JP2003222153A - Motive power transmission device and motive power transmission method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an effective technique for preventing tooth hammer in a spline fitting portion in a motive power transmission device containing the spline fitting portion. <P>SOLUTION: A gear 14 driven by an engine and a drive shaft 12 of an oil pump are fitted by means of the spline. In the spline fitting portion, spatial portions 15 are formed respectively between hole side teeth portions 14c and shaft side teeth portions 12b and synthetic-resin fillers 16 are intervened between each of the spatial portions 15 to eliminate peripheral directional gaps between the hole side teeth portions 14c and the shaft side teeth portions 12b by intervening synthetic resinous fillers 16 between each of spatial portions 15. Thereby, there is provided a structure in which circumferential relative displacement between the gear 14 and the drive shaft 12 is restricted. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device and a power transmission method in which power transmission between a first rotating body and a second rotating body is performed via a spline fitting portion.

[0002]

2. Description of the Related Art This type of power transmission device is used as a power transmission device for transmitting the power of an engine to an oil pump used for lubricating the engine, for example.
As shown in FIGS. 7 and 8, an oil pump 101 is attached to a cylinder block 100 of the engine,
The drive shaft 102 of the oil pump 101 is
Gear 103 driven by a crank gear (not shown)
It is fitted with a spline. 8 is a sectional view showing the spline fitting portion. In FIG. 7, 104 indicates a part of the case of the oil pump 101, and 105 indicates a part of the pump rotor (drive rotor).

[0003]

During the operation of the oil pump 101, the pressure of the oil is constantly fluctuated due to the intermittent pumping (discharging) operation of the oil by the pump rotor. Therefore, when a power transmission device of the type that transmits power through a spline fitting portion is used as the power transmission device of the oil pump, the hole side tooth portion 103 of the gear 103 is accompanied by the pressure fluctuation.
Teeth are generated due to backlash (circumferential gap) existing between a and the shaft side tooth portion 102a of the drive shaft 102. In general, both the gear 103 and the drive shaft 102 are made of metal, so that a tapping sound is generated by hammering metal teeth. Note that in spline fitting that is premised on the attachment and detachment of the gear 103 and the drive shaft 102, the occurrence of backlash cannot be avoided due to the fitting tolerance.

The present invention has been made in view of the conventional problems described above, and an object thereof is to prevent gear rattling in a spline fitting portion in a power transmission device having a spline fitting portion. To provide effective technology above.

[0005]

In order to achieve the above object, a power transmission device according to the present invention has a structure as described in each of the claims. In the power transmission device according to the first aspect, the power transmission between the first rotating body and the second rotating body is performed via the spline fitting portion.
The spline hole formed in the first rotating body and the second
At the spline fitting portion formed on the rotating body with the spline shaft, a padding is interposed in at least one space formed between the hole side tooth portion and the shaft side tooth portion, and the padding causes the first rotation. The relative displacement of the body and the second rotating body in the circumferential direction is restricted. Therefore, according to the invention described in claim 1, the backlash between the hole side tooth portion and the shaft side tooth portion in the spline fitting portion is substantially absorbed,
The tooth striking between the hole side tooth portion and the shaft side tooth portion is prevented. Therefore, even when the first rotating body and the second rotating body are made of metal, it is possible to reduce or prevent noise due to tooth hammering between metal teeth.

In this case, as the filling material interposed in the space between the hole-side tooth portion and the shaft-side tooth portion, a material having a minimum elasticity required only during the assembling is preferable. It is preferably resin or synthetic rubber (corresponding to claims 2 and 3). In the case of synthetic resin,
For example, urethane resin and nylon resin are preferable, and acrylonitrile butadiene rubber (N
BR) is preferred. Further, in a power transmission device (corresponding to claim 6) in which the first rotating body is a gear driven by the engine and the second rotating body is a drive shaft of an oil pump (corresponding to claim 6), the padding is made resistant in consideration of a use environment. It is preferable to have properties such as abrasion resistance, oil resistance, and heat resistance.

According to another aspect of the power transmission device of the present invention, the padding has a rod-shaped portion interposed between the hole side tooth side surface and the shaft side tooth side surface. According to this, in the spline fitting portion, for example, the rod-shaped portion can be easily assembled by inserting (press-fitting) the space portion formed between the hole-side tooth portion side surface and the shaft-side tooth portion side surface. . In this case, if the insertion tip of the rod-shaped portion is formed into a tapered surface, it is effective in improving the insertability.

