JPH08296717A - Gear structure - Google Patents

Abstract

PURPOSE: To prevent the occurrence of faulty tooth bearing, wear, and noise of a gear by eliminating the disturbance of attitude of the gear caused by the driving force applied to the gear even in a canti-lever support structure. CONSTITUTION: A drive gear 3 is pivoted rotatably on the side part of a cylinder block 1. Also a rotating shaft part 5 is formed on the drive gear 3. A through- hole 7 is formed in the rotating shaft part 5, and a spiral groove 8 is formed in the through-hole 7. Then the connecting part 13a of a trochoid pump 12 is inserted into the through-hole 7. A helical spline 15 is formed in the connecting part 13a, and engaged with the spiral groove 8. When the drive gear 3 is driven by the start of an engine, the trochoid pump 12 is rotated following the engagement of the spline 15 with the spiral groove 8. In rotating, a thrust force acts between the spline 15 and the spiral groove 8, and the attitudes of the drive gear 3 and the trochoid pump 12 are controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear structure including a gear and a connecting shaft inserted in the gear.

[0002]

2. Description of the Related Art Conventionally, a rotary shaft with a gear is often used as a power transmission means in a place where a mounting space is small. FIG.
Indicates the rotating shaft with gears. The geared rotary shaft 50 is
It is used as a drive gear for driving the oil pump for driving the oil pump of the engine. Hereinafter, the rotating shaft with gear 50 will be referred to as a drive gear. The drive gear 50 includes a cylinder block 51 and a cylinder block 51.
It is arranged between the chain cover 52 and the chain cover 52. In the drive gear 50, the rotary shaft portion 50 a is inserted into the support hole 53 of the cylinder block 51.
It is rotatably supported with respect to 1. Drive gear 5
The zero gear portion 50b is formed at one end of the rotary shaft portion 50a, and the driving force from the crankshaft is transmitted through a reduction gear (not shown). The rotating shaft portion 50a has a through hole 54.
In the inner peripheral surface of the through hole 54, a large number of linear grooves 55 are formed at equal intervals in parallel with the central axis.

Trochoid pump 60 which is an oil pump
The connecting shaft 61 extending in the rotation axis direction from the drive gear passes through the support hole 57 formed in the bearing portion 56 of the chain cover 52 and is inserted into the through hole 54 of the drive gear 50. On the outer peripheral surface of the distal end portion of the connecting shaft 61, splines 62 composed of a large number of linear teeth are formed at equal intervals in parallel with the central axis, and the splines 62 are formed in the linear groove 55 of the through hole 54.
To fit. The spline 62 and the linear groove 55 are fitted to each other, so that the connecting shaft 61 is connected to the rotating shaft portion 50a such that it cannot rotate but can move in the axial direction.

Accordingly, the connection shaft 61, that is, the trochoid pump 60 is rotated by the rotation of the drive gear 50.
The movement of the drive gear 50 in the axial direction is caused by the inner surface of the bearing portion 56 of the chain cover 52 and the cylinder block 5.
1 and the inner wall surface 51b of the through hole 53.

[0005]

By the way, the drive gear 50 has a so-called cantilever type support structure in which the rotary shaft portion 50a is rotatably inserted into the support hole 53. Further, since the drive gear 50 can be easily attached / detached when the chain cover 52 is attached / detached, a sufficient clearance is provided between the outer periphery of the rotary shaft portion 50a of the drive gear 50 and the inner periphery of the support hole 53. Was needed. Therefore, when the driving force from the crankshaft is applied to the gear portion 50b of the drive gear 50, the drive gear 50
The gear position was disturbed by its driving force. as a result,
There have been problems that the gears have poor tooth contact, wear, and noise. In order to prevent this, it is necessary to increase the processing accuracy of the drive gear 50, which causes a problem of high cost.

The present invention has been made in order to solve the above-mentioned problems, and its object is to eliminate the disturbance of the gear posture due to the driving force applied to the gear even in the case of a cantilever type support structure and to prevent the tooth contact of the gear. It is an object of the present invention to provide a gear structure capable of preventing defects, wear, and noise.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 inserts a connecting shaft into an insertion hole provided at the center of the gear, and moves the connecting shaft in the axial direction with respect to the connecting shaft of the gear. In a gear structure whose movement is limited by the casing,
The gist of the invention is to form an engaging portion that engages the insertion hole and the connecting shaft with each other and applies a force in the opposite direction, and brings the gear into contact with the one-way casing during driving.

According to a second aspect of the present invention, in the first aspect of the present invention, the engaging portion of the insertion hole is a spiral groove formed in a spiral shape, and the engaging portion of the connecting shaft has a spiral shape. It is the gist that it is a helical spline formed.

[0009]

Therefore, according to the first aspect of the invention, the connecting shaft is inserted into the through hole of the gear, and the inserting hole and the connecting shaft are engaged by the engaging portion of the inserting hole and the engaging portion of the connecting shaft. Have been combined. Then, when the gear rotates, the engagement causes the connecting shaft to rotate. At the time of this rotation, the engagement portion applies forces to the gear and the connecting shaft in directions opposite to each other in the axial direction. Therefore, the gear is brought into contact with the casing by the force of the opposite direction acting in the axial direction, and rotates in the contacted state. Therefore, the gear rotates in a stable state.

