JPH073023Y2 - Fluid energy converter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a fluid energy converter used as a fluid pump or a fluid motor, and more particularly to improvement of a casing portion thereof.

[Prior Art] In a fluid energy converter of this type, that is, in a general radial piston type hydraulic pump / motor or a special hydraulic pump / motor described later, the opening end of the casing is In many cases, a rear cover is attached to a lid, and a cylinder barrel arranged in the casing is supported by the rear cover via an eccentric shaft or a pintle. With such a configuration,
Due to the influence of the high-pressure working fluid,
A large radial staggering force acts on the rear cover. In addition, there is a situation in which smooth operation is impaired unless the casing and the rear cover are accurately positioned and joined together.

Therefore, in the conventional case, a spigot portion is provided between the casing body and the rear cover, a flange coupling portion is provided outside the spigot portion, and a fastening tool such as a bolt is fixed to the flange coupling portion to fix the both. I try to connect it firmly and accurately.

[Problems to be solved by the invention] However, in order to secure high positioning accuracy in the spigot part, high-precision machining is required, and if the accuracy is too high, it takes time to fit each other. There's a problem. Further, since the flange coupling portion has to be provided on the outside of the spigot portion, there is a problem that the outer diameter dimension of the casing becomes large and it is difficult to make it compact.
Especially when two fluid energy converters of this type are installed next to each other, one of which is used as a pump and the other of which is used as a motor, that is, two fluid energy converters are unitized.
When constructing an HST or HMT type transmission, there is a problem that the overall size must be extremely large due to the radial bulk of both.

The present invention aims to solve the above problems easily and surely.

[Means for Solving the Problems] In order to achieve the above object, the present invention is characterized in that a screwing structure having a spiral taper surface is adopted in a connecting portion between a casing body and a cover. is there.

That is, in the fluid energy converter according to the present invention, a tapered surface having an angle of 45 ° or less with respect to an axis is spirally formed on the inner or outer circumference of the opening end of the casing body, and The cover is provided with a spiral tapered surface having the same angle as the tapered surface and a locking surface for locking the opening end surface of the casing body, and the tapered surface forming portion of the casing body is the tapered surface forming portion of the cover. In addition, the opening end surface is screwed to a position where it is locked to the locking surface.

[Operation] With such a configuration, the outer circumference or the inner circumference of the opening end of the casing body having the tapered surface formed in a spiral shape,
If a cover having spiral taper surfaces that make the same angle is screwed and screwed until it comes into contact with the opening end surface of the casing body, the taper surface of the casing body becomes the taper of the cover. It sticks so that it rides on the surface. As a result, the taper guiding action is exerted, and the cover and the casing body are brought into a predetermined positioning state. In this state, however, the radial gap between the casing body and the cover is completely eliminated.

Moreover, since these tapered surfaces form a small inclination of 45 ° or less with respect to the shaft center, the tapered surface of the cover slides along the tapered surface of the casing body even when a radial load is applied. Nothing can happen at all. Therefore, even if a radial staggering force acts between the casing body and the cover due to the influence of the fluid pressure, no positional deviation occurs between the casing body and the cover.

Further, since the tapered surface is provided in a spiral shape, the casing body and the cover can be easily connected by the same operation as the screw connection, and moreover, the opening end surface of the casing body is engaged with the locking surface of the cover. By stopping the positioning, both can be accurately positioned in the axial direction.

Therefore, with such a structure, the casing body and the cover can be joined reliably and accurately without using the spigot portion and the flange coupling portion.

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

The fluid energy converter shown in FIGS. 1 to 3 is disclosed in
The structure is as shown in Japanese Patent Laid-Open No. 58-77179.
That is, this energy converter is rotatably fitted to the casing 1 and the inner circumference 1a of the casing 1 through a plurality of first hydrostatic bearings 2 and is provided at a portion corresponding to each hydrostatic bearing 2. A torque ring 4 having an inner plane 3 inside, and a plurality of torque rings arranged inside the torque ring 4 and having their tip surfaces abutted on the inner plane 3 via a second hydrostatic bearing 5. And the pistons 6 of the
And a cylinder barrel 8 forming a space 7 for fluid inflow and outflow, and a cylinder barrel 8 rotatably supported so as to be capable of reciprocating in a direction orthogonal to the axis m of the casing 1 and the torque ring 4. The pintle 9 and the space 7 that will increase in volume when the casing 1 and the torque ring 4 are rotated relative to each other with the axis n of the pintle 9 eccentric from the axis m of the casing 1. And a pair of fluid flow paths 11 and 12 respectively communicating with the space 7 whose volume is to be reduced. Then, the fluid filled in each space 7 is guided to the corresponding first and second hydrostatic bearings through the fluid passages 13 and 14, and the fluid introduced into the first hydrostatic bearing 2 is The static pressure and the static pressure of the fluid introduced into the second static pressure bearing 5 generate a couple of force around the rotational axis m in the torque ring 4.

