Bearing retaining device and air circuit breaker

Abstract

A bearing retaining device is provided that can retain a bearing without increasing the number of components even if a sheet metal frame is thinner than the axial thickness of the bearing. The bearing retaining device (1) of the present invention comprises: a bearing (4); a stepped shaft (3) that is freely rotatably retained on the bearing (4); and a sheet metal frame (2) having a thickness less than or equal to the axial thickness of the bearing (4) and provided with a bearing mounting hole (2a) for mounting the bearing (4), the bearing (4) having an outer ring (4b) and an inner ring (4a), and the stepped shaft (3) having a stepped portion (3a) at its end and a reduced diameter across the stepped portion (3a). A small diameter portion (3b) is formed, and the small diameter portion (3b) is inserted into the inner ring (4a) until the step portion (3a) abuts the inner ring (4a) on the inner side surface (4c) side of the bearing (4), and a claw portion (2b) is provided on the circumferential surface (2e) of the bearing mounting hole (2a), and the claw portion (2b) extends axially from the mounting hole edge portion (2f) on the outer wall surface (2d) side of the sheet metal frame (2) and abuts the outer ring (4a) on the outer side surface (4d) side of the bearing (4).

Description

Technical Field

[0001] The present invention relates to a bearing retaining device applied to an air circuit breaker and an air circuit breaker using the bearing retaining device. Background Art

[0002] Typically, a bearing is assembled into a housing having a thickness equal to or greater than the thickness of the bearing in the axial direction, and supports a shaft to thereby achieve rotational motion.

[0003] Meanwhile, in air circuit breakers, bearing retaining devices, which function to position and retain the bearings that rotatably support the shafts in the switching mechanisms, utilize sheet metal frames thinner than the axial thickness of the bearings to achieve overall system weight reduction. Directly inserting the bearings into the sheet metal frames makes it difficult to restrict their movement relative to the shaft's swinging direction, making it difficult for the sheet metal frames to maintain their bearing positioning and retention functions.

[0004] In conventional air circuit breakers, to suppress swinging of the bearing shaft, the bearing is inserted into a support portion having a thickness sufficiently greater than that of the sheet metal frame and then assembled to the sheet metal frame to position and retain the bearing (see, for example, Patent Document 1).

[0005] Patent Document 1: Japanese Utility Model Application Publication No. 5-69843 Summary of the Invention

[0006] In the circuit breaker disclosed in Patent Document 1, when assembling the bearings to the sheet metal frame (the "mechanical frame" in Patent Document 1), a support portion is required to insert and retain the bearings. This leads to a larger number of components, increased product weight, and increased assembly time. Furthermore, the increased assembly time leads to a decrease in assembly accuracy due to accumulated tolerances.

[0007] The present invention is proposed to solve the above-mentioned problems. It obtains a sheet metal frame with a plate thickness thinner than the axial thickness of the bearing, does not increase the number of components, can stably bear the load, and can reduce assembly time. It has a bearing retaining device with high reliability bearing positioning and retaining functions.

[0008] Furthermore, an air circuit breaker using the bearing retaining device was obtained.

[0009] The bearing retaining device involved in the present invention comprises: a bearing; a stepped shaft, which is freely rotatably retained in the bearing; and a sheet metal frame, the thickness of which is less than or equal to the axial thickness of the bearing, and is provided with a bearing mounting hole for mounting the bearing, the bearing having an outer ring, an inner ring inside the outer ring, an inner side surface opposite to the insertion direction of the stepped shaft, and an outer side surface opposite to the inner side surface, the stepped shaft having a step portion and a small diameter portion formed by reducing the diameter across the step portion at the end portion, the small diameter portion being inserted into the inner ring until the step portion abuts the inner ring on the inner side surface of the bearing, the sheet metal frame having an inner wall surface on the side where the bearing is mounted and an outer wall surface on the side opposite to the inner wall surface in the thickness direction, the bearing mounting hole having a claw portion extending axially from the mounting hole edge portion on the outer wall surface side and abutting the outer ring on the outer side surface of the bearing.

[0010] Furthermore, the air circuit breaker according to the present invention has the bearing holding device according to the present invention mounted on a circuit breaker body.

[0011] Effects of the Invention

[0012] According to the bearing retaining device involved in the present invention, even if the sheet metal frame is thinner than the axial thickness of the bearing, the positioning and retaining functions of the bearing can be achieved without increasing the number of components, which can reduce assembly man-hours and prevent deterioration of assembly accuracy.

[0013] Furthermore, according to the air circuit breaker including the bearing holding device according to the present invention, it is possible to reduce the weight of the product and improve the reliability of the product by reducing the number of components. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a perspective view of the air circuit breaker according to Embodiment 1 of the present invention.

[0015] Figure 2 This is a perspective view showing a portion of a drawer frame cut away in a state where a circuit breaker body is drawn out from the drawer frame in the air circuit breaker according to the first embodiment of the present invention.

[0016] Figure 3 This is a perspective view showing a portion of a drawer frame cut away in a state where the circuit breaker body of the air circuit breaker according to Embodiment 1 of the present invention is inserted into the drawer frame.

[0017] Figure 4 This is a side cross-sectional view showing a tripped state in which a closing spring of a circuit breaker body is released in the air circuit breaker according to the first embodiment of the present invention.

[0018] Figure 5 It is a side cross-sectional view showing the disconnected state of the circuit breaker body in which charging is completed in the air circuit breaker according to the first embodiment of the present invention.

[0019] Figure 6 It is a side cross-sectional view showing a closed state of a circuit breaker body in the air circuit breaker according to Embodiment 1 of the present invention.

[0020] Figure 7 This is a front view of a main shaft in the air circuit breaker according to the first embodiment of the present invention.

[0021] Figure 8 It is an exploded perspective view of the bearing holding device according to the first embodiment of the present invention.

[0022] Figure 9 It is a side view of the outer wall surface side of the sheet metal frame of the bearing retaining device according to the first embodiment of the present invention.

