Brush module for rotary electric machine

Abstract

CONSTITUTION: A terminal and a base of a brush module have a through-hole at a center. A recess extending in a radial direction from the through-hole of the terminal includes a positioning portion for a brush holder. The brush holder includes a brush housing hole, a spring housing hole, a locking protrusion provided at an end of the spring housing hole on a through-hole side, and a protrusion penetrating the recess of the terminal. The protrusion includes a to-be-positioned portion that is positioned by the positioning portion of the recess. A tip end of the brush is exposed to the through-hole side, and a bottom part of the brush is housed in the brush housing hole. A coil-shaped constant force spring is provided in the spring housing hole to urge the bottom part of the brush, a pull-out portion of the constant force spring extends in the spring housing hole, and a base end of the pull-out portion is locked to the locking protrusion.EFFECT: The force for urging a brush by means of a constant load spring is used to fix a brush holder to a terminal so as to restrict vibration of the brush holder, and a compact brush module is obtained.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a brush module for a rotating electric machine. [Background technology]

[0002] In a rotating electric machine that uses brushes, the brushes are housed in a brush holder, and the brush holder is fixed to a plate-shaped member. The plate-shaped member is used to align the brush holder with the slip ring of the rotating electric machine, bringing the brush into contact with the slip ring of the rotating electric machine, and the brush is biased toward the slip ring of the rotating electric machine by a spring.

[0003] A brush module for a rotating electric machine is required to have a compact structure, to have little vibration of the brush holder, and to bias the brush to the slip ring with a constant force. For example, Patent Document 1 (JP2018-503019) discloses a brush module in which a brush holder, a cage, and a spiral spring are arranged on a plate. In this method, an arm extending from the end of the spring penetrates an opening provided in a side wall of the brush cage so that the arm can press the brush. However, this structure requires space for arranging the spring and the arm, and is not suitable for compacting the brush module.

[0004] In addition, in Patent Document 2 (JP2018-85865), a terminal is attached to one side of the brush holder as a power supply conductor in order to secure space for attaching a switch, etc. to the brush holder. However, in this structure, complex processing such as bending is performed to prevent the terminal from coming into contact with other components, and installation space is still required. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP2018-503019 [Patent Document 2] JP2018-85865 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a brush module for a rotating electric machine that biases a brush toward a slip ring of the rotating electric machine, by fixing a brush holder to a plate-shaped member and suppressing vibration of the brush holder. Another object of the present invention is to provide a compact brush module and to bias the brush toward the slip ring with a constant force. [Means for solving the problem]

[0007] The brush module for a rotating electric machine of the present invention includes a disk-shaped base made of an insulating material, a pair of terminals each made of a conductive, substantially disk-shaped plate and disposed on both the front and back sides of the base, a brush holder attached to each terminal, and a brush housed in the brush holder, The terminal and the base have a through hole at the radial center, The terminal includes a recess extending radially from the through hole and having a positioning portion for the brush holder; The brush holder is a brush receiving hole having a tip end facing the through hole and a base end facing the opposite side to the through hole and extending from the tip end to the base end; a spring accommodating hole that overlaps with a circumferential center of the terminal of the brush accommodating hole in a plan view and is located on an opposite side of the terminal from the brush accommodating hole; A locking projection is provided at an end of the spring accommodating hole on the through hole side; A protrusion is provided which penetrates the recess of the terminal, The protrusion has a positioned portion that is positioned by the positioning portion of the recess, The brush is accommodated in the brush accommodating hole, with the tip of the brush exposed to the through hole and the bottom of the brush accommodated in the brush accommodating hole, Further, a coil-shaped constant force spring is provided and accommodated in the spring accommodation hole, The coil portion of the constant force spring biases the bottom of the brush. A drawn-out portion drawn out from the coil portion of the constant force spring extends through the spring accommodating hole toward the through hole, The base end of the lead-out portion is engaged with the engaging projection.

[0008] The constant force spring biases the brush toward the slip ring with a constant force, and the reaction force that the brush receives from the slip ring is applied to the brush holder through the constant force spring. This reaction force positions the brush holder in the terminal, reduces vibration of the brush holder, and keeps the brush holder in a constant position. This keeps the brush in stable contact with the slip ring, and fixes the brush holder to the terminal in a constant position.

