JPS5821081B2 - Rotary Souch - Google Patents

Abstract

An improved rotor and gear assembly for rotary mechanisms of the trochoidal type, in which a rotor having a central bore is mounted for rotation on a shaft, with a bearing between the rotor bore and the journal portion of the shaft. An internally toothed ring gear is secured to a side face of the rotor for engagement with a stationary spur gear to maintain phasing between the rotor and its trochoidal housing during the planetary and rotary motion of the rotor within the housing. The ring gear is mounted on the rotor in such a manner as to maintain concentricity therewith while permitting differences in thermal expansion between the materials of the rotor and the gear, and without imposing stress on the mounting means or the bearing without causing distortion in the gear or the rotor.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to trochoidal rotary devices for pumps, compressors, internal combustion engines, and fluid motors, and more particularly to the trochoid-to-gear mating portion of such rotary devices.

In prior art devices of this type, the journal bearing of the shaft had a cylindrical extension of the ring gear as described in U.S. Pat. No. 3,111,261.

In this patent, the ring gear was radially keyed to the trochanter to prevent relative rotation between these parts, yet to allow differential thermal expansion to occur.

The gear was held axially by a ring nut at the end of the bearing sleeve.

However, when the trochanter thermally expands, the bearing sleeve separates from the hole in the trochanter, creating an excessive gap between the two, so the bearing sleeve is surrounded by a second bearing sleeve that is tightly compressed and fitted within the trochanter. Thereby, a resulting gap is created between the shaft journal and the adjacent inner bearing sleeve and between the inner bearing sleeve and the outer bearing sleeve.

This arrangement requires very precise manufacturing and fitting of the parts, increasing manufacturing and assembly costs.

Furthermore, although the differential expansion of the parts in the radial direction was attempted to be absorbed, the ring nut held the bearing sleeve in the axial direction, so that the differential expansion in the axial direction was not absorbed.

A similar structure is shown in U.S. Pat. No. 3,230,789, in which a single bearing with radially extending splines is used and the trochanter is splined around the outer circumference of the bearing sleeve. is arranged in engagement with.

A ring gear is bolted to the splines of the bearing.

Although this structure is somewhat cheaper than the one described above, it is nevertheless still expensive and slippage will inevitably occur along the spline surface due to differential expansion, so a radially extending spline should have a trochanter around it. Must be highly polished before placement.

Furthermore, since the gear is tightly bolted to the splines of the bearing, thermal expansion of the bearing is suppressed.

U.S. Pat. No. 3,383,936 discloses a spline connection between the trochanter and the gear to prevent the gear from rotating relative to the trochanter, but to create a differential radial expansion. An example of expensive equipment is shown.

The device of this patent also provides for a tight axial attachment between the gear and the trochanter such that axial expansion of these components places tension on these components.

In the device described in U.S. Pat. No. 3,400,604, the gear is prevented from rotating relative to the rotor by a dowel pin that is tightly fitted to the gear and the rotor. It is stated that the radial expansion is transmitted to the gear by equally spaced nail pins, thus holding the rotor and gear concentrically.

However, this device was found to be unsuitable because the gear is stronger than the rotor and has a lower coefficient of thermal expansion, which limits the expansion of the trochanter, causing distortion and putting tension on the nail pin.

The present invention prevents the bearing from rotating relative to the trochanter or from any lateral movement relative to it, and allows the gear and rotor to thermally expand both radially and axially. The present invention provides a trochanter and gear combination for a lochoid-type rotation mechanism that is held concentrically and is prevented from warping, and the mounting is such that no thermal distortion occurs in the device.

These advantages are achieved by supporting the gear on pins or dowels with a tight fit on the body of the trochanter and with a tight fit circumferentially on the gear but allowing thermal expansion in the radial direction.

It is therefore an object of the present invention to provide a rotor and gear combination for a trochoidal rotary device that allows the components to undergo different thermal expansions without straining or distorting the components. It is.

