JPH04287873A - Inscribing type gear motor - Google Patents

Abstract

PURPOSE:To provide an inscribing type gear motor of a long life and little noise. CONSTITUTION:The rotating direction terminal ends of both rotors 2, 3 at an inlet 10 and the rotating direction starting ends of both rotors 2, 3 at a protruding port 11 are set in such positions as to partition a space less by 3-20% in volume than a space with the maximum volume among spaces formed between tooth faces of both rotors 2, 3.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] This invention provides two
This invention relates to an internal gear motor having two gears (an outer rotor and an inner rotor).

0002

2. Description of the Related Art Hitherto, as this type of internal gear motor, those shown in FIGS. 3 and 4 are known.

The internal gear motor shown in these figures has a ring-shaped outer rotor 2 loosely inserted into a casing 1 so as to be freely rotatable, and a support shaft 4 inserted through the casing 1. The inner rotor 3 is rotatably supported by the inner rotor 3. The inner peripheral surface of the outer rotor 2 has a tooth surface 2 having N teeth (N=7 in the example).
A is formed on the outer circumferential surface of the inner rotor 3, and tooth surfaces 3a each having (N-1) teeth are formed between these tooth surfaces 2a and 3a. A space S is defined by contact between the apex and the inner circumferential surface of the outer rotor 2 .

When the inner rotor 3 is rotated around the rotation center O1, the outer rotor 2 rotates around the rotation center O2 while maintaining contact with the inner rotor 3, and the space S gradually changes its volume. And these spaces S...
When it is located at the part indicated by the symbol A on the straight line passing through the centers of rotation O1 and O2, its volume becomes the maximum, and when it is located at the part indicated by the symbol B, its volume is the minimum, and during that time, its volume is the maximum. It gradually increases and decreases as it rotates.

Furthermore, in the casing portion facing the end surfaces of both rotors 2 and 3, there is a suction port (high-pressure side port) that opens toward the space S and supplies fluid such as high-pressure hydraulic oil into the space S. ) 5 and a discharge port (low-pressure side port) 6 for discharging fluid from within the space S are opposed to both sides of the straight line connecting the rotation centers O1 and O2 and extend along the rotational direction of both the rotors 2 and 3. It is formed in such a way that it exists. The terminal end of the suction port 5 in the rotational direction of both rotors 2 and 3 and the starting end of the discharge port 6 in the rotational direction of both the rotors 2 and 3 partition a space S having the largest volume among the spaces S between the tooth surfaces. This is because setting it at this position maximizes the so-called volumetric efficiency and maximizes the efficiency of the gear motor.

In the gear motor having such a configuration, when high pressure fluid is supplied from the suction port 5, this pressure fluid flows into the space S on the left side in FIG. The support shaft 4 is rotated in the direction in which the object is enlarged, that is, in the direction shown by the arrow in the figure, and the support shaft 4 is rotated accordingly, producing an output that rotates the rotated object. Furthermore, as both rotors 2 and 3 rotate, the space S moves while shrinking and opens into the discharge port 6, so that the pressure fluid is discharged.

[0007] The tooth profile of the tooth surfaces 2a and 3a may be an involute type, a cycloid type, or the like in addition to the trochoid type in this example.

[0008]

[Problems to be Solved by the Invention] However, in the internal gear motor having the above configuration, the minute pulsations of the pressure fluid generated in the hydraulic supply source, and the transmission between the outer rotor and the inner rotor caused in part by this minute pulsation, are difficult to solve. Due to fluctuations in torque, vibratory forces are constantly acting on both rotors in the direction of rotation, and this force causes the specified clearance between the tooth surfaces of both rotors to be set in consideration of machining accuracy. In the range of In addition, the tooth surfaces are damaged due to collisions between the tooth surfaces, which significantly shortens the life of the rotor.

[0009]

OBJECTS OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an internal gear motor that produces less noise and has a longer life.

0010

[Means for Solving the Problems] In order to achieve the above object, an internal gear motor of the present invention includes an outer rotor and an inner rotor in a casing, and the outer rotor and the inner rotor are formed in the casing. In an internal gear motor, a high-pressure side port and a low-pressure side port are formed that open toward the space between the tooth surfaces and extend along the rotational direction of both rotors. and the starting end of the low-pressure side port in the rotational direction of both rotors at a position that partitions a space whose volume is reduced by 3 to 20% from the space where the volume is maximum among the spaces between the tooth surfaces. It is set at a position on the low pressure side port side.

[0011]

[Operation] In the internal gear motor of the present invention, the terminal end of the high-pressure side port in the rotational direction of both rotors and the starting end of the low-pressure side port in the rotational direction of both rotors are located in the space between the tooth surfaces of the two rotors. 3 to 3 from the space with the largest volume
Since the position is set to partition the space where the volume has decreased by 20%, the space with the largest volume (hereinafter referred to as the maximum space) gradually shrinks due to the rotation of both rotors, and becomes 3 to 20% of the maximum volume.
% volume, the space is sealed, but since the maximum space before sealing is partially open to the high pressure side port, as the maximum space decreases, the pressure fluid in the maximum space decreases. A portion of the pressure fluid flows back into the high pressure side port, which suppresses the micro pulsations of the pressure fluid that occur in the hydraulic supply source.

