JPH0744780Y2 - Trochoid type oil pump - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention can reduce frictional resistance and prevent noise.
The present invention relates to a trochoidal type oil pump having good pump efficiency.

[Conventional technology and its problems]

Conventionally, a trochoidal oil pump consisting of an outer rotor and an inner rotor formed on trochoidal teeth is used to pump oil to an engine lubrication system of an automobile or the like, and in particular, has a smaller structure and lower noise than a gear type oil pump. It has many advantages, and is widely used in general mass-produced engines.

By the way, in the trochoidal type oil pump, a gap between the pump body and the outer rotor (body side clearance), a gap between the outer rotor and the inner rotor (chip clearance), and a gap between the rotor and the pump cover (cover side). (Clearance) causes pump efficiency and discharge force to decrease. In particular, if the cover side clearance is too large, the suction port and the discharge port will be in communication with each other, and the pump efficiency will be extremely reduced. This time, the cover side clearance will be small, and the flatness of the rotor side surface and the pump body When the flatness of the circular surface is poor, a lot of shavings occur at the partition between the suction port and the discharge port provided on the pump body, which not only generates noise but also discharges metal scraps into the oil. When oil circulates in hydraulic equipment, it may cause inconvenient problems such as adversely affecting each equipment, or
There was a serious defect that the pump body, pump cover, rotor, etc. were damaged and could not be used.

[Means for Solving the Problems]

Therefore, as a result of earnest and repeated studies to solve the above-mentioned problems, the inventor has found that the present invention is applied to the outer rotor and the inner rotor, which are installed in the rotor chamber of the casing, from the tooth root circle near the root circle of the outer rotor. The outer relief part with a minute depth is formed on the entire circumference on the side surfaces up to, and the inner relief part with a minute depth is formed on the entire circumference on the side surface from the vicinity of the root circle of the inner rotor to the tip circle. An outer rotor and an inner rotor may be a trochoidal type oil pump provided so as to communicate with an inter-tooth space between the outer rotor and the inner rotor, or an outer rotor and an inner rotor installed in a rotor chamber of a casing. Around the inner surface of the rotor chamber of the casing that corresponds to the position of the facing surface from near the root circle of the inner rotor to near the root circle of the inner rotor. A trochoidal type oil pump is provided in which a casing relief portion having a minute depth is formed, and the casing relief portion is provided in communication with the interdental space, whereby frictional resistance can be reduced, noise can be prevented, and pump efficiency can be improved. It is good and can prevent remarkable damage, and solves the above-mentioned subject.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

Reference numeral A denotes a casing, which is separable from the pump body 1 and the pump cover 2. A rotor chamber 3 is formed inside the casing A. In particular,
A rotor chamber 3 as a cylindrical recess is formed inside the pump body 1, and a substantial rotor chamber 3 is formed with the inner surface of the disc-shaped pump cover 2. An outer rotor 4 having internal teeth (five teeth in the embodiment) provided in the rotor chamber 3,
The inner rotor 5 provided with external teeth (four teeth in the embodiment) is eccentrically installed while being meshed with each other. The outer rotor 4 and the inner rotor 5 have trochoidal teeth, and the inner rotor 5 has one tooth less than the outer rotor 4 by one tooth. Are configured to rotate with a delay of one tooth. Further, the inner rotor 5 is always rotated at any rotation angle.
Of the inner rotor 5 comes into contact with the tooth top or the tooth bottom of the outer rotor 4, and an inter-tooth space s is formed between the outer tooth and the adjacent tooth top of the inner rotor 5, and the inter-tooth space s is During one revolution, it grows and shrinks, then inhalation,
Discharge is performed.

A suction port 6 and a discharge port 7 are formed on both left and right sides (see left and right sides in FIG. 2) of the circular surface 1a of the rotor chamber 3 of the pump body 1, and a port partition 8 is formed therebetween. . Passage from its suction port 6
It is constructed so as to communicate with the outside of the casing A via the discharge port 7 and the passage 9b, respectively (see FIGS. 6 and 7).

The rotor or the casing A is provided with a relief portion to form a gap. There are a plurality of examples in which the relief portion is formed.

The first embodiment of the escape portion is shown in FIG. 1, FIG. 3, FIG. 4, and FIG.
As shown in the figure etc., the outer clearance that reduces the wall thickness by a small amount on the side surface (including both one side surface and both side surfaces) from the root circle D _4b to the tip circle D _4c of the outer rotor 4 Part 4a
Are formed all around. Further, the side surfaces than near the root circle D _5b of the inner rotor 5 until the addendum circle D _5c, inner relief portion 5a as the wall thickness becomes very small amount thinner is formed on the entire circumference. The outer escape portion 4a and the inner escape portion 5a are provided so as to communicate with the inter-tooth space s between the outer rotor 4 and the inner rotor 5. An example formed on only one side surface is described in FIG. 7, and an example formed on both side surfaces is clearly shown in FIG. 1, FIG. Both the circular surface 1a of the pump body 1 and the inner surface 2a of the pump cover 2 in the first embodiment of the relief portion are formed as flat surfaces. Further, in the outer relief portion 4a and the inner relief portion 5a, specifically, an appropriate amount to be shaved so that the wall thickness is thin is about 0.005 mm to about 0.015 mm, and the interdental space s It is preferable that the oil (fluid) trapped inside is leaked to the outside in a minute amount.