Another object of the invention is to provide a rotor and gear combination in which the gear is held concentrically with the rotor.

Another object of the invention is a rotor-gear combination having bearings for the shaft journal, the unique way of supporting the gears ensuring that the bearings are not compressed either radially or axially. It's about giving your body.

Another object of the invention is to provide a rotor and gear combination in which the materials of the rotor body and ring gear have different coefficients of thermal expansion.

Another object of the present invention is to provide a rotor and gear combination in which the body of the rotor is made of a relatively lightweight metal.

Other objects and advantages of the present invention will be understood from the following description with reference to the accompanying drawings.

1 and 2 show three convexly curved working surfaces 1.
A rotor 11 is shown having a generally triangular profile having a 20-b shape and suitable for use in a trochoidal rotary device having a 20-b housing.

Although the present invention will be described with respect to such a trochoidal rotary device, the principles of the invention may be applied to other trochoidal rotary devices such as 10-b, 30-b, etc. where the rotor has a contour other than that shown. It is understood that it can also be applied to

The body of the rotor is hollow and includes a circumferential wall portion 13, a hub portion 17 connected to the circumferential wall portion 13 by a pair of parallel side walls 14, 16 and suitable ribs or webs 18.

Each active surface 12 has a recess 19 whose dimensions and shape are chosen depending on the intended use of the rotary device, but in some cases, for example in pumps or compressors, this recess is omitted. You can also do that.

The prior art seals on the top and sides of the rotor have been omitted as they are not necessary for an understanding of the invention.

Side wall 14 has a circular center hole 21 and side wall 16 has holes 22 which allow for the attachment of internal components during assembly and for the passage of lubricating and cooling fluids during operation. do.

The hub part 17 has a bore 23 passing through the axis of rotation, in which a bearing 24 is accommodated.

The bearing 24 may be of the sleeve type, roller bearing, or other conventional type, and when assembled, the rotary device is supported on the eccentric portion 26 of the rotating shaft 27.

As in prior art trochoidal rotary machines, the rotor supports a ring gear 28 that meshes with a spur gear (not shown) supported in the wall of the rotary machine housing during operation.

These ring gears and spur gears serve to properly align and index the trochoidal housing within which the rotor rotates.

The hub portion 17 is machined flat and has an end surface 29 that is perpendicular to the axis of rotation and that is coaxial with the body of the rotor and the bearing 24 and coaxial with the axis of the eccentric portion 26 of the shaft. A ring gear 28 is attached to the ring gear 28.

As shown, the gear 28 is retracted entirely within the rotor's hollow interior, but in some cases it may be positioned within the bore 21 with its axially outer surface flush with the outer surface of the side wall 14. Alternatively, a small portion may protrude beyond the side wall of the rotor to abut the end wall of the nozzing.

When a rotary device is activated, the rotor becomes quite hot.

This occurs especially when the rotary device is an internal combustion engine, but also in the case of pumps pumping hot liquids or compressors in which gas is compressed and fluid motors driven by hot fluids. do.

Thus, the rotor material undergoes thermal expansion during operation of the rotary device and then contracts upon cooling.

Such a rotor is designed to reduce weight and to ensure that the weight of the rotor produces as little bearing friction as possible and therefore consumes as little power as possible, whether power is generated by an engine or power is applied to a pump or other mechanism. Made of aluminum or its alloys to prevent

Although gears do not transmit torque, they typically wear due to friction and are subject to intermittent cyclic loading as the rotor moves laterally across the bearing gap due to the wave loading of the rotary device.

Therefore, the gears are made of suitable gear steel.

In this way, if the rotor and gears are made of different materials, especially in the case of a lightweight rotor, aluminum and its alloys generally have twice the coefficient of thermal expansion of steel, so the gears and the rotor may be different. have different coefficients of friction.

Rotors are sometimes made of spheroidal graphite cast iron, a material that is not as thermally responsive as aluminum but still more thermally responsive than gear steel.

