JPH0451693B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel multi-point contact internal gear suitable for use in oil motors and oil pumps.

[Conventional technology]

Among oil motors and oil pumps, there are gear motors and gear pumps that are constructed using gears with special tooth shapes, but among the gears used in these,
Trochoid gears are a typical example of gears in which the difference in the number of teeth between an internal gear and an external gear is 1, and the external gear rotates while continuously contacting the internal gear at multiple points.

In this system, a plurality of volume-variable spaces are always formed between an external gear and an internal gear, and fluid is caused to flow in and out of these multiple volume-variable spaces according to the rotation of the gear, thereby producing oil. It constitutes the motor and oil pump.

[Problem that the invention seeks to solve]

However, when constructing an oil motor or oil pump using the above-mentioned trochoid gear, the internal gear is usually fixed to a casing etc. to extract the rotational output of the external gear. Since it rotates and revolves around the gear, it was necessary to extract or apply rotation through a special joint.

For oil motors and oil pumps, it is more efficient to connect the gear directly to the shaft without using a special joint to extract or apply rotation, and there are fewer failures, so the external gear only generates rotational motion. Although it would be advantageous if the trochoidal gear is configured so that rotational torque is transferred between the internal gear and the external gear, it is preferable to have the internal gear perform only revolutions and rotate the external gear only by rotation. It was not possible to configure it to retrieve the output as .

Furthermore, since rotational torque is transferred between the internal gear and the external gear, there is a problem in that the friction between the gears is large and the tooth surfaces are heavily worn.

[Means for solving problems]

In the present invention, in order to solve the above-mentioned problems, the tooth profile of the internal gear is symmetrical with respect to the root curve whose shape is arbitrarily determined as long as it does not interfere with the external gear and the tooth profile center line. and a tip curve consisting of a circular arc that has a large radius of curvature and expands toward the center, and a side surface whose shape is arbitrarily determined as long as it does not interfere with the external gear, and which extends from both end points of the tip arc to the bottom curve. When the external gear revolves or rotates relative to the internal gear, the tooth profile of the external gear is defined by the tooth tip of the internal gear in a coordinate system fixed to the external gear. A tooth root curve formed as an envelope of a circular arc, a pair of side tooth profile curves formed as movement loci of both end points of the tooth tip arc of the internal gear and connected to the tooth root curve, and the above pair of side tooth profile curves. The tooth tip point of the internal gear is connected to the tooth tip arc of the internal gear and the tooth tip curve that engages with the tooth tip arc of the internal gear as a second mesh. It is supported so that it can rotate freely around a central axis.

[Effect]

When a multi-point contact internal gear is configured as described above, the torque exchange between the gears is theoretically zero, so the friction between the gears is small, and the wear on the tooth surfaces is reduced. Since it is possible to restrict the external gear so that it can only revolve, and to make the external gear only rotate, the mechanism for extracting the rotation to the outside becomes extremely simple.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an explanatory diagram showing an embodiment of the multi-point contact internal gear according to the present invention, FIG. 2 is an explanatory diagram showing the tooth profile curve of the internal gear in the embodiment shown in FIG. FIG. 3 is an explanatory diagram showing the root curve of an external gear, FIGS. 4 to 7 are explanatory diagrams showing the tip curve of the external gear,
FIGS. 8 to 11 are explanatory views showing side curves of external gears, and FIGS. 12 to 19 are explanatory views showing one embodiment of the multi-point contact internal gear of the present invention used as an oil motor. It is.

Figures 1 to 11 show the contour lines of the internal gear and external gear on a cross section perpendicular to the axis.
In the figures to FIG. 11, 1 is an internal gear, 2 is an external gear, the center of the internal gear 1 is O, the center point of the external gear 2 is O', and the tooth profile center line of the external gear 2 is l, m,
Let it be n.

The multi-point contact internal gear of the present invention consists of an internal gear with N teeth and an external gear with (N-1) teeth, but as shown in FIG. 1, in this embodiment, N= Case 4 is shown. Therefore, the number of teeth of the internal gear is 4, and the number of teeth of the external gear is 3.

The external gear 2 is always in contact with the internal gear 1 at four locations, and the center of the external gear 2 is in contact with the internal gear 1 at all times.
The internal gear 1 performs a revolution movement around the center O so that O′ rotates along the circle indicated by the chain line in the figure, and at the same time, it rotates around its own center O′ in the opposite direction. By doing so, four sections of volume varying space are always defined between the inner surface of the internal gear 1 and the inner surface of the internal gear 1.

In the state shown in FIG. 1, the external gears 2 are A, B,
Inscribed in internal gear 1 at four points C and D, internal gear 1
There are four sections of volumetric variation spaces P, Q,
The contact points A, B, C, and D move on the tip curve of the internal gear 1 according to the revolution and rotation of the external gear 2 with respect to the internal gear 1, and P, Q, R, and S repeat expansion and contraction alternately due to the rotational movement of the external gear 2, respectively.

Next, referring to FIG. 2, the tooth profile curve of the internal gear 1 in the embodiment shown in FIG. 1 will be explained.

