JPS597036B2 - Internal gear pump motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in internal gear pump motors, and more particularly, to an internal gear pump motor equipped with an improved filler piece that divides the space between the teeth of a pinion and an internal gear into a low pressure region and a high pressure region. Regarding.

Due to its structure, internal gear pumps (or motors) have difficulty compensating for pressure wear on the tips of their teeth, and most internal gear pumps on the market do not have a mechanism for compensating for pressure wear on the tips of their teeth.

An example of an internal gear pump with a tooth tip pressure wear compensation mechanism is shown in Japanese Patent Publication No. 51-23721, in which a component called a radial piston is placed outside the internal gear, and the piston is guided to the back pressure chamber. There is a system that uses hydraulic pressure to press the internal gear from the outside against the pinyan and filler piece to seal the tips of the teeth of both gears and compensate for wear.

This method has the disadvantage that the radial piston is further placed outside the internal gear, increasing the external size of the pump, and because the internal gear, filler piece, and radial piston are floating parts, differences in component dimensions are extremely important. The disadvantage is that it has to be strictly controlled.

One way to improve these shortcomings is to guide the pinion and internal gear with their own bearings.In other words, the internal gear is not floating like the pinion, and is placed so that only rotational movement is possible in the running position. This is to compensate for pressure wear in the radial direction from the space surrounded by the tooth tip circle of the gear, that is, from the inside of the internal gear.

The following patents relate to methods for radial pressurization from the inside of internal gears:

U.S. Patent No. 3,486,459 creates a slit in the filler piece and introduces pressure oil into the slit to elastically deform the filler piece outward to seal the tooth tips. There is a problem.

Also, JP-A-52-16008, JP-A-52-9940
No. 8 has a fully split filler piece and a needle preloaded with a spring is placed between the outer piece and inner piece to provide radial preventive force and pressure wear compensation on the tooth tips. There were problems such as the shape of the piece was complex and difficult to process, and there were many small parts that raised concerns about durability.

It is an object of the present invention to provide an internal gear pump motor having a split filler piece that eliminates the drawbacks of conventional products, does not require a radial piston, has a simple structure, is easy to manufacture, and is durable. Therefore, is the present invention a filler piece? A plate-shaped inner piece that makes oil-tight sliding contact with the tooth tip of the pinion, a plate-shaped outer piece that makes oil-tight sliding contact with the tooth tip of the internal gear, and is press-fitted in the axial direction with the outer periphery of the inner piece and outer piece in contact with each other. It is formed by a plurality of elastic pipes, a high-pressure side stopper pin and a low-pressure side stopper pin that support these members in the circumferential direction, and a space surrounded by the inner piece, outer piece, and high-pressure side stopper pin is communicated with the high-pressure side by a communication passage. It was made to look like this.

With this configuration, the inner piece and the outer piece are always pressed against the tips of the teeth of both gears due to the elasticity of each part constituting the filler piece, and are brought into oil-tight sliding contact to perform a sealing action.

Furthermore, when pump pressure is generated, the pressure oil is transferred to the inner 2-piece,
It enters the space surrounded by the outer piece and the high-pressure side stopper pin via the connecting passage, fills the outer high-pressure side half area of the elastic pipe, presses it toward the low-pressure side, causes elastic deformation, and further presses the inner piece and outer piece. and seal the tooth tip.

Moreover, these inner piece and outer piece are held stably in the circumferential direction by a high-pressure side stopper pin and a known low-pressure side stopper pin that cooperates with the inner piece, thereby stabilizing pump operation.

In this way, the present invention includes both stopper pins, an inner piece,
The structure uses the elasticity of the outer piece and the elastic pipe that presses both to compensate for wear on the tooth tip seal, so there is no need for strict processing tolerances, the structure is simple, and it can be manufactured separately, making it inexpensive. It is possible to provide an internal gear pump motor having a split filler piece that is easy to use, does not require a radial piston, and is made of a member with a simple shape that is difficult to break, so it is durable.

