JP6175017B2 - Planetary gear - Google Patents

Description

  The present invention relates to a planetary gear.

  Conventionally, it has a pinion, a pinion shaft that rotatably supports the pinion via a bearing, a carrier that fixes the pinion shaft, and a washer interposed between the pinion side surface and the carrier side surface, The pinion shaft includes a planetary gear device in which a lubricating oil passage for supplying lubricating oil to the bearing is formed. The pinion side surface is formed with a groove that extends from the inner peripheral side end portion to the outer peripheral side end portion of the pinion side surface and guides and discharges the lubricating oil supplied to the bearing (see, for example, Patent Document 1).

JP-A-2005-249052

  By the way, in the configuration of the lubricating path for discharging the lubricating oil through the groove formed on the side surface of the pinion as in the conventional planetary gear device (planetary gear), the lubricating path is not always sufficient, and the supply of the lubricating oil is necessary. There is a risk that sufficient lubrication oil cannot be supplied to the location.

  When the lubricating oil is not sufficiently supplied, for example, there is a problem that wear of sliding parts such as a bearing race becomes remarkable and the reliability of the planetary gear is lowered.

  Therefore, an object is to provide a planetary gear with improved reliability.

  A planetary gear (100) according to an embodiment of the present invention is formed on a cylindrical gear portion rotatable around a central axis and one end side in the axial direction of the gear portion, and has a larger diameter than the gear portion. A sun gear (140) having a flange (143), a plurality of pinion gears (130) engaged with the gear portion of the sun gear (140), and a base (111) rotatable about the central axis; A plurality of columnar portions (112) rising in the axial direction from the base portion (111), and the base portion (111) supports one end (131) of a rotation shaft of the plurality of pinion gears (130). (110) and a plurality of columnar portions (112) of the carrier (110) are fixed to the plurality of columnar portions (112) and have through-holes (121) penetrating in the thickness direction, and rotating shafts of the plurality of pinion gears (130) A cover (120) that pivotally supports the other end (132), and a thrust bearing (160) disposed between the flange (143) and the cover (120), The carrier (110) has a tapered portion (114) at a corner portion on the radially inner side of the end portion (112C) where the columnar portion (112) contacts the cover (120), and the through-hole (121) The cover (120) has a portion overlapping the taper portion (114) in the axial direction on one end side where the cover (120) contacts the carrier (110), and the thrust bearing (160) in the axial direction on the other end side. It has a part that overlaps the race (161).

  A planetary gear with improved reliability can be provided.

It is a fragmentary sectional view showing a part of transmission including planetary gear 100 of an embodiment. It is a figure which expands and shows a part of FIG. 1 is a diagram showing a planetary gear 100. FIG. 1 is a diagram showing a planetary gear 100. FIG.

  Embodiments to which the planetary gear of the present invention is applied will be described below.

<Embodiment>
FIG. 1 is a partial sectional view showing a part of a transmission including a planetary gear 100 according to an embodiment. FIG. 2 is an enlarged view showing a part of FIG. 3 and 4 are views showing the planetary gear 100. FIG. 3A is a plan view, FIG. 3B is a cross-sectional view taken along arrow A1-A2 in FIG. 3A, and FIG. 4 is a view showing a cross-section taken along arrow A2-A3 in FIG. .

  Hereinafter, the radial direction, the circumferential direction, and the axial direction are defined with respect to the central axis I of the planetary gear 100 as a reference, and the inner side and the outer side in the radial direction about the central axis I. The inner side in the radial direction refers to the direction toward the central axis I in the radial direction, and the outer side in the radial direction refers to the direction opposite to the central axis I in the radial direction. The central axis I is equal to the rotation axis of the planetary gear 100.

  In the following, the plan view means viewing from the axial direction.

  The planetary gear 100 includes a carrier 110, a cover 120, a pinion gear 130, a sun gear 140, a ring gear 150, and a thrust bearing 160 as main components. For convenience of explanation, the sun gear 140 and the ring gear 150 are omitted in FIGS. 3 and 4.

  FIG. 1 shows a state in which planetary gear 100 is incorporated in a transmission 1 for a hybrid vehicle that is an example of a speed change mechanism. The transmission 1 supplies lubricating oil to the planetary gear 100 and other components of the transmission 1 from the in-axis oil passages 2 </ b> A and 2 </ b> B located inside the rotating member 2 disposed on the central axis.