[0023] Figure 10 It is a perspective view of the bearing holding device according to the first embodiment of the present invention.

[0024] Figure 11 It is a cross-sectional view showing a bearing holding device according to Embodiment 1 of the present invention.

[0025] Figure 12 It is a cross-sectional view showing a bearing holding device according to a second embodiment of the present invention.

[0026] Figure 13 It is an enlarged perspective view of a bearing mounting hole of a sheet metal frame of a bearing retaining device according to a third embodiment of the present invention.

[0027] Figure 14 It is a perspective view showing a sheet metal frame in a bearing retaining device according to a fourth embodiment of the present invention.

[0028] Figure 15 It is a cross-sectional view showing a bearing holding device according to a fourth embodiment of the present invention.

[0029] Figure 16 It is a perspective view of a bearing holding device according to a fifth embodiment of the present invention.

[0030] Figure 17 It is a cross-sectional view showing a bearing holding device according to a fifth embodiment of the present invention. DETAILED DESCRIPTION

[0031] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following embodiments, the same components are denoted by the same reference numerals.

[0032] Implementation method 1.

[0033] Figure 1is a perspective view of the air circuit breaker according to the first embodiment. Figure 2 This is a perspective view showing a portion of the drawer frame of the air circuit breaker according to the first embodiment, in which the breaker body is drawn out from the drawer frame. Figure 3 This is a partially cutaway perspective view of the pull-out frame of the air circuit breaker according to the first embodiment, in a state where the circuit breaker body is inserted into the pull-out frame. Figure 4 1 is a side sectional view showing a tripped state in which a closing spring of the air circuit breaker according to the first embodiment is released. Figure 5 is a side sectional view showing the disconnected state of the air circuit breaker according to the first embodiment after charging is completed. Figure 6 It is a side cross-sectional view showing a closed state of the air circuit breaker according to the first embodiment.

[0034] exist Figure 1 In the embodiment, the air circuit breaker 300 is composed of a circuit breaker body 100 for opening and closing the circuit and a drawer frame 200 for housing the circuit breaker body 100 in a drawer-type manner. The circuit breaker body 100 is covered by a frame 101 composed of a molded case 101a and a molded cover 101b. A drawer mechanism 15 for drawing the circuit breaker body 100 out of the drawer frame 200 is provided at the bottom of the frame 101. An ON button 11 is provided on the front of the frame 101. Figure 4 The charging arm 24 shown in the side cross-sectional view moves to close the movable contact 43; the OFF button 12, which makes Figure 4 The trip latch 31 shown in the side cross-sectional view is actuated to trip the movable contact 43; and the handle 13, which will Figure 4 The closing spring 17 shown in the side section is manually charged.

[0035] An insertion hole 14 is provided on the front surface of the pull-out mechanism 15 , into which a pull-out handle (not shown) used when pulling out the circuit breaker body 100 is inserted.

[0036] The drawer frame 200 is provided with a retractable drawer rail 200 a on one end of which the circuit breaker body 100 is mounted.

[0037] like Figure 3 As shown, the circuit breaker body 100 is inserted into the drawer frame 200. Generally, the circuit breaker body 100 is used in a state of being inserted into the drawer frame 200.

[0038] When the circuit breaker body 100 needs to be pulled out from the pull-out frame 200 for maintenance or other reasons, Figure 3 From the inserted state of the circuit breaker body 100 shown, the pull-out handle (not shown) inserted from the insertion hole 14 is rotated. Figure 3The circuit breaker body 100 moves in the direction of arrow E and is pulled out from the pull-out frame 200 to a predetermined position. Then, the circuit breaker body 100 is pulled out from the pull-out frame 200 to form a Figure 1 Shown in the pulled-out position.

[0039] Next, the opening and closing mechanism of the circuit breaker body 100 will be described.

[0040] like Figure 4 、 Figure 5 ,like Figure 6 As shown, the frame 101 is composed of a molded housing 101a and a molded cover 101b. The cam shaft 21 is rotatably supported on the sheet metal frame 2 ( Figure 2 The cam shaft 21 is used as an axis to fix the charging cam 22 and the ratchet 23. A cam side roller 22a is provided between the charging cam 22 and the ratchet 23. The outer periphery of the charging cam 22 forms a circumferential cam surface 22b.

[0041] Above the charging cam 22, there is a charging arm 24 that rotates around a fixed shaft 24a. An arm-side roller 24b is provided at one end of the charging arm 24 to roll the circumferential cam surface 22b of the charging cam 22. As a result, the charging cam 22 is rotated together with the charging arm 24 around the fixed shaft 24a. A working surface 24c is formed on the upper surface of the middle abdomen of the charging arm 24. Figure 4 、 Figure 5 、 Figure 6 As shown in FIG. 2 , the charging arm 24 has a shape in which the radius of curvature changes toward the right. A spring hook pin 24d is provided at the other end of the charging arm 24.

[0042] To the right of charging cam 22, a guide plate 18 is fixed to frame 101, holding closing spring 17. Guide plate 18 has an elongated hole 18a. A spring hook pin 24d extends through elongated hole 18a, allowing it to move along the hole. This moves along the hole to charge closing spring 17.

[0043] The first closing latch 25 is rotatably mounted on the fixed shaft 24a, and has a latch side roller 25a in the middle portion thereof, and two action surfaces are formed on the end surface of one end side, which can engage with the cam side roller 22a. One of the action surfaces is formed on the first closing latch 25. Figure 4 The limiting surface extending in the vertical direction at the right end of the charging cam 22 is limited to further rotation when the cam side roller 22a contacts the limiting surface. Figure 4In the middle, there is a permissive surface extending obliquely downward to the left from the lower end of the above-mentioned limiting surface. When the cam side roller 22a contacts this surface, the counterclockwise rotation of the charging cam 22 is allowed. In addition, when the energy storage of the closing spring 17 begins, the cam side roller 22a is as follows. Figure 5 As shown, it engages with the allowable surface.