Embodiments of the present invention will be described below with reference to the drawings. In FIGS. 1 to 3, a pinion 3 is supported by a bearing 12 of a housing 1 and a bearing 13 of a housing 2.

The internal gear 4 that meshes with this is supported by a bearing 14 of the housing 1.

On both sides of both gears, there are side plates 15, 16 which have the function of compensating pressure wear in the axial direction in the high pressure region.

The side plates 15 and 16 may omit the pressure wear compensation function or may be integrated with the housings 1 and 2.

The following parts are incorporated into the tooth tip spaces of both gears as filler pieces to separate the suction area and the cavity pressure area.

In other words, the inner piece 5 that seals the tooth tip of the pinion 3
There are an outer piece 6 that seals the tooth tips of the internal gear 4, and a plurality of highly elastic pipe parts 9, 10, 11 having approximately the same length as the width of the pinion 3 held between them.

The low pressure side stopper pin 7 is supported by the housings 1 and 2, and supports the preload of the elastic pipe pushed into the wedge space formed by the inner piece 5 and outer piece 6 with a certain preload, and also allows the pump to generate full pressure. In this case, the hydraulic pressure acting on the inner piece 5, outer piece 6, and elastic pipe material 9 is supported.

The high pressure side stopper pin 8 is used to prevent the inner piece 5 and outer piece 6 from being caught by both gears when the pump is started.

The number of elastic pipes 9, 10, 11 may be any plural number such as 3 or 2, and the inner piece 5 is pressed into the wedge space formed by the inner piece 5 and the outer piece 6 with a certain preload force. is pressed against the tooth tip of the pinion 3, and the outer piece 6 is pressed against the tooth tip of the internal gear 4.

Therefore, when the pinion 3 meshes with the internal gear 4 and is driven, the pressure oil generated by the pumping action of both gears seals the tooth tips and the pressure of the pump increases.

In the space surrounded by the inner piece 5, the outer piece 6, and the pin 8, cutouts 1γ and 18 are provided as communication passages for guiding pressure oil from the high-pressure side toward the elastic pipes 9, 10, and 11.

In addition, the elastic pipes 10 and 11 other than the elastic pipe 9 that are in contact with the stopper pin 7 have cutouts 19 and 20 on their end surfaces to introduce pressure oil.
is provided.

The pressure oil passing through these notches 17, 18, 19, 20 fills the outer lower half area of the elastic pipe 9.

The notches 17, 18, 19, 20 may be radial through holes, or instead of the notches, one or both of the side plates 15, 16 may correspond to these notches as communication paths with the high pressure side. It goes without saying that you can also serve miso.

The elastic pipe 9 is further pressed against the stopper pin 7 by the pressure oil guided from the high-pressure side through the communication path and is further elastically deformed, thereby sealing the pressure oil more reliably at the contact point between the inner piece 5 and the outer piece 6. I can do that.

In order to increase the elastic deformation of the elastic pipe 9, the side plates 15,1
6 can be provided with a slot that communicates the inside of the elastic pipe 9 with the low pressure side to allow the inside of the elastic pipe 9 to communicate with the suction side.

Appropriate preload can be obtained by incorporating an elastic pipe with a larger outer diameter and pushing it into the wedge formed by the inner piece 5 and outer piece 6 using the stopper pin 7.

As described above, it is possible to compensate for pressure wear in the radial direction of the internal gear pump motor using the easily manufactured elastic pipe, inner piece, and outer piece, so that an inexpensive internal gear pump motor can be provided.

In the above-mentioned case, the elastic pipe 9 and the stopper pin 7 are in line contact, and the surface pressure becomes quite high. In order to prevent this, Fig. 4 shows a sliding pad 21 with a cylindrical receiving surface that enables surface contact. Elastic pipe 22 and stopper pin 23
It was installed between.

In this example, there are only two elastic pipes, 22 and 24, and there are no notches on the end faces to guide the pressure oil. Inner piece 25 and outer piece 26 are provided with through holes 27 and 28 or end face notches for introducing pressure oil from the gear side.

