JP2018173156A - Double shaft structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double shaft structure capable of suppressing deviation of a position of a cylindrical rotational shaft in a radial direction of rotation, in assembly of a structure where another rotational shaft is inserted into the cylindrical rotational shaft.SOLUTION: On an inner peripheral surface of an input shaft 21, a small-diameter surface 82 is formed on right and left sides of an opposite portion 81, facing an opening 44 of a communication oil passage 43 of a pump drive shaft 32, so as to avoid the opposite portion 81, wherein an inner diameter of the small-diameter surface is smaller than the opposite portion 81. Consequently, the small-diameter surface 82 approaches an outer peripheral surface of the pump drive shaft 32 with respect to the opposite portion 81. Namely, an interval D1 between the small-diameter surface 82 and the outer peripheral surface of the pump drive shaft 32 is smaller than an interval D2 between the opposite portion 81 and the outer peripheral surface of the pump drive shaft 32.SELECTED DRAWING: Figure 1

Description

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

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

  A plurality of rotating shafts are used in the transmission. In the transmission, a cylindrical rotating shaft is of course used, but since it is necessary to supply hydraulic oil and lubricating oil to each part, rotation with an axial oil passage (an oil passage formed on the rotation axis) is required. Many shafts and cylindrical rotating shafts are also used. Further, in the transmission, another rotating shaft is inserted into the cylindrical rotating shaft, and oil is interposed 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. A path may be formed.

Japanese Patent Laying-Open No. 2015-145682

  In a double 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 the case of the transmission when they are assembled. In this case, when the position of the rotary shaft is shifted in the radial direction when the cylindrical rotary shaft is passed through the insertion port, the end of the rotary shaft comes into contact with the case, and the case is cracked or chipped. There is a fear.

  An object of the present invention is to prevent the position of the cylindrical rotating shaft from shifting in the 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 double shaft structure.

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

  According to this structure, the hollow part extended in an axial direction is formed in the 1st rotating 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 rotary shaft that surrounds the outer periphery of the first rotary 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 in the rotation radial direction of the second rotation shaft when the first rotation shaft and the second rotation shaft are assembled is the range of the gap between the outer peripheral surface of the first rotation shaft and the small diameter surface of the second rotation shaft. Can be suppressed within. As a result, the assembling property between the first rotating shaft and the second rotating shaft can be improved.

  In addition, since the positional deviation in the rotational radial direction of the second rotating shaft during assembly of the first rotating shaft and the second rotating shaft is suppressed, an insertion port is formed in a case or the like that accommodates the double shaft structure. 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, the second rotating shaft can be prevented from coming into contact with the case, and cracks caused by the contact can be prevented. Or occurrence of chipping in the case can be suppressed.

  The end of a cylindrical rotary shaft used in a transmission may be integrally formed with a flange or a fixed sheave for a pulley, and it is necessary to pass the end of the rotary shaft through an 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-described 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 this case, a gap between the outer peripheral surface of the first rotating shaft and the inner peripheral surface of the second rotating shaft is defined as the in-shaft oil. It can be used as an inter-shaft oil passage through which oil supplied from the passage through the opening flows. Therefore, it can be said that the above-described double shaft structure is particularly suitable for a transmission that needs to supply hydraulic oil or lubricating oil to each part.

  And since the small-diameter surface of the second rotating shaft is formed to avoid the portion facing the opening of the first rotating shaft in the rotating 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-shaft oil passage, oil can be favorably discharged from the opening to the inter-shaft oil passage. As a result, the pipe resistance received by the oil supplied to the inter-shaft oil passage can be lowered, and when the oil flowing through the inter-shaft oil passage is hydraulic oil, the hydraulic response can be ensured.

  According to the present invention, when the first rotary shaft and the second rotary shaft are assembled, the positional deviation in the rotational radial direction of the second rotary shaft is determined between the outer peripheral surface of the first rotary shaft and the small-diameter surface of the second rotary shaft. It can suppress within the range of the clearance 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 transmission unit to which the double shaft structure concerning one Embodiment of this invention was applied.

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

<Configuration of transmission unit>
FIG. 1 is a cross-sectional view showing a part of a transmission unit 1 to which a double shaft structure according to an embodiment of the present invention is applied. In FIG. 1, the hatching indicating the cross section is omitted.

  The transmission unit 1 is a unit that is mounted on a vehicle, changes the torque generated by the engine (engine torque) and transmits the torque 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 by engine torque. The front cover 11 has a substantially disc shape, and the front cover 11 swells in a cylindrical shape toward the engine side (right side in FIG. 1, hereinafter referred to as “right side”) at the center of the front cover 11. A center piece 16 is formed. A relatively thick cylindrical bearing member 17 is provided integrally with the center piece 16 inside the center piece 16.

  The pump impeller 12 is disposed 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 able to rotate integrally with the front cover 11.

