JP6705321B2 - Planetary gear mechanism - Google Patents

Description

The present disclosure relates to a planetary gear mechanism including a sun gear, a ring gear, and a carrier that rotatably supports a plurality of pinion gears.

Conventionally, as a planetary gear mechanism included in a multi-speed transmission, two sun gears, a ring gear, a plurality of short pinion gears that mesh with one of the two sun gears, and a plurality of short pinion gears that mesh with the other of the two sun gears. Is known, and a Ravigneaux type planetary gear mechanism including a long pinion gear and a carrier that rotatably supports a plurality of short pinion gears and long pinion gears is known (for example, see Patent Document 1). The carrier of this Ravigneaux type planetary gear mechanism is integrally molded by casting, and has an annular first support that supports one end of a short pinion shaft that is inserted into the short pinion gear and one end of a long pinion shaft that is inserted into the long pinion gear. The shaft support portion, an annular second shaft support portion that supports the other end of the long pinion shaft, and the other end of the short pinion shaft between the first shaft support portion and the second shaft support portion in the axial direction. It has a 3rd shaft support part and a plurality of bridge parts which extend in the direction of an axis at intervals in the peripheral direction, and connect the perimeter of the 1st shaft support part, the 2nd shaft support part, and the 3rd shaft support part. ..

JP, 2005-105726, A

In the conventional planetary gear mechanism as described above, it is necessary to sufficiently secure the rigidity of the carrier that supports the plurality of pinion shafts. However, if the thicknesses of the first, second and third shaft support portions and the bridge portion are increased in order to secure the rigidity of the carrier, the carrier and the planetary gear mechanism are increased in size and weight.

Therefore, the main object of the invention of the present disclosure is to ensure good rigidity of the carrier while suppressing an increase in the size and weight of the carrier and the planetary gear mechanism including the carrier.

A planetary gear mechanism of the present disclosure is a planetary gear mechanism including a carrier that rotatably supports a plurality of pinion gears, and is formed of a material having a thermal expansion coefficient smaller than that of the material forming the carrier, An annular member is fixed to the carrier by press fitting so as to surround at least a part.

By fixing the annular member to the carrier by press-fitting in this way, compressive stress can be applied to the carrier, so that tensile stress is generated in the carrier due to the action of centrifugal force and the torsion associated with the transmission of rotational torque. It becomes possible to suppress. Furthermore, for example, when the temperature of the carrier increases due to high speed rotation of the pinion gear, the expansion amount of the carrier becomes larger than the expansion amount of the annular member, so that the compressive stress applied to the carrier by the annular member is further increased. Can be large. As a result, it is possible to secure good rigidity of the carrier while suppressing an increase in the size and weight of the carrier and the planetary gear mechanism including the carrier.

It is a schematic structure figure of a power transmission device containing a planetary gear mechanism of this indication. 3 is an operation table showing a relationship between each shift speed and operating states of a clutch and a brake in the transmission of the power transmission device of FIG. 1. FIG. 2 is a velocity diagram showing a ratio of a rotation speed of each rotary element to an input rotation speed in the transmission of the power transmission device of FIG. 1. It is a sectional view showing a carrier of a planetary gear mechanism of the present disclosure. It is a perspective view showing a carrier of a planetary gear mechanism of the present disclosure. It is a perspective view showing a carrier of a planetary gear mechanism of the present disclosure. It is a perspective view showing a carrier of a planetary gear mechanism of the present disclosure.

Next, modes for carrying out the invention of the present disclosure will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a power transmission device 10 including a planetary gear mechanism of the present disclosure. The power transmission device 10 shown in the figure is connected to a crankshaft of an engine (internal combustion engine) (not shown) and/or a rotor of an electric motor as a drive source that is vertically mounted on the front part of a rear-wheel drive vehicle. Power (torque) from the engine or the like can be transmitted to the left and right rear wheels (driving wheels) not shown. As shown in the figure, the power transmission device 10 shifts the power transmitted from the transmission case (stationary member) 11, the starting device (fluid transmission device) 12, the oil pump 17, the engine and the like to the input shaft (input member) 20i. The automatic transmission 20 and the like, which are transmitted to the output shaft (output member) 20o, are included.

The starting device 12 is a front cover 13 that is connected to a crankshaft of an engine and/or a rotor of an electric motor via a drive plate (not shown), and an input side having a pump shell tightly fixed to the front cover 13. Pump impeller 140, output-side turbine runner 142 connected to input shaft 20i of automatic transmission 20, pump impeller 140, and hydraulic oil (ATF) from turbine runner 142 to pump impeller 140 disposed inside turbine runner 142 It includes a torque converter (fluid transmission device) having a stator 143 that rectifies the flow of, a one-way clutch 144 that limits the rotation direction of the stator 143 to one direction, and the like. The starting device 12 may include a fluid coupling that does not have the stator 143.

Further, the starting device 12 connects the front cover 13 connected to the crankshaft of the engine and the like and the input shaft 20i of the automatic transmission 20 to each other, and also releases the connection between the lockup clutch 15 and the front cover 13. The damper mechanism 16 that damps vibrations with the input shaft 20i of the automatic transmission 20 is included. In the present embodiment, the lockup clutch 15 is configured as a multi-plate friction hydraulic clutch having a plurality of friction engagement plates (friction plates and separator plates). However, the lockup clutch 15 may be a single-plate friction hydraulic clutch.

The oil pump 17 includes a rotor 170 connected to the pump impeller 140 of the starting device 12 via a chain 18, an external gear (drive gear) 171 having a plurality of external teeth and rotating integrally with the rotor 170, and an external It includes an internal gear (driven gear) 172 that has a plurality of internal teeth that are one more than the total number of external teeth that mesh with the external teeth of the tooth gear 171, and that is arranged eccentrically with respect to the external gear 171. The oil pump 17 is driven by the power from the engine transmitted through the chain 18 and the like, sucks the hydraulic oil stored in an oil pan (not shown), and pressure-feeds it to a hydraulic control device (not shown).