As mentioned above, the terminal end of the high pressure side port and the starting end of the low pressure side port are placed at a position that separates the space between the tooth surfaces whose volume is reduced by 3 to 20% from the space where the volume is maximum. The setting is that less than 3% is almost the same as the maximum space, so backflow of pressure fluid does not occur, and 2%
This is because if it exceeds 0%, the volumetric efficiency will decrease and the efficiency as a gear motor will deteriorate.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of an internal gear motor according to the present invention, and the same parts as those of the conventional example shown in FIGS. 3 and 4 are denoted by the same reference numerals, and the explanation thereof will be omitted.

The gear motor shown in FIG. 1 differs from the gear motor shown in FIGS. 3 and 4 in the configuration of the suction port and discharge port.

That is, FIG. 3 shows the space S formed between the tooth surfaces 2a and 3a of the outer rotor 2 and the inner rotor 3.
...The space indicated by the symbol S1 is 3 to 20% of the maximum space.
In this state, the space S1 is partitioned at the end side A1 in the rotational direction by contact between the tooth surface 2a and the tooth surface 3a located on the straight line connecting the rotation centers O1 and O2 of both rotors 2 and 3. , A starting end side A2 in the rotation direction is partitioned off by contact between the tooth surface 2a and the tooth surface 3a adjacent in the rotation direction from this A1.

The suction port (high pressure side port) 10 has its terminal end located at the rotation center O1 in the rotational direction of both rotors 2 and 3.
, O2, that is, the position A1 is set. On the other hand, the discharge port (low pressure side port)
11, the starting ends of both rotors 2 and 3 in the rotational direction are set at the above-mentioned position A2. Note that the other configurations of the suction port 10 and the discharge port 11 are similar to the conventional example shown in FIG. 3 above.

When operating the gear motor configured as described above, pressure fluid is supplied from the hydraulic supply source to the suction port 10.
When supplied to the space S, this pressure fluid flows into the space S on the left side in FIG. The shaft 4 rotates to rotate the rotated body, and as the rotors 2 and 3 rotate, the space S becomes the maximum space, and then moves in the circumferential direction while shrinking and enters the discharge port 6. It opens and the pressure fluid is discharged. By repeating this, both rotors 2 and 3 are continuously rotated by the pressure fluid.

In the above case, due to the rotation of both rotors 2 and 3, the space S located on the suction port 10 side gradually expands to the maximum space, and then gradually contracts, but the maximum space 3
When the space S1 has a volume of ~20%, the space S1 is sealed. The maximum space before this seal is suction port 1
0, so as the maximum space is reduced, a part of the pressure fluid in the maximum space flows back into the suction port 10,
This suppresses minute pulsations of the pressure fluid that occur in the hydraulic supply source.

Therefore, it is possible to suppress the relative vibrations between the two rotors 2 and 3 caused by minute pulsations of the pressure fluid generated in the hydraulic supply source, as well as the vibrations between the outer rotor casing and the outer rotor, thereby suppressing noise. In addition, it is possible to improve the life of the rotors 2 and 3.

Next, the effects of this invention will be demonstrated by giving experimental examples. That is, the gear motor of this example and the conventional gear motor were manufactured, operated under the same conditions, and the noise was measured. The conditions were an oil pressure of 50 kg, an oil temperature of 80° C., and a rotation speed of 2000 rpm. The results are shown in Figure 2.

As is clear from this figure, the noise characteristics of the example are that the frequency distribution is narrower than that of the conventional one, the total amount of wasted energy spent on noise is small, and in particular, there is less harsh high-frequency noise. This is clearly shown.

[0022]

As explained above, according to the internal gear motor of the present invention, the terminal end of the high-pressure side port in the rotational direction of both rotors and the starting end of the low-pressure side port in the rotational direction of both rotors are This is the position that partitions the space between the tooth surfaces of the rotor, which has a volume reduced by 3 to 20% from the space with the maximum volume, and is set on the low pressure side port side, so that the rotation of both rotors When the maximum space gradually shrinks to a space with a volume of 3 to 20% of the maximum space, the space is sealed, but since the maximum space before sealing is partially open to the high pressure side port, the maximum space As the space is reduced, a portion of the pressure fluid in the maximum space flows back to the high pressure side port, and this can suppress minute pulsations of the pressure fluid that occur in the hydraulic pressure supply source. Therefore, it is possible to suppress the relative vibrations between the two rotors caused by minute pulsations of the pressure fluid generated in the hydraulic supply source, as well as the vibrations between the outer rotor and the casing, thereby suppressing noise. This has the excellent effect of increasing the life of the rotor.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of a gear motor according to an embodiment of the present invention.

FIG. 2 is a graph showing noise characteristics.

FIG. 3 is a front sectional view of a conventional gear motor.

FIG. 4 is a side sectional view of a conventional gear motor.

[Explanation of symbols]

1 Casing 2 Outer rotor 3 Inner rotor 2a, 3a　Tooth surface 10 Suction port (high pressure side port) 11 Discharge port (low pressure side port) S Space

Claims (1)

[Claims] 1. An annular outer rotor rotatably provided in a casing, and a disc-shaped inner rotor inscribed in the outer rotor and rotating in the same direction as the outer rotor, A high-pressure side port and a low-pressure side port are provided in the casing and open toward the space between the tooth surfaces formed on the inner circumferential surface of the outer rotor and the outer circumferential surface of the inner rotor, and extend along the rotational direction of both rotors. In an internal gear motor in which a port is formed, the terminal end of the high-pressure side port in the rotational direction of both rotors and the starting end of the low-pressure side port in the rotational direction of both rotors are connected by a volume of the space between the tooth surfaces. 3-20 from the maximum space
An internal gear motor characterized in that the internal gear motor is set at a position that partitions a space whose volume is reduced by % and is located at a position on the low pressure side port side.