JPS60220262A - Oil pump for transmission - Google Patents

Abstract

PURPOSE:To allow an ample delivery rate during high speed operations and also to improve the increment of the delivery rate relative to the increase in the pump speed by fixedly attaching an impeller to a shaft which is rotatably supported by a bearing 4 outside a casing 2 and by providing a pump cover which covers the outside of the impeller. CONSTITUTION:The structure of a centrifugal pump comprises an impeller 9 which is attached to a shaft that is rotatably supported by a bearing 4 outside a casing 2, and a pump cover 11 which covers the outside of the impeller and has a delivery side pump chamber 13 on the side of the bearing 4. The lubricant is supplied from the delivery side pump chamber 13 through an oil path 15 to lubricated parts inside the casing 2. By such a centrifugal pump structure, the delivery rate does not decrease even during high speed pump operations, and the ample supply of lubricant can forcibly be performed to the inside of the casing 2 during high speed operations.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention provides a speedometer drive gear assembly for an automobile transmission in which the abrasive oil is loosened by a pump driven by the rotation of a shaft. This invention relates to transmission oil pumps that supply oil to transmissions.

(Prior art) Conventionally, in automobile transmissions, lubricating oil is supplied to bearings and oil seals by scraping up lubricating oil as the transmission gear rotates, but depending on the arrangement of the gears, sufficient lubrication may not be possible. Oil supply may not be possible.

Therefore, by installing a worm gear pump in front of the speedometer drive gear (worm) attached to the rear drive shaft of the transmission, it is known to forcibly supply lubricating oil to the knee process 1. ,13N
P-20s Figure 1 shows a conventional oil pump using a 11-speed transmission for a four-wheel drive vehicle as an example. 1 is a drive shaft to which power is transmitted from the engine side; drive shaft 1 The power is transmitted to the rear drive shaft 3 at a reduction ratio according to soft switching of a gear mechanism provided within the casing 2.

The rear drive shaft 3 is rotatably supported on the casing 2 via a ball bearing 4, and a speedometer drive gear 5 is mounted coaxially on the inside of the bearing 4. The meter driven gear 6 is engaged, and a speedometer cable provided to the speedometer driven gear 6 is rotated to display speed.

Here, since the speedometer drive gear 5 and the speedometer driven gear 6 have orthogonal rotation axes, a worm gear mechanism is used, and the speedometer drive gear 5 becomes a worm and the speedometer driven gear 6 becomes a worm wheel.

On the other hand, since an oil pump is installed at 10 m11 of the speedometer drive gear 5, it is only necessary to remember the outer part 11111 of the worm 7a attached to the rear drive shaft 3 and attach the cylindrical cover 7. Lubricating oil passes through the gap between ball bearing 4114 and
It can be pressurized and supplied to meshing parts such as 11 splines, needle bearings, etc.

However, such a conventional screw pump
As shown in Figure 2 D, for oil pumps with 4
When the pump rotation speed N exceeds a certain rotation speed, the discharge amount Q decreases, and at high speed rotation the amount of lubricant used increases.
There was a risk of a shortage of lubricating oil.

(Object of the invention) The present invention was made in view of the above problems, and
To provide an oil pump for a transmission that can obtain a sufficient discharge amount even during high-speed rotation and improve the rate of increase in the discharge amount with respect to an increase in pump rotation, thereby obtaining appropriate pump performance.

(Structure of the Invention) In order to achieve this object, one aspect of the present invention is to provide an impeller mounted on the shaft outside the casing which is rotatably supported by a bearing, and a discharge side mounted on the bearing side provided covering the outside of the impeller. A centrifugal pump structure is constructed with a pump cover forming a pump chamber, and lubricating oil is supplied from the discharge side pump chamber to a lubricating portion inside the casing via an oil passage. Another aspect of the present invention is to provide a centrifugal pump structure in the outer details of the bearing where the speedometer drive gear is installed, and to obtain a screw pump structure using the speedometer drive gear and the centrifugal pump in order to obtain an unprecedentedly high pump performance. The structures are arranged in series in the axial direction.

