JP2546482Y2 - Rotation detection device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation detecting device for detecting the number of revolutions of a rotating body such as an output shaft of an engine.

[0002]

2. Description of the Related Art As this kind of conventional rotation detecting device,
For example, a device shown in FIG. 7 is known as a device for detecting the number of revolutions of an engine (measurement target). That is, the housing 1 is attached to a transmission case of an engine (not shown), and an O-ring 2 for preventing leakage of lubricating oil in the transmission is provided on an outer peripheral portion of the housing 1. A transmission shaft (shaft member) 3 is rotatably provided inside the housing 1, and a driven gear 4 that meshes with a gear (rotary body) in the transmission is attached to a distal end of the transmission shaft 3. .

The transmission shaft 3 has a spiral oil groove 5 formed on the outer periphery, and lubricates the outer peripheral surface by introducing lubricating oil in the transmission. A coupling part 6 is formed at the base end of the transmission shaft 3, and a drive shaft 8 for rotating and driving a magnetic rotor 7 is connected to the coupling part 6. Magnetic rotor 7
Is a multi-polarized end face 7a.
A magnetically sensitive element 9 is provided so as to be close to a. The rotation detection means 10 is constituted by the magnetic rotor 7 and the magnetic sensing element 9.

[0004]

However, in the above-mentioned conventional rotation detecting device, since the outer peripheral surface of the transmission shaft 3 is lubricated using the lubricating oil in the transmission, the lubricating oil on the transmission shaft 3 is sufficient. The mounting position on the mission must be considered so as to penetrate, and there is a problem that mounting is troublesome. Then, there is a problem that it cannot be attached to a measurement object that does not use lubricating oil.

The present invention has been made to solve the above-mentioned problem, and an object of the invention is to provide a rotation detecting device capable of smoothly supporting a shaft member with a bearing member without using lubricating oil in an object to be measured. It is to provide a device.

[0006]

In order to achieve the above object, the present invention provides a shaft member for transmitting the rotation of a rotating body provided on an object to be measured to a rotation detecting means,
A bearing member rotatably holding the shaft member, wherein the shaft member is made of resin
And a grease reservoir having a hollow interior and communicating from the grease reservoir to the outer peripheral surface.
It is characterized by having a plurality of grease supply holes.

[0007] Also, the invention of claim 2, the outer peripheral surface of the <br/> shaft member of the first aspect, a plurality of grooves along the axial direction is formed
The grease supply hole communicates with the groove .

Further, according to the invention of claim 3 , a spiral groove is formed on the outer peripheral surface of the shaft member of claim 1 .
The grease supply hole communicates with the groove .

[0009]

According to the first aspect of the present invention, since the shaft member is formed of a resin,
The coefficient of friction of the shaft member against the member
You. In addition, the grease in the grease reservoir flows gradually from the grease supply hole to the outer peripheral surface of the shaft member, and the lubrication between the shaft member and the bearing member is maintained for a long time. Therefore, the shaft member can be smoothly supported by the bearing member without using the lubricating oil provided in the object to be measured,
It can be attached to a free position on the measurement object to detect rotation.

[0010] Also, in the invention of claim 2, since a plurality of grooves along the axial direction on the outer peripheral surface of the shaft member is formed, to form a shaft member with large resin material of thermal expansion coefficient than the bearing member Even so, the circumferential expansion component of the shaft member can be absorbed by the groove, and this circumferential expansion component can be prevented from becoming a radial expansion component. Therefore, it is not necessary to increase the gap between the shaft member and the bearing member in consideration of thermal expansion, and the gap between the shaft member and the bearing member can be reduced. Therefore, the shaft member is smoothly supported by the bearing member. be able to. Further, since the groove increases the heat radiation area on the outer peripheral surface of the shaft member, it is possible to suppress a rise in the temperature of the shaft member, and from this point, it is possible to reduce the gap between the shaft member and the bearing member. In addition, since the temperature of the shaft member can be kept low, deterioration of the shaft member can be reduced. In addition, since grease is supplied to the groove, grease can be supplied evenly to the entire outer peripheral surface of the shaft member.

