JP2000130357A - Manufacture of roller holding ring for hydraulic pressure motor pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the sliding and rotation of a roller in a roller holding hole. SOLUTION: In the manufacturing method of the roller holding ring of a hydraulic pressure motor pump, wherein an internal gear is composed of a roller holding ring having semicircular roller holding holes in its inner periphery and a roller rotatably fitted in each roller holding hole, an external gear is inscribed and engaged with the internal gear, and a motor operation or a pump operation is obtained by using the capacity change of a space formed between both tooth shapes, a roller holding hole 131a is cut and machined as a full-circle hole with respect to a ring base material 151 before the inner diameter ϕDA of the roller holding ring base material 151 is machined up to a finishing diameter, and after the inner surface of the roller holding hole 131a is surface-finished by roller banishing machining, the inner diameter of the roller holding ring is expanded machined up to the finishing diameter, and in this way a roller holding ring having a semicircular roller holding hole is obtained. A part between the roller holding hole and the roller is lubricated in a state nearly similar to fluid lubrication.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic motor / pump in which a motor action or a pump action is obtained by utilizing a change in volume of a space formed between both tooth forms of an internal gear and an external gear. And a method of manufacturing a roller holding ring that forms a part of the internal gear.

[0002]

2. Description of the Related Art First, as an example of this type of hydraulic motor / pump, a known trochoid type hydraulic motor will be described with reference to FIGS.

This trochoid type hydraulic motor is composed of three parts: an output mechanism A, a displacement mechanism B, and a valve mechanism C. The output mechanism A has an output shaft 2 rotatably supported by a bearing 1. The displacement mechanism B includes the internal gear 3
And an external gear 4 internally meshed therewith, and a volume change chamber 11 is formed between the tooth profiles of both gears. The valve mechanism section C has a valve plate 5 that switches the flow path of the pressure oil by rotating, and distributes and supplies the pressure oil supplied from the pump to the volume change chamber 11 of the displacement mechanism section B and returns. It serves to collect the oil on the side from the volume change chamber 11.

A torque is transmitted between the output mechanism A and the displacement mechanism B by a first transmission shaft 6, and a torque is transmitted between the displacement mechanism B and the valve mechanism C by a second transmission shaft 7. You. For this purpose, both ends of the first transmission shaft 6 are engaged with the output shaft 2 of the output mechanism A and the external gear 4 of the displacement mechanism B by loose splines 61 and 62, respectively. Both ends of the seventh transmission shaft 2 are engaged with the external gear 4 of the displacement mechanism B and the valve plate 5 of the valve mechanism C by loose splines 71 and 72, respectively.

Here, the first transmission shaft 6 serves to remove the oscillating component of the oscillating rotation of the external gear 4 generated in the displacement mechanism portion B and take out only the rotation component to the output shaft 2 as a rotational force. Fulfill. In addition, the second transmission shaft 7 has a function of removing a swing component of the swing rotation of the external gear 4 generated in the displacement mechanism B and extracting only the rotation component to the valve plate 5 as a rotational force.

The internal gear 3, which is one of the components of the displacement mechanism B, includes a roller holding ring 32 having a plurality of semicircular roller holding holes 31 along the axial direction on the inner periphery thereof, A roller 33 which is fitted into the hole 31 and forms an arcuate tooth shape at a portion exposed from the roller holding hole 31. Further, a trochoidal tooth profile is adopted as the tooth profile of the external gear 4, and the number of teeth of the external gear 4 is set to be one less than the number of teeth of the internal gear 3. Further, the center O2 of the external gear 4 is eccentric with respect to the center O1 of the internal gear 3, and the number of teeth of the internal gear 3 (in the illustrated example, (7 in the case) are formed.

Next, the operation will be described.

When pressure oil is selectively sent to a predetermined volume change chamber 11 of the displacement mechanism B via the valve mechanism C, the volume change chamber 11 sequentially changes in volume (expands and contracts), and the external teeth The gear 4 swings around the center O1 of the internal gear 3.
This rotational force is transmitted from the external gear 4 to the output shaft 2 via the first transmission shaft 6, and only the rotation component without eccentric motion is extracted from the output shaft 2 to the outside.