(Example) FIG. 3 is a cross-sectional explanatory diagram showing one embodiment of the present invention.

First, to explain the configuration, 2 is the casing of the transmission and 6
4) The rear drive shaft 3 is rotatably supported on the casing 2 by a sealed bearing 4. A speedometer drive gear 5 is attached to the stepped shaft portion of the rear drive shaft 3, which is outside the seal bearing 4 (11111 on the right in the figure), and is prevented from rotating by fitting a protrusion 8. A speedometer driven gear 6 meshes with the speedometer from a direction perpendicular to the speedometer. The speedometer drive gear 5 has an impeller 9 fixed to the rear drive shaft 3 with a rotation stopper fitted with a protrusion 10, a pump cover 11 is provided to cover the outside of the impeller 9, and a pump cover 11 is provided to cover the outside of the impeller 9. The cover 11 has a mounting 2 flange 12 integrally formed on the bearing side, and is fixed at a position covering the impeller 9 by being sandwiched between the casing 2 and another casing 2'. Also, the seal bearing 491 of the pump cover 11! A discharge side pump chamber 13 is formed in I, and an opening hole 1 is formed in the rear drive shaft 3 facing the discharge side pump chamber 13 in a direction perpendicular to the axis.
4 is formed. This opening hole 14 communicates with an oil passage 15 formed in the axial direction inside the rear drive shaft 3,
The oil passage 15 communicates with a lubricating oil supply portion (not shown) in the casing 2, for example, a meshing portion such as a spline and other bearings. This impeller 9, pump cover 11
and a discharge side pump chamber 13, forming a centrifugal pump structure.

Next, the operation of the embodiment shown in FIG. 3 will be explained.

When the impeller 9 is rotated by the rear drive shaft 3, a vortex is generated by the impeller 9, and the $4 oil flows from the speedometer drive gear 5 side through the gap between the speedometer drive gear 5 (-11 and the impeller 9) and flows into the discharge side pump chamber. 13, and the sea bream lubricant is supplied to the lubricated portion in the casing 2 through the opening hole]4 of the rear drive shaft 3 and the oil passage 15.

As shown in the graph of FIG. 4, the discharge fiilQ of the centrifugal pump structure consisting of the impeller 9 and the pump cover 11 with respect to the pump rotation speed N is determined by the discharge i! l:Q has a characteristic that increases almost linearly, and it is possible to supply violet sea bream lubricant according to the rotation speed of the impeller 9, that is, the rear drive shaft 3.

FIG. 5 is an explanatory cross-sectional view showing another embodiment of the present invention. This embodiment is characterized in that a screw pump structure using a speedometer drive gear and a centrifugal pump structure shown in FIG. 3 are connected in the axial direction. A speedometer drive gear 5 and an impeller 9 are sequentially coated on the shaft from the outside, and the speedometer drive gear 5 and the impeller 9 are fixed and prevented from rotating by fitting the projections 8 and 10 of the impeller 9F1. The meter drive gear 5 is supported in a floating state with a pair of elastic rings 16 interposed between the meter drive gear 5 and the rear drive shaft 3.

In this way, a pump cover 18 is provided outside the speedometer drive gear 5 and impeller 9 mounted on the rear drive shaft 3, and the pump cover 18 is supported by sandwiching the mounting flange portion 12 between the casings 2 and 2'. , a screw pump structure and a centrifugal pump structure are integrally connected to the speedometer drive gear 5, impeller 9, and pump cover 18 in the axial direction. Cover 18 on the sealed bearing 4 side
A discharge side bong chamber 13 is formed inside the bong, and pressure is applied so that lubricating oil pressurized by a pump can be supplied to the lubricated portion through the discharge side pump chamber 13, the opening hole 14, and the oil passage 15.

Next, to explain the operation of the embodiment shown in FIG. 5, the speedometer drive gear 5 and the impeller 9 are simultaneously rotated by the IL 11 by the rear drive shaft 3, and the speedometer drive gear 5 is brought into a floating state via the elastic ring 14. Since the pump cover 18 is supported by
This provides an alignment effect that maintains a constant clearance between the two, and this clearance is usually about 1.5 microns. The lubricating oil pressurized by the rotation of the speedometer drive gear 5, that is, by the rotation of the screw pump, is pressurized by the centrifugal pump structure by the rotation of the impeller 9, and is transferred to the rear drive through the opening hole 14 opened to the discharge side pump chamber 13. Lubricating oil is forcibly supplied via the oil passage 15 inside the shaft 3.

