JP4698177B2 - Automatic transmission oil pump - Google Patents

Description

  The present invention relates to an oil pump for an automatic transmission, and more particularly to a technology for reducing the size and weight of an oil pump body.

  Automatic transmissions mounted on vehicles include automatic transmission hydraulic fluid (ATF: automatic transmission) for fluid transmission and lockup of torque converters, engagement and disengagement of clutches and brakes of transmissions, and lubrication and cooling of various parts of the mechanism. A fluid oil pump is provided as means for supplying fluid (referred to as oil in this specification).

  The oil pump of the automatic transmission has a structure in which the pump gear is arranged in the pump case, and the deformation of the pump case increases the leakage. Therefore, the leakage is reduced by using iron material for the pump case and increasing the rigidity. It was common to configure less.

  On the other hand, recently, the demand for weight reduction has become stronger, and the use of aluminum pump cases has been promoted. Specifically, the pump case includes a pump body and a pump cover. The gear chamber is on the pump body side. For this reason, considering the deformation of the pump body, the body side will naturally be iron, and the pump cover side will be aluminum die cast, but with the conventional method, the iron pump body side takes some size. This was a factor that hindered weight reduction.

The reason why the pump body is prevented from being reduced as described above is related to the transmission case. An oil pump as a hydraulic power source of an automatic transmission is disposed between a torque converter and a transmission, and is used as a partition wall that separates the two, and is also used as a front support that directly or indirectly supports both shafts. The Therefore, the pump cover connects the valve body arranged at the lower part of the transmission and the engaging element arranged at the front side of the transmission, that is, the hydraulic servo of the clutch and brake and the torque converter arranged in front of the oil pump. Many oil passages are arranged inside. These oil passages are mainly oil passages that extend between the outer peripheral side and the inner peripheral side of the pump cover, but the outer periphery of the pump body has a large diameter that matches the inner diameter of the transmission case. On the other hand, since the inner circumference is a small diameter that matches the outer diameter of the stator shaft, the outer end side of the oil passage can be arranged with a margin in the lower half circumference part of the pump cover, whereas the inner end side Are arranged around the entire circumference of the pump cover. Due to the positional relationship between the outer end side and the inner end side, a part of the oil passage is an arcuate oil passage that bends along the peripheral surface of the pump cover in order to prevent the oil passage from intersecting in the middle. Such arc-shaped oil passages are virtually impossible to machine into the pump cover, and are thus formed on the mating surfaces of the pump cover and the pump body (see Patent Document 1).
JP 11-315790 A

  FIG. 4 shows an example of the oil passage arrangement as described above. In this example, the oil passage b opened obliquely downward to the right on the outer periphery of the pump cover a bends in an arc shape as an oil groove on the mating surface c and extends to a position on the opposite side of about 180 °. It can be seen that it is communicated with the circumferential axial oil hole e. FIG. 5 shows a cross section of an oil pump employing the above-described oil passage arrangement. As shown in the drawing, the arcuate oil groove b on the mating surface is against the pump body outer diameter (outer diameter up to the lower bolting position of the two fastening bolts in the figure) that is necessary for the arrangement of the pump gear g. The oil groove b passes through the outside. This is the reason why the pump body is hindered from being reduced in size, mainly the outer diameter D of the pump body.

  For these reasons, in order to achieve further miniaturization of the pump body, it is considered that the oil passage formed by the groove of the mating surface may be configured as an oil hole in the pump cover. However, the pump cover made of aluminum die-casting is high-pressure casting, so there are many casting holes, and when oil holes are formed by machining in the pump cover, it is between the parts where adjacent oil passages intersect. In the past, there has been no formation of cross oil holes by machining in the pump cover.

  On the other hand, when the pump cover is formed by low pressure casting, the number of casting holes is reduced. Therefore, if the pump cover is formed by this low pressure casting, it is considered that the problem of leakage can be avoided even by forming oil holes by machining in the pump cover.

  The present invention has been devised in view of the circumstances as described above, and eliminates a supply oil passage and a lubricating oil passage that are caused to circulate in the circumferential direction at the mating surface of the pump body and the pump cover, thereby providing a pump body or a pump. The main object is to reduce the weight of the entire oil pump by reducing the outer shape of the cover, thereby reducing the pump body or pump cover occupying the entire oil pump.

