JP2003158851A - Wiring connection device for vehicle motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a wiring connection device which connects inside and outside wirings of a case of a vehicle motor with each other through the wall-through part of the case airtightly and has high strength against a thermal load. SOLUTION: Electrically insulating bushes 2 are inserted into through-holes 38 formed through a case wall 31 of a motor case 3 and fixed to the case wall 31 so as not to fall out by a fixing means 22 protruding radially from the bushes 2. Conductive adaptor terminals 4 are inserted into the inner holes 21 of the bushes 2, and ends 62 and 66 of wires 61 and 65 inside and outside the motor case 3 are connected with the conductive adaptor terminals 4. O-rings 28 and 44 are provided between the inner circumferential surfaces of the through-holes 38 and the outer circumferential surfaces of the bushes 2, and between the inner circumferential surfaces of the bushes 2 and the outer circumferential surfaces of the conductive adaptor terminals 4 respectively so as to provide air-tight sealing. As an axial load produced by thermal stress is not applied to the bush and the adaptor terminal, loosening and cracking due to the repetitive thermal stress in a wiring connection device can be avoided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring connecting device for a vehicle motor, and more particularly to a wiring connecting device for connecting the ends of electric wires inside and outside the motor to each other.

[0002]

2. Description of the Related Art A motor power line connects a motor coil inside a motor case with a motor driver outside the motor case, and is always routed through the motor case on the way. In a wiring connection device for a motor for use, a cable connector is arranged inside or outside the case near a portion penetrating the motor case, and electric cables inside and outside the motor are connected to each other via the cable connector.

By the way, since the wiring inside the motor case has a short distance and the accommodation space is narrow, a considerable ingenuity is required in the structure and the connecting method in order to connect the electric wires inside and outside the motor with the connector inside the case. On the other hand, it is necessary to prevent rainwater and dust from entering the motor case. In addition, if oil is enclosed in the motor case, the oil will flow out between the conductors in the cable and out of the motor case. It is necessary to prevent so-called oil spillage, and in order to deal with these problems with a normal connector connection, it is necessary to seal both the connector portion and the case wall penetrating portion of the electric cable. Such a configuration leads to an increase in the size of the cable connecting portion.

On the other hand, in the lead-out structure of a liquid-sealed rotary electric machine which is an induction motor used for pump operation and in which a liquid for cooling a winding is enclosed in a rotary electric machine frame, as a seal structure of a lead-through frame penetrating portion, Conventionally, special edition Sho 59
There is a lead-out structure described in JP-A-21247. In this conventional technology structure, an insulating conductor integrally molded with an insulating coating and a seal ring arranged in a brim around the outer periphery is inserted into an opening of the frame, and the insulating conductor is framed by a seal ring and a nut screwed into the conductor. A seal structure is adopted in which the frame is pressed against and the frame is prevented from coming off and the opening is prevented from leaking.

Further, in a submersible electric motor in which cooling water circulates in the electric motor frame and the stator winding is immersed in water, a relay terminal for drawing the electric motor winding out of water is provided in the electric motor frame. Conventionally, there is a structure described in the microfilm of Japanese Utility Model Application No. 56-160006 (Japanese Utility Model Application Laid-Open No. 58-66856). In this conventional technique, a nut is formed by protruding a flange in a part of the axial direction, inserting a rod-shaped conductor including the flange with an insulating member into a through hole of an electric motor frame, and screwing the conductor into the flange and the conductor. A sealing structure is employed in which the motor frame is pressed against the motor frame to prevent the motor frame from coming off and the through hole from leaking.

[0006]

In both of the above-mentioned prior art wiring connection devices, each has a bulge portion (seal ring, flange) provided on the conductor side and a nut screwed into the conductor,
The conductor is fastened and fixed to the motor case (frame or electric motor frame) with axial fastening force. However, in the structure in which the conductor is fixed by the load load in the axial direction as in these prior arts, in the case where the driving load fluctuation is extremely large such as the vehicle motor, the thermal load fluctuation (from the motor to the conductor is accompanied by the driving load fluctuation). Change in the amount of heat generated by the conductor itself due to the heat transmitted to the motor case and the change in the current flowing in the conductor), the difference in the coefficient of thermal expansion between the conductor and the motor case, which are usually made of materials with different physical properties, Axial force due to nut tightening may become excessive or weak. Therefore, in the wiring connection device having such a structure, the fixing to the motor case becomes loose or the stress becomes excessive, and there is a possibility of electrical contact failure or disconnection.
Further, since the seal structure in these wiring connection devices also depends on the close contact due to the axial force, the loose contact causes the liquid in the motor case to be biased.

