Motor housing structure

Abstract

The utility model provides a motor casing structure. The motor casing structure includes the casing of inside accomodating motor, and the casing cover of covering this casing, is formed with the shaft insertion opening of inserting the motor shaft of installing the resolver rotor on the casing cover, resolver stator is assembled on the casing cover in the state of surrounding the outer periphery of resolver rotor, forms a plurality of notch parts for making chuck claw insertion of the robot of making resolver stator automatic assembly operation on the opening edge portion of shaft insertion opening, a plurality of notch parts are structured, each recesses to the radial outside of shaft insertion opening, and mutually separates intervally along the circumferential direction of shaft insertion opening and is arranged. Based on the above structure of the utility model, the automatic assembly operation of resolver stator by robot can be realized.

Description

Technical Field

[0001] This utility model relates to a motor housing structure. Background Technology

[0002] Motors used in hybrid vehicles typically include a rotary transformer (rotation angle sensor) for detecting the rotational angle of the motor shaft. This rotary transformer comprises a rotor and a stator. The rotor is assembled integrally with the motor shaft. The stator is annular and configured to surround the outer circumference of the rotor. The cross-sectional shape of the rotor (the shape of the cross-section perpendicular to the axis) is, for example, elliptical. The stator has multiple teeth along its circumference, each wound with a rotary transformer coil.

[0003] When the rotary transformer coil is energized (AC), if the motor shaft rotates, the rotary transformer rotor (an elliptical rotor) will also rotate. The gap between the outer circumference of the rotor and the stator changes periodically in the circumferential direction due to the presence or absence of teeth. Therefore, the air gap permeability between the rotor and stator will change periodically. With this periodic change in air gap permeability, the voltage in the rotary transformer coil will also change periodically. By detecting this periodic voltage change, the rotation angle of the motor shaft can be detected.

[0004] In addition, the motor is housed inside a motor housing (in hybrid vehicles, this refers to the transmission drive axle housing that houses the gearbox, differential gears, etc.). The rotary transformer stator is assembled onto the housing cover of the motor housing.

[0005] Figure 6 is a cross-sectional view illustrating the assembly of the rotary transformer stator c onto the housing cover b of the motor housing a. As shown in Figure 6, in the motor housing a, a shaft insertion opening e is provided on the housing cover b on the side extending in the direction of the motor shaft d for inserting the motor shaft d. A rotary transformer rotor f is assembled on the outer circumferential surface of the motor shaft d at a position corresponding to the shaft insertion opening e. The rotary transformer stator c is annular, with multiple teeth g (the rotary transformer coil is omitted in Figure 6) formed circumferentially on one end face. As indicated by the arrows in Figure 6, each tooth g is inserted between the edge of the shaft insertion opening e and the rotary transformer rotor f, so that the rotary transformer stator c overlaps with the housing cover b of the motor housing a, and then secured with bolts, thus mounting the rotary transformer stator c onto the housing cover b of the motor housing a.

[0006] Previously, the assembly of the rotary transformer stator c onto the housing cover b of the motor housing a was done manually by the operator. That is, the operator needed to align the center of the rotary transformer stator c with the center of the shaft insertion opening e while simultaneously overlapping the rotary transformer stator c onto the housing cover b of the motor housing a to complete the installation.

[0007] Because the installation of the rotary transformer stator c is quite complicated, there is a need for automated assembly by a robot. For example, as shown by the imaginary lines in Figure 6, a robot could use multiple chucks h to hold various parts of the outer periphery of the rotary transformer stator c and assemble the rotary transformer stator c onto the motor housing a.

[0008] However, in this situation, a portion of the contact surface i of the rotary transformer stator c, which contacts the housing cover b of the motor housing a, is covered by the robot's chuck jaw h. When the rotary transformer stator c approaches the housing cover b of the motor housing a, the chuck jaw h will abut against the housing cover b. Due to the obstruction of the chuck jaw h, the contact surface i of the rotary transformer stator c cannot make contact with the housing cover b of the motor housing a, thus making it difficult to achieve automated assembly of the rotary transformer stator c by the robot. Utility Model Content

[0009] In view of the above situation, the purpose of this utility model is to provide a motor housing structure that enables robots to automatically assemble the stator of a rotary transformer.