According to the second aspect of the present invention, since the engaging portion is formed in a spiral shape, the forces acting in the rotation of the gear and the connecting shaft in the mutually opposite directions are the forces in the rotation direction due to the rotation. It is generated by the component force in the axial direction generated by the engaging portion.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the present invention will be described below with reference to FIG. As shown in FIG. 1, a support hole 2 is formed on the side surface of a cylinder block 1 as a casing. A drive gear 3 as a gear is attached to the support hole 2. A chain cover 4 is attached to the cylinder block 1, and the drive gear 3 is arranged between the cylinder block 1 and the chain cover 4.

The drive gear 3 has a rotating shaft portion 5 having a circular cross section.
And a gear unit 6. A through hole 7 as an insertion hole is formed in the rotary shaft portion 5. On the inner peripheral surface 7a of the through hole 7, a plurality of spiral grooves 8 serving as spiral engaging portions are formed at equal intervals. The drive gear 3 is rotatably supported by the cylinder block 1 by rotatably inserting the rotary shaft portion 5 into the support hole 2 via a bush (not shown), for example. Normally, machining between the gear portion 6 and the cylinder block 1, between the gear portion 6 and the chain cover 4, and further between the base end 5a of the rotary shaft portion 5 and the bottom surface 2a of the support hole 2 is performed. There is also a problem with the assembling accuracy, and a clearance is formed that allows the drive gear 3 to move slightly in the axial direction. For the same reason, a slight clearance is formed between the outer circumference of the rotary shaft portion 5 and the outer circumference of the support hole 2. The gear portion 6 is formed at one end of the rotary shaft portion 5, and the gear portion 6 has a plurality of teeth. The driving force from the crankshaft is transmitted to the gear portion 6 via a reduction gear (not shown).

A storage hole 9 penetrating the chain cover 4 is formed at a position of the chain cover 4 corresponding to the drive gear 3. The housing hole 9 is formed with a small-diameter small housing hole 10 located on the drive gear 3 side and a large-diameter large housing hole 11 located on the opposite side. A trochoid pump 12 is provided in the storage hole 9.

The trochoid pump 12 has a main body 14 composed of a driving gear (not shown) arranged inside and a driven gear (not shown) arranged outside the trochoid pump 12, and extends in the rotation axis direction from the driving gear. And a connecting shaft 13. Connection shaft 1
The connecting portion 13a of No. 3 has a spline (hereinafter, “helical spline”) as an engaging portion formed of a plurality of spiral teeth.
Say. ) 15 are formed at equal intervals corresponding to the spiral groove 8.

The trochoid pump 12 is arranged such that the connecting portion 13a is inserted into the through hole 7 through the small storage hole 10 and the main body 14 is stored in the large storage hole 11. In this case, the helical spline 15 of the connecting portion 13a
And the spiral groove 8 of the through hole 7 are screwed into and engaged with each other.

With the drive gear 3 and the trochoid pump 12 configured as described above, the automobile engine starts,
When the driving force from the crankshaft is transmitted to the drive gear 3, the drive gear 3 rotates around the rotating shaft portion 5. Then, in accordance with this rotation, in addition to the force in the rotational direction, the thrust in the spiral groove 8 of the rotary shaft portion 5 is directed toward the inside of the cylinder block 1 as a component of the force in the axial direction (positive thrust force). Works.

At this time, the connecting portion 1 of the trochoid pump 12
3a rotates according to the force in the rotation direction. At the time of this rotation, a load is applied to the trochoid pump 12, and due to this load, a force that suppresses rotation acts on the trochoid pump 12 in the rotation direction. Therefore, the helical spline 15 of the trochoid pump 12 has a thrust force (negative force) directed toward the chain cover 2 side opposite to the positive thrust force as a component force in the rotational direction of the helical spline 15 in the axial direction. Thrust force) acts.

Due to these positive and negative thrust forces, the helical spline 15 and the spiral groove 8 are pulled outward in the thrust direction. Then, the drive gear 3 is moved to the cylinder block 1 side by the positive thrust force, and the base end 5a of the shaft portion 5 is supported by the support hole 2
It rotates while being in contact with the bottom surface 2a. That is, the drive gear 3 and the cylinder block 1 rotate in contact with each other. In this case, a slight clearance is formed between the cylinder block 1 and the gear portion 6. In this way, when the drive gear 3 rotates,
The position, that is, the posture is controlled.

Therefore, according to the present embodiment, the drive gear 3 is inserted into the support hole 2, and the helical spline 15 of the trochoid pump 12 is inserted into the spiral groove 8 to be engaged with the drive gear 3 and the support hole. It is possible to easily transmit the driving force without fixing 2 and 2 with a bolt or the like.

