JP7477018B1 - Scissor gear and scissors gear system - Google Patents

Abstract

To provide a scissors gear capable of applying a biasing force to a sub gear with a simple configuration.
[Solution] This scissors gear S100 comprises a main gear 10 connected to a shaft 41, a sub-gear 20 that is rotatable circumferentially relative to the main gear 10 and arranged to form an oil passage 30 between it and the main gear 10, and a supply passage 45 that supplies lubricating oil to the oil passage 30 in the inner peripheral region of the main gear 10 and the sub-gear 20, and the sub-gear 20 has a protrusion 25 that generates a force that rotates the sub-gear 20 circumferentially relative to the main gear 10 due to the flow of lubricating oil flowing through the oil passage 30 from the inner peripheral side to the outer peripheral side.
[Selected figure] Figure 3

Description

The present invention relates to a scissors gear and a scissors gear system.

In a gear train that transmits driving force from the engine via a crank, gear rattle occurs when gears collide with each other due to fluctuations in crank rotation and cam drive torque. The vibrations generated by the gear rattle are transmitted through the gear bearings to the main body of the engine block, worsening engine noise. A method has been proposed to combat gear rattle by using a scissors gear, which pinches the mating gear between two teeth to suppress relative movement of the gears and reduce noise pollution.

To reduce rattle noise, for example, it is known to use a scissors gear in which a C-shaped spring is placed between the main gear and the sub gear in the direction of their rotation, one end of which is engaged with the stopper pin of the main gear and the other end of which is engaged with the stopper pin of the sub gear (see, for example, Patent Document 1).

JP 2022-115424 A

Conventional scissor gears have a structure in which a C-shaped spring placed between the main gear and the sub gear applies a biasing force to the sub gear, which creates the problem of a complex scissor gear structure.

Therefore, the present invention has been made in consideration of these points, and aims to provide a scissors gear that can apply a biasing force to a sub-gear with a simple configuration, and a scissors gear system equipped with the same.

The scissors gear of one embodiment of the present invention is a scissors gear including a main gear connected to a shaft, a sub-gear that is rotatable in the circumferential direction relative to the main gear and is arranged to form an oil passage between the main gear and the sub-gear, and a supply flow passage that supplies lubricating oil to the oil passage in the inner peripheral region of the main gear and the sub-gear, and the sub-gear has a protrusion that generates a force that rotates the sub-gear in the circumferential direction relative to the main gear by the flow of lubricating oil that flows through the oil passage from the inner peripheral side to the outer peripheral side.

The sub-gear may have a plurality of the protrusions, and the plurality of protrusions may be arranged along the circumferential direction of the sub-gear.

The supply passage may be formed in the shaft.

The oil passage may have a port for supplying the lubricating oil between the teeth of the main gear and the teeth of the sub gear.

The scissors gear system of one embodiment of the present invention is a scissors gear system including the above-described scissors gear that transmits the driving force of an engine, a supply mechanism that supplies lubricating oil to the scissors gear, and a control device that controls the operation of the supply mechanism, and when the engine speed becomes equal to or greater than a threshold value while the lubricating oil is being supplied to the oil passage at a first supply amount, the control device operates the supply mechanism to supply the lubricating oil at a second supply amount that is greater than the first supply amount.

The control device may change the operation of the supply mechanism to supply the lubricating oil at the first supply amount when the output value of a sensor that detects the volume of the rattle noise of the scissors gear becomes less than a threshold value while the supply mechanism is supplying the lubricating oil at the second supply amount.

The present invention has the effect of providing a scissors gear and a scissors gear system that can apply a biasing force to a sub-gear with a simple configuration.

FIG. 2 is a diagram for explaining a configuration of a scissors gear system. FIG. FIG. FIG. 13 is a diagram for explaining the function of a scissors gear. 13 is a flow chart showing control of motion changes in a scissors gear system.

The following describes an embodiment of the present disclosure with reference to the drawings. FIG. 1 is a diagram for explaining the configuration of a scissors gear system. FIG. 2 is an exploded perspective view of the scissors gear. FIG. 3 is a cross-sectional view of the scissors gear. FIG. 4 is a diagram for explaining the function of the scissors gear. In each drawing, the components of the scissors gear system are shown diagrammatically, and the shapes of components in one drawing may not match the shapes of components in another drawing, but these differences are not essential to the present invention.