Furthermore, in the invention of claim 3, coloration operations and effects similar to those of the preceding claims 2.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

First, a first embodiment of the present invention will be described with reference to FIGS. In FIG. 1, reference numeral 11 denotes a housing formed so as to be attachable to, for example, a transmission (not shown) of an engine which is an object to be measured. Lubricating oil leaks from the inside of the transmission 11 into the outer periphery of the housing 11. An O-ring 12 is provided to prevent this. The housing 11 is formed by aluminum die-casting. A bearing hole (bearing member) 11 a having a circular cross section for holding a transmission shaft (shaft member) 15, which will be described later, is provided at the axial center of the housing 11 from the distal end side. It is formed toward the end. The bearing hole 11a is one in which roundness, straightness, surface roughness of the inner surface, and the like are precisely finished by machining or the like, and a rotational motion extracting member 13 is inserted into the bearing hole 11a from the distal end side. ing.

As shown in FIG. 2, the rotational movement extracting member 13 is formed by integrally forming a driven gear 14 and a transmission shaft 15 coaxially with a resin such as nylon or polyphenylene sulfide. The driven gear 14 meshes with a gear (rotating body) in a transmission (not shown), and the transmission shaft 15 is divided into a distal end portion 15a and a proximal end portion 15b by an annular groove 16 formed on the outer periphery. Spiral grooves 17 are provided on the outer periphery of the distal end portion 15a and the proximal end portion 15b, respectively.
Is formed, and a grease reservoir 18 is formed at the axis of the base end portion 15b.

The grease reservoir 18 is formed in a hollow hole having a circular cross section so as to reach the annular groove 16 from the base end face of the base end 15b. A plurality of grease supply holes 19 are formed so as to penetrate. The grease supply hole 19 has a diameter of about 0.1 mm to 2 mm. The diameter of the grease supply hole 19 is determined so that the grease in the grease reservoir 18 does not excessively enter the spiral groove 17 and does not become insufficient.

A coupling part 20 is formed on the base end side of the base end part 15b. Coupling part 20
Has a pair of grooves 21 extending from the base end surface of the base end portion 15b to the front end side. A drive shaft (shaft member) 23 that rotates the magnetic rotor 22 so as to engage with the grooves 21 is formed. It is connected. The magnetic rotor 22 is shown in FIG.
As shown in the figure, the end face 22a is a multi-pole magnetized disk. The drive shaft 23 has a base end fixed coaxially to the axis of the magnetic rotor 22 and is formed by inserting the magnetic rotor 22 with a resin such as nylon or polyphenylene sulfide. A portion of the drive shaft 23 close to the magnetic rotor 22 is rotatably supported by a slide bearing (bearing member) 24.

Further, a hollow grease reservoir 25 is formed on the drive shaft 23 so as to penetrate through the portion of the slide bearing 24 from the distal end side, and a portion where the slide bearing 24 is fitted from the grease reservoir 25. A plurality of grease supply holes 26 penetrating to the outer peripheral surface of the grease are formed. The grease supply hole 26 is formed with a diameter of about 0.1 mm to 2 mm, and the diameter is determined so that the grease in the grease reservoir 25 does not run out to the outer peripheral surface and does not run out. . A key 27 that engages with the groove 21 of the coupling portion 20 of the transmission shaft 15 is provided on the outer periphery of the distal end of the drive shaft 23.

The base end of the housing 11 has a through hole 11b formed continuously with the bearing hole 11a, and the end cap 2 is closed so as to close this opening.
8 is fixed. The magnetically sensitive element 2 is mounted on the end cap 28 so as to be close to the end face 22 a of the magnetic rotor 22.
9 are provided. The magnetic rotor 22 and the magnetic sensing element 29 constitute a rotation detecting unit 30.

The magnetic sensing element 29 is formed of a Hall element or the like, and emits an electric signal in accordance with the number of rotations of the magnetic rotor 22, and electrically connects to a terminal 31 provided on the end cap 29. It is connected to the. Terminal 3
Numeral 1 is connected to an indicating instrument or the like (not shown) to send an electric signal generated by the magnetically sensitive element 29 to the indicating instrument or the like.

