CN113653722A

CN113653722A - Shaft, apparatus including the same, and machining method for the same

Info

Publication number: CN113653722A
Application number: CN202010396647.6A
Authority: CN
Inventors: 袁晚春; 刘仕强
Original assignee: Emerson Climate Technologies Suzhou Co Ltd
Current assignee: Gulun Environmental Technology Suzhou Co ltd
Priority date: 2020-05-12
Filing date: 2020-05-12
Publication date: 2021-11-16
Anticipated expiration: 2040-05-12
Also published as: WO2021227369A1; CN113653722B

Abstract

The invention relates to a shaft for a rotary drive, comprising: a straight first shaft portion having a first axis of rotation; a straight second shaft portion having a second axis of rotation, the second shaft portion continuous with the first shaft portion, wherein the second axis of rotation intersects the first axis of rotation and forms a first angle. The invention also relates to a device comprising the shaft and a machining method for the shaft.

Description

Shaft, apparatus including the same, and machining method for the same

Technical Field

The invention relates to a shaft for a rotary drive. The invention also relates to a device comprising the shaft and a machining method for the shaft.

Background

This section provides background information related to the present disclosure and is not necessarily prior art.

In the field of air conditioning compressors, a drive shaft of the compressor is bent by a load such as a driving force and a force generated by a weight. In the development of an efficient and environmentally friendly inverter compressor, in order to better predict the design life of the bearing of the eccentric shaft of the scroll compressor, such deformation of the eccentric shaft when subjected to a force must be considered. Therefore, the pre-bent shaft technology is adopted in the design. The pre-bending shaft technology is a technology for improving the maximum bearing capacity of a shaft by pre-manufacturing an eccentric shaft made of low-carbon steel of a scroll compressor to have a certain curvature, namely, introducing a certain degree of reverse bending of a shaft neck under a light load working condition so as to reduce the bending of the shaft neck of the compressor under a heavy load working condition.

The purpose of the pre-bent shaft technology is to apply a shaft with a smaller diameter to a compressor with a larger cooling capacity, thereby effectively reducing the cost, and improving the performance of the compressor by reducing the friction loss at the journal. The pre-bent shaft technology is applied to partial models at present.

In the manufacture of pre-bent shafts, the shaft is pre-bent by pressing the shaft to yield the material of the shaft and cause non-recoverable plastic deformation. When the bearing is loaded by driving force, the pre-bent shaft is designed to just offset part of bending deformation, so that the contact fit of the shaft neck and the bearing achieves a better effect.

However, since the shaft is pressed to cause material yield, the prebending portion needs to be processed to have a smaller diameter, which deteriorates the material strength to some extent. In addition, the pressing process is poorly controlled, requiring slow, gradual attempts at pressing loads, or press over-head. If the shaft is larger in size, the demands on the capacity of the pressing equipment are higher. Therefore, additional equipment and tools for the pre-bending process are needed, so that the manufacturing cost is high. In addition, the positioning capability of the pre-bending position in the circumferential direction is poor, and the tolerance range is large, so that the effect of overcoming load deformation is unstable.

Disclosure of Invention

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

It is an object of the present invention to provide a shaft for a rotary drive, an apparatus comprising the shaft and a method of machining a shaft which overcome the above-mentioned disadvantages of the prior art.

In one form, the invention relates to a shaft for a rotary drive, comprising: a straight first shaft portion having a first axis of rotation; a straight second shaft portion having a second axis of rotation, the second shaft portion continuous with the first shaft portion, wherein the second axis of rotation intersects the first axis of rotation and forms a first angle.

In some configurations, the first angle is greater than or equal to 0.03 ° and less than or equal to 0.14 °.

In some configurations, the first shaft portion is a main shaft portion and the second shaft portion is a journal portion that mates with the bearing, the first shaft portion having an axial dimension that is greater than an axial dimension of the second shaft portion.

In some configurations, the second shaft portion has a maximum dimension D in the radial direction in a plane perpendicular to the first axis of rotation, the first shaft portion has a diameter D, and 0.025 ≦ D-D |/D ≦ 0.1.

In some configurations, the relationship between the length W of the second shaft portion in the direction of the first axis of rotation and the maximum dimension d is: w/d is more than or equal to 1.1 and less than or equal to 1.7.