When this motor is used as a pump, conversely, by applying rotational power to the output shaft 2, the pressure oil is taken out through the valve plate 5 due to the volume change of the volume change chamber 11. It is.

The above trochoid type hydraulic motor (pump)
In this case, the internal gear 3 and the external gear 4 perform a function of transmitting power and partitioning the volume change chamber 11 by internally meshing with each other. In order to fulfill only the function of power transmission, it is sufficient if only a part of the tooth profile of the internal gear 3 and a part of the tooth profile of the external gear 4 are internally meshed. 4 can be modified so that only the concave portion of the tooth profile of the external gear 4 meshes with the tooth profile of the internal gear 3 to maintain strength and reduce wear. When used as a pump, a function of strictly dividing the volume change chamber 11 is also required.
The individual tooth profiles must always mesh.

Therefore, since there are many contact portions between the tooth profiles, in order to achieve downsizing and high pressure, among components having a meshing portion or a sliding portion, the external gear has a high strength characteristic, and Tooth gears must be made to have high hardness characteristics, and therefore both external gears and internal gears are usually made of a metal material having a relatively high coefficient of friction. However, this has led to a reduction in power conversion efficiency and an increase in the temperature of the working fluid.

Therefore, it has been proposed that a low friction material is lined on the surface of the tooth profile and that a thin electroless film of nickel is applied to the surface of the tooth profile to lower the friction coefficient.
In fact, the problem of wear has not yet been sufficiently solved.

On the other hand, conventionally, it has been known that a chemical conversion treatment film such as a phosphate film is formed on a sliding portion of a hydraulic device to reduce the friction coefficient of the sliding portion. The chemical conversion coating itself has a low coefficient of friction, but has a low coefficient of friction because it holds a large amount of lubricating oil on minute irregularities.

It is conceivable to form the above-mentioned known chemical conversion coating on the toothed meshing portion or sliding contact surface of the trochoid type hydraulic motor. There is a drawback that it comes off.

Accordingly, the present applicant has proposed a contact surface which can reduce the friction coefficient of the contact surface between the external gear and the internal gear of the trochoid type hydraulic motor / pump and can reduce the power loss. In order to provide the following, an irregular surface is formed in a tooth trace direction of a tooth profile and a direction intersecting with the tooth trace direction of the tooth profile as disclosed in Japanese Patent Publication No. 3-3075 (Japanese Patent No. 1645246). The present invention has proposed a tooth-shaped contact surface including a contact surface on which is formed and a chemical conversion coating formed on the contact surface with a film thickness lower than the height of the unevenness.

[0016]

However, these known methods all focus on reducing the friction coefficient between the contact surfaces of the tooth profiles of the external gear and the internal gear. It did not have the idea of improving the sliding rotation of the roller (performing liquid lubrication).

Therefore, conventionally, the roller holding hole is formed by broaching or a small-diameter grindstone 40 as shown in FIG.
It was only processed by grinding using, but it did not mean that special finishing was performed.

More specifically, in the cutting by a conventionally known broach, cutting (cutting of the material) is performed until the final step of the processing, and therefore, as shown in FIG.
The roughness in the circumferential direction of No. 1 varies depending on the abrasion state and sharpness of the broach, but the limit is about 5 to 10 μm. Similarly, even in the grinding process of FIG. 11, since the material is subjected to shearing processing up to the final step, as shown in FIG. 13, the circumferential roughness of the roller holding hole 31 is limited to about 1 to 2 μm. Met.

Therefore, the friction loss when the roller 33 slides and rotates in the roller holding hole 31 accompanying the meshing between the external gear 4 and the internal gear 3 becomes large, which lowers the efficiency particularly at the time of starting. Or shortening the life of parts or increasing noise.

The present invention has been made in view of the above circumstances, and improves the efficiency of the roller, improves the service life, and reduces the friction loss between the roller and the roller holding hole by improving the sliding rotation of the roller in the roller holding hole. It is an object of the present invention to provide a method of manufacturing a roller holding ring which can reduce noise and forms a part of an internal gear of a hydraulic motor / pump.