  For example, ATF (Automatic Transmission Fluid) may be used as the lubricating oil. ATF functions as a refrigerant. ATF is supplied to the in-shaft oil passages 2A and 2B from an oil pump (not shown).

  Here, a description will be given of a mode in which the transmission 1 is a hybrid vehicle. However, the transmission 1 is an electric vehicle or an automatic transmission of a vehicle that does not include a motor as a power source but uses an internal combustion engine as a power source. There may be.

  Here, the description of the configuration around the planetary gear 100 in FIG. 1 is omitted. Hereinafter, the carrier 110, the cover 120, and the thrust bearing 160 among the components of the planetary gear 100 will be described.

  The carrier 110 has a base part 111, a columnar part 112, an engagement part 113, a taper part 114, an opening part 115, and a mounting hole 116.

  The base 111 is a member located at the center of the carrier 110, and an opening 115 is formed at the center in plan view. A gear portion 115 </ b> A is formed on the inner peripheral surface of the opening 115. In addition, four columnar portions 112 are formed outside the base portion 111 in the radial direction.

  The columnar portion 112 is erected so as to surround the opening 115 from the outside in the radial direction of the base 111. The columnar portion 112 has an inner peripheral surface 112A, an outer peripheral surface 112B, and an end portion 112C. The end portion 112 </ b> C is an end portion that comes into contact with the cover 120 and is located on the side opposite to the base portion 111 in the axial direction.

  The four columnar portions 112 are formed at equal intervals in the circumferential direction in plan view, and have the same configuration. The columnar portion 112 is curved in an arc shape in plan view, and an engaging portion 113 is formed at the tip of the columnar portion 112. A cover 120 is attached to the columnar portion 112.

  The engaging portion 113 further extends from the end portion 112 </ b> C side of the columnar portion 112, is formed along the circumferential direction, and is inserted into the engaging hole 122 of the cover 120. The engaging portion 113 is an example of an extending portion. A protrusion 113A is formed along the circumferential direction on the radially inner side of the tip of the engaging portion 113. The protruding portion 113 </ b> A protrudes from the engaging hole 122 in a state where the engaging portion 113 is inserted into the engaging hole 122. The protrusion 113A is provided to hold the race 161 of the thrust bearing 160.

  The tapered portion 114 is formed by chamfering the corner portion on the inner peripheral surface 112A side of the end portion 112C of the columnar portion 112. Since the columnar portion 112 is curved in an arc shape in plan view, the tapered portion 114 formed at the corner of the end portion 112C is also curved in an arc shape in plan view.

  The tapered portion 114 is formed so as to have a portion that overlaps the through hole 121 of the cover 120 in plan view (see FIG. 4). The taper portion 114 having a portion overlapping the through hole 121 in plan view means that at least a part of the taper portion 114 only needs to overlap with the through hole 121 in plan view.

  The opening 115 is formed at the center of the base 111 in plan view, and a gear portion 115A is formed on the inner peripheral surface. 115 A of gear parts engage with the gear part formed along the outer periphery of the sun gear 140.

  The attachment hole 116 is a through hole that penetrates the base 111 in the axial direction, and is formed between the four columnar portions 112 in a plan view. One end 131 of the pinion shaft of the pinion gear 130 is held in the mounting hole 116. Note that the gear portion of the pinion gear 130 is rotatably supported by a pinion shaft via a bearing.

  The cover 120 has a through hole 121, an engagement hole 122, an opening 123, a mounting hole 124, and a peripheral part 125. The cover 120 is an annular member attached to the engaging portion 113 of the columnar portion 112 of the carrier 110. The member combining the cover 120 and the carrier 110 constitutes a carrier assembly.

  The through hole 121 penetrates the peripheral portion 125 of the cover 120 in the axial direction. The through hole 121 may be formed so that the opening on the carrier 110 side has a portion overlapping the tapered portion 114 in a plan view on the inner side in the radial direction than the engagement hole 122. Further, the opening on the thrust bearing 160 side may be formed so as to have a portion overlapping with the race 161 in plan view. Two through holes 121 are formed at equal intervals in the circumferential direction in plan view.