In some configurations, a boss is provided on a side of the second shaft portion opposite the first shaft portion, a distance between an axial end face of the boss and an end face of the second shaft portion adjacent to the boss in the direction of the first rotation axis is a shoulder height h1, and a relationship between the shoulder height h1 and a length W of the second shaft portion in the direction of the first rotation axis is: h1/W is more than or equal to 0.1 and less than or equal to 1.

In some configurations, the second shaft portion is fitted with a bearing, and a ratio of a length W of the second shaft portion in the direction of the first rotation axis to a height H of the bearing in the direction of the first rotation axis is 0.95 or more and 1.30 or less.

The invention also relates to a device comprising the shaft.

In some configurations, the apparatus is a scroll compressor comprising a scroll compression mechanism and a main bearing housing for supporting the scroll compression mechanism, the rotary drive means is a motor, a first shaft portion is attached to and rotatably driven by a rotor of the motor, a second shaft portion is supported by the main bearing housing via a bearing, an end of the shaft proximate the second shaft portion is further formed with an eccentric portion for driving the scroll compression mechanism, the eccentric portion has a drive surface for driving the scroll compression mechanism, the drive surface is substantially perpendicular to a plane in which the first and second axes of rotation lie.

The invention also relates to a method for machining a shaft, comprising the step of machining a blank in a non-plastic deforming manner to form a shaft, wherein the shaft comprises a straight first shaft part having a first axis of rotation and a straight second shaft part having a second axis of rotation, the second axis of rotation intersecting the first axis of rotation and forming a first angle, the second shaft part being continuous with the first shaft part.

In some forms the first shaft portion is formed by machining a blank and the second shaft portion is formed by machining a blank.

In some forms, the method of processing further comprises the steps of: prior to the step of forming the first shaft portion, gripping the blank based on the first axis of rotation such that the blank is rotatable about the first axis of rotation; and prior to the step of forming the second shaft portion, clamping the blank based on the second axis of rotation such that the blank is rotatable about the second axis of rotation.

In some forms, the method of processing further comprises the steps of: clamping the blank based on the first or second axis of rotation such that the blank is rotatable about the first or second axis of rotation; making a cutting edge of a tool of a machining device parallel to a first rotation axis so as to form a first shaft portion; and making the cutting edge of the tool of the machining device parallel to the second rotation axis so as to form a second shaft portion.

In some forms, the second shaft portion is machined by a cylindrical grinder.

In some forms the first shaft portion is a main shaft portion and the second shaft portion is a journal portion that mates with the bearing, wherein the first shaft portion has an axial dimension that is greater than an axial dimension of the second shaft portion, and the main shaft portion is machined prior to the journal portion.

The shaft according to the invention is designed beforehand to form a predetermined angle between the journal portion and the main shaft. When a driving force is applied to the crank pin of the shaft, the pre-inclined journal portion is bent, which allows the journal portion to have a larger contact area with the bearing, thereby being better fitted, thereby reducing local contact stress and achieving the effect of increasing the bearing capacity of the bearing.

In addition, compared with a bending process, the machining process is utilized to machine the shaft, so that the precision and operation can be conveniently controlled, the strength of the shaft cannot be damaged, the production line flow of a compressor of a final assembly plant is reduced, and the production efficiency is improved.

Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

Drawings

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

FIG. 1 is a cross-sectional view of a compressor including a shaft according to the present invention;

figure 2 shows a portion of a drive assembly of a compressor comprising a shaft according to the present invention and associated upper and lower counterweight assemblies;

FIG. 3 is a side view of a shaft according to a first embodiment of the present invention;

FIG. 4 is a side view of a shaft according to a second embodiment of the present invention;

FIG. 5 is a view of the operation of the shaft according to the first embodiment of the present invention in cooperation with a bearing under zero load;

FIG. 6 is a view of the operation of the shaft in cooperation with a bearing under load according to the first embodiment of the present invention;

FIG. 7 is an illustration of a first step in the machining of a shaft according to a first embodiment of the present invention; and

fig. 8 is an illustration of a second step in the machining of a shaft according to the first embodiment of the present invention.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Detailed Description

Exemplary embodiments will now be described more fully with reference to the accompanying drawings.

The exemplary embodiments are provided so that this disclosure will be thorough and will fully convey the scope to those skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that should not be construed as limiting the scope of the disclosure. In some exemplary embodiments, well-known methods, well-known device structures, and well-known technologies are not described in detail.