[0010] As a technical solution to the above-mentioned technical problems, the present invention provides a motor housing structure, which includes a housing that internally houses a motor and a housing cover that covers the housing. A shaft insertion opening is formed on the housing cover for inserting a motor shaft on which a rotary transformer rotor is mounted. The rotary transformer stator is assembled on the housing cover in a state that surrounds the outer periphery of the rotary transformer rotor. The feature is that: multiple notches are formed at the edge of the shaft insertion opening for inserting the chuck jaws of a robot that performs the automatic assembly operation of the rotary transformer stator; the multiple notches are configured such that each is recessed radially outward from the shaft insertion opening and is spaced apart from each other along the circumferential direction of the shaft insertion opening.

[0011] The advantage of the motor housing structure described above is that it enables automated assembly of the rotary transformer stator by a robot. Specifically, because multiple notches are formed at the edge of the shaft insertion opening for the robot's chuck jaws to insert into, during automated assembly of the rotary transformer stator by a robot, when the robot moves the outer periphery of the rotary transformer stator to the housing cover using the chuck jaws, the rotary transformer stator can contact the housing cover without obstruction by inserting the chuck jaws into the notches formed at the edge of the shaft insertion opening on the housing cover. In other words, by inserting the chuck jaws into the notches formed on the housing cover, the rotary transformer stator can be moved to a position contacting the edge of the opening of the housing cover. As a result, the rotary transformer stator can be assembled at the edge of the shaft insertion opening in a manner that surrounds the outer periphery of the rotary transformer rotor. Thus, automated assembly of the rotary transformer stator by a robot is achieved.

[0012] In addition, in the above-described motor housing structure of this utility model, it is preferable that the notch is positioned to correspond to the position of the chuck claws that hold the outer periphery of the rotary transformer stator when the robot performs the automatic assembly operation.

[0013] Based on the above structure, the structure of the housing cover can be made to correspond to the structure of a robot that performs automatic assembly operations of the rotary transformer stator. Attached Figure Description

[0014] Figure 1 is a cross-sectional view of the configuration position of the rotary transformer and its surrounding structure in an embodiment of this utility model.

[0015] Figure 2 is a side view of the variable speed drive axle housing in an embodiment of this utility model.

[0016] Figure 3 is a perspective view showing the automatic assembly operation of the rotary transformer stator in an embodiment of the present invention.

[0017] Figure 4 is a schematic diagram showing the state in which the stator of the rotary transformer is in contact with the housing cover of the variable speed drive axle in an embodiment of the present invention.

[0018] Figure 5 is a schematic diagram showing the state of the rotary transformer cover after installation in an embodiment of the present invention.

[0019] Figure 6 is a cross-sectional view illustrating the operation of assembling a rotary transformer stator onto a housing cover of a motor housing in the prior art. Detailed Implementation

[0020] The embodiments of this utility model will now be described with reference to the accompanying drawings.

[0021] In this embodiment, the motor housing structure of this utility model is described as being applied to the transmission drive axle housing of a hybrid electric vehicle (the motor housing referred to in this utility model).

[0022] Figure 1 is a cross-sectional view of the configuration position of the rotary transformer 3 and its surrounding structure in this embodiment. Figure 2 is a side view of the transmission drive axle housing 2 in this embodiment (viewed from the direction of arrow II in Figure 1). In Figure 2, arrow Fr indicates the front of the vehicle body, arrow Rr indicates the rear of the vehicle body, and arrow U indicates the top. Additionally, Figure 2 shows the state before the rotary transformer is installed in the transmission drive axle housing 2.

[0023] As shown in Figure 1, the motor 1 is housed inside the transmission drive axle housing 2. The transmission drive axle housing 2 includes a housing body 21 and a housing cover 22. The housing cover 22 is assembled to the opening end face of the housing body 21 on the opening side. The housing body 21 and the housing cover 22 together constitute the housing space S for housing the motor 1.

