JP6862249B2 - Double shaft structure - Google Patents

Description

The present invention relates to a double shaft structure in which a rotating shaft is inserted or inserted into another cylindrical rotating shaft, and particularly to a double shaft structure suitable for a vehicle transmission.

In a vehicle such as an automobile, the power from the drive source is input to the transmission (transmission), and the power shifted by the transmission is transmitted to the drive wheels via a differential gear or the like.

A plurality of rotation axes are used in the transmission. Of course, a columnar rotating shaft is also used in the transmission, but since it is necessary to supply hydraulic oil and lubricating oil to each part, rotation with an axial oil passage (oil passage formed on the rotating axis). Shafts and cylindrical rotating shafts are also often used. Further, in the transmission, another rotating shaft is inserted in the cylindrical rotating shaft, and oil is inserted between the rotating shafts, that is, between the outer peripheral surface of the inner rotating shaft and the inner peripheral surface of the outer rotating shaft. Roads may be formed.

Japanese Unexamined Patent Publication No. 2015-145682

In a dual shaft structure in which another rotating shaft is inserted into a cylindrical rotating shaft, the cylindrical rotating shaft may be passed through an insertion port formed in a transmission case at the time of assembling them. In this case, if the position of the rotating shaft shifts in the radial direction when the cylindrical rotating shaft is passed through the insertion port, the end of the rotating shaft comes into contact with the case, causing cracks or chips in the case. There is a risk.

An object of the present invention is to prevent the position of the cylindrical rotating shaft from shifting in the rotational radial direction when the cylindrical rotating shaft (second rotating shaft) and another rotating shaft (first rotating shaft) are assembled. It is possible to provide a dual axis structure.

In order to achieve the above object, the double shaft structure according to the present invention is a double shaft structure in which the first rotating shaft is inserted or inserted into a cylindrical second rotating shaft, and the double shaft structure is used. Then, a hollow portion extending in the axial direction is formed on the first rotating shaft, an opening communicating with the hollow portion is formed on the outer peripheral surface of the first rotating shaft, and an opening and rotation are formed on the inner peripheral surface of the second rotating shaft. A small-diameter surface having an inner diameter smaller than that of the facing portion (close to the outer peripheral surface of the first rotating shaft) is formed so as to avoid the opposing portions facing in the radial direction.

According to this configuration, a hollow portion extending in the axial direction is formed on the first rotation shaft. An opening communicating with the hollow portion is formed on the outer peripheral surface of the first rotating shaft. A small-diameter surface is formed on the inner peripheral surface of the second rotating shaft that surrounds the outer circumference of the first rotating shaft, avoiding the facing portion that faces the opening in the rotational radial direction. The inner diameter of the small-diameter surface is smaller than the inner diameter of the facing portion, and the small-diameter surface is closer to the outer peripheral surface of the first rotating shaft than the facing portion. Therefore, the positional deviation of the second rotating shaft in the rotational radial direction when the first rotating shaft and the second rotating shaft are assembled is within the range of the gap between the outer peripheral surface of the first rotating shaft and the small diameter surface of the second rotating shaft. Can be suppressed within. As a result, the assembling property between the first rotating shaft and the second rotating shaft can be improved.

Further, since the positional deviation of the second rotating shaft in the rotational radial direction when the first rotating shaft and the second rotating shaft are assembled is suppressed, an insertion port is formed in a case or the like in which the double shaft structure is accommodated. , When it is necessary to pass the second rotating shaft through the insertion port for assembling the first rotating shaft and the second rotating shaft, it is possible to prevent the second rotating shaft from coming into contact with the case, and cracking due to the contact. It is possible to prevent the case from being chipped or chipped.

At the end of the cylindrical rotating shaft used for the transmission, a flange-shaped overhanging gear or a fixed sheave of the pulley may be integrally formed, and it is necessary to pass the end of the rotating shaft through the insertion port. In some cases, gears and fixed sheaves tend to come into contact with the case. Therefore, it can be said that the above-mentioned double shaft structure is particularly suitable for a transmission.

Further, the hollow portion of the first rotating shaft can be used as an in-shaft oil passage, and in that case, the gap between the outer peripheral surface of the first rotating shaft and the inner peripheral surface of the second rotating shaft is filled with the in-shaft oil. It can be used as an inter-axle oil passage through which oil supplied from the passage through an opening flows. Therefore, it can be said that the above-mentioned double shaft structure is particularly suitable for a transmission that needs to supply hydraulic oil or lubricating oil to each part.