To achieve the above object, the present invention will become from the pump body (12) housing the pump gear (11), mating surface on said pump body (12a, 13a) and pump cover (13) for coupling with the previous SL the port Npukaba comprises at least three lubricating oil passage for supplying lubricating oil (L8) to the supply oil passage for supplying the engagement pressure (L5 to L7, L9) and a predetermined lubricant portion for controlling the predetermined engaging elements in the oil pump (1) of the automatic transmission, the supply oil passage and said lubricating oil passage is formed within the front Symbol pump cover, at least one of said supply oil passage and said lubricating oil passage, the pump straight oil passage extending generally radially between the outer peripheral side and inner peripheral side of the cover with are plurality before Kipo Npukaba as (L6, L7), other less of the oil supply passage or the lubricating oil passage When One of the linear oil passages intersects the non-communication state outside the mating surface, and the oil passage (L1) for sucking oil into the pump gear and the oil discharge from the pump gear on the mating surface. The basic feature is that only the oil passage (L2) is formed.
Further, at least one of the supply oil passage and the lubricating oil passage is configured to be a bent oil passage (L8).
The pump cover in each configuration is preferably made of a low-pressure cast aluminum material.
More specifically, the oil pump constitutes a partition that separates the transmission (2) housing portion and the torque converter (3) housing portion of the automatic transmission.
The pump cover may have a diameter that covers an opening of the transmission housing portion of the automatic transmission, and the pump body may have a smaller diameter than the pump cover.
The bent oil passage is configured by communicating an oil passage extending in a tangential direction with respect to the outer periphery of the mating surface and an oil passage extending in a generally radial direction from the outer periphery of the pump cover to the inner periphery.

In the configuration of the present invention, by eliminating the supply oil passage and the lubricating oil passage formed by the grooves formed on the mating surfaces of the pump body and the pump cover, the area of the mating surface is reduced to the extent that those oil passages can be eliminated. The pump body or the pump cover can be reduced in size. This reduces the weight ratio of the pump cover or pump body to the entire pump case, thereby reducing the weight of the entire pump case.
In particular, in the configuration crossed to a non-communicated state straight oil passage and the bent oil passage constituting the supply oil passage and the lubricating oil passage outside than the mating surface of the pump body and pump cover, and the outer position against the Ponpukaba over the inner peripheral side position is locatable without increasing the thickness of the combined surface definitive bending oil passage located on the opposite side of the linear oil passage to Ponpukaba over.
Further, an oil passage extending tangentially with respect to the outer peripheral mating surface bent oil passage, in the case of the configuration comprising generally communicates with an oil passage extending in a radial direction from the outer circumference to the inner circumference of Ponpukaba over, bending oil passage machinery It can be formed by a combination of processable straight oil passages.
In addition, when the pump cover is made of aluminum low-pressure cast material, the problem of leakage can also be avoided by forming oil holes in the pump cover by machining. If the diameter covers the opening of the housing and the pump body is smaller than the pump cover, the pump body, which is usually made of iron, is miniaturized, so the weight of the pump case as a whole is further reduced. Made prominent.

  The oil pump according to the present invention also serves as a partition that separates the transmission housing portion and the torque converter housing portion of the automatic transmission and a support that supports the shaft of the transmission, and in particular, the pump cover is housed in the transmission of the automatic transmission. It is effective to apply a diameter that covers the opening of the part and a smaller diameter than the pump cover. Further, it is effective that the bent oil passage formed in the pump cover is configured as an oil passage having one end positioned downward on the outer peripheral side of the pump cover and the other end positioned upward on the inner peripheral side. By doing so, the oil passages in the pump cover where the oil passages for clutches and brakes, which are increasing in number due to the recent increase in the number of stages, are also complicated by combining them with the support, are combined with the pump body and the pump cover. It is possible to arrange them neatly without providing an oil groove on the surface, whereby the pump body can be miniaturized.

  FIG. 1 shows a front axial section of an automatic transmission provided with an oil pump according to a first embodiment of the present invention. As shown in FIG. 1, the oil pump 1 is disposed between the transmission 2 and the torque converter 3 including the lock-up clutch 32 so as to function as a partition wall that separates them and also as a front support. . The oil pump 1 includes a pump gear 11, a pump body 12 that accommodates the pump gear 11, and a pump cover 13 that closes an end surface of the pump body 12. The pump cover 13 is formed with a mating surface 13a with the pump body 12 at a position retracted from the front surface of the cover 13 on the front surface (left side in the figure) and an O-ring between the cylindrical peripheral surface surrounding the mating surface 13a The pump body 12 is fitted in a peripheral surface sealed state via a sealing member such as the like, and is fixed and integrated with the pump cover 13 by bolting.

  As shown in FIG. 2 with the pump body removed and seen from the front side of the transmission, the pump cover 13 is made of a low-pressure cast of aluminum material, with the transmission input shaft 21 shown in FIG. A hollow stator shaft 22 to be fitted and a shaft insertion hole 13b for inserting a triple shaft of an impeller hub shaft 31 comprising a hollow shaft fitted to the outer periphery of the stator shaft 22 are provided. It is configured in a generally circular disk shape that fits. The pump cover 13 is roughly configured as an oil groove that opens into the mating surface 13a with the pump body 12 for sucking oil into the pump gear (see FIG. 1) 11 and discharging oil from the pump gear 11. And an oil passage configured as an oil hole in the pump cover that opens to the peripheral surface of the shaft insertion hole 13b, and also communicates with the valve body 29. An oil passage composed of an oil hole in the pump cover that leads to an axial oil hole that opens into the mating surface 13a around the shaft insertion hole 13b (these oil holes lead to the oil passage in the shaft of the input shaft 21); Is formed. Hereinafter, the configuration of these oil passages will be described.