The second embodiment of the relief portion is, as shown in FIGS. 6 and 8,
Outer rotor 4 installed in rotor chamber 3 of casing A
In the inner rotor 5, the entire circular surface 1a or inner surface 2a of the rotor chamber 3 of the casing A corresponding to the facing surface position from the vicinity of the root circle D _4b of the outer rotor 4 to the vicinity of the root circle D _5b of the inner rotor 5. A casing escape portion B having a minute depth is formed on the entire circumference. The casing escape portion B is
The body escape portion 1b and the cover escape portion 2b are collectively referred to.

As an example of the casing escape portion B (second embodiment), which is the body escape portion 1b, as shown in FIGS. 5 and 8, from the vicinity of the root circle D _4b of the outer rotor 4 to the tooth bottom of the inner rotor 5. a circular surface 1a of the port partition portion 8 of the pump body 1 which corresponds to the outer diameter surface position to around the circle D _5b is present, the body relief portion 1b is formed. In this case, the outer rotor 4 and the inner rotor 5 include the outer escape portion 4a.
Also, the inner escape portion 5a is not formed. In the body relief portion 1b, the appropriate amount to be cut so that the wall thickness becomes a minute amount is about 0.005 mm to about 0.015 mm, and the oil (fluid (fluid) trapped in the interdental space s It is preferable that a small amount) leaks to the outside.

Further, as an example of the casing escape portion B (second embodiment) which is the cover escape portion 2b, as shown in FIG. 6, from the root circle D _4b of the outer rotor 4 to the root circle D of the inner rotor 5,
_A cover escape portion 2b is also formed on the inner surface 2a of the pump cover 2 corresponding to the outer diameter surface position up to the vicinity of _5b . Also in this case, the outer escape portion 4a and the inner escape portion 5a are not formed in the outer rotor 4 and the inner rotor 5.
In the fourth embodiment, the amount of cutting so that the wall thickness is reduced by a minute amount is the same as in the case of FIG.

Further, as an example of the casing escape portion B (second embodiment) which is the cover escape portion 2b which is the body escape portion 1b, both the body escape portion 1b and the cover escape portion 2b may be provided as shown in FIG. .

Further, as shown in FIGS. 9 to 11, a balance port P is formed in the pump cover 2 as required. The balance ports P correspond to the suction port 6 and the discharge port 7, respectively, and are formed in two places with substantially the same size and position. The balance ports P, P have no passage or the like and are simply formed in a concave shape.

In the case of the first embodiment of the relief portion, the one shown in FIG. 9 has an outer relief portion 4a and an inner relief portion 5a, and, in addition to this, the outer relief portion 4a and the inner relief portion 5a.
Is provided so as to be located on the pump cover 2 side where the balance ports P, P are formed.

In addition, in the case of the second embodiment of the escape portion, the casing escape portion B which is the body escape portion 1b or the cover escape portion 2b is formed in the case of the second embodiment of the escape portion. For example, as shown in FIGS. 10 and 11, the pump cover 2
A cover escape portion 2b is formed on the inner surface 2a where the balance ports P, P are present. Also in this case, the outer escape portion 4a and the inner escape portion 5a are not formed in the outer rotor 4 and the inner rotor 5.

In the figure, 10 is a drive shaft, which is inserted and fixed to the inner rotor 5. A packing 11 is interposed and fixed between the pump body 1 and the pump cover 2. Reference numeral 12 is a fastener such as a bolt and a nut. The fastener 12 secures the flange portion of the pump body 1 and the peripheral edge portion of the pump cover 2 to each other.

[Effect of device]

In the invention of claim 1, the rotor chamber 3 of the casing A is
In the outer rotor 4 and the inner rotor 5 installed inside the outer rotor 4, from the vicinity of the root circle D _4b of the outer rotor 4 to the tip circle D _4c
The outer relief portion 4a having a minute depth is formed on the entire circumference on the side surfaces up to and around the root circle D _5b of the inner rotor 5 and the tip circle D _5c.
The inner relief portion 5a having a minute depth is formed on the entire circumference on the side surfaces up to the outer relief portion 4a and the inner relief portion 5a, and the inter-tooth gap s between the outer rotor 4 and the inner rotor 5 is formed.
By using the trochoidal type oil pump provided in communication with the first, it is possible to firstly eliminate galling and to have excellent pump efficiency, to prevent noise, and secondly to have good durability, and thirdly. Metal dust is discharged into the oil, and when the oil circulates in the hydraulic equipment, it is possible to prevent each equipment from being adversely affected, and fourthly, it is possible to reduce fluctuations in pulsation.