As shown in FIG. 1, the scissors gear system 1 of this embodiment includes a scissors gear S100, a supply mechanism 2, a control device 3, and a sensor 4. As an example, the scissors gear system 1 is configured as a part of a mobile mechanism that transmits the driving force of a vehicle engine 5.

As shown in FIG. 2, the scissors gear S100 has the main gear 10, the sub gear 20, a shaft 41, and a flange 42 as its main components. One of the features of the scissors gear S100 of this embodiment is that the sub gear 20 is provided with a protrusion 25, and the flow of lubricating oil supplied between the main gear 10 and the sub gear 20 acts on the protrusion 25 to generate a force that rotates the sub gear 20 relative to the main gear 10 (described in detail later). That is, in this embodiment, a C-shaped spring is not provided between the main gear 10 and the sub gear 20, and the sub gear 20 rotates by hydraulic pressure.

The main gear 10 is a gear with gear teeth formed on its outer periphery and a through hole formed in its center. As an example, the main gear 10 is a helical gear. The main gear 10 has a gear body 11 and a cylindrical portion 12. The main gear 10 is connected to the shaft portion 41a of the shaft 41, and rotates together with the shaft 41 in response to the rotation of the shaft 41.

The gear body 11 is formed in a disk shape, with teeth formed on the outer periphery. As an example, the gear body 11 is formed integrally with the cylindrical portion 12. The gear body 11 has a recess 11a formed on the surface facing the sub-gear 20. The recess 11a is a portion where the annular region of the gear body 11 is partially formed thin.

The cylindrical portion 12 is formed to protrude from the gear body 11 and has a shape that surrounds the shaft 41. Specifically, the cylindrical portion 12 is a cylindrical bush that surrounds the shaft portion 41a of the shaft 41. An oil supply hole 12a is formed in the cylindrical portion 12.

The sub gear 20, like the main gear 10, has gear teeth formed on its outer periphery, and is, for example, a helical gear. A through hole is formed in the center of the sub gear 20, and the sub gear 20 is supported by the cylindrical portion 12 of the main gear 10. The sub gear 20 is configured so that it can move around the cylindrical portion 12. This allows the sub gear 20 to rotate circumferentially relative to the main gear 10.

To rotate the sub gear 20, a protrusion 25 is formed on the side of the sub gear 20, protruding from the side. The protrusion 25 is a structural part that generates a force in a direction that rotates the sub gear 20 in the circumferential direction relative to the main gear 10 by the lubricating oil that flows radially from the inner circumference side to the outer circumference side between the main gear 10 and the sub gear 20. In this example, the protrusions 25 are multiple wing portions arranged along the circumferential direction of the sub gear 20.

As a specific example, the protrusion 25 has a shape that generates a circumferential rotational force due to the pressure difference between the lubricating oil pressure on the inner circumference side and the lubricating oil pressure on the outer circumference side. The protrusion 25 is not limited to a specific shape as long as it can generate such a rotational force (biasing force). The protrusion 25 may be, for example, a streamlined wing like blade.

When the sub-gear 20 is subjected to a biasing force generated by the protrusion 25 receiving the flow of lubricating oil, as shown in FIG. 4, the teeth 10a of the main gear 10 and the teeth 20a of the sub-gear 20 sandwich the teeth 50a of the mating gear 50. When torque fluctuations occur in the vehicle's transmission mechanism, the teeth 50a of the gear 50 bias the teeth 20a of the sub-gear 20, causing the sub-gear 20 to rotate relative to the main gear 10. A circumferential biasing force is applied to the teeth 50a, which suppresses the rotation of the gear 50 and reduces the occurrence of rattle.

The shaft 41 (see FIG. 2) is a shaft that rotates, for example, by the driving force of an engine. The shaft 41 has an axle portion 41a that is inserted into the through hole of the main gear 10 and the through hole of the sub gear 20. A flow passage for supplying lubricating oil is formed inside the shaft 41, which will be described later.

The flange 42 is fixed to the tip side of the shaft portion of the shaft 41. The flange 42 is fixed to the shaft 41, for example, by a bolt B (see FIG. 3).