  First, the suction oil passage L1 configured as an oil groove that opens in the mating surface 13a opens to the back side (the side facing the transmission) on the lower left side of the pump cover 13, and the shaft insertion hole 13b in the mating surface 13a. It is configured as an oil groove extending in an arc along the outer periphery. In addition, the discharge oil passage L2 is configured as a groove that opens to the lower right rear surface of the pump cover 13 and opens to the front surface side in the mating surface 13a.

Next, one of the oil passages configured as an oil hole in the pump cover that opens to the peripheral surface of the shaft insertion hole 13b is a torque converter-in oil passage L3 for supplying oil to the torque converter (see FIG. 1). The oil passage L3 is configured as a linear oil hole in the cover by drilling that extends substantially horizontally from the left outer periphery of the pump cover 13 to the peripheral surface of the shaft insertion hole 13b. The other oil passage is a torque converter out oil passage L4 for discharging oil from the torque converter, and this oil passage L4 extends from the position of the shaft insertion hole 13b from the position of approximately 45 degrees on the lower right side of the outer periphery of the pump cover 13. Each of them is bent and extended halfway to the peripheral surface, and is configured as a drilled linear oil hole in the cover. Details of the oil passage L4 will be described later.

In this example, there are provided five oil passages including oil holes in the pump cover that communicate with the five oil holes in the axial direction that open in the mating surface 13a around the shaft insertion hole 13b. The first oil passage L5 is a supply oil passage for a C-1 clutch (not shown) as an engagement element of the transmission, and this oil passage L5 is located at a position approximately 45 degrees on the lower right side of the pump cover 13. Thus, it is constituted by a straight and generally radial drill hole extending from the outer periphery to the vicinity of the outer periphery of the shaft insertion hole 13b and connected to the axial oil hole L5 ′. The second oil passage L6 is also a supply oil passage for a C-2 clutch (see FIG. 1) as an engaging element of the transmission, and this oil passage L6 is substantially horizontal from the outer right side of the pump cover 13. And a straight and generally radial drill hole connected to the axial oil passage L6 ′. The third oil passage L7 is a supply oil passage for lockup ON for the lock-up clutch 32 as engagement elements for locking up the torque converter (see Fig. 1) 3, the oil passage L7, the pump It is composed of straight and generally radial drill holes extending from the right side of the outer periphery of the cover 13 to the vicinity of the outer periphery of the shaft insertion hole 13b substantially in parallel with the oil passage L6 for the C-2 clutch and connected to the axial oil passage L7 '. Yes. The fourth oil passage L8 is a lubricating oil passage, the oil passage L8 is drill each straight extending bent on the way from the outer left position slightly below the pump cover 13 to the axial oil bore L8 " This oil passage L8 will be described later in detail, and a fifth oil passage L9 is used for a C-3 clutch (see FIG. 1) as an engagement element of the transmission. This oil passage L9 is a linear and generally radial drill hole extending linearly from a position of approximately 45 degrees on the lower left side of the outer periphery of the pump cover 13 and connected to the axial oil passage L9 ′. Has been.

  In FIG. 2, an oil hole L10 in the cover at a position of approximately 45 degrees on the lower left side of the outer periphery of the pump cover 13 that extends short outside the mating surface 13a is a supply oil passage for the B-1 brake. As can be seen with reference to FIG. 1, this oil passage L10 is an oil passage that leads to an oil chamber of a hydraulic servo that is exceptionally configured with the back side of the pump cover 13 as a cylinder.

  The configuration according to the features of the present invention is applied to the oil passage L4 for torque converter out and the lubricating oil passage L8. The oil path L4 for the torque converter out extends from the position approximately 45 degrees at the upper right of the outer periphery of the pump cover 13 to a position in contact with the shaft insertion hole 13b in a generally radial direction, and is a straight oil hole L4 ′ connected to the shaft insertion hole 13b. A bent oil passage is formed by a linear oil hole that extends linearly in a tangential direction to the outer periphery of the mating surface 13a from the outer periphery of approximately 45 degrees on the lower right side of the pump cover 13 and communicates with the linear oil hole. is doing. Note that the outer peripheral side end of the linear oil hole L4 'extending in the radial direction is closed.