[0021]

SUMMARY OF THE INVENTION The present invention considers the power transmission characteristics of an external gear and an internal gear, and most of the meshing between the external gear and the internal gear (roller) is in rolling contact. However, paying attention to the sliding contact between the roller and the roller holding hole, by making the lubrication between the roller and the roller holding hole closer to fluid lubrication, high efficiency, long life and low noise Is realized at low cost.

That is, according to the present invention, a roller holding ring having a plurality of semicircular roller holding holes along an axial direction on an inner periphery thereof, the roller holding ring rotatably fitted to each of the roller holding holes, and An internal gear is constituted by a roller that forms an arcuate tooth shape at a portion exposed from the roller holding hole, and an external gear having a tooth shape corresponding to the arcuate tooth shape is internally meshed with the internal gear. In the method of manufacturing the roller holding ring of a hydraulic motor / pump that obtains a motor action or a pump action by utilizing a change in volume of a space formed between the two tooth forms, a step of cutting the roller holding hole, And a step of plastically finishing the inner surface of the roller holding hole by roller burnishing.

Here, the roller burnishing process means that a pressure roller having a smooth surface is rotated while being pressed against the inner surface of the roller holding hole, and the roller holding roller is subjected to plastic deformation and work hardening on the inner surface of the roller holding hole. This is a method of processing the inner surface of the hole into a smooth finished surface.

By performing the roller burnishing, the height of the unevenness on the inner surface of the roller holding hole can be reduced to less than 0.5 μm, and the metal structure on the surface of the roller holding hole can be made dense. As a result, high efficiency and long life can be realized.

As another method, for example, a mirror surface portion having a larger diameter is formed at the final stage of a punching tool in broaching, and a pin holding hole is formed at the final stage of the mirror surface having the larger diameter. A method of plastic working by crushing the inner surface of the punching tool is also conceivable, but in this method, when the punching tool is moved in the axial direction, only the inner surface is worked along the axial direction, so that a sufficient effect cannot be obtained. That has been confirmed. In the present invention, after the cutting, mirror finishing is performed by roller burnishing, so that a good mirror surface can be obtained.

By the way, in order to finish the inner surface of the roller holding hole by plastic working, when the "radial" inner surface is to be finished by roller burnishing, this working method is different from the cutting work. There is a problem that it is extremely difficult to machine the inner surface of the steel sheet while setting the correct center. For this reason, even if smoothness can be ensured in terms of surface roughness, it is not possible to finish a precise (dimension) semicircle required for a roller holding hole of this kind of pump motor as it is.

Therefore, the invention of claim 2 provides a roller holding ring having a plurality of semicircular roller holding holes along an axial direction on an inner periphery thereof, the roller holding ring being rotatably fitted to each of the roller holding holes, and An internal gear is constituted by a roller that forms an arcuate tooth shape at a portion exposed from the roller holding hole, and an external gear having a tooth shape corresponding to the arcuate tooth shape is internally meshed with the internal gear. The method for manufacturing a roller holding ring of a hydraulic motor / pump which obtains a motor action or a pump action by utilizing a change in volume of a space formed between the two tooth forms includes the roller holding hole as a whole circular hole. A step of cutting the roller holding hole base material having an inner diameter (including zero) to be obtained as a whole circular hole with the roller holding hole, and after the cutting step, forming an inner surface of each roller holding hole by roller burnishing. The step of processing and finishing, by expanding the inner diameter of the roller holding ring base material to the finishing diameter after the plastic working and finishing step, opening the inner peripheral side portion of each of the roller holding holes that have been internally finished as a whole circular hole. Then, the above-described problem is solved by including the step of forming the semicircular roller holding hole.