When an element or layer is referred to as being "on," "engaged to," "connected to" or "coupled to" another element or layer, the element or layer may be directly on, engaged, connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly engaged to," "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers present. Other terms used to describe the relationship between elements (e.g., "between … …" and "directly between … …", "adjacent" and "directly adjacent", etc.) should be interpreted in a similar manner. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

The principles of the present disclosure are suitable for incorporation in many different types of equipment, such as scroll compressors and rotary compressors, including hermetic machines, open drive machines, and non-hermetic machines. For purposes of illustration, compressor 10 is shown as a low side hermetic scroll refrigeration compressor (i.e., a compressor in which the motor is disposed in the suction pressure region of the compressor), as shown in fig. 1. It will be understood that the principles of the present disclosure also apply to high side compressors (i.e., compressors in which the motor is disposed in the discharge pressure region of the compressor).

Fig. 1 shows a compressor 10. The compressor 10 may include a sealed housing assembly 12, a bearing housing assembly 14, a drive assembly 16, a compression mechanism 18, a seal assembly 20, a lower counterweight assembly 22, and an upper counterweight assembly 24. The bearing housing assembly 14, the drive assembly 16, the compression mechanism 18, the seal assembly 20, and the lower and

upper counterweight assemblies

22, 24 may be housed in the housing assembly 12.

The housing assembly 12 may generally form a compressor housing and may include a cylindrical shell 26, an end cap 28 at an upper end portion of the housing assembly 12, a transversely extending partition 30, and a base 32 at a lower end portion of the housing assembly 12. The end cap 28 and the partition 30 may generally define a discharge chamber 34. The housing 26, the partition 30, and the base 32 may generally define a suction chamber 40. A suction inlet fitting 38 may be attached to the housing assembly 12 and may be in communication with a suction chamber 40. Partition 30 may include a discharge passage 42, with compression mechanism 18 communicating with discharge chamber 34 via discharge passage 42.

The bearing housing assembly 14 may be attached to the housing assembly 12 (specifically the housing 26 in the figures) and may include a main bearing housing 44 and a bearing 46 housed in the main bearing housing 44. Compression mechanism 18 is supported by main bearing housing 44.

The drive assembly 16 (rotary drive, e.g., a motor) may include a stator 50, a rotor 52, and a shaft 54. The stator 50 may be press-fit into the housing assembly 12 (specifically the housing 26 in the figures). The rotor 52 may be attached to a shaft 54 and may rotatably drive the shaft 54. Shaft 54 may be rotatably supported near an upper end by main bearing housing 44 via bearing 46. A bottom bearing assembly 48 is disposed in base 32. Shaft 54 may be rotatably supported near a lower end via bottom bearing assembly 48.

Compression mechanism 18 may generally include an orbiting scroll 58 and a non-orbiting scroll 60. The orbiting scroll 58 may include an end plate 62, the end plate 62 having a spiral wrap 64 on an upper surface of the end plate 62. Fixed scroll member 60 may include an end plate 74 and a spiral wrap 76 projecting downwardly from end plate 74. The spiral wrap 76 of the non-orbiting scroll 60 may meshingly engage the spiral wrap 64 of the orbiting scroll 58 to create a series of moving fluid pockets. Throughout the compression cycle of compression mechanism 18, the fluid pockets defined by spiral wraps 64, 76 may decrease in volume as one moves from a radially outer position (at the suction pressure) through a radially intermediate position (at the intermediate pressure) to a radially inner position (at the discharge pressure), thereby compressing the working fluid.

The end plate 62 of the driven scroll member 58 may have a cylindrical hub 68 projecting downwardly therefrom. The cylindrical hub 68 may have a drive bushing 70 rotatably disposed therein the cylindrical hub 68. The shaft 54 may include an eccentric crank pin 56 (also referred to as an eccentric). Crank pin 56 is drivingly engaged in drive bushing 70.

As shown in fig. 2, the crank pin 56 is provided with a flat drive surface 78. The flat drive surface 78 of crank pin 56 may drivingly engage a corresponding flat surface in the inner bore of drive bushing 70 to provide a radially compliant drive. Thus, the driving force generated by the driving unit 16 is transmitted to the transmission bushing 70 via the crank pin 56 of the shaft 54, and then transmitted to the cylindrical hub 68 of the orbiting scroll 58 via the transmission bushing 70, thereby causing the orbiting scroll 58 to orbit.