  The turbine runner 13 is disposed between the front cover 11 and the pump impeller 12, and is provided to be rotatable about a rotation axis common to the front cover 11.

  The lockup clutch 14 is disposed between the front cover 11 and the turbine runner 13. The lockup clutch 14 is engaged by a hydraulic pressure 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. Combined / released.

  The stator 15 is disposed 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. A right end portion 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 on the input shaft 21 so as not to be relatively rotatable.

  The outer periphery 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 at the right end of the stator shaft 22 (via a one-way clutch). A space is provided between the stator shaft 22 and the turbine runner 13, and a gap 23 between the input shaft 21 and the stator shaft 22 is engaged via the stator shaft 22 and the turbine runner 13. It communicates with the side oil chamber 19.

  The oil pump 4 is disposed 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 the rotation axis common to the input shaft 21 and is inserted into the input shaft 21. Thereby, 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 are engaged with each other, thereby being splined with 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. Thus, 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 accommodated in the pump housing 31 and is spline-coupled to the pump drive shaft 32 so as to be integrally rotatable. Thus, 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. As the pump gear 33 rotates, oil pressure is generated in the oil pump 4, and the oil pressure is supplied to a valve body (not shown).

  On the left and right sides of the pump gear 33, seals 38 and 39 are provided that 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 through which oil (hydraulic pressure) is supplied from the valve body. An axial oil passage 42 is formed in the pump drive shaft 32. The shaft center oil passage 42 is opened 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 the other end having an opening 44 opened on the peripheral surface of the pump drive shaft 32. The oil passage 42 communicates with the inter-shaft oil passage 36 between the input shaft 21 and the pump drive shaft 32 via the communication oil passage 43. As a result, oil pressure can be supplied from the supply oil passage 41 to the inter-shaft oil passage 36 between the input shaft 21 and the pump drive shaft 32 through the shaft center oil passage 42 and the communication oil passage 43. It can be supplied as an operating pressure to the release side oil chamber 18 of the torque converter 2 through the intermediate oil passage 36. The operating pressure is generated, for example, by adjusting the line pressure using a linear solenoid valve provided in the valve body.

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

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

  In addition, a right end portion of the rotation shaft 61 extending in parallel with the rotation axis of the input shaft 21 is disposed at a position spaced in the rotation radial direction with respect to the left end portion of the input shaft 21. A driven gear 62 that meshes with the drive gear 51 is fitted on the right end portion of the rotating shaft 61 so as not to be relatively rotatable. The driven gear 62 includes a substantially cylindrical boss 63, a substantially annular plate-shaped web 64 that extends in the rotational radial direction from the left end portion of the boss 63, and a substantially cylindrical rim 65 that surrounds the outer periphery of the web 64. Yes. 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 fitted on the boss 63 of the driven gear 62 at the right 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, and the outer ring is held in the housing recess 73 so as not to be relatively rotatable.

  In addition, a circular holding opening 75 is formed in the case 72 with a wall portion 74 surrounding the housing recess 73 therebetween. A bearing 76 is fitted into the holding opening 75, and the input shaft 21 is rotatably held by the case 72 via the bearing 76.

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

  On the inner peripheral surface of the left end portion of the input shaft 21, avoiding the facing portion 81 facing the opening 44 of the communication oil passage 43 of the pump driving shaft 32 in a state assembled with the pump driving shaft 32, A small diameter surface 82 having an inner diameter smaller than that of the facing portion 81 is formed on the left side and the right side. Therefore, in a state where the input shaft 21 and the pump drive shaft 32 are 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, in a state where the input shaft 21 and the pump drive shaft 32 are assembled, the gap D1 between the small diameter surface 82 and the outer peripheral surface of the pump drive shaft 32 is between the facing portion 81 and the outer peripheral surface of the pump drive shaft 32. Is smaller than the gap D2. 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 externally fitted to the pump drive shaft 32 in a state where the pump drive shaft 32 is assembled to the case 72, the positional deviation in the rotational radial direction of the input shaft 21 is determined. Can be suppressed within a range of a 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 in the rotational radial direction of the input shaft 21 when the pump drive shaft 32 and the input shaft 21 are assembled is suppressed, 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 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

  In addition, the small-diameter surface 82 of the input shaft 21 is formed so as to avoid a portion opposed to the opening 44 of the communication oil passage 43 formed in the pump drive shaft 32 in the rotational radial direction. 36 can discharge oil satisfactorily. As a result, the pipe resistance received by the oil supplied to the inter-shaft oil passage 36 can be reduced, and the responsiveness of the hydraulic pressure supplied from the inter-shaft oil passage 36 to the lockup clutch 14 can be ensured.

<Modification>
As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  For example, in the above-described embodiment, the double shaft structure including the input shaft 21 and the pump drive shaft 32 is taken up, but the present invention can also be applied to other double shaft structures provided in the transmission unit 1. The present invention is not limited to the transmission 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-described configuration within the scope of the matters described in the claims.

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

Claims (1)

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

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