The automatic transmission 20 is configured as a 10-speed transmission, and as shown in FIG. 1, an output shaft connected to the left and right rear wheels via an input shaft 20i, a differential gear (not shown), and a drive shaft. In addition to 20o, a single pinion type first planetary gear 21 and a second planetary gear 22, a double pinion type planetary gear and a single pinion type gear which are arranged side by side in the axial direction of the automatic transmission 20 (input shaft 20i and output shaft 20o) are provided. And a Ravigneaux type planetary gear mechanism 25 as a compound planetary gear mechanism configured by combining with a pinion type planetary gear. Further, the automatic transmission 20 includes a clutch C1 (first clutch) as a first engagement element and a clutch C2 (second clutch element) for changing the power transmission path from the input shaft 20i to the output shaft 20o. Second clutch), clutch C3 (third clutch) as third engagement element, clutch C4 (fourth clutch) as fourth engagement element, brake B1 (first brake) as fifth engagement element, and A brake B2 (second brake) as a sixth engagement element is included.

In the present embodiment, the first and second planetary gears 21 and 22 and the Ravigneaux type planetary gear mechanism 25 are arranged such that the Ravigneaux type planetary gear mechanism 25 and the second planetary gear unit 22 are arranged from the starting device 12 or the engine side (the left side in FIG. 1). , The first planetary gear 21, that is, the single pinion type planetary gear constituting the Ravigneaux type planetary gear mechanism 25, the double pinion type planetary gear constituting the Ravigneaux type planetary gear mechanism 25, the second planetary gear 22, the first planetary gear 21. It is arranged in the transmission case 11 so as to be lined up in this order. As a result, the Ravigneaux type planetary gear mechanism 25 is arranged on the front side of the vehicle so as to be close to the starting device 12. The first planetary gear 21 is arranged on the rear side of the vehicle so as to be close to the output shaft 20o. Further, the second planetary gear 22 is arranged between the Ravigneaux type planetary gear mechanism 25 and the first planetary gear 21 in the axial direction of the input shaft 20i, the output shaft 20o and the like.

The first planetary gear 21 includes a first sun gear 21s which is an external gear, a first ring gear 21r which is an internal gear arranged concentrically with the first sun gear 21s, a first sun gear 21s and a first ring gear 21r, respectively. A plurality of first pinion gears 21p that mesh with each other, and a first carrier 21c that holds the plurality of first pinion gears 21p rotatably (rotatably) and revolvably. In the present embodiment, the gear ratio λ1 of the first planetary gear 21 (the number of teeth of the first sun gear 21s/the number of teeth of the first ring gear 21r) is set to, for example, λ1=0.277.

As shown in FIG. 1, the first carrier 21c of the first planetary gear 21 is always connected (fixed) to an intermediate shaft (intermediate shaft) 20m of the automatic transmission 20 connected to the input shaft 20i. Thereby, when the power is transmitted from the engine to the input shaft 20i, the power from the engine is always transmitted to the first carrier 21c via the input shaft 20i and the intermediate shaft 20m. Further, the first carrier 21c functions as an input element of the first planetary gear 21 when the clutch C4 is engaged, and idles when the clutch C4 is released. Further, the first ring gear 21r functions as an output element of the first planetary gear 21 when the clutch C4 is engaged.

The second planetary gear 22 includes a second sun gear 22s which is an external gear, a second ring gear 22r which is an internal gear arranged concentrically with the second sun gear 22s, a second sun gear 22s and a second ring gear 22r, respectively. It has a plurality of second pinion gears 22p that mesh with each other and a second carrier (planetary carrier) 22c that holds the plurality of second pinion gears 22p rotatably (rotatably) and revolvably. In the present embodiment, the gear ratio λ2 of the second planetary gear 22 (the number of teeth of the second sun gear 22s/the number of teeth of the second ring gear 22r) is set to, for example, λ2=0.244.

As shown in FIG. 1, the second sun gear 22s of the second planetary gear 22 is integrated (always connected) with the first sun gear 21s of the first planetary gear 21, and is always integrated with the first sun gear 21s (and Coaxial) to rotate or stop. However, the first sun gear 21s and the second sun gear 22s may be separately configured and always connected via a connecting member (first connecting member) not shown. The second carrier 22c of the second planetary gear 22 is always connected to the output shaft 20o and always rotates or stops integrally (and coaxially) with the output shaft 20o. As a result, the second carrier 22c functions as an output element of the second planetary gear 22. Further, the second ring gear 22r of the second planetary gear 22 functions as a fixable element of the second planetary gear 22.

The Ravigneaux planetary gear mechanism 25 includes a third sun gear 23s and a fourth sun gear 24s which are external gears, a third ring gear 23r which is an internal gear arranged concentrically with the third sun gear 23s, and a third sun gear 23s. A plurality of third pinion gears (short pinion gears) 23p that mesh with each other, a plurality of fourth pinion gears (long pinion gears) 24p that mesh with the fourth sun gear 24s and the plurality of third pinion gears 23p, and mesh with the third ring gear 23r. The third pinion gear 23p and the third carrier 23c that holds the plurality of fourth pinion gears 24p rotatably (rotatably) and revolvably.