Thus, as shown in FIG. 1, in this device, a high-pressure fluid is passed through the first fluid flow path 11 to the third side through the first fluid flow path 11 with the axis n of the pintle 9 decentered from the rotation axis m. When supplied to the space 7 existing in the right area A in the figure, a couple force for rotating the torque ring 4 in the arrow S direction is generated in the torque ring 4, and the function as a motor is exerted. Further, if the torque ring 4 is rotated by an external force, for example, in the direction of arrow R, a high-pressure fluid is discharged from the first fluid flow passage 11 (arrow Q).
(See) and the function as a pump is performed.

The casing 1 of such a fluid energy converter comprises a casing main body 21 and a rear cover 22 which is attached to the open end of the casing main body 21. The casing body 21 is a cup-shaped member that houses the torque ring 4, the piston 6 and the cylinder barrel 8 and has a rear end opened. The opening end of the casing body 21
A tapered surface 23 is formed on the inner circumference of 21a. The tapered surface 23 is 45 ° with respect to the axis m of the casing body 21.
It has a constant width with the following angle α and is formed in a spiral shape. That is, this taper surface 23 is a helical taper surface. A steep slope 24 having a constant width is formed between the ridge-side edge and the valley-side edge of the tapered surface 23.

On the other hand, the rear cover 22 is a disk-shaped member that supports the cylinder barrel 8 via the pintle 9, and has a trapezoidal groove 22a with which a base end portion 9a of the pintle 9 is slidably engaged. The rear cover 22 has an annular locking surface 25 for locking the opening end surface 21b of the casing body 21, and a circular bulge portion 26 formed inside the locking surface 25. A spiral taper surface 27 having the same angle as the taper surface 23 is provided on the outer circumference of the circular bulging portion 26.
The tapered surface 27 has a constant width that also forms an angle α with the axis m of the casing body 21, and is formed in a spiral shape at the same pitch as the tapered surface 23.

Then, the portion of the rear cover 22 where the tapered surface 27 is formed is screwed into the portion where the tapered surface 23 of the casing main body 21 is formed until the opening end surface 21b is locked to the locking surface 25. Are tightening.

With such a structure, the spiral taper surface 23 provided on the inner periphery of the casing body 21 due to the reaction force received by the casing body 21 from the locking surface 25 of the rear cover 22 is the taper surface 27 of the rear cover 22. Close up as you ride on. As a result, a taper guiding action is exerted, and the casing body 21 and the rear cover 22 are joined together in a correctly positioned state.

In this state, the casing body 21 and the rear cover are
The radial gap with 22 is completely eliminated. Moreover,
Since these tapered surfaces 23, 27 have a small inclination of 45 ° or less with respect to the axial center, even if a considerably large radial load is applied to the casing body 21, the tapered surfaces in the casing direction 21. It is difficult for 23 to slip along the tapered surface 27 of the rear cover 22. Therefore, even if a relative radial staggering force acts between the casing body 21 and the rear cover 22 due to the fluid pressure, no positional displacement occurs between the two. That is, in the case of a screw that has a helical surface that makes a steep slope of 45 ° or more with respect to the axis, like a normal screw, when a radial load acts, it causes slippage between members along the helical surface and misalignment occurs. However, if the taper surfaces 23 and 27 as described above are adopted, the relative position between the casing body 21 and the rear cover 22 can be accurately maintained as long as the ordinary members are used in a common load range. Will be done.