[0044] A second closing latch 26 is provided above the first closing latch 25, rotating about a fixed shaft 26a. A latch-side roller 25a engages with the lower end of the second closing latch 26. The upper end of the second closing latch 26 engages with a closing lever 27, a portion of which is cut into a D-shaped cutout, and has a side projection and a stepped engagement portion formed below.

[0045] In addition, the second closing latch 26 is released by a return spring (not shown). Figure 4 The closing lever 27 is manually operated by the ON button 11 or turned on (rotated in the clockwise direction) by a solenoid or the like.

[0046] In addition, if Figure 2 As shown, a track detection rod 51 for detecting the pulled-out state of the circuit breaker body 100 is provided on the inner side of the side of the pull-out frame 200. Figure 4 The closing plate 56 fixed to the track detection rod 51, the shaft 53, the linkage plate 54 and the push rod 55 rotate the closing plate 56, thereby Figure 4 The closing lever 27 is shown to be actuated and the closing spring 17 is released.

[0047] The main shaft 28 described later is rotatably supported by the sheet metal frame 2 ( Figure 2 shown).

[0048] like Figure 4 As shown, the closing toggle mechanism 29 is composed of two links, a first link 29a and a second link 29b, connected by a center pin 29d. The second link 29b is connected to the second link arm 28b ( Figure 7 shown) link.

[0049] A link-side roller 29e is rotatably supported around the center pin 29d and is positioned so as to abut against the operating surface 24c when the closing toggle mechanism 29 is bent.

[0050] A connecting rod lever 30 is provided above the closing toggle mechanism 29 and is rotatably supported on a fixed shaft 30a. The first connecting rod 29a side of the closing toggle mechanism 29 is connected to one end side via a pin 30b. A rod side roller 30c is provided in the middle of the connecting rod lever 30 and is rotatably supported on a fixed shaft 30a. Figure 4A trip latch 31 rotatably supported on the fixed shaft 26a is provided on the left side of the rod side roller 30c. The side surface of the trip latch 31 engages with the rod side roller 30c, and the upper end engages with a trip lever 32 having a partially D-cut shape. The trip latch 31 is released by a return spring (not shown). Figure 4 The trip lever 32 is manually operated by the OFF button 12 or is tripped (rotated counterclockwise) by a solenoid or the like.

[0051] Next, the energy storage action of the closing spring 17 and the contact closing action are described. Figure 4 In the tripped state, if the handle 13 is manually pressed in the direction of the arrow D, the ratchet 23 is rotated in the counterclockwise direction, and the charging cam 22 coaxially fixed to the cam shaft 21 is rotated in the counterclockwise direction, then the arm side roller 24b supported on the left end of the charging arm rotates along its circumferential cam surface 22b, so that the arm side roller 24b is rotated in the Figure 5 As a result, the charging arm 24 rotates clockwise around the fixed shaft 24a, and the spring hook pin 24d provided at the other end is rotated in the left direction. Figure 4 The middle part moves downward and the closing spring 17 stores energy.

[0052] On the other hand, the second closing latch 26 is biased in the counterclockwise direction by a return spring (not shown), so that the side projection at the lower end of the second closing latch 26 abuts against the latch side roller 25a. Figure 5 The operator presses it to the right in an attempt to rotate the first closing spring key 25 in the clockwise direction, but the lower surface of one end side of the first closing spring key 25, that is, the allowing surface and the cam side roller 22a are in contact with each other, so the cam side roller 22a becomes a stopper and the first closing spring key 25 remains in a state where it cannot rotate.

[0053] After the closing spring 17 has charged, if the charging cam 22 further rotates counterclockwise, the cam-side roller 22a separates from the lower surface, or the permissive surface, of one end of the first closing latch 25. At this point, the first closing latch 25 rotates clockwise, and the latch-side roller 25a also rotates clockwise, disengaging from the side projection at the lower end of the second closing latch 26, freeing the lower end of the second closing latch 26.

[0054] As a result, the second closing spring key 26 rotates in the counterclockwise direction through the return spring, and the upper end of the second closing spring key 26 exceeds the closing rod 27. When it moves to the left of the closing rod 27, the spring key side roller 25a of the first closing spring key 25 engages with the engaging part of the lower end of the second closing spring key 26, preventing the movement of the second closing spring key 26.

[0055] At this time, at the upper end of the second closing latch 26, the closing lever 27 is rotated counterclockwise by a return spring (not shown) to enter the second state ( Figure 6 Even if a clockwise rotational force acts on the second closing latch 26, it will act as a stopper against it.

[0056] After the closing spring 17 has stored energy, the charging arm 24 rotates clockwise, and its working surface 24c moves to the Figure 5 The connecting rod side roller 29e moves downwards and tries to separate from the connecting rod side roller 29e of the closing toggle mechanism 29. Through the bending force of the closing toggle mechanism 29, the connecting rod side roller 29e follows the downward movement of the working surface 24c. Figure 5 Therefore, the pin 30b of the other end of the closing toggle mechanism 29 moves downward, so the connecting rod lever 30 rotates in the counterclockwise direction, and the rod side roller 30c also rotates in the counterclockwise direction.

[0057] As a result, the trip latch 31 is rotated in the clockwise direction by the return spring. When the trip latch 31 exceeds the trip lever 32 and moves to the right, the rod side roller 30c and the recessed portion ( Figure 5 ) is engaged, and the trip lever 32 is rotated in the clockwise direction by a return spring (not shown). Even if a counterclockwise rotational force acts on the trip latch 31, it acts as a stopper therefor.

[0058] The closing toggle mechanism 29 is not bent above the prescribed bending state, so it becomes Figure 5 The charging cam 22 rotates approximately one circle by pressing the handle 13 several times, and finally becomes Figure 5 The arm side roller 24b of the charging arm 24 reaches a position slightly proximal to the maximum radius of the charging cam 22, and the cam side roller 22a again abuts against the end face of the first closing spring key 25, i.e., the limiting face, and becomes a stopped state.