In the power transmission device according to the fifth aspect of the present invention, the filling has a plurality of rod-shaped portions, and the rod-shaped portions are connected to each other by the connecting portions extending in the circumferential direction. According to this, since the plurality of rod-shaped portions are connected to each other, it is convenient for assembling between the shaft-side tooth portion and the hole-side tooth portion.

According to a seventh aspect of the power transmission method, in the power transmission device, the power transmission between the first rotating body and the second rotating body is performed via the spline fitting portion.
It is possible to rationally prevent toothing between the hole side tooth portion and the shaft side tooth portion due to backlash of the spline fitting portion during power transmission.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. The present embodiment is applied to a power transmission device that transmits the power of a vehicle engine to an oil pump used to lubricate the engine. 1 is a vertical cross-sectional view of a power transmission device, FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, FIG. 3 is an enlarged view of part B of FIG. 2, and FIG. 4 is a padding interposed in a spline fitting portion. FIG. As shown in FIG. 1, a trochoidal type oil pump 10 as a driven body used for lubricating the engine is mounted near the engine which is a drive source.
Pump case 11 (partially shown in the figure)
It is fixed to the cylinder block 1 of the engine by fastening means such as bolts. A gear 14 driven by a crank gear (not shown) is rotatably attached to the cylinder block 1, and a drive shaft 12 of the oil pump 10 is spline-fitted to the gear 14. The gear 14 and the drive shaft 12 are both made of metal. A pump rotor 13 (a drive rotor is simply shown in the drawing) is housed in the pump case 11, and the pump rotor 13 is driven by the drive shaft 12. The gear 14 corresponds to the first rotating body in the present invention, and the drive shaft 12 corresponds to the second rotating body in the present invention.

Next, the power transmission structure of the spline fitting portion, which is a feature of the present embodiment, will be described with reference to FIGS. In the spline fitting portion, a spline hole 14b is formed in the boss portion 14a of the gear 14, and a spline shaft portion 12a is formed on the outer peripheral surface of the drive shaft 12. The hole side tooth portion 14c formed in the spline hole 14b and the shaft side tooth portion 12b formed in the spline shaft portion 12a are provided at 90 ° intervals.
A space 15 having a predetermined size is formed between the side surface of the hole-side tooth portion 14c and the corresponding side surface of the shaft-side tooth portion 12b. Then, a filling 16 is interposed (filled) in the space 15 over the entire length of the spline fitting portion, and power is transmitted from the hole side tooth 14c to the shaft side tooth 12b through the filling 16. There is.

The padding 16 is arranged in a space 15 between the teeth and has a plurality of rod-shaped portions 16a extending in the axial direction and having a substantially rectangular cross section, and the rod-shaped portions 16a are arranged at appropriate intervals in the axial direction. And a plurality of thin-walled connecting pieces 16b (corresponding to the connecting portions in the present invention) that connect the rod-shaped portions 16a to each other, and are formed in a cylindrical shape with slits as a whole. The connecting pieces 16b are provided on the inner peripheral side that covers the tooth tips of the hole-side tooth portions 14c and the outer peripheral side that covers the tooth tips of the shaft-side tooth portions 12b.

The rod-shaped portion 16a preferably has a certain degree of elasticity in order to intervene in close contact with the side surface of the hole-side tooth portion 14c and the side surface of the shaft-side tooth portion 12b without a gap, while the space portion on the other hand. In the state after the elastic deformation interposed in 15, it is preferable that the hardness is set so as not to be elastically deformed by the load during the operation of the oil pump 10. That is, the rod-shaped portion 16a is a minimum necessary for interposing between the tooth portions 14c and 12b in consideration of the tolerance between the hole-side tooth portion 14c and the shaft-side tooth portion 12b of the spline fitting portion to be clearance fit. It is set to have elasticity. Thus, the rod-shaped portion 16a of the filling 16 interposed in the space 15
Thus, the relative displacement of the drive shaft 12 and the gear 14 in the circumferential direction is restricted.

The padding 16 preferably has abrasion resistance, oil resistance, heat resistance, etc., and is made of, for example, a synthetic resin such as urethane resin or nylon resin or a synthetic material such as acrylonitrile butadiene rubber (NBR). It is made of rubber.