Such a Ravigneaux type planetary gear mechanism 25 is a compound planetary gear mechanism configured by combining a double pinion type planetary gear (third planetary gear) and a single pinion type planetary gear (fourth planetary gear). That is, the third sun gear 23s, the third carrier 23c, the third and fourth pinion gears 23p and 24p, and the third ring gear 23r of the Ravigneaux type planetary gear mechanism 25 constitute a double pinion type third planetary gear. Further, the fourth sun gear 24s, the third carrier 23c, the fourth pinion gear 24p, and the third ring gear 23r of the Ravigneaux type planetary gear mechanism 25 constitute a single pinion type fourth planetary gear. Further, in the present embodiment, the Ravigneaux type planetary gear mechanism 25 has a gear ratio λ3 (the number of teeth of the third sun gear 23s/the number of teeth of the third ring gear 23r) of the double pinion type third planetary gear, for example, λ3= 0.488, and the gear ratio λ4 of the single planetary fourth planetary gear (the number of teeth of the fourth sun gear 24s/the number of teeth of the third ring gear 23r) is, for example, λ4=0.581. It

In addition, among the rotary elements forming the Ravigneaux type planetary gear mechanism 25 (third and fourth planetary gears), the fourth sun gear 24s is a fixable element of the Ravigneaux type planetary gear mechanism 25 (second fixing of the automatic transmission 20). Capable element). Furthermore, as shown in FIG. 1, the third carrier 23c is always connected (fixed) to the input shaft 20i, and the third carrier 23c is connected to the first planetary gear 21 via an intermediate shaft 20m as a connecting member (second connecting member). It is always connected to the first carrier 21c. Thereby, when the power is transmitted from the engine to the input shaft 20i, the power from the engine is always transmitted to the third carrier 23c via the input shaft 20i. Therefore, the third carrier 23c functions as an input element of the Ravigneaux type planetary gear mechanism 25. The third ring gear 23r functions as a first output element of the Ravigneaux type planetary gear mechanism 25, and the third sun gear 23s functions as a second output element of the Ravigneaux type planetary gear mechanism 25.

The clutch C1 includes a first sun gear 21s of the first planetary gear 21, a second sun gear 22s of the second planetary gear 22, and a third ring gear 23r, which is a first output element of the Ravigneaux type planetary gear mechanism 25, which are always connected to each other. The connection is released and the connection is released. The clutch C2 connects the first sun gear 21s of the first planetary gear 21, the second sun gear 22s of the second planetary gear 22, and the third sun gear 23s, which is the second output element of the Ravigneaux type planetary gear mechanism 25, to each other. The connection is released and the connection is released. The clutch C3 connects the second ring gear 22r of the second planetary gear 22 and the third ring gear 23r, which is the first output element of the Ravigneaux type planetary gear mechanism 25, to each other and disconnects them from each other. The clutch C4 connects the first ring gear 21r, which is an output element of the first planetary gear 21, and the output shaft 20o to each other, and disconnects them.

The brake B1 non-rotatably fixes (connects) the fourth sun gear 24s, which is a fixable element of the Ravigneaux type planetary gear mechanism 25, to the transmission case 11 as a stationary member, and the fourth sun gear 24s is fixed to the transmission case 11. On the other hand, it is rotatably released. The brake B2 non-rotatably fixes (connects) the second ring gear 22r, which is a fixable element of the second planetary gear 22, to the transmission case 11, and the second ring gear 22r is fixed to the transmission case 11 as a stationary member. It is released freely.

In the present embodiment, as the clutches C1 to C4, a hydraulic servo including a piston, a plurality of friction engagement plates (friction plates and separator plates), an engagement oil chamber to which hydraulic oil is supplied, a centrifugal hydraulic pressure cancel chamber, and the like are provided. A multi-plate friction type hydraulic clutch (friction engagement element) having is adopted. Further, as the brakes B1 and B2, a multi-plate friction hydraulic brake having a hydraulic servo configured by a piston, a plurality of friction engagement plates (friction plates and separator plates), an engagement oil chamber to which hydraulic oil is supplied, and the like. Is adopted. The clutches C1 to C4 and the brakes B1 and B2 are operated by supplying and discharging hydraulic oil by the hydraulic control device.

FIG. 2 shows an operation table showing the relationship between each shift stage of the automatic transmission 20 and the operating states of the clutches C1 to C4 and the brakes B1 and B2, and FIG. 3 shows the rotation speed of the input shaft 20i in the automatic transmission 20 ( The speed diagram which shows the ratio of the rotation speed of each rotary element with respect to (input rotation speed) is shown. The automatic transmission 20 provides the forward speed and the reverse speed from the first speed to the tenth speed by setting the clutches C1 to C4 and the brakes B1 and B2 to the states shown in the operation table of FIG.

As shown in FIG. 3, ten rotating elements of the first and second planetary gears 21 and 22 and the Ravigneaux type planetary gear mechanism 25 (however, since the first sun gear 21s and the second sun gear 22s are always connected to each other). , Substantially 9 rotating elements in total) are arranged in the order shown from the left side in FIG. 3 at intervals according to these gear ratios λ1, λ2, λ3, λ4. According to the order of arrangement on the velocity diagram, in the present embodiment, the first sun gear 21s is the first rotating element of the automatic transmission 20, and the first carrier 21c is the second rotating element of the automatic transmission 20. The first ring gear 21r is the third rotating element of the automatic transmission 20. Also, the second sun gear 22s is the fourth rotating element of the automatic transmission 20, the second carrier 22c is the fifth rotating element of the automatic transmission 20, and the second ring gear 22r is the fourth rotating element of the automatic transmission 20. .. Furthermore, the fourth sun gear 24s is the seventh rotating element of the automatic transmission 20, the third carrier 23c is the eighth rotating element of the automatic transmission 20, and the third ring gear 23r is the ninth rotating element of the automatic transmission 20. The third sun gear 23s is the tenth rotating element of the automatic transmission 20.

The gear ratios λ1 to λ4 of the first and second planetary gears 21 and 22 and the third and fourth planetary gears are not limited to those described above. Further, in the automatic transmission 20, at least one of the clutches C1 to C4 and the brakes B1 and B2 may be a meshing engagement element such as a dog clutch or a dog brake. For example, in the automatic transmission 20, a dog brake may be employed as the brake B2 that is continuously engaged when forming the first forward speed to the fourth forward speed and is engaged when forming the reverse speed. Good. Further, in the automatic transmission 20, at least one of the first and second planetary gears 21 and 22 may be a double pinion type planetary gear, and the Ravigneaux type planetary gear mechanism 25 is, for example, a Simpson type or CR-type. It may be replaced with a compound planetary gear mechanism such as a CR type. Further, the automatic transmission 20 described above may be modified into a transmission mounted on a front-wheel drive vehicle.