[0059] Then, even if the handle 13 is further pressed, the ratchet 23 only rotates idly, the charging cam 22 does not rotate, and the energy storage of the closing spring 17 is completed.

[0060] exist Figure 5In this state, the spring hook pin 24d is pressed upward by the release force of the closing spring 17, exerting a counterclockwise force on the charging arm 24. This force is transmitted to the charging cam 22 via the arm-side roller 24b, so that the cam-side roller 22a presses the end surface, i.e., the restriction surface, of the first closing latch 25 in the counterclockwise direction. As a result, the latch-side roller 25a of the first closing latch 25 presses the lower end engaging portion of the second closing latch 26 to the left, attempting to rotate the second closing latch 26 in the clockwise direction. However, the closing lever 27 at the upper end of the second closing latch 26 acts as a stopper, preventing the second closing latch 26 from rotating in the clockwise direction.

[0061] In this state, if Figure 1 When the ON button 11 is pressed, the closing lever 27 rotates in the clockwise direction to perform the connection operation, and the lock of the upper end of the second closing spring key 26 performed by the closing lever 27 is released, so the second closing spring key 26 rotates in the clockwise direction, and the engagement between the lower end engaging portion and the spring key side roller 25a is disengaged.

[0062] As a result, the cam side roller 22a rotates in the same direction while rotating the first closing latch 25 in the counterclockwise direction. The charging cam 22 also rotates in the same direction. Therefore, the arm side roller 24b supported at the left end of the charging arm 24 falls into the step portion of the circumferential cam surface 22b of the charging cam 22. The charging arm 24 is closed by the release force of the closing spring 17. Figure 6 As shown, when rotating in the counterclockwise direction, the working surface 24c causes the connecting rod side roller 29e of the closing toggle mechanism 29 to jump up.

[0063] Therefore, the left link of the closing toggle mechanism 29 moves upward, trying to rotate the link lever 30 in the clockwise direction, but the rod side roller 30c abuts against the trip latch 31, and the trip latch 31 locks the counterclockwise movement through the trip rod 32. Therefore, the closing toggle mechanism 29 extends to the right, and in order to rotate the second link arm 28b in the counterclockwise direction, the movable contact 43 moves to the right and becomes Figure 6 In the state shown, the contact 43a and the contact 44a provided on the conductor 44 are connected.

[0064] exist Figure 6 In the shown on state, the closing toggle mechanism 29 is pressed to the left by the pressing force of the crimping spring 45, and a clockwise rotational force is applied to the connecting rod lever 30 via the pin 30b, and the trip latch 31 is pressed in the counterclockwise direction via the rod side roller 30c, but the trip latch 31 is prevented from rotating in the counterclockwise direction by the trip rod 32.

[0065] In this state, if Figure 1When the OFF button 12 is pressed, the trip lever 32 rotates counterclockwise to perform the tripping operation. The trip latch 31 rotates counterclockwise due to the above-mentioned force, so that the rod side roller 30c disengages from the recess of the trip latch 31, and the connecting lever 30 rotates clockwise. As a result, the pin 30b at the other end of the closing toggle mechanism 29 moves upward, and the closing toggle mechanism 29 bends. At this time, the connecting rod side roller 29e of the closing toggle mechanism 29 moves to the left along the working surface 24c of the charging arm 24. The pin 29c drives the insulating link 41 to the left, causing the movable contact 43 to move to the left, and the contacts 43a and 44a become disconnected, returning to the closed position. Figure 4 Then, repeat the above steps.

[0066] Next, the structure of the shaft, which is the rotation axis of the opening and closing mechanism, will be described using the main shaft 28 as an example.

[0067] Figure 7 FIG. 2 is a front view of a main shaft 28, which is an example of a shaft in an air circuit breaker. Figure 7 As shown, an insulating link arm 28a and a second link arm 28b having the same shape as the insulating link arm 28a are fixed to the main shaft 28. The insulating link arm 28a and the second link arm 28b are provided with a pin 42 and a pin 29c for driving the link, respectively.

[0068] The main shaft 28 is a stepped shaft having a stepped portion 28c and a small diameter portion 28d formed by reducing the diameter across the stepped portion 28c at both ends in the axial direction. The small diameter portion 28d of the main shaft 28 is fixed to a bearing mounted on the sheet metal frame 2 and is rotatably supported.

[0069] In the air circuit breaker 300 , as part of the components of the switching mechanism, shafts such as the main shaft 28 and the cam shaft 21 are rotatably supported by bearings attached to the sheet metal frame 2 fixed to the housing 101 .

[0070] Next, the structure of a bearing holding device, which is a device having a function of positioning and holding a bearing attached to the frame 101 of the circuit breaker body 100 , will be described.

[0071] Figure 8 It is a diagram showing the structure of the bearing holding device 1 according to the first embodiment. Figure 8 (a) is an exploded perspective view of the bearing retaining device 1, Figure 8 (b) Yes Figure 8 An enlarged view of the portion indicated by the dashed line A in (a). Figure 8 (c) Yes Figure 8 (a) is an enlarged schematic view of the bearing 4 on the left side.

[0072] Figure 9It is a side view of the outer wall surface side of the sheet metal frame 2 of the bearing retaining device 1.

[0073] Figure 10 It is a perspective view showing the bearing retaining device 1 .

[0074] Figure 11 yes Figure 10 A cross-sectional view of the bearing retaining device 1 at the position of the dot-dash line B is shown.

[0075] The bearing holding device 1 according to the first embodiment includes a bearing 4 , a stepped shaft 3 rotatably held by the bearing 4 , and a sheet metal frame 2 having a bearing mounting hole 2 a for mounting the bearing 4 .