Therefore, unlike the conventional one, it is not necessary to provide a spigot portion between the casing body and the rear cover and to strictly set the relative tolerance between the casing main body and the rear cover, so that the machining can be facilitated and the assembly difficulty can be reduced. It can be resolved without difficulty.

Further, since the casing body 21 can be positioned by bringing its opening end surface 21b into contact with the locking surface 25 of the rear cover 22, positioning reproducibility in the axial direction is also good.

Moreover, if it is such a thing, both taper surfaces 23,27
When they are screwed together and tightened, a wedge action is caused between the tapered surfaces 23 and 27 not only in the rotational direction but also in the axial direction, which makes it difficult to loosen. Further, according to this configuration, since the flange joint portion is not necessary, the maximum outer diameter of the casing 1 can be reduced, and the entire device can be made compact. 5 and 6 are explanatory views for clearly showing this effect. That is, in the one shown in FIG. 5, the fluid energy converter I2 having the same configuration is arranged next to the fluid energy converter I1 described above, and the rear covers 22, of the fluid energy converters I1 and I2 are arranged. 22 are integrated. The rear cover 22 connects the first and second fluid flow passages 11 and 12 of the one fluid energy converter I1 and the first and second fluid flow passages (not shown) of the other fluid energy converter I2.
They are connected to each other through first and second communication passages 28 and 29 formed on both sides of the inside, respectively, whereby a so-called HST type hydraulic transmission is constituted. Then,
In such a usage mode, each fluid energy converter I
If the casing main body 21 of 1 and I2 and the rear cover 22 are joined by screwing the helical taper surfaces 23 and 27 described above, the separation distance between the casing main bodies 21 of the fluid energy converters I1 and I2 is increased. La can be made extremely small. On the other hand, in the case of the conventional example shown in FIG. 6, the casing main body a and the rear cover b of the fluid energy converters II1 and II2 are positioned by the spigot portion c, and the bolt e is attached to the flange joint portion d provided outside thereof. Since the casing main body a and the rear cover b are joined by fixing the above, it is difficult to reduce the distance Lb between the casing main bodies a. Therefore, in the present invention, the outer diameter size can be significantly reduced compared to the conventional device, and the overall size and weight of the device can be reduced.

In the above embodiment, the case where the tapered surface is formed on the inner circumference of the opening end portion of the casing body has been described, but the present invention is not necessarily limited to such a case, and for example, on the outer circumference of the casing body. A spiral tapered surface may be provided, and a tapered surface that is screwed into the tapered surface may be provided on the inner circumference of the recessed portion provided in the rear cover.

Further, the internal structure of the fluid energy converter is not limited to that described above, and the present invention can be similarly applied to, for example, an ordinary radial piston type pump / motor.

[Advantages of the Invention] With the above-described configuration, the present invention accurately positions the casing main body and the cover without inconvenience that high-precision processing is required and assembly work is troublesome. In addition to being able to join, even if a large radial staggering force acts between the casing body and the cover, the positioning state is not impaired, and the maximum outer diameter of the entire device is reasonably ensured. It is possible to provide an excellent fluid energy converter that can be reduced in size to reduce size and weight.

[Brief description of drawings]

1 to 5 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view, FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG.
FIG. 4 is a cross-sectional view, FIG. 4 is a partial cross-sectional view showing an enlarged view of an arrow IV in FIG. 1, and FIG. 5 is an explanatory view showing a mode of use. FIG. 6 is an explanatory view corresponding to FIG. 5 showing a conventional example. 1 …… Casing 21 …… Casing body 21b …… Opening end face 22 …… Cover (rear cover) 23 …… Tapered surface 25 …… Locking surface 27… Tapered surface

Claims (1)

[Scope of utility model registration request] 1. A fluid energy converter in which a cover for supporting a cylinder barrel is mounted on a casing body in a positioned state, wherein the casing body is provided with an inner end or an outer periphery of an opening end portion of 45 ° with respect to an axis. A tapered surface having the following angle is formed in a spiral shape, and a spiral tapered surface having the same angle as the tapered surface is formed on the cover,
A locking surface for locking the opening end surface of the casing body is provided, and the tapered surface forming portion of the casing body is positioned at the tapered surface forming portion of the cover, and the opening end surface is positioned so as to be locked by the locking surface. Fluid energy converter characterized by being screwed up to.