FIG. 4 is a sectional view showing the third carrier 23c of the Ravigneaux type planetary gear mechanism 25 of the automatic transmission 20, and FIGS. 5 and 6 are perspective views showing the third carrier 23c.

As shown in FIGS. 4 to 6, the third carrier 23c includes a first shaft support portion 231, a second shaft support portion 232, a plurality of third shaft support portions 233, and a first shaft support portion 231 respectively. It includes a plurality of first bridge portions 234 connecting the corresponding third shaft support portions 233 and a plurality of second bridge portions 235 connecting the second shaft support portions 232 and the corresponding third shaft support portions 233, respectively. These first to third shaft support portions 231, 232, 233 and the first and second bridge portions 234, 235 are integrally formed by casting an aluminum alloy.

The first shaft support portion 231 of the third carrier 23c is formed in an annular shape and has a center hole 231o into which the input shaft 20i and the third sun gear 23s, which are not shown in FIG. 4 and the like, are inserted. Further, the first shaft support portion 231 is provided with a plurality of first pinion shaft support holes 231S at intervals in the circumferential direction of the first shaft support portion 231. The first pinion shaft support hole 231S is a through hole extending in the axial direction of the third carrier 23c, and one end of the short pinion shaft 230 inserted into the third pinion gear 23p is inserted into each first pinion shaft support hole 231S. To be done. Further, in the first shaft support portion 231, a plurality of second pinion shaft support holes 231L are arranged at intervals in the circumferential direction of the first shaft support portion 231. The second pinion shaft support hole 231L is a through hole that extends in the axial direction of the third carrier 23c between the adjacent first pinion shaft support holes 231S, and each second pinion shaft support hole 231L has a fourth pinion gear 24p. One end of the long pinion shaft 240 that has been inserted into is inserted.

Further, the first shaft support portion 231 is formed with a plurality of positioning holes (through holes) 231y that extend radially inward from the outer peripheral surface and open at the corresponding first pinion shaft support holes 231S. Each short pinion shaft 230 is positioned with respect to the first shaft support portion 231 or the third carrier 23c by the locate pin 230p inserted into the corresponding positioning hole 231y. Further, on the inner peripheral portion of the first shaft support portion 231, there are provided oil collecting recesses 231r that are recessed radially outward, and first correspondingly extending radially inward from the bottom surface of the oil collecting recesses 231r. A plurality of oil holes 231a opened at the pinion shaft support holes 231S, and a plurality of oil holes 231b opened at the corresponding second pinion shaft support holes 231L extending radially inward from the bottom surface of the oil collecting recess 231r. Are formed.

As shown in FIG. 4, each oil hole 231a communicates with an oil hole 230a formed in the short pinion shaft 230 and extending in the radial direction, and each oil hole 231b extends in the radial direction formed in the long pinion shaft 240. It communicates with the oil hole 240a. The short pinion shaft 230 has an internal oil passage 230b communicating with the oil hole 230a and extending along the axis of the short pinion shaft 230, and a short pinion extending radially outward from the internal oil passage 230b. An oil hole 230c that opens on the outer peripheral surface of the shaft 230 is formed. Further, in the long pinion shaft 240, an internal oil passage 240b communicating with the oil hole 240a and extending along the axis of the long pinion shaft 240, and a long pinion extending radially outward from the internal oil passage 240b. An oil hole 240c that opens on the outer peripheral surface of the shaft 240 is formed.

As a result, the hydraulic oil scattered around the first shaft support portion 231 of the third carrier 23c is collected in the oil collecting recess 231r, and the collected hydraulic oil is shorted to the oil hole 231a of the first shaft support portion 231. It flows into the oil hole 230c through the oil hole 230a and the internal oil passage 230b of the pinion shaft 230, and also through the oil hole 231b of the first shaft support portion 231 and the oil hole 240a and the internal oil passage 240b of the long pinion shaft 240. It flows into the oil hole 240c. Thereby, the needle bearing 230n arranged between the short pinion shaft 230 and the inner peripheral surface of the third pinion gear 23p, the thrust washers 230w arranged on both sides of the third pinion gear 23p in the axial direction, and the long pinion shaft 240 are arranged. Hydraulic oil can be supplied as a lubricating/cooling medium to the needle bearing 240n arranged between the inner peripheral surface of the fourth pinion gear 24p and the thrust washers 240w arranged on both sides in the axial direction of the fourth pinion gear 24p. Becomes

The second shaft support portion 232 of the third carrier 23c is also formed in an annular shape like the first shaft support portion 231, and is a center through which the input shaft 20i and the fourth sun gear 24s, which are not shown in FIG. 4 and the like, are inserted. It has a hole 232o. In addition, a plurality of pinion shaft support holes 232L are formed in the second shaft support portion 232 so as to axially oppose the corresponding second pinion shaft support holes 231L of the first shaft support portion 231. They are arranged at intervals in the circumferential direction of 232. The pinion shaft support hole 232L is a through hole extending in the axial direction of the third carrier 23c, and the other end of the long pinion shaft 240 inserted into the fourth pinion gear 24p is inserted into each pinion shaft support hole 232L.

Further, the second shaft support portion 232 is formed with a plurality of positioning holes (through holes) 232y that extend radially outward from the inner peripheral surface and open at the corresponding pinion shaft support holes 232L. Each long pinion shaft 240 is positioned with respect to the second shaft support portion 232, that is, the third carrier 23c by the locate pin 240p inserted into the corresponding positioning hole 232y. Further, on the outer peripheral portion of the second shaft support portion 232, an annular protrusion (rib) 232a thinner than the portion around the pinion shaft support hole 232L of the second shaft support portion 232 is projected outward in the radial direction. A plurality of caulking recesses 232r are formed on the outer peripheral surface of the protrusion 232a at intervals in the circumferential direction of the second shaft support portion 232. As shown in FIGS. 4 to 6, the outer diameter of the second shaft support portion 232, that is, the protrusion 232 a is set to be larger than the outer diameter of the first shaft support portion 231.