  Here, having the portion where the opening on the carrier 110 side of the through hole 121 overlaps with the tapered portion 114 means that at least a part of the opening on the carrier 110 side of the through hole 121 overlaps with the tapered portion 114 in plan view. means. Similarly, that the opening on the thrust bearing 160 side of the through hole 121 has a portion overlapping with the race 161 in plan view, that at least part of the opening on the thrust bearing 160 side of the through hole 121 overlaps with race 161 in the plan view. It means to do.

  The engagement hole 122 is formed so as to penetrate the peripheral portion 125 in the axial direction on the radially outer side than the through hole 121 and to have an arc shape in the circumferential direction. Four engagement holes 122 are formed, and an engagement portion 113 positioned at the tip of the columnar portion 112 of the carrier 110 is inserted into each of the engagement holes 122. The radially outer surface of the engaging portion 113 is welded along the circumferential direction with the portion of the engaging hole 122 of the peripheral portion 125.

  The opening 123 is an opening formed in the center of the annular cover 120 in plan view. The inner peripheral surface 123A of the opening 123 is located on the radially inner side of the inner peripheral surface 112A of the columnar portion 112 in a cross-sectional view parallel to the central axis I (see FIG. 4).

  The attachment holes 124 penetrate the circumferential portion 125 in the axial direction, and are formed at four equal intervals in the circumferential direction. The attachment holes 124 are formed alternately with the engagement holes 122 in the circumferential direction. The mounting hole 124 holds the other end 132 of the pinion shaft of the pinion gear 130.

  The peripheral portion 125 is a member that constructs an annular cover 120 in plan view, and as described above, the through hole 121, the engagement hole 122, the opening portion 123, and the attachment hole 124 are formed.

  The thrust bearing 160 includes races 161 and 162 and a bearing 163 (see FIG. 2).

  The race 161 is an annular member that comes into contact with the cover 120. The outer peripheral surface of the race 161 is in contact with the protruding portion 113 </ b> A of the cover 120. The race 161 is in contact with the cover 120 so as to be rotatable with respect to the cover 120.

  The race 162 is in contact with the flange 143 of the sun gear 140. The race 162 is an annular member having an L-shaped cross section. The bearing 163 is provided between the races 161 and 162.

  The thrust bearing 160 having such a configuration pivotally supports the cover 120 and the flange 143 of the sun gear 140 so as to be rotatable in the thrust direction.

  Next, main flow paths of ATF as a refrigerant when the rotating member 2 rotates in the transmission 1 (see FIG. 1) including the planetary gear 100 of the embodiment will be described.

  As the rotary member 2 rotates, ATF supplied to the inside of the on-axis oil passages 2A and 2B by an oil pump (not shown) flows into the oil passages 3A and 3B by centrifugal force.

  The ATF that has flowed into the oil passage 3A flows in the direction of the thrust bearing 160 via the oil passage 141A provided on the one end 141 side of the sun gear 140 as shown by an arrow in FIG. And the base portion 111 of the carrier 110, and reaches the inner peripheral surface 112A of the columnar portion 112 of the carrier 110.

  The ATF flows from the right side to the left side in the figure along the inner peripheral surface 112A by centrifugal force, flows outward in the radial direction along the tapered portion 114 formed at the corner of the end portion 112C, and the inside of the through hole 121 of the cover 120 Flow into.

  The ATF that has flowed into the through hole 121 is injected into the race 161 of the thrust bearing 160, flows radially outward through the gap between the protrusion of the cover 120 and the race 161, and the protrusion 113A of the carrier 110 It flows out of the gap between the race 161.

  In this way, the thrust bearing 160 has a path between the other end 142 of the sun gear 140 and the base 111 of the carrier 110 in addition to a path through which the ATF is supplied from between the cover 120 and the sun gear 140 through the oil path 141A. A path through which the ATF is supplied between the cover 120 and the race 161 through the tapered portion 114 is secured through reaching the inner peripheral surface 112A of the columnar portion 112. Such an additional path is a path that cannot be obtained when the end portion 112C covers the inflow port of the through hole 121 without the tapered portion 114 being formed.

  Therefore, according to the embodiment, it is possible to provide the planetary gear 100 in which the ATF path for cooling the thrust bearing 160 is sufficiently secured and the reliability is improved.

  For example, in cases where cooling or lubricating oil is insufficient between the cover 120 and the race 161, the planetary gear 100 of the embodiment provides a very effective solution.