The power transmission device according to this embodiment is configured as described above. Therefore, when the engine is driven and the gear 14 is rotated via the crank gear, the drive shaft 12 is rotated via the spline fitting portion to operate the oil pump 10. Power transmission from the hole side tooth portion 14c to the shaft side tooth portion 12b in the spline fitting portion at this time is performed via the padding 16. By the way, when the oil pump 10 is in operation, the pumping (discharging) operation of oil by the pump rotor is intermittently performed. Therefore, the pressure of the oil pump 10 constantly fluctuates. Even if a relative rotation difference (circumferential displacement) occurs between the drive shaft 12 and the gear 14 based on this pressure fluctuation, the padding 16 is provided between the hole side tooth portion 14c and the shaft side tooth portion 12b. The padding 16 restricts the circumferential displacement.

As described above, according to the present embodiment, the padding 16 is interposed between the hole side tooth portion 14c and the shaft side tooth portion 12b to substantially eliminate the backlash of the spline fitting portion. Drive shaft 12 due to (absorbed) configuration
The circumferential displacement between the gear 14 and the gear 14,
The power is smoothly transmitted from the drive shaft 12 to the drive shaft 12, and tooth flapping due to backlash is prevented. As a result, noise caused by hammering between the metal teeth is prevented. In addition, in the present embodiment, all the tooth portions 12
Since the padding 16 is interposed between b and 14c, it is also effective in eliminating the contact between the metal teeth and suppressing the generation of abnormal noise due to the direct contact between the metal teeth.

The assembling of the filling 16 to the spline fitting portion is performed, for example, by inserting the filling 16 into the spline shaft portion 12a or the spline hole 14b in advance while inserting the spline shaft portion 12a into the spline hole 14b. After fitting the portion 12a into the spline hole 14b, the filling 16 is inserted between the spline shaft portion 12a and the spline hole 14b. In this case, in the present embodiment, the padding 16 is formed of an integral body in which the rod-shaped portions 16a are connected to each other by the connecting pieces 16b, which is convenient when performing the above-mentioned assembly work. In addition, the spline shaft portion 12a is connected to the spline hole 14
After fitting to b, the spline shaft portion 12a and the spline hole 1
In the case of assembling the padding 16 with 4b, the tip of the rod-shaped portion 16a is formed into a tapered surface. Thereby, insertability can be improved.

Next, another embodiment of the present invention will be described with reference to FIGS. In the above-described embodiment, the space portion 1 is provided between the shaft side tooth portion 12b and the hole side tooth portion 14c.
5 is set and the padding 16 is interposed in each space 15, but in another embodiment shown in FIGS. 5 and 6, this is partially changed. As shown in the figure, in the spline fitting portion between the drive shaft 12 and the gear 14, the space portions 15 are formed at two points (or one location) which are point-symmetrical positions in the circumferential direction, and the space 16 is filled with the padding 16. Intervening. The material of the padding 16 is similar to that of the above-described embodiment.

The padding 16 is interposed in the space 15 between the shaft side tooth portion 12b and the hole side tooth portion 14c (the transmitting direction is indicated by an arrow). With the stuffing 16 interposed, the stuffing 1
In the spline fitting portion where 6 is not interposed, as shown in the drawing, the back surface 14d of the hole side tooth portion 14c in the rotation direction (traveling direction) contacts the front surface 12c of the shaft side tooth portion 12b.
As a result, the relative displacement of the drive shaft 12 and the gear 14 in the circumferential direction is restricted. On the other hand, a clearance C (backlash) corresponding to the fitting tolerance between the front surface 14e of the hole side tooth portion 14c and the back surface 12d of the shaft side tooth portion 12b.
However, the gap C is substantially absorbed by the above-described mode of restricting the relative displacement of the drive shaft 12 and the gear 14 in the circumferential direction due to the interposition of the padding 16. As described above, according to the other embodiments as well, it is possible to prevent the metal teeth of the shaft-side tooth portion 12b and the hole-side tooth portion 14c from hitting each other due to backlash, and suppress the generation of noise.