In view of such circumstances, the present invention is fixed to the motor case wall in an insulating and sealed state without depending on the fastening force in the axial direction, while preventing oil from rising and rainwater, dust and the like from entering. An object of the present invention is to provide a wiring connection device for a motor for a vehicle that connects the ends of electric wires inside and outside the motor to each other without requiring a special arrangement space.

[0008]

In order to solve the above-mentioned problems, the present invention is directed to a motor case having a through hole penetrating the case wall, and a retainer fixed to the case wall by being inserted into the through hole. And an electrically conductive adapter terminal having a connecting means for connecting the ends of the electric wires inside and outside the motor case, which are inserted into the inner hole of the bush. And an O-ring between the inner peripheral surface of the through hole and the outer peripheral surface of the bush and between the inner peripheral surface of the bush and the outer peripheral surface of the adapter terminal. It is configured that the ends of the electric wires inside and outside the motor case are respectively sealed and connected to the connecting means of the adapter terminal.

It is effective that the joint surface of the fixing means with the motor case in the above structure is oriented perpendicular to the axial direction of the bush. Also, the motor case is
It is effective to have a structure in which a joint portion facing the fixing means of the bush is provided in the vicinity of the through hole into which the bush is inserted.

[0010]

According to the present invention having such a structure, the bush is fixed to the motor case without being applied with an axial force, and is inserted into the adapter as a conductive material. It functions as an electrical insulating material and supporting member for the motor case of the terminal, and the O-ring between the adapter terminal and bush and the motor case and bush does not depend on the axial force and is affected by thermal expansion and contraction in the axial direction. Not as a peripheral seal, it acts as a seal between them.

Therefore, according to the present invention, the bush itself is fixed to the case wall by the fixing means projecting in the radial direction so as not to come off, so that the entire bush and the adapter terminal are not subjected to axial stress for fixing. For,
It is possible to prevent the occurrence of cracks due to repeated thermal expansion and contraction of these members under a stress-loaded state, and further to prevent electrical contact failure and disconnection due to loose fixing to the motor case. In addition, oil leakage and dust inflow from the gap caused by the difference in the coefficient of thermal expansion also occur between the inner peripheral surface of the motor case and the outer peripheral surface of the bush and between the inner peripheral surface of the bush and the outer peripheral surface of the adapter terminal. By disposing the ring, it is possible to reliably shut off by sealing at the peripheral surface that does not depend on the tightening force in the axial direction.

According to the second aspect of the invention, since the joint surface of the fixing means to the case is arranged to be perpendicular to the axial direction of the bush, the bush is inserted into the through hole of the case. Only by this, the fixing means can be aligned on the joint surface with respect to the motor case. Therefore, it becomes easy to dispose and fix the bush on the motor case, so that the assembling property is improved.

According to the third aspect of the present invention, since the joint portion is arranged in the motor case so as to face the fixing means of the bush, the bush and the fixing means are simply inserted into the motor case. By the contact of the joint portion, the axial position of the bush with respect to the motor case can be easily adjusted, and the assembling property is improved.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION A wiring connection device for a vehicle motor according to the present invention will be described below with reference to the embodiments shown in the drawings. Figure 1
1 shows an axial cross section of the first embodiment, FIG. 2 shows an end surface viewed in II direction of FIG. 1, and FIG. 3 shows an end surface viewed in III direction of FIG. 1. This device has a through hole 38 penetrating a wall of the case 31. The formed motor case 3, the electrically insulating bush 2 which is fitted into the through hole 38 and fixed to the wall of the case 31 by fastening bolts 29, and the inner hole 21 of the bush 2 are fitted to the inside and outside of the motor case 3. Electric wires (specifically, electric wire cables described later) 61,
Connection means (similarly screw holes and eyes) 41, 42 for connecting the end portions of 65 (similarly to terminal fittings and conductor bundles) 62 and 66
And a conductive adapter terminal 4 having. And
The joint surface of the fixing means 22 of the bush 2 to the motor case 3 is oriented perpendicular to the axial direction of the bush 2 as shown in FIG. In addition, the motor case 3 includes the bush 2
In the vicinity of the through hole 38 into which is inserted, there is a joint portion formed of a wall of the case 31 facing the fixing means 22 of the bush 2.
Further, the O-rings 28 and 44 seal between the inner peripheral surface of the through hole 38 and the outer peripheral surface of the bush 2 and between the inner peripheral surface of the bush 2 and the outer peripheral surface of the adapter terminal 4 to connect the adapter terminal 4 to each other. The ends 41 and 66 of the electric wires 61 and 65 inside and outside the motor case 3 are connected to the means 41 and 42, respectively.