Since the small diameter surface of the second rotating shaft is formed so as to avoid the portion facing the opening of the first rotating shaft in the rotational radial direction, the hollow portion of the first rotating shaft is used as an in-shaft oil passage. When the gap between the first rotating shaft and the second rotating shaft is used as an inter-axis oil passage, oil can be satisfactorily discharged from the opening to the inter-shaft oil passage. As a result, the pipeline resistance received by the oil supplied to the inter-shaft oil passage can be reduced, and when the oil flowing through the inter-shaft oil passage is hydraulic oil, the responsiveness of the hydraulic pressure can be ensured.

According to the present invention, the positional deviation of the second rotating shaft in the rotational radial direction when the first rotating shaft and the second rotating shaft are assembled is set to the outer peripheral surface of the first rotating shaft and the small diameter surface of the second rotating shaft. It can be suppressed within the range of the gap. As a result, the assembling property between the first rotating shaft and the second rotating shaft can be improved.

It is sectional drawing which shows a part of the transmission | transmission unit to which the dual shaft structure which concerns on one Embodiment of this invention is applied.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Structure of transmission unit>
FIG. 1 is a cross-sectional view showing a part of a transmission unit 1 to which the dual shaft structure according to the embodiment of the present invention is applied. Note that in FIG. 1, the addition of hatching indicating a cross section is omitted.

The transmission unit 1 is a unit mounted on a vehicle that shifts torque generated by the engine (engine torque) and transmits it to the drive wheels, and includes a torque converter 2 and an automatic transmission 3.

The torque converter 2 includes a front cover 11, a pump impeller 12, a turbine runner 13, a lockup clutch 14, and a stator 15.

An engine output shaft (not shown) is connected to the front cover 11, and the front cover 11 rotates integrally with the engine output shaft due to engine torque. The front cover 11 has a substantially disc shape, and the front cover 11 bulges toward the engine side (right side in FIG. 1, hereinafter referred to as “right side”) in a cylindrical shape at the center of the front cover 11. , The center piece 16 is formed. Inside the center piece 16, a relatively thick cylindrical bearing member 17 is provided integrally with the center piece 16.

The pump impeller 12 is arranged on the side opposite to the engine side with respect to the front cover 11 (left side in FIG. 1, hereinafter referred to as "left side"). The pump impeller 12 is provided so as to be rotatable integrally with the front cover 11.

The turbine runner 13 is arranged between the front cover 11 and the pump impeller 12 and is rotatably provided about a rotation axis common to the front cover 11.

The lockup clutch 14 is arranged between the front cover 11 and the turbine runner 13. The lockup clutch 14 is engaged by the hydraulic difference between the release side oil chamber 18 between the lockup clutch 14 and the front cover 11 and the engagement side oil chamber 19 between the lockup clutch 14 and the pump impeller 12. Go / released.

The stator 15 is arranged between the pump impeller 12 and the turbine runner 13.

The automatic transmission 3 includes an input shaft 21.

The input shaft 21 extends on a rotation axis common to the torque converter 2. The right end of the input shaft 21 is inserted into the torque converter 2. The turbine runner 13 of the torque converter 2 is spline-coupled to the input shaft 21 and is supported by the input shaft 21 so as not to rotate relative to each other.

The outer circumference of the input shaft 21 is surrounded by a substantially cylindrical stator shaft 22. A gap 23 is provided between the input shaft 21 and the stator shaft 22. The right end of the stator shaft 22 is inserted into the torque converter 2. The stator 15 of the torque converter 2 is supported (via a one-way clutch) at the right end of the stator shaft 22. There is a gap between the stator shaft 22 and the turbine runner 13, and the gap 23 between the input shaft 21 and the stator shaft 22 is engaged with the stator shaft 22 and the turbine runner 13 via the gap 23. It communicates with the side oil chamber 19.

An oil pump 4 is arranged on the left side of the input shaft 21. The oil pump 4 includes a pump housing 31, a pump drive shaft 32, and a pump gear 33.

The pump drive shaft 32 extends on a rotation axis common to the input shaft 21 and is inserted into the input shaft 21. As a result, the input shaft 21 and the pump drive shaft 32 have a double shaft structure.