First embodiment

A first embodiment according to the present invention is explained below with reference to fig. 3.

Fig. 3 shows a side view of the shaft 54. As shown, the shaft 54 is provided with a crank pin 56, a journal portion 80, a main shaft portion 82, and a shaft tail 84 from top to bottom along its axial direction, respectively, wherein at least the journal portion 80 and the main shaft portion 82 are straight cylindrical portions. The main shaft portion 82 may be referred to as a first shaft portion, the journal portion 80 may be referred to as a second shaft portion, the journal portion 80 is continuous with the main shaft portion 82, and an axial dimension of the main shaft portion 82 is greater than an axial dimension of the journal portion 80.

The driving surface 78 of the crank pin 56 of the shaft 54 is perpendicular to the plane of the drawing of fig. 3 and is therefore shown as a straight line segment in fig. 3. The main shaft portion 82 is fitted to the rotor 52. Shaft tail 84 fits within bottom bearing assembly 48. The main shaft portion 82 and the shaft tail 84 share a first axis of rotation X1. The journal portion 80 is supported by the bearing 46 and has a second rotation axis X2 in the axial direction.

As shown in fig. 3, the first rotation axis X1 intersects the second rotation axis X2, and the first rotation axis X1 forms a first angle α with the second rotation axis X2. Preferably, the plane in which the first axis of rotation X1 and the second axis of rotation X2 lie is perpendicular to the drive surface 78. Preferably, the first angle α is equal to or greater than 0.03 ° and equal to or less than 0.14 °. The inventors have found that a first angle a in the above range enables better contact between the journal portion 80 and the bearing 46 when the shaft 54 is loaded. On the other hand, if the first angle α is too small, the effect of the journal portion 80 and bearing 46 contact will be similar to a straight shaft design where the journal portion 80 is exactly coincident with the axis of the main shaft portion 82, and when the shaft 54 is loaded, a local stress concentration will occur at the upper edge of the bearing 46; if the first angle α is too large, it may cause local stress concentrations at the lower edge of the bearing 46 when loaded, and may also affect the strength of the shaft 54 or cause the shaft 54 to be oversized. The first angle α is too small or too large to obtain the optimal effect of full bearing area loading.

In the first embodiment according to the present invention as shown in fig. 3, the journal portion 80 has a first shoulder portion 802 extending radially outward beyond the outer periphery of the main shaft portion 82 on the side near the crank pin 56, and a second shoulder portion 804 extending radially outward beyond the outer periphery of the main shaft portion 82 in a direction opposite to the direction in which the first shoulder portion 802 extends on the side near the main shaft portion 82. The distance between the points at which the first shaft shoulder portion 802 and the second shaft shoulder portion 804 are each farthest from the first rotation axis X1 in the radial direction of the shaft 54 (the largest dimension that the journal portion 80 has in the radial direction) is d. The ratio of the maximum dimension D to the diameter D of the main shaft portion 82 is 1.025 or more and 1.1 or less.

Further, as shown in FIG. 3, a boss is provided on the side of the journal portion 80 opposite to the main shaft portion 82, the distance between the axial end face of the boss and the end face of the journal portion 80 adjacent to the boss in the direction of the first rotation axis X1 is a shoulder height h1, and when the journal portion 80 has a length W in the direction of the first rotation axis X1, 0.1. ltoreq. h 1/W. ltoreq.1. The proportion of h1/W needs to be controlled to be in a proper range as much as possible according to bearing load and product design requirements. Too large of a range may result in large drive bushing 70 and bearing 46 spacing, causing crank pin 56 to deflect too far.

Further, the relationship between the length W of the journal portion 80 in the direction of the first rotation axis X1 and the above-described maximum dimension d satisfies: w/d is more than or equal to 1.1 and less than or equal to 1.7. The relationship is selected according to the application range of the bearing.

Second embodiment

A second embodiment according to the present invention is explained below with reference to fig. 4.