(Lubricating oil passages and surrounding structures)
3, in the scissors gear S100 of this embodiment, an oil passage 30 is formed between the main gear 10 and the sub gear 20. The oil passage 30 extends from the inner periphery side to the outer periphery side of the scissors gear S100 in the region between the main gear 10 and the sub gear 20.

To supply lubricating oil to the oil passage 30, the shaft 41 is provided with a supply passage 45. The supply passage 45 is a passage through which the lubricating oil supplied from the supply mechanism 2 (see FIG. 1) flows. The supply passage 45 supplies the lubricating oil to the oil passage 30 through the opening 41b of the shaft portion 41a of the shaft 41 and the oil supply hole 12a of the cylindrical portion 12.

The oil passage 30 has a port 32 that supplies lubricating oil between the teeth of the main gear 10 and the teeth of the sub gear 20. The end of the port 32 is open, which allows the port 32 to release the pressure of the lubricating oil. In this example, the cross-sectional area of the port 32 is smaller than the cross-sectional area of the inner circumference side of the oil passage 30.

Referring again to FIG. 1, the supply mechanism 2 is a mechanism for supplying lubricating oil to the scissors gear S100. The supply mechanism 2 has a pump that pumps the lubricating oil toward the scissors gear S100. The pump may be, for example, the oil pump of the engine 5, or a pump provided separately from the oil pump of the engine 5. The pump may be configured so that the supply amount increases or decreases in conjunction with the rotation speed of the engine 5 (the supply amount increases with an increase in the rotation speed). Alternatively, the pump may perform an operation of supplying lubricating oil at a first supply amount and an operation of supplying lubricating oil at a second supply amount that is greater than the first supply amount.

Sensor 4 is a sensor that detects the volume of the rattle sound of the scissors gear S100. Sensor 4 is disposed, for example, near a transmission mechanism including the scissors gear S100, and detects the rattle sound generated from the scissors gear S100. Sensor 4 is connected to control device 3, and the output value of sensor 4 is provided to control device 3.

The control device 3 controls the operation of the supply mechanism 2. Specifically, the control device 3 starts and stops the operation of the pump by, for example, giving a control signal to start and stop the operation of the pump. The control device 3 causes the supply mechanism 2 to perform an operation of supplying lubricating oil at a first supply amount and an operation of supplying lubricating oil at a second supply amount.

In the scissors gear S100 of this embodiment, the sub gear 20 is configured to be biased by hydraulic pressure, so the sub gear 20 is not biased unless hydraulic pressure is generated. Therefore, the control device 3 continuously operates the supply mechanism 2 to supply lubricating oil to the scissors gear S100, for example, while the engine 5 is operating and the scissors gear S100 is rotating or can rotate. Specifically, the control device 3 operates the supply mechanism 2 so that the first supply amount of lubricating oil is supplied to the oil passage 30.

As a result, lubricating oil is supplied to the oil passage 30, and the lubricating oil flows from the inner circumference side to the outer circumference side due to the pressure of the pump of the supply mechanism 2 and the centrifugal force caused by the rotation of the scissors gear S100. This flow of lubricating oil biases the sub gear 20 in the circumferential direction, causing the scissors gear S100 to function as a scissors gear.

(Operation change control)
Fig. 5 is a flowchart showing the control of the operation change in the scissors gear system. The rattle noise tends to become louder when the engine speed increases. Therefore, in one embodiment, it is preferable to increase the amount of lubricating oil supplied to the scissors gear S100 and perform control to temporarily increase the biasing force. This control will be described below with reference to the flowchart in Fig. 5.

First, in step S1, the engine 5 starts, and the control device 3 operates the supply mechanism 2 so that the first supply amount of lubricating oil is supplied to the oil passage 30. This applies a biasing force to the sub gear 20.

Then, when the rotation speed of the engine 5 becomes equal to or higher than the threshold value, the control device 3 operates the supply mechanism 2 so that the supply mechanism 2 supplies lubricating oil at a second supply amount that is greater than the first supply amount. Specifically, in step S2, the control device 3 determines whether the rotation speed of the engine 5 is equal to or higher than the threshold value set as the rotation speed value at which the rattle noise is expected to become louder. If the answer is No in step S2, the same step is repeated.

If the answer is Yes in step S2, the control device 3 operates the supply mechanism 2 in step S3 so that the supply mechanism 2 supplies the lubricating oil at the second supply amount.