[0009] The constant force spring and its pull-out portion are accommodated in the direction of the through-hole in the brush holder, resulting in a compact brush module. If the spring accommodation hole is a through-hole that penetrates the brush holder, the brush can be cooled by the ventilation of the spring accommodation hole. The constant force spring can be set in the brush holder by engaging its base end with the engagement protrusion.

[0010] Preferably, the brush has a lead fixed to one side thereof, and the brush holder has a groove on one side thereof for passing the lead through, so that the lead can be easily pulled out from the groove.

[0011] Preferably, the brush holder is T-shaped in front view from the through hole side, with the apex of the T positioned on the terminal. The width of the brush holder along the circumferential direction of the terminal is narrower at the spring accommodating hole portion than at the brush accommodating hole portion. The T-shaped brush holder increases the rigidity of the brush holder.

[0012] Preferably, the brush housing hole and the spring housing hole are through holes that pass through the brush holder. For example, a brush holder using a coil spring needs to have its bottom closed due to the spring force, but compared to such a case, the present invention uses a constant load spring and has a spring locking portion inside the brush holder, making the brush holder more compact. In addition, the brush housing hole and the spring housing hole have ventilation properties that allow the brush to be cooled. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a plan view of a brush module for a rotating electric machine according to an embodiment of the present invention; [Diagram 2] Partial plan view of a terminal in an embodiment [Diagram 3] FIG. 1 is a side view of a brush module for a rotating electric machine according to an embodiment of the present invention; [Figure 4] FIG. 2 is a plan view of a brush and a brush holder in the embodiment; [Diagram 5] 1 is a bottom view of a brush and a brush holder in an embodiment; [Figure 6] A longitudinal cross section of the brush and brush holder along the VV direction in Figure 4. [Figure 7] 1 is a side view of a brush and a brush holder in an embodiment; [Figure 8] FIG. 11 is a partial plan view of a terminal according to a second embodiment; [Figure 9] FIG. 11 is a front view of a brush holder according to a second embodiment; [Figure 10] 11 is a bottom view of the brush holder according to the second embodiment; BEST MODE FOR CARRYING OUT THEINVENTION

[0014] The following are preferred embodiments for carrying out the present invention. The present invention is not limited to the embodiments, but is defined by the claims, and can be modified by adding matters known to those skilled in the art to the embodiments. EXAMPLES

[0015] 1 to 7 show a brush module 2 of an embodiment. As shown in Fig. 1 to 3, approximately disk-shaped terminals 6, 6 made of metal plates are provided on both the top and bottom of a disk-shaped base 4 made of an insulating material such as synthetic resin. A through hole 9 is provided in the radial center of the base 4 and the terminals 6, 6, through which a slip ring 8 of a rotating electric machine (not shown) passes. The rotating electric machine is, for example, an EESM (wound field type DC synchronous motor), such as the main motor of an electric vehicle. The type of rotating electric machine is arbitrary, and it is mounted, for example, in a hybrid electric vehicle (HEV), a generator, etc.

[0016] Three brush holders 10 are arranged in each of the terminals 6, 6, symmetrically above and below the base 4, and with a phase shift of 120° with respect to the through hole 9. The number of brush holders 10 per terminal 6 is, for example, 1 to 6, and the brush holders 10 may be made of metal or synthetic resin. Each brush holder 10 accommodates one brush 12, and the brush 12 is slidable relative to the brush holder 10 in the radial direction of the through hole 9. The leads 14 of the brush 12 are fixed to the terminal 6 by welding or the like.

[0017] The terminal 6 has recesses 13 at, for example, three locations on the outer periphery, and receives the engaging portion 15 of the base 4. The module 2 is engaged with a housing (not shown) (the housing of the brush module 2) at the engaging portion 15 by a bush or a bolt and nut, etc. The terminal 6 has rivet holes 18 at, for example, three locations, to which the bottom 19 of the rivet 17 is fixed. The reference numeral 20 denotes the head of the rivet 17. Then, the positive and negative external leads 20, 21 are connected to the terminal. That is, the terminal 6 is fixed to the base 4 by the rivet 17, and the bottom 19 is received in the rivet hole 18 so that the bottom 19 does not come into contact with the terminal 6. The connection between the terminal 6 and the external lead 21 is made by welding. The terminal 6 may be fixed to the base 4 by a bolt and nut, etc., instead of the rivet 17. As described above, the terminal of the present invention is a part of the current-carrying circuit to the slip ring, and the fixing members such as the engaging portion 15 and the rivet 17 are structured so as not to come into electrical contact with the other terminal.