Fig. 4 shows a side view of the shaft 54'. As shown, the shaft 54 'is provided with a crank pin 56, a journal portion 80', a main shaft portion 82, and a shaft tail 84, respectively, from top to bottom in the axial direction thereof. The driving surface 78 of the crank pin 56 of the shaft 54' is perpendicular to the plane of the drawing of fig. 4 and is therefore shown as a straight line segment in fig. 4. The main shaft portion 82 is fitted to the rotor 52. Shaft tail 84 fits within bottom bearing assembly 48. The main shaft portion 82 and the shaft tail 84 share a first axis of rotation X1. The journal portion 80' is supported by the bearing 46 and has a second axis of rotation X2 in the axial direction.

As shown in fig. 4, the first rotation axis X1 intersects the second rotation axis X2, and the first rotation axis X1 forms a first angle α with the second rotation axis X2. Preferably, the plane in which the first axis of rotation X1 and the second axis of rotation X2 lie is perpendicular to the drive surface 78. Preferably, the first angle α is equal to or greater than 0.03 ° and equal to or less than 0.14 °. The inventors have found that a first angle a in the above range enables better contact between the journal portion 80 and the bearing 46 when the shaft 54 is loaded. On the other hand, if the first angle α is too small, the journal portion 80 may not function to better contact the bearing 46; if the first angle α is too large, the strength of the shaft 54 may be affected or oversized.

In the second embodiment according to the present invention as shown in fig. 4, the journal portion 80 'has a first shoulder portion 802' extending radially outward to be flush with the outer peripheral surface of the main shaft portion 82 or to be close to being flush with the outer peripheral surface of the main shaft portion 82 on the side close to the crank pin 56, and has a second shoulder portion 804 'extending radially outward to be flush with the outer peripheral surface of the main shaft portion 82 or to be close to being flush with the outer peripheral surface of the main shaft portion 82 in the direction opposite to the extending direction of the first shoulder portion 802' on the side close to the main shaft portion 82. The distance between the points at which the first shaft shoulder portion 802 ' and the second shaft shoulder portion 804 ' are each farthest from the first rotation axis X1 in the radial direction of the shaft 54 (the largest dimension of the journal portion 80 in the radial direction) is d '. The ratio of the maximum dimension D' to the diameter D of the main shaft portion 82 is greater than or equal to 0.9 and less than or equal to 0.975.

Further, as shown in FIG. 4, a boss is provided on the side of the journal portion 80 'opposite to the main shaft portion 82, the distance in the direction of the first rotation axis X1 between the axial end face of the boss and the end face of the journal portion 80' adjacent to the boss is a shoulder height h1 ', and the journal portion 80 has a length W' in the direction of the first rotation axis X1 such that 0.1. ltoreq. h1 '/W'. ltoreq.1. The proportion of h1 '/W' needs to be controlled to a proper range as much as possible according to bearing load and product design requirements. Too large of a range may result in large drive bushing 70 and bearing 46 spacing, causing crank pin 56 to deflect too far.

Further, the relationship between the length W ' of the journal portion 80 ' in the direction of the first rotation axis X1 and the above-described maximum dimension d ' satisfies: w '/d' is more than or equal to 1.1 and less than or equal to 1.7. This relationship is selected for the range of applications of the bearing.

Combining the first and second embodiments, the journal portion 80 has a maximum dimension D (or D') in the radial direction on a plane perpendicular to the first rotation axis X1, and the main shaft portion 82 has a diameter D, such that 0.025. ltoreq. D-D. ltoreq/D.ltoreq.0.1. This is for the purpose of facilitating the formation of the first angle alpha in the above-mentioned range and ensuring that the strength of the shaft is not too weakened. Therefore, the size of D (or D') is controlled to be close to D but not equal to D.

Furthermore, it will be appreciated by those skilled in the art that the shaft according to the present invention is not limited to application to a rotary drive device such as a motor for a scroll compressor, but may be applied to other rotary drive devices that are subjected to eccentric loads during operation.

Shaft operation according to the invention

The operation of the shaft 54 according to the first embodiment of the present invention will be described below with reference to fig. 5 and 6, taking the shaft 54 as an example.

Fig. 5 shows the operation of shaft 54 with zero load acting on the driving surface 78 of crank pin 56 of shaft 54. The shaft 54 is supported by the bearing 46 at the journal portion 80. The ratio of the length W of the journal portion 80 in the direction of the first rotation axis X1 to the height H of the bearing 46 in the axial direction of the shaft 54 is 0.95 or more and 1.30 or less. In the first embodiment shown in fig. 3, the ratio is 0.95 or more and 1.10 or less. In the second embodiment shown in fig. 4, the ratio is 1.10 or more and 1.30 or less.