The control device 3 further changes the operation of the supply mechanism 2 to supply the lubricant at the first supply amount when the output value of the sensor 4 falls below the threshold value while the lubricant is being supplied at the second supply amount. Specifically, in step S4, the control device 3 determines whether the output value of the sensor 4 is below the threshold value set as a value indicating that the rattle noise has decreased. If the answer to step S4 is No, the same step is repeated.

If the answer is Yes in step S4, in step S5, the control device 3 changes the operation of the supply mechanism 2 so that the supply mechanism 2 supplies the lubricating oil at the first supply amount. For example, when the engine 5 is stopped, the control device 3 ends the above series of flows.

(Effects of Scissors Gear S100)
According to the scissors gear S100 configured as above, lubricating oil is supplied to the oil passage 30 between the main gear 10 and the sub gear 20, and the flow of the lubricating oil is received by the protruding portion 25, generating a biasing force for rotating the sub gear 20. Due to this configuration, it is not necessary to provide a C-shaped spring between the main gear 10 and the sub gear 20 as in the conventional scissors gear, and the configuration of the scissors gear S100 can be simplified. In addition, the impact force of the gear rattle is buffered by the lubricating oil, so that the transmission of vibration to the gears and bearings is reduced.

In addition, as shown in FIG. 3, if a port 32 is provided at the end of the oil passage 30, the lubricating oil is supplied to the teeth of the main gear 10 and the teeth of the sub gear 20 through this port 32, so that the scissors gear S100 and the gear 50 can be well lubricated.

<Modification>
Although the embodiment of the present invention has been described above with reference to the drawings, the present invention may be modified as appropriate. For example, although only one oil supply hole 12a is illustrated in Fig. 2, multiple oil supply holes 12a may be provided along the circumferential direction. The same applies to the opening 41b of the shaft 41.

Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist of the invention. For example, all or part of the device can be configured by distributing or integrating functionally or physically in any unit. In addition, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effect of the new embodiment resulting from the combination also has the effect of the original embodiment.

REFERENCE SIGNS LIST 1 Scissor gear system 2 Supply mechanism 3 Control device 4 Sensor 5 Engine 10 Main gear 10a Teeth 11 Gear body 11a Recess 12 Cylindrical portion 12a Oil supply hole 20 Sub gear 20a Teeth 25 Projection 30 Oil passage 32 Port 41 Shaft 41a Shaft portion 41b Opening 42 Flange 45 Supply passage 50 Gear 50a Teeth B Bolt S100 Scissor gear

Claims (6)

A main gear connected to the shaft;
A sub gear is provided rotatably in a circumferential direction relative to the main gear and is arranged to form an oil passage between the sub gear and the main gear;
a supply flow passage for supplying lubricating oil to the oil passage in an inner peripheral region of the main gear and the sub gear;
A scissors gear comprising:
The sub gear is
a scissors gear having a protrusion that generates a force in a direction that rotates the sub gear in a circumferential direction relative to the main gear by a flow of lubricating oil flowing through the oil passage from the inner periphery side to the outer periphery side. The sub gear has a plurality of the protrusions,
The plurality of protrusions are arranged along the circumferential direction of the sub gear.
The scissors gear according to claim 1 . The supply passage is formed in the shaft.
The scissors gear according to claim 1 or 2. The oil passage has a port for supplying the lubricating oil between the teeth of the main gear and the teeth of the sub gear.
The scissors gear according to claim 1 or 2. The scissors gear according to claim 1 for transmitting a driving force of an engine;
a supply mechanism for supplying lubricating oil to the scissors gear;
A control device for controlling an operation of the supply mechanism;
A scissors gear system comprising:
The control device includes:
When the engine speed becomes equal to or higher than a threshold value in a state where the lubricating oil is supplied to the oil passage at a first supply amount, the supply mechanism is operated to supply the lubricating oil at a second supply amount that is larger than the first supply amount.
Scissor gear system. The control device includes:
when an output value of a sensor that detects a magnitude of a rattle noise of the scissors gear becomes less than a threshold value while the supply mechanism is supplying the lubricating oil at the second supply amount, the operation of the supply mechanism is changed so as to supply the lubricating oil at the first supply amount.
6. The scissor gear system of claim 5.