5) located at the rear of the motor (3) for supporting the rear of the rotor shaft (31).

9. The electric tool according to claim 5, wherein: The speed reduction mechanism (4) comprises a planet carrier (41) and an inner gear ring (42), a planet gear (43) and a sun gear (44) that mesh in sequence, wherein the sun gear (44) is coaxially connected to the rotor shaft (31), the planet gear (43) is mounted on the planet carrier (41), and the planet carrier (41) is connected to the inner wall of the gear box (1) via a third bearing (6).

10. The electric tool according to claim 9, wherein: The electric tool (100) further comprises a transmission mechanism (7), which comprises a main shaft (71); the planetary carrier (41) is integrally formed at the rear end of the main shaft (71), and the sun gear (44) is integrally formed at the front end of the rotor shaft (31).

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