According to a third aspect of the present invention, there is provided a roller holding ring having a plurality of semicircular roller holding holes along an axial direction on an inner periphery thereof; An internal gear is constituted by a roller that forms an arcuate tooth shape at a portion exposed from the roller holding hole, and an external gear having a tooth shape corresponding to the arcuate tooth shape is internally meshed with the internal gear. In the method of manufacturing the roller holding ring of the hydraulic motor / pump which obtains a motor action or a pump action by utilizing a change in volume of a space formed between the two tooth forms, the roller holding ring is opened on an inner peripheral side thereof. A step of cutting the semicircular roller holding hole, and after the cutting step, by fitting a circular guide having a semicircular hole corresponding to the roller holding hole formed on the inner periphery of the roller holding ring on its inner periphery. , The guide A step of forming an entire circular hole by a semicircular hole formed on the outer periphery and a semicircular roller holding hole on the roller holding ring side, and after the guide fitting step, the entirety formed by combining the guide and the roller holding ring. The inner surface of the hole
The above problem has been solved by including a step of performing plastic working by roller burnishing and a step of removing the guide from the roller holding ring after the plastic working finishing step.

According to a fourth aspect of the present invention, in any one of the first to third aspects, a step of forming a chemical conversion coating film on the inner surface of the roller holding hole after the roller burnishing of the roller holding ring is completed. By including the above, the above problem has been solved.

[0030]

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

The apparent configuration of the hydraulic pump / motor according to the present embodiment is almost the same as that shown in FIGS. 9 and 10 and is different in the details of the roller holding ring 32 forming the internal gear 3. Configuration and manufacturing method. Therefore, first, an embodiment of a method for manufacturing the roller holding rings 132 and 232 (the roller holding ring of the present invention is denoted by the same reference numeral as the reference numeral of the conventional roller holding ring) will be described.

In general, in the case of this type of hydraulic motor / pump, since the meshing portion and the sliding contact surface must be machined with a high-strength member with high precision, the roller holding rings 132 and 232 of the internal gear must be It is made of spheroidal graphite cast iron specified by JIS G5502, carbon steel for mechanical structure specified by JIS G4051, or a sintered iron-based metal molded product.

The manufacturing method of the first embodiment will be described with reference to FIGS.

In this manufacturing method, an appropriate number of bolt holes 152 are formed in the roller holding ring base material 151 in the first step, as shown in FIG. Roller holding ring substrate 1 here
The inner diameter φDA of 51 is set smaller than the finished diameter φDB (FIG. 5). In an extreme case, a roller holding ring substrate having no hole at the center (inner diameter φDA = 0) may be prepared.
Then, as shown in FIG. 2, the roller holding ring base material 151 is cut with a drill or the like so that the roller holding hole 131 a is a whole hole. Here, after drilling,
Reaming or fine boring is preferred.

In the next step, the inner surface of each roller holding hole 131a formed as a whole circular hole is finished by roller burnishing as shown in FIGS. More specifically, a tapered pressure roller 155 having a smooth surface
With a roller holding hole 131 by a tapered mandrel 156.
a, and by rotating in this state, a pressure exceeding the yield point of the material is applied to the inner surface of the roller holding hole 131a to cause plastic deformation and work hardening, while smoothing the inner surface of the roller holding hole 131a. Plastic working on the surface.

Note that the taper of the mandrel 156 and the taper of the compaction pin 155 are opposite to each other, and their respective axes CL1 and CL2 are not parallel.
The center CL2 of the pressure roller 155 is slightly inclined so that the outermost line of the roller is parallel to the roller holding hole 131a.

In the final step, as shown in FIG. 5, the inner diameter of the roller holding ring base material 151 is enlarged from φDA to a finishing diameter φDB, thereby forming each roller holding hole 131a whose inner surface is finished as a whole circular hole. A roller holding ring 132 having a semicircular roller holding hole 131 is obtained by opening the inner peripheral portion of the ring.

According to the roller holding ring 132, the circumferential surface roughness of the inner surface of the rolled roller holding hole 131 can be easily set to 0.1 to 0.5 μm as shown in FIG. It is possible to obtain a semicircle with accurate dimensions. Accordingly, when the internal gear motor / pump as shown in FIGS. 9 and 10 is manufactured by incorporating the roller holding ring 132, a fluid lubrication state can be formed between the roller 33 and the roller holding hole 131. As a result, the sliding rotation of the roller 33 can be improved. As a result, better rolling contact with the external gear 4 can be maintained,
A trochoid hydraulic pump motor with high efficiency, long life and low noise can be obtained at low cost.