The tip curve of the internal gear 1 is symmetrical with respect to the tooth profile center line OL, and consists of an arc that swells toward the center and has a radius of curvature r. The radius r of this arc is the internal gear 1
The tooth tip curve is set to the maximum value within the limit where the tooth bottom curve of the external gear 2 has first meshing.

A tooth profile curve other than the tooth tip curve of the internal gear 1, i.e.
Since the tooth bottom curve and the side curve are not related to meshing with the external gear, they can be arbitrarily determined to the extent that they do not interfere with the external gear during rotation. In this embodiment, the tooth root curve is an arc centered on the center O of the internal gear 1, and the side curve is a pair of symmetrical arcs with respect to the tooth profile center line OL extending from both end points of the tooth tip arc to the tooth root curve. Make it a straight line. The diameters of these circular arcs and the angles of the pair of straight lines with respect to the center line OL may be set so as not to interfere with the tooth profile curve of the external gear 2 after determining it as described later.

Next, the tooth profile curve of the external gear will be explained with reference to FIGS. 3 to 10.

The tooth bottom curve of the external gear 2 is defined by the tooth bottom curve of the internal gear 1 in the coordinate system fixed to the external gear 2 when the external gear 2 performs the above-mentioned revolution and rotation movement relative to the internal gear 1. It is formed as an envelope of a circular arc.

Figure 3 shows the case where the tooth profile curve of the internal gear 1 is determined as described above, and the external gear 2 sequentially revolves counterclockwise by 15 degrees with respect to the internal gear 1 and simultaneously rotates clockwise by 5 degrees. The outline of the internal gear 1 appearing in the coordinate system fixed to the external gear 2 is indicated by a dashed-dotted line,
The broken line and the two-dot chain line are shown, and the envelope of the tooth tip curve of the internal gear 1 is shown as a solid line, from which the tooth bottom curve of the external gear 2 can be understood. When the tooth bottom curve of the external gear 2 is set in this manner, the external gear 2 and the internal gear 1 are brought into first meshing.

The side tooth profile curve of the external gear 2 is formed as a locus of movement of both end points of the tip arc of the internal gear 1 when the external gear 2 performs the above-mentioned revolution and rotation movement with respect to the internal gear 1. .

4 to 7, the external gear 2 is the internal gear 1.
The locus of both end points of the tooth tip arc that appears on the coordinate plane fixed to external gear 2 when the gear revolves 90 degrees and simultaneously rotates 30 degrees is drawn as a solid line, which can be seen from the figure. These trajectories are drawn in pairs symmetrically with respect to the tooth profile center lines l, m, and n, respectively.

In this case, in the above-mentioned pair of side tooth profile curves, the trajectory drawn by the point at one end of the tooth tip arc of the internal gear and the trajectory drawn by the point at the other end do not connect smoothly at the tooth tip, so The contour line of this portion is set to connect the tooth tip points of the pair of side tooth profile curves and to have second meshing with the tooth tip arc of the internal gear 1.

Figures 8 to 11 show the state when the external gear 2 revolves counterclockwise to a minute angle with respect to the internal gear 1, and simultaneously rotates clockwise to one-third of the revolution angle. It is something.

As shown in FIGS. 8 to 11, the tip curve of the external gear 2 is such that the contact point of the internal gear 1 with the external gear 2 is from the end point M of the tip arc of the internal gear 1 to the end point N. During the switching, it is assumed that there is second meshing with the tip arc of the internal gear 1, and the tooth profile curves on both side surfaces are set so as to be connected smoothly.

The first embodiment of an oil motor using the multi-point contact internal gear of the present invention will now be described.
This will be explained below with reference to FIGS. 2 to 19.

The oil motor shown in this example contains the internal gear and external gear shown in the previous example in a cylindrical casing, and uses the internal gear as an outer rotor and the external gear as an inner rotor. .

In Figures 12 to 19, 3 is an outer rotor;
4 is an inner rotor, 5 is a casing, the center of the outer rotor 3 is O, and the center of the inner rotor 4 is
Let O' be the origin, and the coordinate axes fixed to the casing 5 with O' as the origin are the X and Y axes. 12 to 19 show that the outer rotor 3 is 45mm inside the casing 5.
This figure shows the state when the inner rotor 4 rotates by 15 degrees and the inner rotor 4 rotates by 15 degrees.

The casing 5 houses the outer rotor 3 and the inner rotor 4 therein, and its openings at both ends are closed by an end face member (not shown) at one end having inflow and outflow ports.

The inner rotor 4 is rotatably supported by an output shaft (not shown) so that its center axis coincides with the center axis of the casing 5, and the outer rotor 3 revolves around the casing 5 by means of a plurality of pins 6, 6. In other words, the pins 6, 6 are configured to move in a circular motion as shown by dotted lines in the figure.

Inside the casing 5, between the outer rotor 3 and the inner rotor 4, there are four chambers P, Q,
R and S are formed, and a chamber T with no volume fluctuation is formed between the casing 5 and the outer rotor 3.