Even if the rotor and gears are made of materials with the same thermal response, the difference in thermal expansion occurs because the rotor material is directly exposed to heat and the interface between these parts greatly impedes heat transfer. The problem remains.

For rotary machines to operate efficiently, it is important to maintain the rotor and its attached gears concentrically during the initial warm-up period, during stable operation, and during the cooling period after shutdown.

In the prior art, expansion of the rotor hub was supported when the gear was either tightly bolted and supported, positioned or tightly guided by tight-fitting dowels on both parts. It was speculated that this would be transmitted by the device and expand the gear to the same extent.

However, this turned out not to be the case.

If a tight-fitting dowel is used, the gear side of the hub will be constrained and will not expand as much as the opposite side, resulting in a tapered hole and a tapered bearing as well, so that the bearing is ineffective.

A similar disadvantage arises if the rotor has a flange on which the inner surface of the ring gear seats.

The same problem occurs when tightening the bolts so tightly that no lateral relative movement occurs between the gear and the rotor, which does not address the problem of differential expansion in the axial direction. Deformations also occur in this case.

The present invention allows both the gear and the rotor to freely expand in the radial and axial directions without interfering with each other or applying tension, while at the same time allowing the gear to rotate relative to the rotor. The foregoing limitations are overcome by attaching a first gear to the rotor to prevent movement transverse to the axis of the rotor, thereby holding the rotor and gear concentrically during operation and at rest.

These conditions hold regardless of whether the gear and rotor have the same coefficient of thermal expansion, different coefficients of thermal expansion, or whether either component has a different thermal response. .

The end face 36 of the rotor hub 17 has a plurality of cylindrical nails or pins 31 projecting therefrom a distance less than the thickness of the gear wheel 28.

These pins 31 may be equally angularly spaced as shown, or may have other arrangements.

If at least three pins 31 are required and this number is preferred, a greater number may be used.

The pin 31 is a tight fit in the rotor hub so that it will not loosen even if the component undergoes the maximum expected thermal expansion.

One convenient method of tightly seating the pin is to create an interference fit between the outer surface of the pin and the hole into which the pin fits.

However, the pin can also be secured to the rotor by other convenient methods, such as brazing.

The gear 28 is provided with a plurality of radially slotted holes 32, the number and spacing of which are equal to the number and spacing of the pins 31 passing through it.

The circumferential width of the slot 32 is such that there is a tight interference fit around the outer circumference of the cylindrical pin so that no relative movement occurs between the rotor and the gear.

Similarly, there is no relative lateral movement between the rotor and gear.

Such movement is resisted by the side walls of at least two of the slot holes.

However, the slotted holes 32 are radially elongated to the extent that radial motion between the pin and the slotted holes occurs to allow thermal expansion and contraction without changing the concentric relationship of the parts.

Although the slot hole 32 is shown exaggeratedly elongated in the drawings, it does not actually need to be this long.

The length of the slot hole 32 is determined by the coefficient of thermal expansion between the rotor metal and the gear metal, the maximum temperature of the rotor surface, the thermal gradient between the rotor surface and the pin position, and the pin position. The diameter of the circle being positioned is chosen according to the particular structure.

In a medium sized engine, such as about 60 cubic inches for each rotor, the momentum of the pin relative to the slotted hole is only a few tenths of an inch.

The gear is held axially by an axial locking device consisting of a plurality of equally spaced bolts 33 extending through holes in its circumference (shown in detail in FIG. 4). be).

Each bolt 33 is inserted into a hole 37 provided in the rotor bub 17.
flat layered inner end 3 seated in pressure contact with the flat bottom of
6 has a smooth cylindrical shaped shank portion 34, the bore 37 having a diameter slightly larger than the bolt shank so as not to circumferentially contact the bolt shank.

The bolt 33 has a small diameter threaded extension 38 coaxial with the shank 34 and extending inwardly therefrom to engage a threaded hole 39 in the bub 17.

The bolt extension 38 and the hole 39 are in interference engagement so that once the bolt 33 is screwed in until the inner surface 36 abuts the bub 17, the bolt will not loosen due to thermal expansion.