Each third shaft support portion 233 of the third carrier 23c is arranged between the first and second shaft support portions 231 and 232 in the axial direction. One pinion shaft support hole 233S is formed in each third shaft support portion 233 so as to axially oppose the corresponding first pinion shaft support hole 231S of the first shaft support portion 231. The pinion shaft support hole 233S is a through hole extending in the axial direction of the third carrier 23c, and the other end of the short pinion shaft 230 inserted into the third pinion gear 23p is inserted into each pinion shaft support hole 233S.

Further, on the outer peripheral portion of each third shaft support portion 233, an annular protrusion (rib) 233a that is thinner than the portion around the pinion shaft support hole 233S of the third shaft support portion 233, and from the protrusion portion 233a. Is also located on the side of the first shaft support portion 231 and has a press-fitting surface 233b having a diameter smaller than that of the protrusion 233a. That is, as shown in FIG. 5 and FIG. 6, the protrusion 233a of each third shaft support portion 233 projects radially outward on the second shaft support portion 232 side with respect to the press-fitting surface 233b and at the press-fitting surface 233b. Along the circumference of the third carrier 23c. The outer diameter of the protrusion 233a (third shaft support portion 233) is set to be larger than the outer diameter of the first shaft support portion 231. In addition, each third shaft support portion 233 is formed with an oil hole 233h for supplying hydraulic oil as a lubricating/cooling medium to the meshing portion between the third pinion gear 23p and the third sun gear 23s.

Further, as shown in FIG. 4, the inner peripheral portion of each third shaft support portion 233 is integrated with the hollow inner cylindrical portion 233i. The inner cylinder portion 233i extends from the inner peripheral portion of each third shaft support portion 233 mainly on the first shaft support portion 231 side and coaxially with the third carrier 23c. Further, a spline 233sp is formed on the inner peripheral surface of the inner cylindrical portion 233i. The spline 233sp is fitted with a spline formed on the outer peripheral surface of the input shaft 20i, whereby the input shaft 20i and the third carrier 23c are always connected so as to rotate integrally. Thus, the inner cylindrical portion 233i protruding toward the first shaft supporting portion 231 is interposed between the plurality of third shaft supporting portions 233 arranged between the first and second shaft supporting portions 231 and 232 in the axial direction. By connecting the input shaft 20i with each other, it is possible to favorably prevent the third carrier 23c from tilting with respect to the direction orthogonal to the axial direction of the input shaft 20i.

The plurality of first bridge portions 234 of the third carrier 23c extend in the axial direction at intervals in the circumferential direction of the third carrier 23c, and respectively correspond to the first shaft support portion 231 and the corresponding third shaft support portion 233. Connect the two in between. In addition, the plurality of second bridge portions 235 of the third carrier 23c extend in the axial direction at intervals in the circumferential direction of the third carrier 23c, and the third shaft support portions corresponding to the second shaft support portions 232. Connect both with 233. As shown in FIG. 5 and FIG. 6, the circumferential dimension of each first bridge portion 234 is set shorter than the circumferential dimension of each second bridge portion 235 (in this embodiment, approximately half). ing. As a result, a space for disposing the third pinion gear 23p and a half portion of the fourth pinion gear 24p meshing with the third pinion gear 23p is secured between the first bridge portions 234 adjacent to each other in the circumferential direction. Further, a space for disposing a half portion of the fourth pinion gear 24p that does not mesh with the third pinion gear 23p is secured between the adjacent second bridge portions 235 in the circumferential direction.

Further, the Ravigneaux type planetary gear mechanism 25 of the automatic transmission 20 further includes an annular member 100 mounted on the outer peripheral portion of the third carrier 23c, as shown in FIGS. 4 and 7. The annular member 100 is formed in a substantially cylindrical shape from, for example, a steel material (iron alloy) having a thermal expansion coefficient smaller than that of the aluminum alloy forming the carrier. The annular member 100 is press-fitted into the press-fitting surface 233b of the third shaft support portion 233 so as to surround the outer peripheral portion of the third carrier 23c, that is, the second and third shaft support portions 232 and 233 and the second bridge portion 235. Fixed by.

As shown in FIGS. 4 and 7, the annular member 100 includes a cylindrical small-diameter portion 101 and a large-diameter portion 102 that is axially extended from one end of the small-diameter portion 101 and has a larger diameter than the small-diameter portion 101. including. The small-diameter portion 101 has an axial length that substantially matches the axial length from the end of the protrusion 232a opposite to the third shaft support 233 to the end of the press-fitting surface 233b on the first shaft support 231 side. Have. An annular protrusion 101a is formed at the end of the inner peripheral surface of the small-diameter portion 101 on the side of the large-diameter portion 102 so as to protrude radially inward. The inner diameter of the inner peripheral surface of the annular protrusion 101a is set to be slightly smaller than the outer diameter of the press-fitting surface 233b of the third shaft support portion 233. Further, the inner peripheral surface of the end portion of the small diameter portion 101 opposite to the large diameter portion 102 is formed to have a diameter slightly larger than the outer peripheral surface of the protrusion 232a of the second shaft support portion 232.

Further, as shown in FIG. 7, the small diameter portion 101 is formed with a plurality of oil discharge holes 101h for discharging the hydraulic oil accumulated inside the third carrier 23c. Further, as shown in FIG. 7, a plurality of concave portions 102r are formed on the outer peripheral surface of the large diameter portion 102 at intervals in the circumferential direction. The plurality of recesses 102r are used as detected portions of a rotation sensor (not shown) for detecting the rotation speed of the third carrier 23c, that is, the input shaft 20i.

The annular member 100 as described above is assembled to the third carrier 23c from the first shaft support portion 231 side toward the second shaft support portion 232. That is, the end portion (tip portion) of the annular member 100 on the opposite side to the large diameter portion 102 is fitted (inlay fitting) to the protrusion 232 a of the second shaft support portion 232, and the annular protrusion of the annular member 100. 101a is press-fitted into the press-fitting surface 233b of the third shaft support portion 233. The end surface of the annular protrusion 101a on the side opposite to the large diameter portion 102 side abuts the end surface of the protrusion 233a of the third shaft support portion 233 on the press-fitting surface 233b side, and the tip of the small diameter portion 101 of the annular member 100. The portion is crimped from the outside in the radial direction of the recess 232r formed in the protrusion 232a.