Fig. 6 shows the operation of shaft 54 in the event that the load acting on drive surface 78 of crank pin 56 of shaft 54 is not zero. The shaft 54 is supported by the bearing 46 at the journal portion 80. Thus, under load, the shaft 54 bends at the journal portion 80 such that the angle between the second rotation axis X2 and the first rotation axis X1 of the bent journal portion 80 becomes the second angle β. The second angle beta is equal to or greater than alpha/4 and equal to or less than alpha. This is determined by the stiffness and load of the crank pin 56 in combination with the first angle alpha in order not to cause excessive deflection of the crank pin 56 while ensuring that the bearing 46 is optimally loaded. As is evident in fig. 6, the contact of the journal portion 80 with the bearing 46 increases significantly when loaded.

Technical effects of Pre-Tilt design of axes

As mentioned above, by pre-angling the second axis of rotation of the journal portion of the shaft with the first axis of rotation of the main shaft portion of the shaft, a better load bearing of the pre-angled journal portion is ensured after contact forces with the bearing. Finite element analysis performed by the inventors shows that the pre-tilt journal of the shaft according to the invention has a lower maximum contact stress and a longer bearing load length than the straight shaft, and can achieve the same or even better effect as the pre-bent shaft of the prior art.

Processing method

In the present invention, the shaft 54, in particular, the journal portion 80 and the main shaft portion 82, which are continuous with each other, are formed by a non-plastic deformation processing method. As used herein, "non-plastic deformation" refers to permanent deformation of a material without the application of an external force to cause it to yield. For example, one example of a machining method that is not plastically deformed is a machining method. "machining" refers to the process of removing material from a workpiece on a machine tool (e.g., a lathe, milling machine, planer, and grinder).

A method of machining the shaft 54 according to the first embodiment of the present invention will be described below with reference to fig. 7 and 8 as an example.

First, a blank of the shaft 54 is provided, which may be in the shape of a straight circular shaft and may have a first axis of rotation X1. As is known to those skilled in the art, a billet is either raw stock or part of a finished product before it is finished. The billet may be obtained from a larger billet by casting, forging, or cutting.

As shown in fig. 7, a centering device C is provided at both ends thereof. The centering devices C at both ends of the shaft 54 are located on the first rotation axis X1, and each portion of the shaft 54 is machined in a direction parallel to the first rotation axis X1 by a machining device such as a cylindrical grinder G. Those skilled in the art will appreciate that the machining device is not limited to a cylindrical grinder, and other devices such as a lathe may be used.

Thereafter, as shown in fig. 8, the position of the centering device C at the shaft tail 84 is adjusted such that the re-determined axis is the second rotation axis X2 and the first rotation axis X1 forms the first angle α with the second rotation axis X2. The journal portion 80 is machined in a direction parallel to the first rotation axis X1 by a machining device such as a cylindrical grinder G.

Alternatively, angled machining may also be achieved by changing the orientation of the tool of the machining device. Gripping the billet based on the first rotation axis X1 or the second rotation axis X2 such that the billet is rotatable about the first rotation axis X1 or the second rotation axis X2; making the cutting edge of the tool of the machining device parallel to the first rotation axis X1 so as to form a first shaft portion; and making the cutting edge of the tool of the machining device parallel to the second rotation axis X2 so as to form the second shaft portion.

Finally, the various dimensions of the shaft 54 are measured using gauges known to those skilled in the art.

According to the above method of the present invention, the journal portion 80 is machined to form a predetermined inclination angle with the main shaft portion 82 using a two-step journal portion machining process. The circumferential position degree and the radial offset size precision of the inclination angle are ensured through the tool precision.

It will be understood by those skilled in the art that the steps in the above processing method are not necessarily performed in the above order, but may be performed in any order or even alternately as long as they are not contradictory in each step.

Technical effects of the processing method

Compared with a bent journal portion, the journal portion which is inclined in advance does not need to destroy the strength of the shaft, and residual internal stress and a plastic area are not generated. In addition, a wider range of inclination angles can be obtained by machining such as grinding, rather than bending the journal portion, without fear of strength problems associated with excessive bending of the journal portion. Moreover, the machining processes such as grinding and the like can be finished at suppliers, and an assembly factory does not need to additionally increase equipment, so that the production flow of the compressor of the assembly factory is reduced, and the production efficiency is improved. Compared with the pre-bending process, the machining process such as grinding and the like is utilized for machining, so that the axial precision and the circumferential precision of the shaft, particularly the shaft neck are obviously improved, and the design of the checking fixture is facilitated.