  As shown in FIG. 2, such a tapered portion 114 is formed to have a portion that overlaps with the through hole 121 in a plan view (as viewed from the axial direction), so that the ATF that has flowed into the tapered portion 114 is reliably prevented. The through hole 121 can be guided to the race 161 through the through hole 121. As shown in FIG. 3A, since the through holes 121 are formed at two positions with a 180 ° pitch in the circumferential direction, each time the carrier 110 and the cover 120 rotate once, ATF is injected twice from the through holes 121. Will be.

  In addition, here, a description will be given of a mode in which two through holes 121 provided in the circumferential direction of the cover 120 are used as ATF injection nozzles. However, in order to further increase the injection amount, the number of through holes 121 is further increased. May be.

  Further, the through hole 121 is not limited to the case where the through hole 121 is formed in the cover 120 for the flow path, and the through hole that is originally formed in the cover 120 may be used. For example, the through hole 121 is a hole into which a jig or the like is inserted when the planetary gear 100 is assembled, and may be used for positioning. The through hole 121 is not used in the planetary gear 100 as a finished product. In such a case, when increasing the number of through holes 121, two dummy through holes 121 that are not for positioning may be provided between the two through holes 121 for positioning.

  Further, as described above, an additional path for cooling the race 161 can be obtained simply by forming the tapered portion 114, so that the cooling efficiency can be improved without increasing the discharge amount of the oil pump.

  Further, the tapered portion 114 can be manufactured by simply chamfering the corner of the end portion 112 </ b> C of the columnar portion 112 of the carrier 110. The carrier 110 in which the columnar portion 112 is formed on the base 111 can be manufactured by, for example, scraping a lump of metal. In such a case, the tapered portion 114 can be easily formed by changing the portion to be cut (by simply changing the program of the cutting machine tool), so that almost no additional cost is generated. Cooling performance can be improved. In addition, as a metal lump, a metal lump produced by forging can be used. The carrier 110 can also be manufactured by casting, and may be manufactured by bending a metal plate to form a prototype of the base 111 and the columnar part 112 and then performing cutting.

  Further, since the inner peripheral surface 123A of the opening 123 of the cover 120 is located on the radially inner side than the inner peripheral surface 112A of the columnar portion 112, it passes between the other end 142 of the sun gear 140 and the base 111 of the carrier 110. The ATF that has reached the inner peripheral surface 112 </ b> A of the columnar portion 112 can efficiently flow into the tapered portion 114. The portion adjacent to the left side of the tapered portion 114 (the portion where the inner peripheral surface 123A of the opening 123 formed in the peripheral portion 125 is located) is an example of the adjacent portion. A portion as an adjacent portion of the cover 120 extends radially inward from the inner peripheral surface 112 </ b> A of the columnar portion 112.

  In addition, since the radially outer surface of the engaging portion 113 of the carrier 110 is welded to the engaging hole 122 of the cover 120, a strong joint strength between the carrier 110 and the cover 120 during rotation can be ensured. This is because the resistance to centrifugal force is improved by welding the radially outer side of the engaging portion 113 as compared to the case of welding the radially inner side.

  Further, the outer surface in the radial direction of the engagement portion 113 of the carrier 110 is welded to the engagement hole 122 of the cover 120, thereby providing an outflow path for guiding the ATF that has flowed into the engagement hole 122 from the taper portion 114 to the race 161. Can be secured.

The planetary gear according to the exemplary embodiment of the present invention has been described above, but the present invention is not limited to the specifically disclosed embodiment, and does not depart from the scope of the claims. Various modifications and changes are possible.
The following will be further disclosed regarding the above embodiment.

(1) A sun gear (140) having a cylindrical gear portion rotatable around a central axis and a flange (143) having a diameter larger than that of the gear portion formed on one end side in the axial direction of the gear portion. When,
A plurality of pinion gears (130) engaged with the gear portion of the sun gear (140);
A base (111) rotatable around the central axis, and a plurality of columnar portions (112) standing in an axial direction from the base (111), wherein the base (111) is the plurality of pinion gears ( 130) a carrier (110) holding one end (131) of the shaft;
The plurality of columnar portions (112) of the carrier (110) has a through hole (121) penetrating in the thickness direction and the other end (132) of the shaft of the plurality of pinion gears (130). A cover (120) to hold,
A thrust bearing (160) disposed between the flange (143) and the cover (120),
The carrier (110) has a tapered portion (114) at a radially inner corner of the end portion (112C) where the columnar portion (112) contacts the cover (120),
The through hole (121) has a portion overlapping the tapered portion (114) in the axial direction on one end side where the cover (120) contacts the carrier (110), and the axial direction on the other end side. A planetary gear (100) having a portion overlapping the race (161) of the thrust bearing (160).