As a result, the second and third shaft support portions 232 and 233 (projections 232a and 233a) of the third carrier 23c and the second bridge portion 235 are surrounded by the small diameter portion 101 of the annular member 100. Further, as shown in FIG. 4, the large-diameter portion 102 of the annular member 100 partially overlaps the third and fourth pinion gears 23p and 24p in the axial direction when viewed from the radial direction of the third carrier 23c, and the large-diameter portion 102 has a large diameter. The third ring gear 23r is arranged radially inside the portion 102. Further, in the present embodiment, when the annular member 100 is mounted on the third carrier 23c, as shown in FIG. 4, the outer peripheral surface of the second bridge portion 235 and the inner peripheral surface of the small diameter portion 101 of the annular member 100 are formed. And a small gap is formed between the outer peripheral surface of the protrusion 233a of the third shaft support portion 233 and the inner peripheral surface of the small diameter portion 101 of the annular member 100. ..

As described above, the third shaft support portion 233 of the third carrier 23c is press-fitted so as to surround the second and third shaft support portions 232, 233 (protrusions 232a, 233a) and the second bridge portion 235. Since the third carrier 23c (third shaft support portion 233) can be provided with a compressive stress by being fixed to the third carrier 23c, a tensile stress is generated in the third carrier 23c by the action of centrifugal force and the torsion accompanying the transmission of the rotational torque. It is possible to suppress the occurrence. Further, for example, when the temperature of the third carrier 23c rises as the third and fourth pinion gears 23p, 24p rotate at high speed, the expansion amount of the third carrier 23c becomes larger than the expansion amount of the annular member 100. Therefore, it is possible to further increase the compressive stress applied from the annular member 100 to the third carrier 23c (third shaft support portion 233) and also apply the compressive stress to the second shaft support portion 232 from the annular member 100. it can. As a result, it is possible to suppress an increase in the thickness of the first, second and third shaft support portions 231, 23, 233 and the first and second bridge portions 234, 235 and to increase the size of the third carrier 23c, and thus the Ravigneaux type planetary gear mechanism 25. It is possible to secure good rigidity of the third carrier 23c while suppressing increase in the weight and increase in weight.

Further, in the third carrier 23c, since the protrusions 232a and 233a of the second and third shaft support portions 232 and 233 function as ribs, the second and third shaft support portions 232 and 233, and thus the entire third carrier 23c. The rigidity of can be further improved. Furthermore, the annular member 100 has an annular protrusion 101a that protrudes radially inward from the inner peripheral surface of the small diameter portion 101. Further, on the outer peripheral portion of the third shaft support portion 233 of the third carrier 23c, the annular projection 101a projects radially outward on the downstream side in the press-fitting direction of the annular member 100 with respect to the press-fitting surface 233b into which the annular projection 101a is press-fitted. A protrusion 233a extending in the circumferential direction is formed along the surface 233b. As a result, even if chips (burrs) are generated between the annular protrusion 101a and the press-fitting surface 233b when the annular member 100 is press-fitted, the chips are removed from the annular protrusion 101a of the annular member 100 and the third shaft support portion 233. It is possible to keep it between the protrusion 233a and the protrusion 233a.

Further, by forming a plurality of recesses 102r to be detected portions of the rotation sensor on the outer peripheral surface of the annular member 100 (large diameter portion 102), it is not necessary to prepare a dedicated member having the detected portion of the rotation sensor. Therefore, it is possible to suppress an increase in the number of parts of the Ravigneaux type planetary gear mechanism 25. However, the concave portion 102r may be omitted from the annular member 100, and in this case, the large diameter portion 102 itself may be omitted.

The third carrier 23c is integrally formed of a material containing aluminum as a main component, and the annular member 100 is formed of a material containing iron as a main component, but the present invention is not limited to this. That is, the third carrier 23c may be formed of a material other than an aluminum alloy such as steel, and in this case, the annular member 100 is formed of a material having a thermal expansion coefficient smaller than that of the material forming the third carrier 23c. It should be done.

Further, the structure of the third carrier 23c and the annular member 100 as described above is a compound planet in which two planet gears such as a Simpson type planetary gear mechanism other than the Ravigneaux type planetary gear mechanism 25 and a CR-CR type planetary gear mechanism are combined. It may be applied to a gear mechanism.

Further, in a planetary gear mechanism including a single planetary gear, an annular member is provided on the shaft support portion (carrier) so as to surround a shaft support portion (projection) that supports the end portion of the pinion shaft that is inserted into the pinion gear. It may be fixed by press fitting. Also in this case, the annular member may have an annular protrusion that protrudes radially inward from the inner peripheral surface, and the outer peripheral portion of the shaft support portion has a press-fitting surface into which the annular protrusion of the annular member is press-fitted. A projection located downstream of the press-fitting surface in the press-fitting direction of the annular member may be formed. Further, when the planetary gear mechanism including a single planetary gear has two shaft supporting portions, the annular member may be press-fitted into either one of the two shaft supporting portions, and the annular member may be annularly inserted into both of the two shaft supporting portions. The member may be press-fitted.

In the third carrier 23c, the annular protrusion 101a of the annular member 100 is press-fitted into the press-fitting surface 233b of the third shaft support portion 233, but the present invention is not limited to this. That is, the press-fitting surface may be provided at the end of the second shaft support portion 232, and the annular protrusion may be provided at the end of the annular member 100 opposite to the large diameter portion 102. In this case, the annular member 100 is assembled to the third carrier 23c from the second shaft support portion 232 side toward the first shaft support portion 231 side, and is press-fitted into the second shaft support portion 232. In addition, depending on the location of the third ring gear 23r in the Ravigneaux type planetary gear mechanism 25, the third carrier 23c is arranged so that the annular member 100 surrounds the first and third shaft support portions 231, 233 and the first bridge portion 234. It may be fixed by press fitting. In this case, the press-fitting surface may be provided on either one of the first and third shaft supporting portions 231, 233, and the annular protrusion is provided on one end of the annular member 100 (small diameter portion 101). It should be done.