  The lubricating oil passage L8 extends from a position of approximately 45 degrees on the upper left of the outer periphery of the pump cover 13 to the vicinity of the outer periphery of the shaft insertion hole 13B, and extends in a linear substantially radial direction leading to the axial oil passage L8 ″. A bent oil passage is formed by a straight oil hole extending linearly in a tangential direction from the outer periphery slightly below the left side of the pump cover 13 to the outer periphery of the mating surface 13b and communicating with the linear oil passage extending in the radial direction. Also in this case, the outer peripheral side end of the linear oil hole L8 ′ extending in the radial direction is closed.

  Of these two oil passages, the oil passage L4 for torque converter out intersects the supply oil passage L7 for lock-up and the supply oil passage L6 for the C-2 clutch outside the mating surface 13a. The lubricating oil path L8 intersects the torque converter-in oil path L3 outside the mating surface 13a. With this arrangement, the torque converter-out oil passage L4 and the lubricating oil passage L8 intersect with other linear oil passages while avoiding the mating surface of the pump cover 13 with respect to the pump body. These intersections do not become an element that increases the thickness of the mating surface 13a portion of the pump cover 13.

  Thus, according to this embodiment, a total of seven oil passages that open to the outer periphery of the lower half of the pump cover excluding the suction and discharge oil passages L1 and L2 are arranged around the shaft insertion hole 13b on the inner peripheral side of the pump cover 13. Can be distributed.

  According to this configuration, the outer diameter of the pump body 12, that is, the outer diameter D of the mating surfaces 12 a and 13 a is set to a minimum for oil suction and discharge by the pump gear 11, as shown in FIG. The outer diameter can be reduced to a necessary limit, and the weight can be reduced by reducing the shape of the iron pump body 12 accordingly. On the other hand, the aluminum pump cover 13 has a shape only in the radial direction that fills the reduced portion of the pump body 12, that is, as compared with FIG. 5 showing the conventional example. However, the weight of the oil pump 1 can be reduced as a whole due to the difference in weight between the two materials constituting them.

  Although the present invention has been described in detail based on one embodiment, the present invention is not limited to this embodiment, and can be implemented in various forms within the scope of the matters described in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front axial sectional view of an automatic transmission provided with an oil pump according to a first embodiment of the present invention. It is a front view which removes the pump body of the oil pump and shows a pump cover. It is a fragmentary sectional view of the oil pump. It is a front view which removes the pump body of the oil pump of the conventional automatic transmission, and shows a pump cover. It is a fragmentary sectional view of the conventional oil pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Oil pump 2 Transmission 3 Torque converter 11 Pump gear 12 Pump body 13 Pump cover 12a, 13a Mating surface L1 Oil path for suction L2 Oil path for discharge L4 Bending oil path L5 Supply oil path L6, L7 Supply oil path ( Straight oil passage)
L8 Lubricating oil passage (bending oil passage)
L9 Supply oil passage

Claims (6)

A pump gear (11) pump body (12) for accommodating a result from the mating surface in the pump body (12a, 13a) the pump cover (13) that binds, before Kipo Npukaba, controls the predetermined engaging elements In an oil pump (1) of an automatic transmission comprising at least three supply oil passages (L5 to L7, L9) for supplying engagement oil pressure and at least three lubricating oil passages (L8) for supplying lubricating oil to a predetermined lubricating portion,
It said supply oil passage and said lubricating oil passage is formed within the front Symbol pump cover,
Wherein at least one of the supply oil passage and said lubricating oil passage is in the straight oil passage extending generally radially between the outer peripheral side and inner peripheral side of the pump cover (L6, L7) as before Kipo Npukaba There are several, and
The at least one other of the supply oil passage or the lubricating oil passage and the linear oil passage intersect with each other in a non-communication state outside the mating surface,
An oil pump for an automatic transmission, wherein only the oil passage (L1) for sucking oil into the pump gear and the oil passage (L2) for discharging oil from the pump gear are formed on the mating surfaces. The oil pump of the automatic transmission according to claim 1, wherein at least one of the supply oil path or the lubricating oil path is a bent oil path (L8).   The oil pump for an automatic transmission according to claim 1, wherein the pump cover is made of an aluminum low-pressure cast material.   The oil pump for an automatic transmission according to any one of claims 1 to 3, wherein the oil pump constitutes a partition wall that separates a transmission (2) accommodation portion and a torque converter (3) accommodation portion of the automatic transmission. .   The said pump cover is made into the diameter which covers the opening part of the transmission accommodating part of the said automatic transmission, The said pump body was made into the diameter smaller than a pump cover, The any one of Claims 1-4 characterized by the above-mentioned. The automatic transmission oil pump described.   3. The automatic transmission according to claim 2, wherein the bent oil passage is formed by communicating an oil passage extending in a tangential direction with respect to the outer periphery of the mating surface and an oil passage extending substantially radially from the outer periphery to the inner periphery of the pump cover. Oil pump.

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