[0076] The bearing 4 includes an outer ring 4a and an inner ring 4b located inside the outer ring 4a. The inner ring 4b can rotate relative to the outer ring 4a with minimal resistance. The bearing 4 also has an inner side surface 4c facing the direction of insertion of the stepped shaft 3 and an outer side surface 4d opposite the inner side surface 4c.

[0077] The sheet metal frames 2 have a thickness less than or equal to the axial thickness of the bearing 4 and are fixed to the frame 101, forming a pair of opposing frames. The sheet metal frames 2 have an inner wall surface 2c on the side where the bearing 4 is mounted, and an outer wall surface 2d on the side opposite the inner wall surface 2c in the thickness direction. The inner diameter of the bearing mounting hole 2a, which extends through the sheet metal frame 2, corresponds to the outer ring 4a of the bearing 4. The circumferential surface 2e of the bearing mounting hole 2a has claws 2b extending axially from the mounting hole edge 2f on the outer wall surface 2d side. The claws 2b abut against the outer ring 4a on the outer side surface 4d of the bearing 4 to retain the bearing 4, restricting outward movement of the bearing 4.

[0078] The bearing mounting hole 2a and the claw portion 2b are integrally formed by press working, thereby increasing the strength of the claw portion 2b without increasing the number of processing steps.

[0079] The stepped shaft 3 has a stepped portion 3a and a smaller diameter portion 3b, formed by reducing the diameter across the stepped portion 3a, at each end in the axial direction. The smaller diameter portion 3b of the stepped shaft 3 is inserted into the inner ring 4b of the bearing 4 until the stepped portion 3a contacts the inner ring 4b on the inner side surface 4c of the bearing 4. The smaller diameter portion 3b of the stepped shaft 3 is fixed to the inner ring 4b of the bearing 4, thereby retaining the shaft 3 in a rotatable manner.

[0080] Here, the stepped shaft 3 is a representative example of a shaft structure, corresponding to a shaft such as the main shaft 28, and has the same function as a rotating shaft as the main shaft 28. The stepped portion 3a of the stepped shaft 3 corresponds to the stepped portion 28c of the main shaft 28, and the small diameter portion 3b of the stepped shaft 3 corresponds to the small diameter portion 28d of the main shaft 28.

[0081] For the sake of convenience, the charging cam, arm, etc. are not shown in the figure. The bearing holding device can be similarly configured and has the same function even when the charging cam, arm, etc. are attached to the stepped shaft.

[0082] In addition, for the sake of convenience, Figure 8 , the figure shows a state where there is only one bearing mounting hole for mounting a bearing in the sheet metal frame 2. In the bearing holding device, even when a plurality of bearing mounting holes are mounted on a sheet metal frame, the same structure can be employed and the same function can be achieved.

[0083] In the first embodiment, the claws 2b are discontinuously provided at multiple locations along the mounting hole edge 2f of the bearing mounting hole 2a to clamp the outer ring 4a of the bearing 4. The claws 2b are provided at multiple locations along the mounting hole edge 2f of the bearing mounting hole 2a at approximately equal intervals, thereby improving the stability of holding the bearing 4. Figure 9 An example is shown in which the claw portions 2b are provided at three locations along the mounting hole edge portion 2f.

[0084] In addition, if Figure 10 、 Figure 11 As shown, in the bearing retaining device 1, the bearing 4 is inscribed within the bearing mounting hole 2a provided in the sheet metal frame 2, thereby restricting radial movement of the bearing 4. The outer ring 4a of the bearing 4 abuts against the claws 2b on the outer wall surface 2d of the sheet metal frame 2, while the inner ring 4b of the bearing 4 abuts against the step 3a of the stepped shaft 3. The bearing 4 is clamped together by the claws 2b of the bearing mounting hole 2a and the step 3a of the stepped shaft 3, restricting thrust movement of the bearing 4. This achieves both positioning and retaining functions of the bearing 4.

[0085] The claws 2 b hold the outer ring 4 a of the bearing 4 , and their shapes are not important as long as they can restrict the movement of the bearing 4 in the direction outward from the claws 2 b .

[0086] In addition, if Figure 11 As shown, the claw portion 2b is located on the outer wall surface 2d side and is flush with the outer wall surface 2d. This flush structure prevents the claw portion 2b from interfering with components arranged outside the sheet metal frame, thereby increasing the degree of design freedom in component layout, etc.

[0087] The thickness of the sheet metal frame 2 is less than or equal to the axial thickness of the bearing 4. Therefore, when the bearing 4 is installed in the bearing mounting hole 2a until the outer ring 4a contacts the claw 2b, only the portion of the bearing 4 inserted into the bearing mounting hole 2a contacts the circumferential surface 2e of the bearing mounting hole 2a. In other words, when the bearing 4 is installed in the bearing mounting hole 2a, only a portion of the outer ring 4a is axially inscribed within the circumferential surface 2e of the bearing mounting hole 2a. The remaining portion of the bearing 4 is exposed outward from the inner wall 2c of the sheet metal frame 2 on the side where the claw 2b is not provided.

[0088] The air circuit breaker according to the first embodiment includes the bearing holding device 1 mounted on the frame 101 of the circuit breaker body 100 .

[0089] According to the bearing retaining device involved in embodiment 1, even if the sheet metal frame is thinner than the axial thickness of the bearing, the positioning and retaining functions of the bearing can be achieved without increasing the number of components, which can reduce assembly man-hours and prevent deterioration of assembly accuracy.

[0090] According to the air circuit breaker including the bearing retaining device according to the first embodiment, it is possible to achieve product weight reduction and improved reliability by reducing the number of components.

[0091] Implementation method 2.

[0092] use Figure 12 , a bearing retaining device according to a second embodiment and an air circuit breaker using the bearing retaining device will be described.

[0093] In the second embodiment, descriptions of the same components or corresponding parts as those in the first embodiment of the present invention are omitted. Next, the differences between the bearing holding device according to the second embodiment and the first embodiment will be described with reference to the drawings.