As described above, the planetary gear mechanism of the present disclosure forms the carrier (23c) in the planetary gear mechanism (25) including the carrier (23c) that rotatably supports the plurality of pinion gears (23p, 24p). An annular member (100) formed of a material having a coefficient of thermal expansion smaller than that of the material and fixed to the carrier (23c) by press-fitting so as to surround at least a part of an outer peripheral portion of the carrier (23c). Is.

By fixing the annular member to the carrier by press-fitting in this way, compressive stress can be applied to the carrier, so that tensile stress is generated in the carrier due to the action of centrifugal force and the torsion associated with the transmission of rotational torque. It becomes possible to suppress. Furthermore, for example, when the temperature of the carrier increases due to high speed rotation of the pinion gear, the expansion amount of the carrier becomes larger than the expansion amount of the annular member, so that the compressive stress applied to the carrier by the annular member is further increased. Can be large. As a result, it is possible to secure good rigidity of the carrier while suppressing an increase in the size and weight of the carrier and the planetary gear mechanism including the carrier.

Further, the carrier (23c) may have a shaft support portion (232, 233) for supporting an end portion of the pinion shaft (230, 240) inserted into the pinion gear (23p, 24p), and the ring shape. The member (100) may be fixed to the shaft support portion (232) by press fitting so as to surround the shaft support portion (232, 233). This makes it possible to apply a compressive stress to the shaft support portion from the annular member and to ensure good rigidity of the shaft support portion.

Further, the annular member (100) may have an annular protrusion (101a) that protrudes radially inward from the inner peripheral surface, and the annular member (100a) is provided on the outer peripheral portion of the shaft support (233). 100), a press-fitting surface (233b) into which the annular projection (101a) is press-fitted, and a radial outside of the press-fitting surface (233b) in the press-fitting direction of the annular member (100). A protrusion (233a) extending in the circumferential direction along the press-fitting surface (233b) and surrounded by the annular member (100) may be formed. Thus, even if chips (burrs) are generated between the annular projection and the press-fitting surface during press fitting of the annular member, the chips are retained between the annular projection of the annular member and the projection of the shaft support portion. It becomes possible to keep it. In addition, since the protrusion of the shaft support portion functions as a rib, the rigidity of the shaft support portion and thus the entire carrier can be further improved.

Further, the planetary gear mechanism may be a compound planetary gear mechanism (25) in which two planetary gears (23, 24) are combined. However, it goes without saying that the planetary gear mechanism may include a single planetary gear.

Further, the planetary gear mechanism includes two sun gears (23s, 24s), a ring gear (23r), a plurality of short pinion gears (23p) meshing with one of the two sun gears (23s), and the two sun gears. A plurality of long pinion gears (24p) meshing with the other (24s), the short pinion gears (23p), and the ring gear (23r), and a plurality of short pinion gears (23p) and the plurality of long pinion gears (24p) are rotatable. It may be a Ravigneaux type planetary gear mechanism (25) including the carrier (23c) supported by the above.

Further, the carrier (23c) supports one end of a short pinion shaft (230) inserted into the short pinion gear (23p) and one end of a long pinion shaft (240) inserted into the long pinion shaft (24p). An annular first shaft support part (231), an annular second shaft support part (232) supporting the other end of the long pinion shaft (240), the first shaft support part (231) and the first shaft support part (231). A plurality of third shaft support portions (233), which are arranged at intervals in the axial direction between the two shaft support portions (232) and which respectively support the other ends of the short pinion shafts (230). ) And a plurality of first bridge portions (234) extending in the axial direction at intervals in the circumferential direction and connecting the first shaft support portion (231) and the corresponding third shaft support portion (233). ) And a plurality of second bridge portions (235) extending in the axial direction at intervals in the circumferential direction and connecting the second shaft support portion (232) and the corresponding third shaft support portion (233), respectively. ) And the annular member (100) has the first and third shaft support portions (231, 233) and the first bridge portion (234) or the second and third shaft support portions. (232, 233) and the second bridge portion (235) may be fixed to the carrier (23c) by press fitting so as to surround them.

This suppresses an increase in the thickness of the first, second and third shaft support portions and the first and second bridge portions to suppress the increase in size and weight of the carrier and thus the planetary gear mechanism, while increasing the rigidity of the carrier. It becomes possible to secure it satisfactorily.

Furthermore, the annular member (100) may have an annular protrusion (101a) that protrudes radially inward from the inner peripheral surface, and the annular member is provided on the outer peripheral portion of the third shaft support portion (231). The press-fitting surface (233b) into which the annular projection (101a) of the member (100) is press-fitted, and the second shaft support portion (232) side of the press-fitting surface (233b) are projected radially outward and A protrusion (233a) extending in the circumferential direction along the press-fitting surface (233b) and surrounded by the annular member (100) may be formed, and an outer peripheral portion of the second shaft support portion (232). An annular protrusion (232a) may be formed on the outer periphery of the annular protrusion (232a) that protrudes radially outward and is surrounded by the annular member (100). Accordingly, even if chips (burrs) are generated between the annular protrusion and the press-fitting surface when the annular member is press-fitted, the chips are not allowed to be present between the annular protrusion of the annular member and the protrusion of the third shaft support portion. It is possible to keep it in. In addition, since the protrusions of the second and third shaft support portions function as ribs, the rigidity of the second and third shaft support portions and thus the carrier as a whole can be further improved.

The carrier (23c) may be integrally formed of a material containing aluminum as a main component, and the annular member (100) may be formed of a material containing iron as a main component.

Furthermore, a plurality of recesses (102r), which are the detected portions of the rotation sensor, may be formed on the outer peripheral surface of the annular member (100) at intervals in the circumferential direction. As a result, it is not necessary to prepare a dedicated member having the detected portion of the rotation sensor, and it is possible to suppress an increase in the number of parts of the planetary gear mechanism.