A spline 34 is formed on the outer peripheral surface of the right end portion of the pump drive shaft 32. Then, the right end portion of the pump drive shaft 32 is inserted into the bearing member 17, and the spline 34 and the spline 35 formed on the inner peripheral surface of the bearing member 17 mesh with each other to be spline-coupled to the bearing member 17. ing. A gap is provided between the inner peripheral surface of the input shaft 21 and the outer peripheral surface of the pump drive shaft 32, and an inter-shaft oil passage 36 is formed by the gap. The left end of the inter-shaft oil passage 36 is closed by a seal 37 interposed between the inner peripheral surface of the input shaft 21 and the outer peripheral surface of the pump drive shaft 32, and the right end thereof is open. As a result, the inter-shaft oil passage 36 communicates with the release side oil chamber 18 between the lockup clutch 14 and the front cover 11.

The left end of the pump drive shaft 32 is inserted into the pump housing 31.

The pump gear 33 is housed in the pump housing 31 and is spline-coupled to the pump drive shaft 32 so as to be integrally rotatable. As a result, when the front cover 11 of the torque converter 2 rotates, the pump drive shaft 32 rotates, and the pump gear 33 rotates integrally with the pump drive shaft 32. Due to the rotation of the pump gear 33, oil pressure is generated in the oil pump 4, and the oil pressure is supplied to the valve body (not shown).

Seals 38 and 39 are provided on both the left and right sides of the pump gear 33 to support the pump drive shaft 32 by the pump housing 31 and seal between the pump housing 31 and the pump drive shaft 32.

The pump housing 31 is formed with a supply oil passage 41 for which oil (flood control) is supplied from the valve body. An axial oil passage 42 is formed in the pump drive shaft 32. The axial oil passage 42 is open at the left end of the pump drive shaft 32 and communicates with the supply oil passage 41. Further, the pump drive shaft 32 is formed with a communication oil passage 43 having one end connected to the shaft center oil passage 42 and an opening 44 opened at the peripheral surface of the pump drive shaft 32 at the other end. The oil passage 42 communicates with the intershaft oil passage 36 between the input shaft 21 and the pump drive shaft 32 via the communication oil passage 43. As a result, oil can be supplied from the supply oil passage 41 to the intershaft oil passage 36 between the input shaft 21 and the pump drive shaft 32 through the axial core oil passage 42 and the communication oil passage 43, and the oil pressure can be used as a shaft. It can be supplied as an operating pressure to the open side oil chamber 18 of the torque converter 2 through the oil passage 36. The working pressure is generated by adjusting the line pressure with, for example, a linear solenoid valve provided on the valve body.

<Characteristic part of double shaft structure>
FIG. 2 is a cross-sectional view showing an excerpt of the vicinity of the left end portion of the input shaft 21.

A drive gear 51 is integrally formed at the left end of the input shaft 21. The drive gear 51 has a web 52 projecting from the left end portion of the input shaft 21 in the rotational radial direction, and a substantially cylindrical rim 53 extending rearward from the outer peripheral end portion of the web 52. A large number of gear teeth 54 are formed side by side in the circumferential direction on the outer peripheral surface of the rim 53.

Further, the right end portion of the rotation shaft 61 extending in parallel with the rotation axis of the input shaft 21 is arranged at a position spaced apart from the left end portion of the input shaft 21 in the rotation radial direction. A driven gear 62 that meshes with the drive gear 51 is fitted on the right end of the rotating shaft 61 so as not to rotate relative to each other. The driven gear 62 has a substantially cylindrical boss 63, a substantially annular plate-shaped web 64 extending in the radial direction from the left end of the boss 63, and a substantially cylindrical rim 65 surrounding the outer periphery of the web 64. There is. A large number of gear teeth 66 that mesh with the gear teeth 54 of the drive gear 51 are formed on the outer peripheral surface of the rim 65.

The inner ring of the bearing 71 is externally fitted to the boss 63 of the driven gear 62 on the right side portion of the web 64. A housing recess 73 is formed in the case 72 forming the outer shell of the transmission unit 1, and the bearing 71 is fitted in the housing recess 73 so that the outer ring is held in the housing recess 73 so as not to rotate relative to each other.

Further, the case 72 is formed with a circular holding opening 75 across a wall portion 74 surrounding the accommodating recess 73. A bearing 76 is internally fitted in the holding opening 75, and the input shaft 21 is rotatably held in the case 72 via the bearing 76.