[0094] Figure 12 is with Figure 10 The position of the dot-dash line B shown in FIG is a cross-sectional view of the bearing holding device 102 according to the second embodiment. Figure 12 It is along Figure 9 The illustrated embodiment is a cross-sectional view of a bearing holding device 102 according to a second embodiment, corresponding to a case where claw portions are provided at three locations on a mounting hole edge portion 2f.

[0095] like Figure 12 As shown, in the bearing retaining device 102, the sheet metal frame 202 has an inner wall surface 202c on the side where the bearing 4 is mounted, and an outer wall surface 202d on the side opposite to the inner wall surface 202c in the thickness direction. A claw portion 202b is provided on the circumferential surface 202e of the bearing mounting hole 202a, extending axially from a mounting hole edge portion 202f on the outer wall surface 202d side.

[0096] In contrast to the structure of the first embodiment described above, where the claw portion 2b is flush with the outer wall surface 2d, the bearing retaining device according to the second embodiment has the claw portion 202b protruding outward from the outer wall surface 202d on the outer wall surface 202d side. This protrusion of the claw portion 202b from the outer wall surface 202d of the sheet metal frame 202 allows the bearing 4 to be mounted with an offset in the thrust direction toward the outer wall surface 202d of the sheet metal frame 202. This increases the contact surface between the outer ring 4a of the bearing 4 and the circumferential surface 202e of the bearing mounting hole 202a. This reduces the stress generated in the sheet metal frame 202 and the bearing 4 when a load is applied to the stepped shaft 3.

[0097] Similar to Embodiment 1, in Embodiment 2, claws 202b are provided discontinuously at multiple locations along the mounting hole edge 202f of the bearing mounting hole 202a. The claws 202b grip the outer ring 4a of the bearing 4, and their shape is not necessary as long as they can restrict movement of the bearing 4 outward from the claws 202b.

[0098] The bearing mounting hole 202a and the claw portion 202b are integrally formed by press working.

[0099] In addition, in the bearing holding device according to the second embodiment, the structure other than the claw portion 202 b of the sheet metal frame 202 is the same as that of the bearing holding device according to the above-mentioned first embodiment.

[0100] Furthermore, the air circuit breaker using the bearing retaining device according to the second embodiment can also be configured in the same manner as the air circuit breaker using the bearing retaining device according to the first embodiment.

[0101] According to the bearing retaining device involved in embodiment 2, even if the sheet metal frame is thinner than the axial thickness of the bearing, it can have the positioning and retaining functions of the bearing without increasing the number of components, which can reduce assembly man-hours and prevent deterioration of assembly accuracy.

[0102] Furthermore, since the claw portion protrudes outward from the outer wall surface of the sheet metal frame, the contact surface between the bearing and the bearing mounting hole becomes larger, which can reduce stress generated in the sheet metal frame and the bearing and improve the product life.

[0103] According to the air circuit breaker using the bearing retaining device according to the second embodiment, it is possible to reduce the weight of the product and improve the reliability and life of the product by reducing the number of components.

[0104] Implementation method 3.

[0105] use Figure 13, a bearing retaining device according to a third embodiment and an air circuit breaker using the bearing retaining device will be described.

[0106] In the third embodiment, descriptions of the parts identical to or corresponding to those in the first embodiment of the present invention will be omitted. Hereinafter, differences between the bearing holding device according to the third embodiment and the first embodiment will be described with reference to the drawings.

[0107] Figure 13 is with Figure 8 (a) is an enlarged perspective view of a bearing mounting hole 203a in a sheet metal frame 203 of a bearing holding device according to a third embodiment, corresponding to the portion indicated by the dashed line A.

[0108] like Figure 13 As shown, in embodiment 3, the sheet metal frame 203 has a claw portion 203b extending axially from the mounting hole edge portion 203f on the outer wall side of the sheet metal frame 203 and recesses 203g formed at both ends of the root of the claw portion 203b on the circumferential surface 203e of the bearing mounting hole 203a.

[0109] The bearing mounting hole 203a, claw portion 203b, and recess 203g are integrally formed through a two-stage stamping process. First, the bearing mounting hole 203a and recess 203g are stamped simultaneously. Next, the claw portion 203b is stamped. By forming recess 203g simultaneously with the bearing mounting hole 203a before forming the claw portion 203b, the stress generated during the forming of the claw portion 203b is concentrated on the recess 203g portion. Compared to a case where the recess 203g is not formed, deformation of the bearing mounting hole 203a caused by stress generated around the claw portion 203b can be prevented.

[0110] In the third embodiment, the bearing 4 is held together by the claw portion 203b of the bearing mounting hole 203a and the step portion 3a of the stepped shaft 3. In addition, the mounting hole edge portion 203f is provided at multiple locations along the bearing mounting hole 203a at approximately equal intervals, thereby improving the stability of holding the bearing 4.

[0111] Next, the positional relationship between the claw portion 203 b and the outer wall surface of the sheet metal frame 203 in the bearing holding device according to the third embodiment will be described.

[0112] In the third embodiment, as in the bearing retaining device 1 according to the first embodiment, the claws 203b can be provided flush with the outer wall surface of the sheet metal frame 203. In this case, the claws do not interfere with components disposed outside the sheet metal frame, thereby increasing the degree of design freedom in component layout and the like.

[0113] Alternatively, as in the bearing retaining device 102 according to Embodiment 2, the claw portion 203b can be provided so as to protrude outward from the outer wall surface of the sheet metal frame 203. In this case, the contact surface between the bearing and the bearing mounting hole is increased, which can reduce stress generated in the sheet metal frame and the bearing, thereby increasing the product life.

[0114] When the claw portion 203b protrudes outward from the outer wall surface of the sheet metal frame 203, the bearing mounting hole 203a, the claw portion 203b and the recess 203g are also integrally formed by two-stage stamping.

[0115] The bearing holding device according to the third embodiment has the same structure as the bearing holding device according to the first or second embodiment except for the recess 203 g formed at the base of the claw portion 203 b of the sheet metal frame 203 .