During the rotation of the drive gear 3, the helical spline 15 and the spiral groove 8 which connect the drive gear 3 and the trochoid pump 12 are connected to each other between the spiral groove 8 and the spiral groove 8 in the axial direction of the rotational force. Thrust force is generated as a component force, and the drive force can be easily and reliably positioned at a predetermined position in the thrust direction by the thrust force. In this case, the drive gear 3 is positioned at the position where it abuts on the cylinder block 1, and the drive gear 3 is rotated in the abutting state, so that the drive gear 3 can be rotated in a stable state. Therefore, when the drive gear 3 and the trochoid pump 12 rotate, it is possible to prevent the drive gear 3 from rattling. Further, rattling can be prevented, and failure can be prevented because the connecting structure of the drive gear 3 is simple.

Further, the drive gear 3 and the trochoid pump 1
Since the posture of the drive gear 3 can be controlled and the rattling can be prevented during the rotation of 2, the accuracy (for example, dimensional tolerance) of the spline 15 and the groove 8 can be improved as compared with the case of using the conventional linear spline. Can be relaxed. Therefore, the manufacturing costs of the drive gear 3 and the trochoid pump 12 can be reduced.

Further, the helical spline 15 and the spiral groove 8
The thrust force acting on each helical spline 15 and the spiral groove 8 can be changed / adjusted by changing the spiral condition of.

Further, since the helical spline 15 is formed by cutting out teeth, the strength can be increased and a larger torque can be transmitted as compared with the case where a spiral key is attached to the connecting portion 13, for example.

The present invention is not limited to the above-mentioned embodiments, but may be carried out as follows with appropriate changes without departing from the spirit of the invention. (1) In the above embodiment, as shown in FIG. 2, as the engaging portion on the drive gear 3 side, the inner peripheral surface 7a of the through hole 7 is formed.
The single spiral groove 31 formed in the above is formed. As the engaging portion on the trochoid pump 12 side, a plurality of protrusions 32 spirally arranged are formed on the connecting portion 13. The drive gear 3 and the trochoid pump 12 may be connected by engaging the spiral groove 31 and the protrusion 32. In this case, the number of spiral grooves 31 is one, and the number of protrusions 32 may be the number corresponding to the number of spiral grooves 31, so that the spiral grooves 31 and the protrusions 32 can be easily formed with respect to the drive gear 3 and the trochoid pump 12. it can.

(2) In the above embodiment, the present gear structure is used for the oil pump (trochoid pump 1) of an automobile engine.
It is applied to the drive gear 3 and the connecting shaft 13 for driving 2). This may be applied to other gear groups, for example in the case of gears used in automobile transmissions. Of course, not only the gears used in automobiles,
It may be applied to a group of gears used in various vehicles and various machines.

(3) In the above embodiment, a thrust force for moving the drive gear 3 to the oil pump side is generated to bring the drive gear 3 into contact with the chain cover 4,
The posture may be controlled. That is, the posture is controlled by applying a negative thrust force to the drive gear 3 and a positive thrust force to the trochoid pump 12 so as to exert forces in the opposite directions of pressing inward with each other. May be. In this embodiment, since no force acts between the chain cover 4 and the cylinder block 1, there is no fear of deformation of the chain cover 4.

(4) In the above embodiment, the through hole 7 is formed in the rotary shaft portion 5, but a hole that does not penetrate may be formed as an insertion hole. The technical ideas other than the claims that can be understood from the above embodiments will be described below along with their effects.

(1) In the invention according to claims 1 and 2,
The connecting shaft 13 is a gear structure extending from the trochoid pump 12 for supplying oil to the engine. According to this gear structure, a gear structure for supplying oil to the engine can be easily configured.

[0029]

As described in detail above, according to the first aspect of the present invention, when the gear and the connecting shaft rotate, the engaging portions exert forces in directions opposite to each other in the axial direction, so that the gear is casing. It is possible to rotate the gear and the connecting shaft in a stable state by contacting with the gear. According to the second aspect of the present invention, since the engaging portion is formed in a spiral shape, it is possible to easily exert the forces in directions opposite to each other in the axial direction by the component force in the axial direction of the force in the rotation direction. You can

[Brief description of drawings]

FIG. 1 is a sectional view showing a drive gear and a trochoid pump attached to a cylinder block.

FIG. 2 is a side sectional view showing another example of a drive gear and a trochoid pump.

FIG. 3 is a sectional view showing a drive gear and a trochoid pump mounted on a conventional cylinder block.

[Explanation of symbols]

1 ... Cylinder block as casing, 3 ... Drive gear as gear, 7 ... Through hole as insertion hole, 8 ...
Spiral groove as engaging part, 12 ... Trochoid pump, 13
... connecting shaft, 15 ... helical spline as an engaging portion.

Claims (2)

[Claims] 1. In a gear structure in which a connecting shaft is inserted into an insertion hole provided at the center of a gear, and a movement of the gear in the axial direction with respect to the connecting shaft is restricted by a casing, the insertion hole and the connecting shaft are engaged with each other. A gear structure in which an engaging portion that applies force in the opposite direction is formed so that the gear contacts the casing in one direction during driving. 2. The gear structure according to claim 1, wherein the engaging portion of the insertion hole is a spiral groove formed in a spiral shape, and the engaging portion of the connecting shaft is a helical spline formed in a spiral shape. .