The radius of the circle forming the inner contour of the casing 5 is
Since the radius of the circle forming the outer contour of the outer rotor 3 is set to be larger than the radius of revolution of the outer rotor 3, the outer contour of the outer rotor 3 and the inner contour of the casing 5 are always in contact at one point. Further, it is guided by the circular motion of the pins 6, 6, and performs only a revolution movement within the casing 5 due to the pressure of the fluid.

No rotational torque is generated in the outer rotor 3 even if fluid is introduced into any of the chambers P, Q, O, and S. That is, for example, in the state shown in FIG.
When fluid is introduced into the chambers P and Q and the pressure becomes higher than that in the chambers P and Q, the inner rotor 4 begins to rotate clockwise in the figure, and the outer rotor 3 begins to revolve in the counterclockwise direction in the figure. The moment with respect to the center point O of the pressure that the outer rotor 3 receives from the fluid is balanced for each chamber, so no rotational torque is generated in the outer rotor 3, and therefore it is not forced to rotate around the point O. . However, since the pressure in each chamber of the outer rotor 3 is different, the revolution movement is performed due to the pressure difference. This is the same in the states shown in FIGS. 13 to 19, and the outer rotor 3 does not receive any force from the fluid that causes it to rotate, regardless of the relative positional relationship with the inner rotor 4.

Inner contour line of outer rotor 3 and inner rotor 4
is always in contact with the outer contour line of
Each of these chambers is alternately expanded and contracted by the meshing movement of the inner rotor 4 with the outer rotor 3, and when the expansion process shifts to the contraction process, the capacity of each chamber reaches its maximum, and conversely, During the transition from the contraction process to the expansion process, the volume of the chamber is at its minimum.

Each of the above chambers is connected to an inflow port when it is in the expansion process and to an inflow port when it is in the contraction process by a valve (not shown) similar to a known switching valve that is linked to the outer rotor 3 or the inner rotor 4. The inner rotor 4 is configured to communicate with the outflow port, so that both gears can rotate smoothly, and the fluid is transported from the inflow port to the outflow port, and the inner rotor 4 controls the volumetric flow rate of the fluid flowing through the casing 5. It rotates with an angular velocity proportional to .

It should be noted that the configuration of the present invention is not limited to the above-mentioned embodiment, and in the embodiment, the case where the integer N is 4 is shown, but this is not limited to 4, Any integer greater than or equal to 4 can be adopted, and based on these, an oil pump can be constructed in the same way as in the above embodiment, in which case ports, switching valves, etc. can be changed as appropriate. It is something.

Further, although the multi-point contact internal gear of the present invention is particularly suitable for pumps and motors, it can also be used for other machines such as flowmeters, rotary valves, etc., and the present invention applies to all of them. It encompasses everything.

〔Effect of the invention〕

The multi-point contact internal gear of the present invention has low friction between the gears, so there is little wear on the tooth surfaces, and the tooth profile is simple, so machining is easy. If this product can be manufactured at a low cost and is used to construct an oil motor or oil pump, a multi-point contact internal gear that does not require special joints or cams to extract output or provide rotation can be used. can be provided.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of the multi-point contact internal gear according to the present invention, FIG. 2 is an explanatory diagram showing the tooth profile curve of the internal gear in the embodiment shown in FIG. FIG. 3 is an explanatory diagram showing the tooth bottom curve of an external gear, and FIGS. 4 to 7 are explanatory diagrams showing the tooth tip curve of the external gear.
FIGS. 8 to 11 are explanatory views showing side curves of external gears, and FIGS. 12 to 19 are explanatory views showing one embodiment of the multi-point contact internal gear of the present invention used as an oil motor. It is. 1... Internal gear, 2... External gear, 3... Outer rotor, 4... Inner rotor, 5... Casing, 6, 6
…pin.

Claims (1)

[Scope of Claims] 1. An internal gear having N teeth; and an internal gear that is always inscribed at N locations on a cross section perpendicular to the axis of the internal gear, and that The gear revolves around its central axis and rotates around its own central axis, and there is an N between the inner surface of the internal gear and
In a multi-point contact internal gear consisting of an external gear with the number of teeth (N-1) that defines the volume variation space of the compartment, as long as the tooth profile curve of the internal gear does not interfere with the external gear. A tooth root curve whose shape is arbitrarily determined; a tooth tip curve consisting of an arc that is symmetrical with respect to the tooth profile centerline and has a large radius of curvature and expands toward the center; and a tooth tip curve whose shape is defined as long as it does not interfere with the external gear. A coordinate system fixed to the external gear when the tooth profile curve of the external gear performs the revolution and rotation movement, which is arbitrarily determined and consists of a side curve from both end points of the tip arc to the root curve. A root curve formed as an envelope of the tip arc of the internal gear, and a pair of side surfaces connected to the root curve formed as movement loci of both end points of the tip arc of the internal gear. The multi-point contact internal gear is characterized by comprising a tooth profile curve and a tooth tip curve that connects the tooth tip points of the pair of side tooth profile curves and has second meshing with the tooth tip arc of the internal gear. . 2. The multi-point contact internal gear according to claim 1, wherein the internal gear is rotatably supported, and the external gear is rotatably supported around its central axis.