Explaining these effects in detail, the outer relief portion 4a having a minute depth is formed on the entire circumference on the side surface from the vicinity of the root circle D _4b of the outer rotor 4 to the tip circle D _4c. An inner relief portion 5a with a minute depth is formed all around the side surface from the circle D _5b to the tip circle D _5c , and the outer relief portion is formed.
4a and the inner relief portion 5a are provided so as to communicate with the inter-tooth space s between the outer rotor 4 and the inner rotor 5, so that, for example, when the flatness of the rotor side surface and the flatness of the circular surface inside the pump body are poor. Even if there is, the outer escape portion 4a and the inner escape portion 5a can prevent the port partitioning portion 8 from being scratched, and the noise can be prevented.

At this time, on the side surfaces of the outer rotor 4 and the inner rotor 4, portions other than the relief portions have a predetermined width, so that the inner rotor 4 and rattling while the inner rotor 4 is being driven can be completely eliminated.

As described above, although the occurrence of galling can be prevented, the outer relief portion 4a and the inner relief portion 5a do not allow the oil to flow backward, and are only slightly separated between the rotor and the circular surface 1a of the pump body 1. It is possible to provide a trochoidal type oil pump which is in the form of a film in a certain amount, which has a lubricating action and can prevent noise, and which is durable.

Further, as in the conventional case, when scraping occurs, metal waste is discharged into the oil, and when the oil (fluid) circulates in the hydraulic equipment, inconvenient problems such as adversely affecting each equipment may occur, Alternatively, pump body 1, pump cover 2,
Although there was a serious defect that the rotor etc. were damaged and it became unusable, these defects can be reliably eliminated by providing the outer escape portion 4a and the inner escape portion 5a as in the present invention. .

Further, during the pump operation, the oil (fluid) trapped in the interdental space s formed by the outer rotor 4 and the inner rotor 5 is compressed when the volume of the interdental space s decreases, A part of the trapped oil flows out to the outer escape portion 4a and the inner escape portion 5a, though a little, and it is possible to buffer the sudden pressure change of the oil and prevent the generation of noise and vibration. .

Next, in the invention of claim 2, in the outer rotor 4 and the inner rotor 5 installed in the rotor chamber 3 of the casing A, from the vicinity of the root circle D _4b of the outer rotor 4,
The circular surface 1a or the inner surface 2a of the rotor chamber 3 of the casing A corresponding to the facing position of the inner rotor 5 up to near the root circle D _5b.
The casing relief portion B having a minute depth is formed on the entire circumference, and the casing relief portion B is a trochoidal type oil pump provided in communication with the interdental space s. It can be made highly efficient, which in turn prevents noise, secondly has good durability, and thirdly discharges metal scrap into the oil, which adversely affects each equipment when it circulates in the hydraulic equipment. It is possible to prevent the above-mentioned effects, and fourthly, it is possible to reduce the fluctuation of the pulsation.

Particularly, in the invention of claim 2, the casing escape portion B having a minute depth is formed on the entire circumference of the circular surface 1a or the inner surface 2a of the rotor chamber 3, and unlike the claim 1, the outer rotor 4 and the inner rotor 5 are formed. Instead of providing the respective locations, the same location is formed as the location, and there is an advantage that the processing cost can be reduced.

[Brief description of drawings]

The drawings show an embodiment of the present invention, in which FIG. 1 is a sectional view of the present invention corresponding to a portion taken along the line II of FIG. 2, and FIG. 2 is a side view of the present invention with a pump cover removed. 3 and 4 are perspective views with a part of the outer rotor cut away, FIG. 4 is a perspective view of the inner rotor, FIG. 5 is a perspective view of a pump body, and FIGS. 6 to 9 are other embodiments of the present invention. FIG. 10 is a sectional view of an example, FIG. 10 is a perspective view of a pump cover, and FIG. 11 is a sectional view of another embodiment of the present invention using the pump cover of FIG. A ... Casing, 1 ... Pump body, 1a ... Circular surface, 2 ... Pump cover, 2a ... Inner surface, B ... Casing relief part, 3 ... Rotor chamber, 4 ... Outer rotor, 4a
…… Outer relief, D _4b , D _5b …… Root circle, D _4c , D _5c …
… Tip circle, 5… Inner rotor, 5a… Inner relief part, s… Interdental space.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazuo Tohsaka 1-2757 Hirosawa-cho, Kiryu-shi, Gunma Yamada Mfg. Co., Ltd. (56) Bibliography Sho 55-71007 (JP, U)

Claims (2)

[Scope of utility model registration request] 1. An outer rotor and an inner rotor, which are installed in a rotor chamber of a casing, wherein an outer escape portion having a minute depth is formed on the entire circumference on a side surface from a vicinity of a root circle to a tip circle of the outer rotor. An inner relief portion with a minute depth is formed on the entire circumference on the side surface from the root circle to the tip circle of the rotor, and the outer relief portion and the inner relief portion are in the inter-tooth gap between the outer rotor and the inner rotor. Trochoidal type oil pump characterized by being provided in communication. 2. A circular surface of a rotor chamber of a casing corresponding to a facing surface position from the vicinity of the root circle of the outer rotor to the vicinity of the root circle of the inner rotor in an outer rotor and an inner rotor installed in the rotor chamber of the casing. Alternatively, a trochoidal oil pump is characterized in that a casing escape portion having a minute depth is formed on the entire inner surface and the casing escape portion is provided so as to communicate with the interdental space.