The oil pump shown in FIG. 5 in which the screw pump structure and the centrifugal pump structure are successively connected has the combined characteristics of a screw pump and a centrifugal pump, that is, as shown in FIG. As the pump speed increases, the discharge cap Q increases non-linearly, and as is clear from the comparison with the characteristic graph of the centrifugal pump shown in Fig. 4, the rate of increase in the discharge amount Q with respect to the increase in the pump rotation speed N is improved. In addition to maintaining a sufficient discharge flow rate even at high speed rotation, the rate of change in the discharge itQ with respect to an increase in the pump rotation speed is increased to improve the rise of the discharge amount with respect to an increase in the pump rotation speed.

(Effects of the Invention) As described above, according to the present invention, the impeller is fixed to the shaft portion on the outside of the casing which is rotatably supported by a bearing, and the pump cover covers the outside of the impeller. By providing a centrifugal pump structure, the centrifugal pump structure does not reduce the discharge cover even at high pump rotation speeds, and forces sufficient lubricating oil supply to the inside of the casing during high-speed operation. I can do it.

In addition, by sequentially arranging the threaded bo/b structure using the speedometer drive gear and the centrifugal pump structure in the axial direction, it is possible to obtain pump characteristics in which the discharge rate increases at a high rate with respect to the pump rotation speed of the centrifugal pump and the threaded pump combined. It is possible to obtain a sufficient supply of lubricating oil commensurate with the gear rotation speed of the transmission.

Furthermore, by fixing the pump diameter bead meter drive gear to the casing and placing it outside the T-shaped bearing, this bearing can be brought closer to the main speed machine side, and as a result, the axial centerness between the bearings is improved. The strength of the gear shift +a mechanism side is also strengthened, and the generation of abnormal noise is reduced.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram partially showing a cross section of a conventional transmission equipped with an oil pump, Fig. 2 is a characteristic graph of the screw pump shown in Fig. 1, and Fig. 3 shows an embodiment of the present invention. 4 is a characteristic graph of the centrifugal 4ζ(11) pump structure shown in FIG. 3, FIG. 5 is a sectional view showing another embodiment of the present invention, and FIG. It is a characteristic graph diagram by structure. 1... Drive shaft 2... Casing 3...
・Rear drive shaft 4...Seal bearing 5・
...Speedometer drive gear 6...Speedometer driven gear 8.10...Protrusion 9...Impeller 11, 18...Pump cover 12...Mounting flange] 3...Discharge side pump Chamber 14...Opening hole 15
...Oil passage 16...Elastic ring patent applicant Takashi Iron Works Co., Ltd. Susumu Takeuchi (12), patent attorney for Nissan Motor Co., Ltd. Fig. 2 Bonde 1 rotation number N Fig. 3

Claims (3)

[Claims] (1) A centrifugal pump consisting of an impeller mounted on the shaft outside the casing that is freely supported by a bearing, and a pump cover that covers the outside of the impeller and has a discharge pump chamber on the bearing side. An oil pump for a transmission, characterized in that the oil pump for a transmission is provided with a structure in which lubricating oil is supplied from the discharge side pump chamber to a lubricating part inside the casing via an oil passage. (2) A speedometer drive gear and an impeller are attached to the outer shaft of the casing, which is rotatably supported by a bearing, and the speedometer drive gear and impeller are covered and discharged to the bearing side. By providing a pump cover defining a pump chamber, the screw pump structure and the centrifugal pump structure are connected in the axial direction, and lubricating oil is supplied from the discharge pump chamber to the lubricating part via the oil passage. Transmission oil pump with % ridge. (3) The oil pump for a transmission as described in Items 11 to 2 of the patent application, characterized in that the oil passage is formed inside the shaft portion ij.