[0018] 4 to 7 show the brush 12 and the brush holder 10. In the following, the slip ring side is called the tip or front, and the opposite side is called the base, bottom, or back. The side closer to the base 4 is called the bottom, and the opposite side is called the top. The brush accommodating hole 22 penetrates the brush holder 10 in the longitudinal direction and accommodates the brush 12 in a freely slidable manner. A constant-load spring 24 made of a coiled metal piece is accommodated in the accommodating hole 22, and its coil portion 25 biases the bottom portion 34 of the brush 12 toward the tip side. The drawn-out portion 31 extending from the coil portion 25 of the spring 24 to the base end 30 is accommodated in the spring accommodating hole 26, and the base end 30 is engaged with the engaging projection 28 provided at the tip of the spring accommodating hole 26. The holes 22 and 26 are holes that penetrate the holder 10 in the longitudinal direction, and the spring accommodating hole 26 is located above the brush accommodating hole 22. The spring accommodating hole 26 is located above the brush accommodating portion 22, overlaps with the brush accommodating portion 22 along the circumferential direction of the terminal 6, and is narrower than the brush accommodating portion 22. The base ends of the holes 22 and 26 may be closed.

[0019] The brush 12 is made of graphite or metallic graphite, and may have any composition. It may be, for example, a rectangular parallelepiped shape, with a sliding surface 32 at the tip, and a bottom 34 that is biased by the coil 25 of the constant load spring 24 in the brush housing 22. The lead 14 is fixed to one side of the brush 12, and a lead pull-out groove 42 is provided on the side of the holder 10, through which the lead 14 is pulled out. The top and both sides of the spring housing hole 26 are surrounded by a protrusion 40 of the holder 10. Therefore, the brush holder 10 is T-shaped in the front and back views above the terminal 6, and the top of the T is on the terminal 6. The front side is the through hole 9 side, and the back side is the opposite side. The bottom of the brush holder 10 has a protrusion 44, and on its side there is a positioning taper and a sliding surface 45 with the guide, and there is a base (outside the radial direction of the terminal).

[0020] 2, the terminal 6 has recesses 50, for example, in three locations, which are connected to the through holes 9, and the positioning tapers and guides 52 on both sides of the recesses 50 guide the sliding surface 45 of the holder 10. In addition, the linear side 51 at the bottom of the recess 50 does not contact the holder 10.

[0021] The operation of the embodiment will be described. The coil portion 25 of the constant force spring 24 is accommodated in the brush accommodation hole 22, and the base end 30 is engaged with the engagement projection 28. The brush 12 is also set in the brush accommodation hole 22. Next, the sliding surfaces 45, 45 of the holder 10 are guided by the positioning taper and guides 52, 52 of the terminal 6, and the holder 10 is positioned on the terminal 6. The holder 10 may be attached after the terminal 6 is fixed to the base 4, or the terminal 6 may be fixed to the base 4 after the holder 10 is attached.

[0022] The constant force spring 24 urges the brush 12 towards the slip ring 8 with a constant force, and the reaction force urges the brush holder 10 towards the terminal 6. As a result, the brush holder 10 does not vibrate relative to the terminal 6 and maintains a constant posture, and the force from the constant force spring 24 is used to bring the brush 12 into contact with the slip ring 8 and to maintain the posture of the brush holder 10.

[0023] Since the constant load spring 24 is entirely housed within the brush holder 10, the module 2 is compact. In particular, if the brush housing hole 22 and the spring housing hole 26 are both through holes, the brush holder 10 can be made compact and the ventilation properties of the holes 22, 24 can be utilized to cool the brushes 12. The brush holder 10 is T-shaped when viewed from the front and back, and has high rigidity due to a protrusion 40 protruding from the apex of the T. The through-hole shaped spring housing hole 26 has high ventilation properties, so the brushes 12 can be cooled when the rotating electric machine is in use. The leads 14 can be drawn out from the lead drawing groove 42 and fixed to the terminal 6.

[0024] Example 2 Figures 8 to 10 show a terminal 60 and a brush holder 70 in a second embodiment, which are similar to the embodiment in Figures 1 to 7 except where specifically noted. The terminal 60 has, for example, one to six recesses 62 around a central through hole 9. The recess 62 has tapered portions 64, 64 on both sides of its entrance (both sides in the circumferential direction of the through hole 9), and the tapered portions 64, 64 position the positioning surface of the brush holder 70. The recess 62 has two side portions 66, 66 and a bottom portion 68.