[0116] Furthermore, the air circuit breaker using the bearing retaining device according to the third embodiment can also be configured in the same manner as the air circuit breaker using the bearing retaining device according to the first embodiment.

[0117] According to the bearing retaining device involved in embodiment 3, similar to embodiment 1, even if the sheet metal frame is thinner than the axial thickness of the bearing, the positioning and retaining functions of the bearing can be achieved without increasing the number of components, which can reduce assembly time and prevent deterioration of assembly accuracy.

[0118] Furthermore, by providing recesses at both ends of the claw portion in the sheet metal frame, deformation of the bearing mounting hole caused by stress generated during molding of the claw portion can be prevented, thereby preventing improper mounting of the bearing.

[0119] According to the air circuit breaker using the bearing retaining device according to the third embodiment, the number of components can be reduced, thereby reducing the weight of the product and reducing the number of assembly steps. Deformation of the bearing mounting hole can be prevented, thereby reducing the weight of the product and improving reliability.

[0120] Implementation method 4.

[0121] use Figure 14 and Figure 15 , a bearing retaining device according to a fourth embodiment and an air circuit breaker using the bearing retaining device will be described.

[0122] In the fourth embodiment, descriptions of the parts identical to or corresponding to those in the first embodiment of the present invention will be omitted. Hereinafter, differences between the bearing holding device according to the fourth embodiment and the first embodiment will be described with reference to the drawings.

[0123] Figure 14This is a perspective view of the bearing holding device 104 according to the fourth embodiment, as viewed from the inner wall surface 204 c side of the sheet metal frame 204 .

[0124] Figure 15 It is a cross-sectional view showing a bearing holding device 104 according to a fourth embodiment.

[0125] like Figure 14 As shown, in the bearing retaining device 104 according to the fourth embodiment, the sheet metal frame 204 has an inner wall surface 204c on the side where the bearing 4 is mounted, and an outer wall surface 204d on the side opposite to the inner wall surface 204c in the thickness direction. The sheet metal frame 204 is formed with a bearing mounting hole 204a and a claw portion 204b extending axially from the outer wall surface 204d of the sheet metal frame 204 on a circumferential surface 204e of the bearing mounting hole 204a. The bearing mounting hole 204a and the claw portion 204b are integrally formed by stamping.

[0126] While the claws 2b of the bearing mounting hole 2a in the first embodiment are arranged at multiple locations along the mounting hole edge 2f of the bearing mounting hole 2a at approximately equal intervals, in the fourth embodiment, the claws 204b are formed into a flange shape on the circumferential surface 204e of the bearing mounting hole 204a, extending continuously along the mounting hole edge 204f. Specifically, the claws 204b are shaped so as to be continuous with the mounting hole edge 204f on the outer wall surface 204d side of the centrally-opened disk.

[0127] The continuous flange shape of the claw portion 204b increases the contact surface with the bearing 4, thereby reducing the stress generated in the claw portion 204b when a load is applied to the stepped shaft 3. Compared to the bearing retaining device according to the first embodiment, the movement of the bearing 4 in the swinging direction can be more strongly restricted, and the retaining performance can be improved.

[0128] In addition, if Figure 15 As shown, claw portion 204b is provided flush with outer wall surface 204d of sheet metal frame 204. Since claw portion 204b and outer wall surface 204d of sheet metal frame 204 are provided flush with each other, claw portion 204b does not interfere with components disposed outside the sheet metal frame, thereby increasing design freedom in component layout and other aspects.

[0129] The bearing retaining device 104 according to the fourth embodiment has the same structure as the bearing retaining device according to the first embodiment, except for the sheet metal frame 204. Furthermore, an air circuit breaker using the bearing retaining device according to the fourth embodiment can be configured similarly to the air circuit breaker using the bearing retaining device according to the first embodiment.

[0130] According to the bearing retaining device involved in embodiment 4, similar to embodiment 1, even if the sheet metal frame is thinner than the axial thickness of the bearing, the positioning and retaining functions of the bearing can be achieved without increasing the number of components, which can reduce assembly time and prevent deterioration of assembly accuracy.

[0131] Furthermore, the contact surface between the claw portion of the bearing mounting hole and the bearing is large, thereby reducing stress generated in the claw portion when a load is applied to the stepped shaft. Compared to the bearing retaining device of embodiment 1, the movement of the bearing in the swinging direction can be more strongly restricted, thereby improving retention.

[0132] According to the air circuit breaker using the bearing retaining device according to the fourth embodiment, the number of components can be reduced, thereby reducing the weight of the product and reducing the number of assembly steps. The holding performance of the bearing can be improved, thereby reducing the weight of the product and improving reliability.

[0133] Implementation method 5.

[0134] use Figure 16 and Figure 17 , a bearing retaining device according to a fifth embodiment and an air circuit breaker using the bearing retaining device will be described.

[0135] In the fifth embodiment, descriptions of the same components or corresponding parts as those in the fourth embodiment of the present invention are omitted. Hereinafter, differences between the bearing holding device according to the fifth embodiment and the fourth embodiment will be described with reference to the drawings.

[0136] Figure 16 It is a perspective view showing a bearing holding device 105 according to the fifth embodiment. Figure 17 yes Figure 16 A cross-sectional view taken along the dashed line C shown in FIG.

[0137] like Figure 16 and Figure 17 As shown, in the bearing retaining device 105, the sheet metal frame 205 has an inner wall surface 205c on the side where the bearing 4 is mounted, and an outer wall surface 205d on the side opposite the inner wall surface 205c in the thickness direction. Formed in the sheet metal frame 205 are a bearing mounting hole 205a and a claw portion 205b. The claw portion 205b extends axially from the outer wall surface 205d of the sheet metal frame 205 on the circumferential surface 205e of the bearing mounting hole 205a. The claw portion 205b has a flange shape that continues along the mounting hole edge 205f. The bearing mounting hole 205a and the claw portion 205b are integrally formed by stamping.