The foregoing description of embodiments has been presented for purposes of illustration and description. These descriptions are not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The various elements or features of a particular embodiment may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

1. A shaft for a rotary drive device, comprising:

a straight first shaft portion having a first axis of rotation;

a straight second shaft portion having a second axis of rotation, the second shaft portion being continuous with the first shaft portion,

wherein the second axis of rotation intersects the first axis of rotation and forms a first angle.

2. A shaft as in claim 1, wherein the first angle is 0.03 ° or greater and 0.14 ° or less.

3. The shaft of claim 1, wherein the first shaft portion is a main shaft portion and the second shaft portion is a journal portion that mates with a bearing, the first shaft portion having an axial dimension that is greater than an axial dimension of the second shaft portion.

4. The shaft of claim 1, wherein the second shaft portion has a maximum dimension D in a radial direction in a plane perpendicular to the first axis of rotation, the first shaft portion has a diameter D, and 0.025 ≦ D-D |/D ≦ 0.1.

5. A shaft according to claim 4, characterized in that the relationship between the length W of the second shaft part in the direction of the first axis of rotation and the maximum dimension d is: w/d is more than or equal to 1.1 and less than or equal to 1.7.

6. A shaft as claimed in claim 5, characterized in that a boss is provided on the side of the second shaft part opposite the first shaft part, the distance in the direction of the first axis of rotation between an axial end face of the boss and an end face of the second shaft part adjacent to the boss being a shoulder height h1, the relationship between the shoulder height h1 and the length W of the second shaft part in the direction of the first axis of rotation being: h1/W is more than or equal to 0.1 and less than or equal to 1.

7. A shaft according to claim 1, wherein the second shaft portion is fitted with a bearing, and a ratio of a length W of the second shaft portion in the direction of the first rotation axis to a height H of the bearing in the direction of the first rotation axis is 0.95 or more and 1.30 or less.

8. An apparatus comprising a shaft according to any one of claims 1 to 7.

9. The apparatus of claim 8, wherein the apparatus is a scroll compressor including a scroll compression mechanism and a main bearing housing for supporting the scroll compression mechanism,

the rotation driving device is a motor, the first shaft portion is attached to and driven to rotate by a rotor of the motor, the second shaft portion is supported by the main bearing housing via a bearing,

an end of the shaft adjacent the second shaft portion is further formed with an eccentric portion for driving the scroll compression mechanism, the eccentric portion having a drive surface for driving the scroll compression mechanism,

the drive surface is substantially perpendicular to a plane in which the first and second axes of rotation lie.

10. A machining method for a shaft, characterized by comprising a step of machining a blank in a non-plastic deformation manner to form the shaft,

wherein the shaft comprises a straight first shaft portion having a first axis of rotation and a straight second shaft portion having a second axis of rotation intersecting the first axis of rotation and forming a first angle, the second shaft portion being continuous with the first shaft portion.

11. The method of machining of claim 10, wherein the first shaft portion is formed by machining the blank and the second shaft portion is formed by machining the blank.

12. The process of claim 11, further comprising the steps of:

prior to the step of forming the first shaft portion, gripping the blank based on the first axis of rotation such that the blank is rotatable about the first axis of rotation; and

prior to the step of forming the second shaft portion, gripping the blank based on the second axis of rotation such that the blank is rotatable about the second axis of rotation.

13. The process of claim 11, further comprising the steps of:

clamping the blank based on the first or second axis of rotation such that the blank is rotatable about the first or second axis of rotation;

parallel cutting edges of a tool of a machining device to the first axis of rotation to form the first shaft portion; and

the cutting edge of the tool of the machining device is made parallel to the second rotation axis so as to form the second shaft portion.

14. The machining method according to claim 11, wherein the second shaft portion is machined by a cylindrical grinding machine.

15. The method of machining of claim 11, wherein the first shaft portion is a main shaft portion and the second shaft portion is a journal portion that mates with a bearing, wherein an axial dimension of the first shaft portion is greater than an axial dimension of the second shaft portion, the main shaft portion being machined prior to the journal portion.