Note that the tooth profile of the external gear 4 is as follows.
An arc-shaped tooth profile other than the trochoid tooth profile may be used.

Next, a manufacturing method according to the second embodiment will be described with reference to FIGS.

In this manufacturing method, in the first step, as shown in FIG. 7, an appropriate number of bolt holes 252 are formed in the roller holding ring base material 251 and the inner diameter of the ring base material 251 is processed to a finishing diameter D2. The roller holding ring base material 25
For example, a semicircular roller holding hole 231a is formed from the inner peripheral side of the roller holding ring base material 251 by broaching or grinding (for example, see FIG. 11).

In the next step, as shown in FIG. 8, a circular guide 255 is fitted on the inner periphery of the roller holding ring base material 251. A semicircular hole 256 corresponding to the roller holding hole 231a is formed on the outer periphery of the guide 255, and the semicircular hole 256 formed on the outer periphery of the guide 255 and the semicircular hole on the roller holding ring base material 251 side. Roller holding hole 231a
And the whole circular hole 257 is formed.

Then, in the next step, the entire circular hole 257 formed by the combination of the guide 255 and the roller holding ring base material 251 is subjected to the same roller burnishing processing as in FIGS. Finish the inner surface of 257.

When the finishing is completed, the guide 255 is finally removed from the ring base material 251 to obtain a roller holding ring 232 having a semicircular roller holding hole 231.

According to this method, the surface roughness of the roller holding hole 231 and the accurate semicircular dimension similar to those in FIG. 6 can be obtained, and the same effect is obtained when the roller holding hole 231 is incorporated in the internal gear motor / pump.

A phosphate coating (chemical conversion coating) is applied to the entire roller holding rings 132 and 232 or the roller holding holes 131 and 231 thus processed.
May be formed. Then, although the surface roughness is slightly roughened (deteriorated), a large amount of lubricating oil can be retained due to the properties of the phosphate, and seizure can be suppressed. Further, in the chemical conversion stage, the roller holding holes 13 are formed.
Since the surfaces 1, 231 are smooth, the growth of phosphate on the uneven portion is eliminated, and it is possible to prevent the initial seizure by a thin film and to secure the fluid lubrication by improving the surface roughness.

[0047]

As described above, according to the present invention,
Since a fluid lubrication state can be created between the roller holding hole and the roller, the sliding rotation of the roller can be improved. In particular, if the oil temperature is the same, an oil film can be secured between the roller and the roller holding hole up to a high load, and if the load is the same, an oil film can be secured between the roller and the roller holding hole up to a high temperature region. Can be. Therefore, both the starting efficiency from the stop state and the dynamic efficiency in the operating state can be improved. In addition, improved lubrication can extend component life and reduce noise. In addition, with a simple configuration in which the finishing accuracy of the roller holding hole is increased, it is possible to achieve high output while maintaining compactness. In addition, when a chemical conversion coating is applied, it is possible to both prevent initial seizure and ensure fluid lubrication by improving surface roughness.

[Brief description of the drawings]

FIG. 1 is a plan view of a roller holding ring base material used for describing a method for manufacturing a roller holding ring according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a state where a roller holding hole is formed as a whole circular hole in the roller holding ring base material.

FIG. 3 is a side sectional view showing a state in which roller burnishing is performed on a roller holding hole formed as a whole circular hole;

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3;

FIG. 5 is a plan view of a roller holding ring having a semicircular roller holding hole completed by enlarging the inner diameter of the roller holding ring base material.

FIG. 6 is a diagram showing a circumferential surface roughness of a roller holding hole obtained by burnishing;

FIG. 7 is a plan view after processing a roller holding ring base material used for describing a method for manufacturing a roller holding ring according to a second embodiment of the present invention.

FIG. 8 is a plan view showing a state in which a roller guide hole is formed by fitting a circular guide to the inner periphery of the roller holding ring to form a roller hole capable of performing roller burnishing;

FIG. 9 is a sectional view of a trochoid type hydraulic motor shown as a conventional example of the internal gear motor / pump in question here.