[0138] In contrast to the structure of the bearing retaining device 104 according to the fourth embodiment, in which the claw portion 204b and the outer wall surface 204d of the sheet metal frame 204 are flush with each other, in the fifth embodiment, the claw portion 205b is configured to protrude outward from the outer wall surface 205d on the outer wall surface 205d side. In other words, the claw portion 205b protrudes outward from the outer wall surface 205d and is connected to the mounting hole edge 205f on the outer wall surface 205d side at the outer periphery of the centrally opened disk.

[0139] Because claws 205b protrude outward from outer wall surface 205d of sheet metal frame 205, bearing 4 is mounted offset toward outer wall surface 205d of sheet metal frame 205 in the thrust direction. This increases the contact area between outer ring 4a of bearing 4 and circumferential surface 205e of bearing mounting hole 205a. This reduces stress generated in sheet metal frame 205 and bearing 4 when loads are applied to stepped shaft 3.

[0140] The bearing retaining device 105 according to the fifth embodiment has the same structure as the bearing retaining device according to the fourth embodiment, except for the sheet metal frame 205. Furthermore, an air circuit breaker using the bearing retaining device according to the fifth embodiment can be configured similarly to the air circuit breaker using the bearing retaining device according to the fourth embodiment.

[0141] According to the bearing retaining device involved in embodiment 5, even if the sheet metal frame is thinner than the axial thickness of the bearing, the positioning and retaining functions of the bearing can be achieved without increasing the number of components, which can reduce assembly man-hours and prevent deterioration of assembly accuracy.

[0142] Furthermore, the contact surface between the claw portion of the bearing mounting hole and the bearing is large, thereby reducing stress generated in the claw portion when a load is applied to the stepped shaft. Compared to the bearing retaining device of embodiment 1, the movement of the bearing in the swinging direction can be more strongly restricted, thereby improving retention.

[0143] Furthermore, since the claw portion protrudes outward from the outer wall surface of the sheet metal frame, the contact surface between the bearing and the bearing mounting hole becomes larger, which can reduce stress generated in the sheet metal frame and the bearing and improve the product life.

[0144] According to the air circuit breaker using the bearing retaining device according to the fifth embodiment, it is possible to reduce the weight of the product and improve the reliability and life of the product by reducing the number of components.

[0145] The present invention describes various exemplary embodiments, but the various features, methods, and functions described in one or more embodiments are not limited to the application of specific embodiments and can also be applied to the embodiments individually or in various combinations. Therefore, countless variations not illustrated are envisioned within the technical scope disclosed in this application specification. For example, this includes the case where at least one structural element is deformed, added, or omitted, and the case where at least one structural element is extracted and combined with structural elements of other embodiments.

[0146] Description of the label

[0147] 1, 102, 104, 105 bearing retaining device

[0148] 2, 202, 203, 204, 205 sheet metal frames

[0149] 2a, 202a, 203a, 204a, 205a Bearing mounting holes

[0150] 2b, 202b, 203b, 204b, 205b claws

[0151] 2c, 202c, 204c, 205c inner wall

[0152] 2d, 202d, 204d, 205d outer wall

[0153] 2e, 202e, 203e, 204e, 205e circumferential surface

[0154] 2f, 202f, 203f, 204f, 205f Mounting hole edges

[0155] 3-step shaft

[0156] 3a Step

[0157] 3b small track section

[0158] 4 bearings

[0159] 4a Outer ring

[0160] 4b Inner Circle

[0161] 4c medial surface

[0162] 4d outer side

[0163] 21 Camshaft

[0164] 28 spindle

[0165] 100 Circuit breaker body

[0166] 101 frame

[0167] 300 air circuit breaker

Claims

1. A bearing retaining device, characterized in that: have: bearings; a stepped shaft rotatably held in the bearing; and The sheet metal frame has a thickness less than or equal to the axial thickness of the bearing and is provided with a bearing mounting hole for mounting the bearing. The bearing includes an outer ring, an inner ring inside the outer ring, an inner side surface facing the insertion direction of the stepped shaft, and an outer side surface opposite to the inner side surface. The stepped shaft has a stepped portion and a small diameter portion formed by reducing the diameter across the stepped portion at its end, and the small diameter portion is inserted into the inner ring until the stepped portion abuts against the inner ring on the inner side surface of the bearing. The sheet metal frame has an inner wall surface on the side where the bearing is mounted, and an outer wall surface on the opposite side to the inner wall surface in the thickness direction. The bearing mounting hole has a claw portion on its circumferential surface. The claw portion extends from a mounting hole edge portion on the outer wall surface side toward the axial direction and abuts against the outer ring on the outer side surface side of the bearing.

2. The bearing retaining device according to claim 1, characterized in that: The sheet metal frames are a pair arranged opposite to each other. The stepped shaft has the step portion and the small diameter portion at the end portions on both sides.

3. The bearing retaining device according to claim 1 or 2, characterized in that: The bearing mounting hole and the claw portion are integrally formed.

4. The bearing retaining device according to claim 1 or 2, characterized in that: The claws are provided at a plurality of locations along the edge of the mounting hole.

5. The bearing retaining device according to claim 4, characterized in that: A recess is formed on the circumferential surface of the bearing mounting hole at the base of the claw portion.

6. The bearing retaining device according to claim 1 or 2, characterized in that: The claw portion is in a flange shape that is continuous along the edge of the mounting hole.

7. The bearing retaining device according to claim 1 or 2, characterized in that: The claw portion is provided on the outer wall surface side in the same plane as the outer wall surface.

8. The bearing retaining device according to claim 1 or 2, characterized in that: The claw portion is provided on the outer wall surface side so as to protrude outward from the outer wall surface.

9. An air circuit breaker, comprising: an air circuit breaker having the bearing retaining device according to any one of claims 1 to 8 mounted on a circuit breaker body.

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