In FIG. 1, reference numeral 32 designates a retaining member for the transmission shaft 15.
Has a cylindrical outer peripheral surface fitted into the annular groove 16 of the transmission shaft, and is provided so as to penetrate from outside the housing 11 through the annular groove 16 of the transmission shaft 15.

In the rotation detecting device configured as described above, grease is filled in the grease reservoirs 18 and 25,
The transmission shaft 15 and the drive shaft 23 are assembled in the housing 11 with the outer peripheral surfaces of the transmission shaft 15 and the drive shaft 23 lightly greased. Then, the rotation detection device assembled in this manner is attached to the mission.

When the engine is started in this state, the rotational motion of the gears in the transmission is taken out via the driven gear 14 and further transmitted to the magnetic rotor 22 via the transmission shaft 15 and the drive shaft 23. Then, an electric signal corresponding to the rotation speed of the magnetic rotor 22 is output from the magnetic sensing element 29 to an indicating instrument or the like.

The transmission shaft 15 and the drive shaft 23, which are shaft members, can be sufficiently lubricated by grease applied first in the initial stage. Then, as the use period elapses, the grease applied to the outer peripheral surface is gradually consumed, and the pressure of the grease on the outer peripheral surface gradually decreases. Then,
The pressure of the grease which tends to flow out of the grease reservoirs 18 and 25 by centrifugal force becomes larger than the pressure of the grease on the outer peripheral surface, and the grease is supplied to the grease supply holes 19 and 26.
Through the spiral groove 17 or the outer peripheral surface. Thus, the transmission shaft 15 and the drive shaft 2
3 is stably maintained over a long period of time.

According to the rotation detecting device configured as described above, the lubrication of the transmission shaft 15 and the drive shaft 23 can be stably maintained over a long period of time by the grease in the grease reservoirs 18 and 25. The transmission shaft 15 and the drive shaft 23 can be lubricated without using the lubricating oil in the target, for example, the engine transmission. Therefore, the lubricating oil can be mounted at any position on the transmission without being limited to the position of the lubricating oil in the transmission, and the trouble of determining the mounting position can be eliminated in terms of design.

Moreover, by installing the transmission in a portion of the transmission where no lubricating oil is present, leakage of lubricating oil from the mounting portion of the housing 11 can be reliably prevented.
Further, there is a remarkable effect that the sensor can be attached to a measurement object having no lubricating oil.

In the above-described embodiment, three grease supply holes 19 are formed in a single direction as shown in FIG.
Needless to say, a plurality of may be provided at different positions in the circumferential direction. Preferably, a plurality of pairs of grease supply holes 19 are provided, and the pairs of grease supply holes 19 are arranged at positions 180 degrees apart in the circumferential direction in order to supply all the internal grease by centrifugal force. Similarly, the grease supply hole 26 of the drive shaft 23 is preferably provided at a position 180 degrees apart in the circumferential direction.

Although the grease reservoir 18 is formed only at the base end 15b of the transmission shaft 15 , the grease reservoir 18 is formed so as to penetrate both inside the base end 15b and the distal end 15a, so that the grease reservoir 18 is located between the grease reservoir 18 and the distal end 15a. The grease supply hole 19 may be formed so as to communicate with the spiral groove 17. Further, a grease supply hole 19 may be formed so as to communicate with the annular groove 16 from the grease reservoir 18. Although a spiral groove is not formed in the portion of the slide bearing 24 of the drive shaft 23, a spiral groove 17 similar to the transmission shaft 15 is also formed in this portion, and a grease supply hole 26 communicating with the spiral groove 17 is formed. May be formed.

Further, although the transmission shaft 15 and the driven gear 14 are formed integrally, it goes without saying that they may be formed so as to be separable .

Next, a second embodiment of the present invention will be described with reference to FIGS. However, components common to the first embodiment shown in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof will be omitted.

That is, the housing 41 is attached to an object to be measured, for example, an engine transmission (not shown), via a female screw portion 41a formed on the inner peripheral surface on the distal end side. An introduction hole 41b of a transmission shaft (shaft member) 42 formed coaxially with the female screw portion 41a is formed on the base end side of the portion 41a. Further, a through hole 41c continuous with the introduction hole 41b is opened at the base end of the housing 41.
The end cap 28 is fixed so as to close c.