[0024] The housing cover 22 has a circular shaft insertion opening 23 for inserting the motor shaft 11. The housing cover 22 has a fastening part 22a for fastening the rotary transformer cover 33 of the rotary transformer 3 (described later) with bolts, and a cover body 22b connected to the outer peripheral side of the fastening part 22a and thinner than the fastening part 22a.

[0025] As shown in Figure 2, four bolt insertion holes 22c are provided at 90° intervals along the circumferential direction on the outer peripheral edge of the housing cover 22. These four bolt insertion holes 22c are used to fasten the rotary transformer cover 33 with bolts.

[0026] On the other hand, as shown in Figure 1, the rotary transformer 3 includes a rotary transformer rotor 31, a rotary transformer stator 32, and a rotary transformer cover 33.

[0027] The rotary transformer rotor 31 is fitted onto the outer circumferential surface of the motor shaft 11 and rotates integrally with the motor shaft 11. Specifically, the rotary transformer rotor 31 is positioned on the outer side of the outer circumferential surface of the motor shaft 11, opposite to the fastening portion 22a of the housing cover 22 (left side in Figure 1). The cross-sectional shape of the rotary transformer rotor 31 (the shape of the cross-section perpendicular to the axis) is, for example, elliptical.

[0028] Figure 3 is a perspective view showing the automatic assembly operation of the rotary transformer stator 32. As shown in Figure 3, the rotary transformer stator 32 is configured as an annular shape. The outer diameter of the rotary transformer stator 32 is set to be larger than the inner diameter of the shaft insertion opening 23. As shown in Figure 1, when the rotary transformer stator 32 is assembled on the housing cover 22, the end face of the rotary transformer stator 32 (the end face facing the right in Figure 1) abuts (contacts) with the end face of the fastening part 22a of the housing cover 22 (the end face facing the left in Figure 1).

[0029] As shown in Figure 3, a plurality of teeth 34 protruding radially inward are formed on the inner circumferential surface of the annular rotary transformer stator 32. A rotary transformer coil (not shown) is wound around each tooth 34. Additionally, terminal blocks 32a protruding radially outward for connecting the rotary transformer coil and other wiring are formed on the outer circumferential surface of the rotary transformer stator 32. As shown in Figure 1, with the rotary transformer stator 32 assembled into the housing cover 22 of the transmission drive axle housing 2, the outer periphery of the rotary transformer rotor 31 is surrounded by these teeth 34 on the rotary transformer stator 32.

[0030] As shown in Figure 1, the rotary transformer cover 33 includes a stator clamping portion 33a and a fastening portion 33b. The stator clamping portion 33a is configured in an annular shape and is the part that clamps the rotary transformer stator 32 together with the fastening portion 22a of the housing cover 22. The fastening portion 33b is connected to the outer periphery of the stator clamping portion 33a and is the part that is fastened to the fastening portion 22a of the housing cover 22 by bolts B.

[0031] The principle of the rotary transformer 3 in detecting the rotation angle of the motor shaft 11 is as follows: When the rotary transformer coil is energized (AC), if the motor shaft 11 rotates, the rotary transformer rotor 31 will rotate together with the motor shaft 11. Accompanying the rotation of the rotary transformer rotor 31, the gap between the outer circumferential surface of the rotor 31 and the inner circumferential surface of the stator 32, as well as between the teeth 34, will periodically change in the circumferential direction. Therefore, the air gap permeability between the rotary transformer rotor 31 and the stator 32 will periodically change. With this periodic change in air gap permeability, the voltage of the rotary transformer coil will also periodically change. By detecting this periodic change in voltage, the rotation angle of the motor shaft 11 can be detected.

[0032] In the prior art shown in Figure 6, as described above, the operation of installing the rotary transformer stator c onto the housing cover b of the motor housing a is performed manually by the operator. That is, the operator needs to align the center position of the rotary transformer stator c with the center position of the shaft insertion opening e while overlapping the rotary transformer stator c onto the housing cover b of the motor housing a to complete the installation operation.