[0025] 9 shows the front of the brush holder 70, and FIG. 10 shows the bottom. The brush receiving hole 22, the pull-out portion 31, the protrusion 40, and the lead pull-out groove 42 are the same as those in the embodiment shown in FIG. 1 to FIG. 7. The brush holder 70 has a lower protrusion 72 and a pair of left and right positioning surfaces 74, 74 so as to come into surface contact with the tapered portion 64 of the terminal 60. The shape of the positioning surfaces 74, 74 is the same as that of the tapered portions 64, 64 on both sides of the recess 62. The tapered portion 64 and the positioning surface 74 may have any shape that fits each other, and may be curved or curved, not limited to a straight or flat shape. In addition, a protruding portion 76 is provided below the positioning surface 74, which extends beyond the positioning surface 74 in a plane parallel to the main surface of the terminal 60. The portion where the protruding portion 76 protrudes from the positioning surface 74 becomes a groove 75.

[0026] When the brush 12 contacts the slip ring due to the constant force spring 24, the reaction force is applied from the brush 12 to the brush holder 70, and the positioning surfaces 74 come into surface contact with the tapered portions 64, 64 on both sides of the recess 62. As a result, the brush holder 70 is positioned on the terminal 60, and the position and posture of the brush holder 70 relative to the terminal 60 are stabilized. Other functions and effects are the same as those of the embodiment shown in Figures 1 to 7. [Explanation of symbols]

[0027] 2 Brush Module 4. Bass Terminal 6 8. Slip Ring 9 Through holes 10 Brush holder 12 Brushes 13 Recess 14,16 Lead 15 Engagement part 17 Rivet 18 Rivet holes 19 Bottom 20 heads 21 External Lead 22 Brush receiving hole 24 Constant Force Spring 25 Coil section 26 Spring accommodation hole 28 Locking protrusion 30 proximal end 31 Drawer section 32 Sliding surface 34 Bottom 40 Protrusion 42 Lead outlet groove 44 Protrusion 45 Sliding surface 50 Recess 52 Guide Terminal 60 62 Recess 64 Tapered section 66 Side 68 Bottom 70 Brush holder 72 Lower protrusion 74 Locating Surface 75 Groove 76 Protruding part

Claims

1. A brush module for a rotating electric machine includes a disk-shaped base made of an insulating material, a pair of terminals each made of a conductive, substantially disk-shaped plate and disposed on both sides of the base, a brush holder attached to each terminal, and a brush housed in the brush holder, The terminal and the base have a through hole at a radial center thereof, The terminal includes a recess extending radially from the through hole and having a positioning portion for a brush holder, The brush holder includes: a brush receiving hole having a tip end facing the through hole and a base end facing the opposite side to the through hole and extending from the tip end to the base end; a spring accommodating hole that overlaps with a circumferential center of the terminal of the brush accommodating hole in a plan view and is located on an opposite side of the terminal from the brush accommodating hole; a locking projection provided at an end of the spring accommodating hole on the through hole side; a protrusion penetrating the recess of the terminal; the protrusion has a positioned portion that is positioned by a positioning portion of the recess, The brush is accommodated in the brush accommodating hole, a tip of the brush is exposed to the through hole, and a bottom of the brush is accommodated in the brush accommodating hole, Further, a coil-shaped constant force spring is provided and accommodated in the spring accommodation hole, The coil portion of the constant force spring biases the bottom of the brush. a drawn-out portion drawn out from a coil portion of the constant force spring extends through the spring accommodating hole toward the through hole, A brush module for a rotating electric machine, wherein a base end of the lead-out portion is engaged with the engaging projection.

2. The brush has a lead fixed to one side thereof, 2. The brush module for a rotating electric machine according to claim 1, wherein said brush holder has a groove on one side for passing a lead therethrough.

3. A brush module for a rotating electric machine as claimed in claim 1 or 2, characterized in that the brush holder is T-shaped when viewed from the front from the through hole side, with the apex of the T being positioned on the terminal, and the width of the brush holder along the circumferential direction of the terminal is narrower in the spring accommodating hole portion than in the brush accommodating hole portion.

4. 4. The brush module for a rotating electric machine according to claim 1, wherein the brush accommodating hole and the spring accommodating hole are through holes penetrating the brush holder.

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