  According to the configuration described in (1), the path from the tapered portion (114) to the race (161) that contacts the cover (120) through the through hole (121) is formed, so that the cooling performance is improved. A planetary gear (100) with improved reliability is provided.

  (2) The adjacent portion (123A) adjacent to the tapered portion (114) of the cover (120) extends radially inward from the radially inner portion of the end of the carrier (110). (1) The planetary gear (100) described.

  According to the configuration described in (2), since the adjacent portion (123A) guides the tapered portion (114) in the path from the opposite side in the axial direction to the tapered portion (114) from the adjacent portion (123A), A planetary gear (100) with improved cooling and further improved reliability is provided.

  (3) The planetary gear (100) according to (1) or (2), wherein the carrier (110) and the cover (120) are welded on a radially outer side than the through hole (121).

  According to the configuration described in (3), a sufficient connection strength between the carrier (110) and the cover (120) can be ensured even in a state where a centrifugal force is applied, and a path radially outward from the through hole (121). Can be secured.

(4) The carrier (110) has an extension part (113) extending from the end part (112C) in which the columnar part (112) contacts the cover (120),
The cover (120) has an engagement hole (122) that penetrates in the thickness direction on the outer side in the radial direction than the through hole (121) and engages with the extending portion (113),
The carrier (110) and the cover (120) are welded to the engagement hole (122) on the radially outer surface of the extension part (113), so that the carrier (110) and the cover (120) are more than the through hole (121). The planetary gear (100) according to (3), which is welded radially outward.

  According to the configuration described in (4), a sufficient connection strength between the carrier (110) and the cover (120) can be secured even in a state where a centrifugal force is applied, and the diameter of the engagement hole (122) from the tapered portion (114). It is possible to secure a route through the inner side.

DESCRIPTION OF SYMBOLS 1 Transmission 100 Planetary gear 110 Carrier 111 Base part 112 Columnar part 113 Engagement part 114 Taper part 115 Gear part 116 Attachment hole 120 Cover 121 Through-hole 122 Engagement hole 123 Opening part 124 Attachment hole 125 Circumferential part 130 Pinion gear 131 One end 132 Others End 140 Sun gear 141 One end 142 Other end 143 Housing 150 Ring gear 160 Thrust bearing 161, 162 Race 163 Bearing

Claims (4)

A sun gear having a cylindrical gear portion rotatable around a central axis and a flange having a larger diameter than the gear portion, formed on one end side in the axial direction of the gear portion;
A plurality of pinion gears engaged with the gear portion of the sun gear;
A carrier having a base rotatable around the central axis, and a plurality of columnar portions standing in an axial direction from the base, wherein the base holds one end of the shafts of the plurality of pinion gears;
A cover that is fixed to the plurality of columnar portions of the carrier and has a through-hole penetrating in the thickness direction, and holding the other ends of the shafts of the plurality of pinion gears;
A thrust bearing disposed between the flange and the cover,
The carrier has a tapered portion at a radially inner corner of an end portion where the columnar portion abuts the cover,
The through hole has a portion that overlaps the tapered portion in the axial direction on one end side where the cover abuts on the carrier, and a portion that overlaps the race of the thrust bearing in the axial direction on the other end side. gear.   The planetary gear according to claim 1, wherein an adjacent portion of the cover adjacent to the tapered portion extends radially inward from a radially inner portion of the end portion of the carrier.   The planetary gear according to claim 1 or 2, wherein the carrier and the cover are welded radially outward from the through hole. The carrier has a protruding portion that protrudes from the end where the columnar portion abuts the cover,
The cover has an engagement hole that penetrates in the thickness direction on the outer side in the radial direction than the through hole, and engages with the protruding portion,
4. The planetary gear according to claim 3, wherein the carrier and the cover are welded at a radially outer side than the through hole by welding a radially outer surface of the projecting portion to the engagement hole.

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