Further, it goes without saying that the invention of the present disclosure is not limited to the above-described embodiment, and various modifications can be made within the scope of the extension of the present disclosure. Furthermore, the above-described mode for carrying out the invention is merely one specific form of the invention described in the summary of the invention, and does not limit the elements of the invention described in the summary of the invention. Absent.

INDUSTRIAL APPLICABILITY The invention of the present disclosure can be used in the manufacturing industry of planetary gear mechanisms and the like.

10 power transmission device, 11 transmission case, 12 starter device, 13 front cover, 140 pump impeller, 142 turbine runner, 143 stator, 144 one-way clutch, 15 lock-up clutch, 16 damper mechanism, 17 oil pump, 170 rotor, 171 outside Tooth gear, 172 internal tooth gear, 18 chain, 20 automatic transmission, 20i input shaft, 20m intermediate shaft, 20o output shaft, 21 first planetary gear, 21c first carrier, 21p first pinion gear, 21r first ring gear, 21s 1st sun gear, 22 2nd planetary gear, 22c 2nd carrier, 22p 2nd pinion gear, 22r 2nd ring gear, 22s 2nd sun gear, 23c 3rd carrier, 23p 3rd pinion gear, 23r 3rd ring gear, 23s 3rd sun gear, 24p 4th pinion gear, 24s 4th sun gear, 25 Ravigneaux type planetary gear mechanism, 100 annular member, 101 small diameter portion, 101a annular protrusion, 101h oil discharge hole, 102 large diameter portion, 102r recessed portion, 230 short pinion shaft, 230a, 230c oil hole, 230b internal oil passage, 230n needle bearing, 230p locate pin, 230w thrust washer, 231 first shaft support portion, 231S first pinion shaft support hole, 231L second pinion shaft support hole, 231a, 231b oil hole, 231o Center hole, 231r oil collecting recess, 231y positioning hole, 232 second shaft support portion, 232L pinion shaft support hole, 232a projection portion, 232o center hole, 232r recessed portion, 232y positioning hole, 233 third shaft support portion, 233S pinion shaft Support hole, 233a protrusion, 233b press-fitting surface, 233h oil hole, 233i inner cylinder part, 233sp spline, 234 first bridge part, 235 second bridge part, 240 long pinion shaft, 240a, 240c oil hole, 240b internal oil passage , 240n needle bearing, 240p locate pin, 240w thrust washer, B1, B2 brake, C1, C2, C3, C4 clutch.

Claims (8)

A planetary gear mechanism included in a transmission connected to a vehicle engine, wherein the planetary gear mechanism includes a carrier that rotatably supports a plurality of pinion gears.
An annular member formed of a material having a smaller coefficient of thermal expansion than the material forming the carrier,
The carrier has a shaft support portion that supports an end portion of a pinion shaft that is inserted into the pinion gear,
Said annular member, a planetary gear mechanism that will be press-fitted to the shaft support portion so as to surround the shaft supporting portion of the carrier. The planetary gear mechanism according to claim 1 ,
The annular member has an annular protrusion protruding radially inward from the inner peripheral surface,
In the outer peripheral portion of the shaft support portion, a press-fitting surface into which the annular projection of the annular member is press-fitted, and a radial direction outer side of the press-fitting surface downstream of the press-fitting surface of the annular member and the press-fitting surface. A planetary gear mechanism that extends in the circumferential direction along a surface and has a protrusion that is surrounded by the annular member. The planetary gear mechanism according to claim 1 or 2 , which is a compound planetary gear mechanism in which two planetary gears are combined. The planetary gear mechanism according to claim 3 ,
Two sun gears, a ring gear, a plurality of short pinion gears that mesh with one of the two sun gears, a plurality of long pinion gears that mesh with the other of the two sun gears, the short pinion gear and the ring gear, and the plurality of shorts. A planetary gear mechanism that is a Ravigneaux type planetary gear mechanism including a pinion gear and the carrier that rotatably supports the plurality of long pinion gears. The planetary gear mechanism according to claim 4 ,
The carrier is
An annular first shaft support portion that supports one end of a short pinion shaft that is inserted into the short pinion gear and one end of a long pinion shaft that is inserted into the long pinion shaft,
An annular second shaft support portion that supports the other end of the long pinion shaft,
A plurality of third shaft supports which are arranged at intervals in the circumferential direction between the first shaft support part and the second shaft support part in the axial direction and which respectively support the other ends of the short pinion shafts. Department,
A plurality of first bridge portions extending in the axial direction at intervals in the circumferential direction and connecting the first shaft support portion and the corresponding third shaft support portion, respectively.
A plurality of second bridge portions that extend in the axial direction at intervals in the circumferential direction and that respectively connect the second shaft support portion and the corresponding third shaft support portion,
The annular member is a planet fixed to the carrier by press fitting so as to surround the first and third shaft support portions and the first bridge portion or the second and third shaft support portions and the second bridge portion. Gear mechanism. The planetary gear mechanism according to claim 5 ,
The annular member has an annular protrusion that protrudes radially inward from the inner peripheral surface,
A press-fitting surface into which the annular protrusion of the annular member is press-fitted, and a press-fitting surface that protrudes radially outward from the press-fitting surface on the side of the second shaft support portion and are press-fitted into the outer peripheral portion of the third shaft support portion. A protrusion extending circumferentially along the surface and surrounded by the annular member is formed,
A planetary gear mechanism in which an annular protrusion that is radially outward and is surrounded by the annular member is formed on the outer peripheral portion of the second shaft support portion. The planetary gear mechanism according to any one of claims 1 to 6 ,
The planetary gear mechanism, wherein the carrier is integrally formed of a material containing aluminum as a main component, and the annular member is formed of a material containing iron as a main component. The planetary gear mechanism according to any one of claims 1 to 7 ,
A planetary gear mechanism in which a plurality of concave portions which are to-be-detected portions of a rotation sensor are formed on the outer peripheral surface of the annular member at intervals in the circumferential direction.

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