The transmission shaft 42 transmits the rotational motion of the rotating body in the transmission (not shown) to the drive shaft (shaft member) 43. A key 42a is formed on the outer periphery of the tip. The key 42a has a part of the transmission shaft 42 raised by a press or the like, and fits into a key groove (not shown) formed in a rotating body in the transmission. The proximal end of the transmission shaft 42 is a joint 42b having a square cross section.

The drive shaft 43 is made of a resin such as nylon or polyphenylene sulfide, and has a square centered joint hole into which the joint portion 42b of the transmission shaft 42 is fitted from the distal end side. A portion 43a is formed.
The magnetic rotor 22 is coaxially fixed to the base end of the drive shaft 43. Further, a portion of the drive shaft 43 close to the magnetic rotor 22 is a sliding surface (outer peripheral surface) 43 b rotatably fitted to the slide bearing 24.

As shown in FIG. 5, a plurality of linear grooves 43c extending in the axial direction are formed on the sliding surface 43b. As shown in FIG. 6, the straight groove 43c has a bottom surface 43d formed by an arc-shaped surface centered on the axis.
Side surfaces 43e, 43e adjacent to the bottom surface 43d are formed by surfaces facing in the radial direction from the axis. The linear grooves 43c are formed at equal intervals in the circumferential direction, and the dimension A of the outer peripheral surface between the adjacent linear grooves 43c and the dimension B in the peripheral direction of the bottom surface 43d are formed as in the following formula (1). Have been.

B ≦ A ≦ 2B (1) The dimension B and the dimension D in the depth direction of the side surface 43e are substantially equal.

As shown in the above equation (1), the dimension A is formed to be larger than the dimension B. When the dimension A is smaller than the dimension B, the area where the sliding surface 43b contacts the slide bearing 24 is small. This is because the surface pressure of the sliding surface 43b becomes too large, and the reason why the dimension A is formed to be twice or less the dimension B is as follows. That is, when the temperature of the drive shaft 43 rises, the component that expands in the circumferential direction is:
If the straight groove 43c is not provided, the radial expansion is caused as a component that expands in the radial direction, but if the straight groove 43c is provided, the circumferential expansion component is absorbed by the straight groove 43c,
This circumferential expansion component is prevented from becoming a radial expansion component. However, if the dimension A is larger than twice the dimension B, it is difficult to absorb the circumferential expansion component by the linear groove 43c, and the diameter of the drive shaft 43 increases.

The reason why the dimension B and the dimension D are formed to be substantially equal is that when the dimension D is smaller than the dimension B, the linear groove 43c is shallow. This is because when the dimension D is larger than the dimension B, the linear groove 43c becomes deeper, and the strength of the convex portion of the sliding surface 43b decreases.

According to the rotation detector constructed as described above, when the sliding bearing 24 is formed of metal, the thermal expansion coefficient of the drive shaft 43 formed of resin is larger than that of the sliding bearing 24.
Is larger than the coefficient of thermal expansion, it is necessary to increase the clearance between the slide bearing 24 and the drive shaft 43 in consideration of the thermal expansion. However, a linear groove 43c is formed in the sliding surface 43b of the drive shaft 43.
Are formed, a circumferential expansion component of the drive shaft 43 can be absorbed by the linear groove 43c, and the circumferential expansion component can be prevented from becoming a radial expansion component.
For this reason, compared to the case where there is no linear groove 43c, the sliding bearing 2
The gap between the drive shaft 4 and the drive shaft 43 can be reduced.

Therefore, the play between the slide bearing 24 and the drive shaft 43 can be reduced, and as a result, the drive shaft 4
3 has an effect that it is possible to improve the life and to withstand higher-speed rotation. Further, since the heat radiation area of the sliding surface 43b is increased by the linear groove 43c, it is possible to suppress a rise in the temperature of the drive shaft 43, and from this point, it is also possible to reduce the gap between the slide bearing 24 and the drive shaft 43. it can. Moreover, since the temperature of the drive shaft 43 can be kept low, deterioration of the drive shaft 43 can be reduced.