10 is a sectional view taken along the line XX of FIG. 9;

FIG. 11 is an explanatory view of a conventional method for processing a roller holding hole.

FIG. 12 is a diagram showing a circumferential surface roughness of a conventional roller holding hole when broaching is performed.

FIG. 13 is a diagram showing a circumferential surface roughness of a conventional roller holding hole when grinding is performed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 3 ... Internal gear 4 ... External gear 11 ... Volume change chamber 31, 131, 131a, 231, 231a ... Roller holding hole 32, 132, 232 ... Roller holding ring 33 ... Roller 151, 251 ... Roller holding ring base 255 ... Guide 256 ... Semicircular hole 257 ... Full circular hole

Claims (4)

[Claims] 1. A roller holding ring having a plurality of semicircular roller holding holes along an axial direction on an inner periphery thereof, and a portion rotatably fitted in each of the roller holding holes and exposed from the roller holding holes. And an internal gear is constituted by a roller forming an arcuate tooth profile, and an external gear having a tooth shape corresponding to the arcuate tooth shape is internally meshed with the internal gear, and formed between the two tooth shapes. In the method for manufacturing the roller holding ring of the hydraulic motor / pump which obtains a motor action or a pump action by utilizing a change in volume of the space provided, a step of cutting the roller holding hole; A process of plastically finishing by roller burnishing; and a method of manufacturing a roller retaining ring for a hydraulic motor / pump. 2. A roller holding ring having a plurality of semicircular roller holding holes along an axial direction on an inner periphery thereof, and a portion rotatably fitted in each of the roller holding holes and exposed from the roller holding holes. And an internal gear is constituted by a roller forming an arc-shaped tooth profile, and an external gear having a tooth profile corresponding to the arc-shaped tooth profile is internally meshed with the internal gear, and formed between the two tooth profiles. The manufacturing method of the roller holding ring of the hydraulic motor / pump which obtains a motor action or a pump action by utilizing the change in volume of the space provided, wherein the roller holding ring base having an inner diameter capable of including the roller holding hole as a whole circular hole. Cutting the roller holding hole into a full circular hole in the material, and after the cutting step, plastically finishing the inner surface of each roller holding hole by roller burnishing; By expanding the inner diameter of the roller holding ring base material to the finished diameter after the spinning step, the semicircular roller is opened by opening the ring inner peripheral portion of each roller holding hole whose inner surface is finished as a whole circular hole. A method of manufacturing a roller holding ring of a hydraulic motor / pump, comprising: a step of forming a holding hole. 3. A roller holding ring having a plurality of semicircular roller holding holes along an axial direction on an inner periphery, and a portion rotatably fitted in each of the roller holding holes and exposed from the roller holding holes. And an internal gear is constituted by a roller forming an arc-shaped tooth profile, and an external gear having a tooth profile corresponding to the arc-shaped tooth profile is internally meshed with the internal gear, and formed between the two tooth profiles. The manufacturing method of the roller holding ring of the hydraulic motor / pump which obtains a motor action or a pump action by utilizing the volume change of the space provided, wherein a semicircular roller holding hole opened on the inner peripheral side of the roller holding ring. And a circular guide having a semicircular hole corresponding to the roller holding hole formed on the outer periphery of the roller holding ring on the inner periphery of the roller holding ring after the cutting process, thereby forming the outer periphery of the guide. Semicircular hole Forming a full circular hole with a semicircular roller holding hole on the roller holding ring side, and after the guide fitting step, roller burnishing the inner surface of the full circular hole formed by combining the guide and the roller holding ring. A method of manufacturing a roller retaining ring for a hydraulic motor / pump, comprising: a step of performing plastic working by processing; and a step of removing the guide from the roller holding ring after the plastic working finishing step. 4. The method according to claim 1, further comprising the step of forming a chemical conversion coating on the inner surface of the roller holding hole after the completion of the roller burnishing of the roller holding ring. Of manufacturing a roller retaining ring of a hydraulic motor / pump.