[0033] Because assembling such a rotary transformer stator c is quite cumbersome, there is a need for automated assembly by a robot. For example, as shown by the imaginary lines in Figure 6, a robot could use chuck jaws h to hold multiple parts of the outer periphery of the rotary transformer stator c and assemble the rotary transformer stator c onto the motor housing a.

[0034] However, in this situation, a portion of the contact surface i of the rotary transformer stator c, which contacts the housing cover b of the motor housing a, is covered by the robot's chuck jaw h. When the rotary transformer stator c approaches the housing cover b of the motor housing a, the chuck jaw h will abut against the housing cover b. Due to the obstruction of the chuck jaw h, the contact surface i of the rotary transformer stator c cannot make contact with the housing cover b of the motor housing a, thus making it difficult to achieve automated assembly of the rotary transformer stator c by the robot.

[0035] In this embodiment, by improving the structure of the transmission drive axle housing 2, particularly the structure of the housing cover 22, it is possible to achieve automated assembly of the rotary transformer stator 32 by a robot. Specifically, as shown in Figures 2 and 3, a plurality of notches 24 (three in this case) recessed radially outward are formed at intervals along the circumferential direction at the edge of the shaft insertion opening 23. Each notch 24 is configured as a rectangle, for example, by cutting off a portion of the edge of the shaft insertion opening 23.

[0036] The angular interval between adjacent notches 24 (the angular interval between adjacent notches 24 in the circumferential direction) is consistent with the angular interval between adjacent chuck jaws 4 (see Figure 3) of the robot (the robot that performs the automatic assembly operation of the rotary transformer stator 32). That is, the configuration position of the notches 24 corresponds one-to-one with the setting position of the chuck jaws 4.

[0037] In this embodiment, for example, the robot has three chuck jaws 4 with an angular interval of 120° between them, and the robot uses these three chuck jaws 4 to hold three parts of the outer periphery of the rotary transformer stator 32. Therefore, correspondingly, the angular interval between adjacent notches 24 is also set to 120°.

[0038] In addition, the width dimension of the notch 24 (the circumferential dimension centered on the rotation center of the motor shaft 11) is set to be slightly larger than the width dimension of the chuck jaw 4 (also the circumferential dimension centered on the rotation center of the motor shaft 11).

[0039] Thus, by forming three notches 24 at the edge of the shaft insertion opening 23 on the housing cover 22, as shown in Figure 3, when the robot moves the outer periphery of the rotary transformer stator 32 to the housing cover 22 using three chuck jaws 4, by inserting each chuck jaw 4 into the notch 24 on its corresponding housing cover 22, the chuck jaws 4 can be prevented from contacting the housing cover 22, thereby allowing the rotary transformer stator 32 to come into contact with the housing cover 22. In this way, the rotary transformer stator 32 can be assembled onto the edge of the shaft insertion opening 23 in a state that surrounds the outer periphery of the rotary transformer rotor 31.

[0040] Furthermore, after the rotary transformer stator 32 contacts the housing cover 22 and is assembled onto the housing cover 22, it is necessary to release the grip of each chuck jaw 4 on the rotary transformer stator 32 and allow each chuck jaw 4 to exit the shaft insertion opening 23. That is, when releasing the grip, each chuck jaw 4 needs to be moved radially outward. Therefore, the radial dimension of each notch 24 is set to ensure the space required for each chuck jaw 4 to move to the released position.

[0041] The automatic assembly operation of the rotary transformer stator 32 performed by the robot will be described below. When the robot performs the automatic assembly operation of the rotary transformer stator 32, firstly, as shown in Figure 3, the robot's three chuck jaws 4 hold three parts of the outer periphery of the rotary transformer stator 32. Specifically, the front end of the chuck jaws 4 has jaws 41 and 42 protruding radially inward (radially inward of the rotary transformer stator 32), and the distance between them is consistent with the thickness of the rotary transformer stator 32. The chuck jaws 4 hold the rotary transformer stator 32 by inserting the outer periphery of the rotary transformer stator 32 between jaws 41 and 42.