The axially outer ends of the bolt shank portions 34 are positioned concentrically within holes 41 extending through the gear, and these holes 41 are also slightly smaller than their diameter so as not to contact the bolt shank portions. It has a large diameter.

Hole 41 has a flat-bottomed coaxial counterbore 42 in the outer surface of the gear approximately half the depth of gear 28.

Although the bolt has a flat-bottomed head positioned within it that is slightly smaller in diameter than the counterbore, the length of the shank portion 34 and the depth of the hole 34 in which it seats are such that the head of the bolt is seated. The ratio is such that it leaves a gap 43 of several tenths of an inch without abutting the bottom of the borehole 42.

The dimensions of the gap 43 are determined by the dimensions of the rotary machine, the materials of the rotor and gears, and the expected maximum temperature; therefore, at the maximum expected thermal expansion, the bolt head will exert tension on the gear. do not have.

It will therefore be seen that the gear 28 is axially connected to the rotor bub in such a way that it cannot be separated therefrom.

The gear appears to be slightly loosely supported in its axial direction at room temperature, but this is not important since the clearance under the bolt head is negligible.

It has been found that during operation, the bolt head presses against the rotor bub and rotates without play until the temperature reaches such a value that the gap 43 is almost closed.

It will also be seen that because the pin 31 presses against the side of the slotted hole 32, the gear does not rotate circumferentially relative to the rotor.

Similarly, relative movement of the gear laterally about its axis is resisted by at least two pins pressing against the sides of the slot, or more if three or more pins are used. Resistance is provided by the pin.

It is easy for both parts to have a difference in thermal expansion in either direction, but the difference in thermal expansion can also cause gears,
It does not create tension or distortion in the rotor, supports or bearings or disturb concentricity.

Another embodiment of the invention is shown in FIGS. 5-8.

This example rotor is modified to illustrate the general principles of the gear support system of the present invention and its applicability to rotors of various rotary machines.

Points of detail omitted from the drawings will not be described.

The rotor 11a has an approximately triangular contour with convexly curved working surfaces 12 each having a recess 19, as in the previously described embodiments.

The main body of the rotor is hollow and has a peripheral wall portion 13 and a parallel side surface 1.
4a, 1(ia) and a hub portion 17a connected to the peripheral wall portion 13 by suitable ribs or webs 18.

The hub portion 17a has a bore 23 through the axis of rotation in which a bearing 24 is housed.

In the assembled rotary device, the eccentric portion 26 of the rotary shaft 27 is supported in this hole 23.

A ring gear 28a is seated concentrically with the rotor body and the eccentric portion 26 of the bearing and shaft and pressed against the flat end surface of the rotor hub portion.

The axially inner side of the ring gear 28H is provided with a shouldered extension 46 whose outer surface fits tightly into the hole 23 in the hub portion.

The extension 46 is positioned within the hole 23 when the gear is mounted on the rotor, causing the gear and rotor to be concentric with each other, and this concentric relationship remains unchanged once the gear is supported.

If there is a difference in thermal expansion between the rotor hub and the ring gear, then the thermal expansion at the rotor hub will always be greater than the thermal expansion at the gear, so there will be no stress on either the hub or the gear. The hub only expands radially away from the gear shoulder.

Both parts do not move laterally or circumferentially relative to each other, as in the previously described embodiments, but expand radially to different degrees.

The hub portion 17a has a plurality of dowels 31a projecting axially therefrom and shown as split tubular dowels.

Such a split tube can be compressed during assembly and will fit tightly into the hole in the hub because its natural elasticity will hold it tightly against any thermal expansion of the hub portion.

However, as described above, tubular or solid dowels can be used with either embodiment.

Although three pairs of dowels are shown in FIG. 5, the invention is not limited to the use of any particular number of dowels, except that at least three pairs are used.

Furthermore, the dowels do not necessarily need to be equiangularly spaced in either embodiment, since the rotor can be balanced by other devices if it is convenient to locate the dowels in other arrangements. do not have.