This is to more delicately balance the pressure between the inside and outside of the inner piece and outer piece compared to the above one.3 In other words, in the above one, high pressure oil was guided all the way to the bottom of the elastic pipe 9. In this embodiment, the high pressure oil is guided only to the bottom of the elastic pipe 24.
A pressure intermediate between the suction pressure and the high pressure is introduced between and 22, and it is possible to maintain a more delicate pressure balance for various operating conditions.

The preload of the elastic pipe can also be adjusted by adjusting the thickness of the sliding pad 21.

In the embodiment shown in FIG. 5, the elastic pipe 29 is brought into contact with the inner circumferential surfaces of the inner piece and the outer piece, which have cylindrical receiving surfaces 35 and 36.

Bringing elastic pipes into contact The above two examples are not difficult if the pipes have very high elasticity, but if the elasticity of the pipes is not very high, the dimensional tolerances of the parts must be held very tightly.

In order to avoid this difficulty, an example in which contact between elastic pipes is avoided is shown in FIG. 5.

In this case, the elastic pipe 29 fits into a cylindrical concave surface 35, 36 provided on the inner piece 30 and the outer piece 31.

When using an internal gear motor, rotation is required in both directions, so two filler pieces are arranged symmetrically between the pinion and the internal gear as shown in Figure 6, one for clockwise rotation and one for left rotation. One pin 32 is used as a stopper pan for rotation.

The sliding pad 33 is attached to the pin 32 to reduce the surface pressure.
and the elastic pipe 34.

As described above, the present invention includes a plate-shaped inner piece that brings the filler piece into oil-tight sliding contact with the tooth tip of the pinion, a plate-shaped outer piece that makes oil-tight sliding contact with the tooth tip of the internal gear, and the inner piece and the outer piece. It is made of a plurality of sandwiched elastic pipes and a high-pressure side stopper pin and a low-pressure side stopper pin that support them in the circumferential direction, so the inner piece and outer piece are always placed on the tips of the teeth of both gears due to the elasticity of these parts. Because of the oil-tight sliding contact and seal, it is possible to easily manufacture an internal gear pump motor that can completely compensate for tooth tip wear without requiring strict manufacturing tolerances.

[Brief explanation of drawings]

Fig. 1 is a sectional view along the internal gear side of an internal gear pump motor according to an embodiment of the present invention, Fig. 2 is a sectional view taken along the line 4 is a sectional view of the filler piece portion of another embodiment, similar to FIG. 1, and FIG. 5 is a sectional view of the filler piece portion of yet another embodiment. , FIG. 6 is a sectional view similar to FIG. 1 of an internal gear pump motor according to yet another embodiment. 1, 2... Housing, 3... Pinion, 4... Internal gear, 5, 25, 30
...Inner peace, 6, 26, 31...
... Outer piece, 7, 23, 32 ... Low pressure side stopper pin, 8 ... High pressure side stopper pin,
9, 10, 11, 22, 24, 29, 34...
Elastic pipe, 15, 16...Side plate, 17, 18
, 19, 20, 27, 28... Notch or through hole, 21, 33... Sliding parts} 35
, 36... Cylindrical concave surface.

Claims (1)

[Claims] 1. In an internal gear pump motor consisting of a housing, a pinion and an internal gear that are rotatably housed within the housing and mesh with each other, and a sickle-shaped filler piece disposed between the pinion and the internal gear, the filler piece is a high-pressure side stopper pin supported by the housing, a low-pressure side stopper pin, a plate-shaped inner piece that makes oil-tight sliding contact with the tooth tip of the pinion between both stopper pins, and an oil-tight seal on the internal gear tooth tip between both stopper pins. The inner piece has a plate-shaped outer piece that slides into contact with the inner piece, and a plurality of elastic pipes that are press-fitted in the axial direction so that their outer peripheries are in contact with the inner piece and the outer piece, and that have approximately the same length in the axial direction as the width of the pinion; An internal gear pump motor characterized in that the space surrounded by the outer piece and the high-pressure side stopper pin is connected to the high-pressure side through a passage.