[0042] Next, align the positions of each chuck jaw 4 with the positions of each notch 24 on the housing cover 22. Then, as shown by the arrows in Figure 3, move the rotary transformer stator 32 toward the housing cover 22 and insert each chuck jaw 4 into its corresponding notch 24 until the rotary transformer stator 32 contacts the fastening portion 22a of the housing cover 22. This allows the rotary transformer stator 32 to contact the fastening portion 22a of the housing cover 22 without being obstructed by the chuck jaws 4, thus positioning the rotary transformer stator 32 to surround the outer periphery of the rotary transformer rotor 31. Here, the movement of each chuck jaw 4 is controlled by a control unit located in the robot using a known control method.

[0043] Figure 4 shows the state after the rotary transformer stator 32 contacts the housing cover 22. With the rotary transformer stator 32 in contact with the housing cover 22, the rotary transformer stator 32 is fixed to the housing cover 22, for example, by bolts, to prevent it from falling off. Then, the gripping of the rotary transformer stator 32 by each chuck jaw 4 is released, and each chuck jaw 4 is withdrawn from the shaft insertion opening 23.

[0044] Subsequently, the rotary transformer cover 33 is installed on the housing cover 22, covering the rotary transformer stator 32. That is, as shown in FIG1, the stator clamping portion 33a of the rotary transformer cover 33 and the fastening portion 22a of the housing cover 22 clamp the rotary transformer stator 32 together, and then the fastening portion 33b of the rotary transformer cover 33 is fastened to the fastening portion 22a of the housing cover 22 using bolts B. More specifically, the positions of the plurality of bolt insertion holes 33c (see FIG5) provided on the rotary transformer cover 33 are aligned with the positions of the plurality of bolt insertion holes 22c on the housing cover 22, and then bolts B are inserted into each bolt insertion hole 33c to fasten the fastening portion 33b of the rotary transformer cover 33 to the fastening portion 22a of the housing cover 22. The installation operation of the rotary transformer cover 33 can be performed manually by an operator or automatically assembled by a robot. Thus, the rotary transformer stator 32 is assembled onto the housing cover 22, covered by the rotary transformer cover 33. Figure 5 shows the state of the rotary transformer cover 33 after it has been installed.

[0045] Thus, based on the structure of the housing cover 22 in this embodiment, the automatic assembly operation of the rotary transformer stator 32 by a robot can be realized.

[0046] However, this invention is not limited to the above-described embodiments and can be modified appropriately. For example, the above embodiments were described using the case of applying this invention to the transmission drive axle housing 2 of a hybrid electric vehicle as an example. However, the structure of this invention is also applicable to the housing of a motor mounted on an electric vehicle, and to the housing of a motor mounted on a device other than an automobile.

[0047] In addition, in the above embodiment, the robot has three chuck claws 4 and three notches 24 are formed on the housing cover 22. However, the present invention is not limited to this. It is also possible that the robot has two chuck claws 4 and two notches 24 are formed on the housing cover 22; or, the robot has four or more chuck claws 4 and four or more notches 24 are formed on the housing cover 22.

Claims

1. A motor housing structure, comprising a housing that internally houses a motor, and a housing cover covering the housing, wherein a shaft insertion opening is formed on the housing cover for inserting a motor shaft into which a rotary transformer rotor is mounted, and a rotary transformer stator is assembled on the housing cover in a manner that surrounds the outer periphery of the rotary transformer rotor, characterized in that: Multiple notches are formed at the edge of the shaft insertion opening for inserting the chuck jaws of a robot that performs the automated assembly operation of the rotary transformer stator. The plurality of notches are configured such that each is recessed radially outward of the shaft insertion opening and is spaced apart from each other along the circumference of the shaft insertion opening.

2. The motor housing structure as described in claim 1, characterized in that: The notch is positioned to correspond to the position of the chuck jaws that hold the outer periphery of the rotary transformer stator when the robot performs the automatic assembly operation.

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