The ring gear 28a is radially provided with slot holes 32 having the same number and spacing as the dowels.

The radial depth of the slotted hole 32 is such that it is a tight friction fit to the dowel, thus preventing movement in the lateral and circumferential directions, and radially to allow movement in the radial direction in response to anticipated heat. It has enough play.

The rotation stop device for the axial extension of the gear consists of a plurality of ears 47 extending radially outward from the circumference of the gear, the ears 47 being shown flush with the exposed surface of the gear. However, it is not necessarily necessary to do it this way.

A similar plurality of ears 48 extend radially inwardly from the peripheral wall portion 13 of the rotor body.

The axial inner surface of the rotor ear and the gear ear 4
The outer surface of 7 in the axial direction is the ear-like process 48 and the ear-like process 47.
They overlap with an axial spacing as much as possible to allow for as much expected axial expansion as is allowed in the embodiments described above.

In either embodiment, there need not be more than two axial rotation locking devices provided they are spaced apart from each other in opposite directions, but any number of axial locks may be provided if desired.

It is usually convenient to use as many axial locking devices as dowels and similarly spaced apart.

Furthermore, although the rotor ears 48 of the second embodiment are shown as integral parts of the rotor, the ears may be separate parts bolted or otherwise attached to the rotor. good.

The method of arranging the axial detents when the ears 48 are integral with the rotor is shown in FIG.

When assembling the gear and rotor, the gear is fitted with its cylindrical extension 46 into the hub hole 23 and the ears 47, 48 are offset circumferentially to seat the gear axially. Set it on the end face of the rotor hub.

The gear is then rotated on the hub to properly circumferentially align the ears 47 of the gear below the ears 48 of the rotor.

The gear is already provided with its slotted hole 32, and if the rotor hub is already provided with a corresponding dowel hole, the dowel is positioned.

If the hub does not have holes for dowels, insert the dowels through the slots to assemble.

This is the prior art method of locating corresponding holes in the rotor hub.

The bearing 24 can be positioned in the rotor bore 23 before or after installing the gear by conventional methods.

In some cases, it is desirable to already seat the pegs in the rotor bub before assembling the gear to the rotor hub.

In this case, an ear 48 separate from the rotor can be used, and the gear is seated axially with its slotted hole 32 engaged with the protruding peg, and then the ear 48 is seated in the gear ear. Mount it on the rotor on the protrusion 47.

[Brief explanation of the drawing]

FIG. 1 is an axial elevational view of a rotor and ring gear combination for a trochoidal rotary device with a 20-b peripheral housing, and FIG.
A cross-sectional view taken along the line, Figure 3 is 3- in Figure 2.
4 is an enlarged detail view of FIG. 2; FIG. 5 is an axial elevational view of a further embodiment of the combination; FIG. 5 is a partially sectional elevational view taken along the line 6-6 of FIG. 5, FIG. 7 is an enlarged partial view taken along the line 7-7 of FIG. 6, and FIG. 8 is an enlarged detailed view of a portion of FIG. 5. It is. 11... Rotor, 14, 16... Side part, 212, 3... Hole, 33... Mounting device.

Claims (1)

[Scope of Claims] 1. A rotary device having a rotor and a ring gear concentrically attached to one side of the rotor, and used in a rotary pump, rotary engine, etc. At least three pins are provided on one side of the child and protrude from the same side at intervals in the circumferential direction, and the ring gear has at least three pins each receiving one corresponding pin. The ring gear is attached to the rotor by inserting a pin into the corresponding opening, and the width of the opening in the circumferential direction of the ring gear is set such that the width of the opening in the circumferential direction of the ring gear is related to both sides of the stored pin. In addition, the length of the opening in the radial direction of the ring gear is made larger than the dimension of the pin in the same direction, so that the radial direction of the rotor relative to the ring gear during operation is A rotary device that allows the pin to move within the opening due to relative thermal expansion.