When the input shaft 21 is fitted onto the pump drive shaft 32 in a state where the pump drive shaft 32 is assembled to the case 72, the input shaft 21 is passed through the holding opening 75 from the right side to the left side. At that time, if the input shaft 21 is displaced in the radial direction of rotation, the drive gear 51 may come into contact with the wall portion 74 of the case 72 or the portion surrounding the holding opening 75.

On the inner peripheral surface of the left end of the input shaft 21, the facing portion 81 facing the opening 44 of the communication oil passage 43 of the pump driving shaft 32 in the state of being assembled with the pump driving shaft 32 is avoided, and the facing portion 81 of the facing portion 81 is avoided. Small diameter surfaces 82 having an inner diameter smaller than that of the facing portion 81 are formed on the left side and the right side. Therefore, with the input shaft 21 and the pump drive shaft 32 assembled, the small diameter surface 82 is closer to the outer peripheral surface of the pump drive shaft 32 than the facing portion 81. In other words, with the input shaft 21 and the pump drive shaft 32 assembled, the gap D1 between the small diameter surface 82 and the outer peripheral surface of the pump drive shaft 32 is the facing portion 81 and the outer peripheral surface of the pump drive shaft 32. It is smaller than the gap D2 between them. Further, the gap D1 between the small diameter surface 82 and the outer peripheral surface of the pump drive shaft 32 is smaller than the gap D3 between the inner peripheral surface of the right end portion of the input shaft 21 and the outer peripheral surface of the pump drive shaft 32.

<Effect>
With this configuration, when the input shaft 21 is fitted onto the pump drive shaft 32 in a state where the pump drive shaft 32 is assembled to the case 72, the position shift of the input shaft 21 in the rotational radial direction is detected by the pump drive shaft 32. It can be suppressed within the range of the gap D1 between the outer peripheral surface of the input shaft 21 and the small diameter surface 82 of the input shaft 21. As a result, the assembling property between the input shaft 21 and the pump drive shaft 32 can be improved.

Further, since the positional deviation of the input shaft 21 in the radial direction of rotation is suppressed when the pump drive shaft 32 and the input shaft 21 are assembled, the input shaft 21 is placed in the case 72 when the input shaft 21 is passed through the holding opening 75. It is possible to suppress the contact with the case 72, and it is possible to prevent the case 72 from being cracked or chipped due to the contact. From this point of view, the small diameter surface 82 is formed at a position where the small diameter surface 82 faces the outer peripheral surface of the pump drive shaft 32 in the rotational radial direction at least before the input shaft 21 (drive gear 51) is passed through the holding opening 75. It is preferable that it is.

Moreover, since the small diameter surface 82 of the input shaft 21 is formed so as to avoid the portion of the communication oil passage 43 formed in the pump drive shaft 32 that faces the opening 44 in the radial direction of rotation, the oil passage between the shafts from the opening 44 is avoided. Oil can be satisfactorily discharged to 36. As a result, the pipeline resistance received by the oil supplied to the inter-axis oil passage 36 can be reduced, and the responsiveness of the oil supply supplied from the inter-axis oil passage 36 to the lockup clutch 14 can be ensured.

<Modification example>
Although one embodiment of the present invention has been described above, the present invention can also be implemented in other embodiments.

For example, in the above-described embodiment, the double shaft structure including the input shaft 21 and the pump drive shaft 32 has been taken up, but the present invention can also be applied to another double shaft structure provided in the transmission unit 1. Further, the present invention is not limited to the speed change unit 1, and can be widely applied to a double shaft structure in which the first rotating shaft is inserted or inserted into the cylindrical second rotating shaft.

In addition, various design changes can be made to the above-mentioned configuration within the scope of the matters described in the claims.

21: Input shaft (second rotating shaft)
32: Pump drive shaft (first rotating shaft)
44: Opening 81: Opposing part 82: Small diameter surface

Claims (1)

A double shaft structure in which the first rotating shaft is inserted or inserted into a cylindrical second rotating shaft.
A hollow portion extending in the axial direction is formed on the first rotating shaft.
An opening communicating with the hollow portion is formed on the outer peripheral surface of the first rotating shaft.
On the inner peripheral surface of the second rotating shaft, a small diameter surface having an inner diameter smaller than that of the facing portion is formed so as to avoid the facing portion facing the opening in the rotational radial direction .
The gap between the small-diameter surface and the outer peripheral surface of the first rotating shaft is between the inner peripheral surface of the end opposite to the small-diameter surface and the outer peripheral surface of the first rotating shaft. Double shaft structure that is smaller than the gap of.

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