In the second embodiment, the linear groove 43c is formed on the sliding surface 43b of the drive shaft 43. However, the spiral groove 17 shown in the first embodiment is replaced with the linear groove 43c. It may be formed. Also within the drive shaft 43, shown
Although not shown, a grease reservoir 25 and a plurality of grease supply holes 26 similar to those in the first embodiment are provided .
The grease supply hole 26 communicates with the linear groove 43c. Further, it goes without saying that a linear groove 43c may be formed on the sliding surface of the transmission shaft 15 and the drive shaft 23 of the first embodiment.

[0040]

According to the first aspect of the present invention, a shaft member is provided.
Is made of resin, so that the
The friction coefficient of the g member can be made extremely small. I
Since the grease that gradually flows out of the grease supply hole to the outer peripheral surface of the shaft member can stably maintain the lubrication between the shaft member and the bearing member for a long period of time, the measurement target in which no lubricating oil exists does not exist. To detect the rotation. Therefore,
The shaft member can be smoothly supported by the bearing member without using the lubricating oil in the object to be measured.

[0041] Also, in the invention of claim 2, since grooves along the axial direction on the outer peripheral surface of the shaft member is formed, the shaft member is formed of a material having large thermal expansion coefficient relative to the bearing member Even if the circumferential expansion component of the shaft member is absorbed by the groove, it is possible to prevent the circumferential expansion component from becoming a radial expansion component.
Therefore, it is not necessary to increase the gap between the shaft member and the bearing member in consideration of the thermal expansion, that is, the gap between the shaft member and the bearing member can be reduced, so that the shaft member is smoothly supported by the bearing member. can do. Furthermore, since the groove increases the heat radiation area on the outer peripheral surface of the shaft member, it is possible to suppress a rise in the temperature of the shaft member. In this regard, the gap between the shaft member and the bearing member can be reduced. Can be smoothly supported. In addition, since the temperature of the shaft member can be kept low, deterioration of the shaft member can be reduced. In addition, since grease is supplied to the groove, grease can be supplied evenly to the entire outer peripheral surface of the shaft member.

[0042] Further, in the invention of claim 3, coloration of the same effects as the second aspect.

[Brief description of the drawings]

FIG. 1 is a sectional view of a rotation detecting device shown as a first embodiment of the present invention.

FIG. 2 is a sectional view showing a transmission shaft and a driven gear of the rotation detection device.

FIG. 3 is a sectional view showing a drive shaft of the rotation detection device.

FIG. 4 is a sectional view of a rotation detecting device shown as a second embodiment of the present invention.

FIG. 5 is a sectional perspective view of a main part showing a drive shaft of the rotation detection device.

FIG. 6 is an enlarged view of a VI section in FIG. 5;

FIG. 7 is a cross-sectional view of a rotation detection device shown as a conventional example.

[Explanation of symbols]

 11a Bearing member (bearing hole) 15 Shaft member (transmission shaft) 17 Spiral groove 18 Grease reservoir 19 Grease supply hole 23 Shaft member (drive shaft) 24 Bearing member (sliding bearing) 25 Grease reservoir 26 Grease supply hole 30 Rotation detecting means 42 Shaft member (transmission shaft) 43 Shaft member (drive shaft) 43b Sliding surface (outer peripheral surface) 43c Groove along axial direction (linear groove)

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location G01P 3/487 G01P 3/487 B // F02D 35/00362 F02D 35/00 362G

Claims (3)

(57) [Scope of request for utility model registration] 1. A rotation detecting device comprising: a shaft member for transmitting a rotational motion of a rotating body provided on a measurement object to a rotation detecting means side; and a bearing member for rotatably holding the shaft member. The rotation detection is characterized in that the shaft member has a grease reservoir formed of resin and has a hollow inside, and has a plurality of grease supply holes communicating from the grease reservoir to an outer peripheral surface. apparatus. 2. A plurality of grooves extending in the axial direction are formed on an outer peripheral surface of the shaft member, and the grooves are provided with a grease supply hole.
Rotation detecting device according to claim 1 Symbol mounting, characterized in that the leads. 3. A spiral groove is formed on the outer peripheral surface of the shaft member, and a grease supply hole communicates with the groove.
Rotation detecting device according to claim 1 Symbol mounting, characterized in that that.