The present invention is not limited to the illustrated embodiments, but can be modified as appropriate without departing from the spirit of the invention. For example, in the above-described embodiment, the power transmission device that transmits power to the oil pump 10 for engine lubrication that is driven by the power of the engine is applied, but the driven body that is the power transmission target is the oil pump 10. It is not limited. Also, the oil pump 10
When the driven body is a driven body, it may be of a type different from the trochoid type. In addition, when applied as a power transmission device of the oil pump 10 for engine lubrication, the padding 16 has a minimum elasticity required for assembling to the spline fitting portion, as well as heat resistance due to its use environment. ,Oil resistance,
A synthetic resin or synthetic rubber having abrasion resistance and the like is preferable, but other than urethane resin, nylon resin, or acrylonitrile butadiene rubber (NBR) is used as long as it has the above-mentioned properties. It doesn't matter. The padding 16 may be interposed in at least one space between the shaft-side tooth portion 12b and the hole-side tooth portion 14c of the spline fitting portion. In addition, the padding 16 may intervene in a form in which the space between the shaft side tooth portion 12b and the hole side tooth portion 14c is filled with coating. Furthermore, in the embodiment, the rod-shaped portion 16 is provided over the entire length of the spline fitting portion.
Although the structure in which a is interposed is used, the structure may be changed to a structure in which the padding 16 is formed in a block shape and interposed in a part of the axial length of the spline fitting portion. In addition, the plurality of rod-shaped portions 16
In the case where a constitutes the cylindrical filling 16 connected to each other, in the above-described embodiment, the plurality of rod-shaped portions 1
6a is connected by the connecting pieces 16b arranged at appropriate intervals in the longitudinal direction, but it may be connected by a thin connecting piece over the entire length in the longitudinal direction.

[0021]

As described in detail above, according to the present invention,
In the power transmission device having the spline fitting portion, it is possible to provide an effective technique for preventing gear rattling in the spline fitting portion.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a power transmission device for an oil pump according to an embodiment.

FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, showing an interposing structure of a padding with respect to a spline fitting portion.

FIG. 3 is an enlarged view of part B in FIG.

FIG. 4 is a development view of a padding.

FIG. 5 is a cross-sectional view showing an intervening structure of a padding according to another embodiment.

FIG. 6 is an enlarged view of a C portion of FIG.

FIG. 7 is a vertical sectional view showing a conventional power transmission device for an oil pump.

8 is a cross-sectional view taken along the line DD of FIG.

[Explanation of symbols] 10 oil pump 12 Drive shaft (second rotating body) 12a Spline shaft 12b Shaft side tooth 14 gears (first rotating body) 14a Boss 14b spline hole 14c Hole side tooth 15 Space section 16 stuffing 16a bar part 16b connection piece

Claims (7)

[Claims] 1. A power transmission device in which power transmission between a first rotary body and a second rotary body is performed via a spline fitting portion, wherein a spline hole formed in the first rotary body and Second
In the spline fitting portion formed on the rotating body with the spline shaft, a filling is interposed in at least one space formed between the hole side tooth portion and the shaft side tooth portion, and by the filling, the first A power transmission device, characterized in that a relative displacement in a circumferential direction between a rotating body and a second rotating body is regulated. 2. The power transmission device according to claim 1, wherein the filling is a synthetic resin. 3. The power transmission device according to claim 1, wherein the filling is synthetic rubber. 4. The power transmission device according to claim 1, wherein the filling has a rod-shaped portion interposed between the hole side tooth side surface and the shaft side tooth side surface. A power transmission device characterized by the above. 5. The power transmission device according to claim 4, wherein the padding has a plurality of rod-shaped portions, and the rod-shaped portions are connected to each other by a connecting portion extending in the circumferential direction. Power transmission device characterized by. 6. The power transmission device according to claim 1, wherein the first rotating body is a gear driven by an engine, and the second rotating body is a drive shaft of an oil pump. A power transmission device characterized in that there is. 7. A power transmission method for a power transmission device, wherein power transmission between a first rotary body and a second rotary body is performed via a spline fitting portion, the power transmitting method being formed on the first rotary body. Spline hole and the second
In the spline fitting portion formed on the rotating body with the spline shaft, a filling is interposed in at least one space formed between the hole side tooth portion and the shaft side tooth portion, and by the filling, the first A power transmission method for a power transmission device, comprising: transmitting power between a first rotating body and a second rotating body in a state in which a relative displacement in a circumferential direction between the rotating body and the second rotating body is restricted.