Further, the details of each part will be described. Figure 4
6A and 6B show the details of the bush 2 and the adapter terminal 4 taken out, and the bush 2 serves as a retainer fixing means that projects radially outward from the middle portion of the cylindrical wall of the cylindrical main body. It has a flange 22 and a bolt insertion hole 23 is formed in the flange 22. A seal ring groove 24 is formed in the center of the cylindrical wall, and an O-ring 28 is fitted therein. The electric wire cable 6 is provided at both ends of the cylinder wall.
The retaining ridges 25 and 26 are formed so as to engage with the seal caps 63 and 67 (see FIGS. 1 to 3) to cover the end portions of the components 1, 65. Almost half of the axial length of the inner hole 21 of the bush 2 is a rotation stop hole 21a having a hexagonal inner peripheral surface, and the other half is a cylindrical inner peripheral surface.

On the other hand, the adapter terminal 4 has a solid shaft shape, and a substantially outer half of the shaft has a hexagonal outer peripheral surface into which the rotation stopping hole 21a is fitted, and an inner half has a cylindrical outer peripheral surface. It is said that. At the outer end of the adapter terminal 4, an eye 42 integral with the shaft portion is formed so as to project the conductor wire bundle 66 at the end portion of the outer case cable 65. Adapter terminal 4
In order to connect the end portion of the in-case electric wire cable 61 to the cylindrical shaft portion of, the screw hole 41 extending in the axial direction from the inner end thereof is connected.
Is formed, a seal ring groove 43 is formed on the outer periphery of the shaft portion, and an O-ring 44 is fitted therein.

The wiring connecting device thus constructed is assembled in the following procedure. First, the eye 4 of the adapter terminal 4
The conductor wire bundle 66 exposed from the coating of the electric wire cable 65 is inserted into 2 and connected by copper welding, while the O-ring 44 is fitted in the seal ring groove 43. In this way, the adapter terminal 4 connected and integrated with the electric wire cable 65 is inserted into the inner hole 21 of the bush 2.
And the O-ring 28 is fitted in the seal ring groove 24 of the bush 2. Next, the resin adhesive 68 is flown around the connection portion, and the seal cap 67 is covered before solidifying. Then, the bush 2 is inserted into the through hole 38 of the motor case 3.
The screw hole 37 on the case 3 side with the bolt insertion hole 23 on the bush 2 side so that the bolt 2
Tighten it to 9 and secure it to the wall of the case 31. After that, the bolt through hole (not shown) of the terminal fitting 62 crimped to the conductor wire bundle exposed from the coating of the in-case electric wire cable 61 and the screw hole 41 of the adapter terminal 4 are aligned and fastened with the bolt 64. At this time, the accompanying rotation of the adapter terminal 4 due to the screw tightening is prevented by the engagement of the hexagonal outer peripheral surface of the bush 2 with the rotation stop hole 21a.

In the wiring connecting device thus constructed,
The bush 2 functions as an electric insulating material and a supporting member for the motor case 3 of the adapter terminal 4 as a conductive material fitted and inserted therein, and the adapter terminal 4 is transmitted between the conductor wires in both electric wire cables 61, 65. Fulfills the function of blocking leakage of fluid. Therefore, according to this wiring connection device, the through hole 38 portion that requires oil / water tightness is prevented from coming off from the case 31 by the bolt 29 and sealed by the peripheral surface of the immovable bush 2, particularly the O-ring 28. Since the oil rising that travels between the conductor wire bundles is blocked by the adapter terminal 4,
Since it is possible to effectively prevent oil leakage and rainwater intrusion from the connecting device portion that penetrates the motor case 3, and furthermore, the connection of both electric wire cables 61 and 65 to the adapter terminal 4 is welded or bolted, it is extremely A small wiring connection device can be provided.

Next, FIGS. 7 to 9 show a second embodiment in which the shape of the adapter terminal is changed. In this embodiment,
The adapter terminal 4A has a separate structure including a terminal 40A as a connecting means for fixing the end portion of the in-case electric wire cable and a sheath-like main body 49A covering the terminal 40A. Then, a semi-cylindrical protrusion 45 protruding from the inner end of the terminal 40A.
A and the conducting wire 66A at the end portion of the electric wire cable 65A outside the case are directly welded to each other, and the periphery of the connecting portion is fixed and sealed with an epoxy resin sealing material 69A. The terminal 40
The inner end side of A and the inner end side of the main body 49A are detented by fitting the hexagonal peripheral surfaces together, and a hexagonal detent groove 46A and a seal ring groove 43A are formed on the outer periphery of the main body 49A. An O-ring 44A is fitted in the groove. Terminal 4
0A is provided with a connecting means composed of a screw hole 41A as in the previous example. An outer peripheral groove 47A is formed at the outer end of the main body 49A, and a seal cap 69A is covered from the outer periphery of the case outer wire cable 65A to the outer peripheral groove 47A.

The wiring connection device of this embodiment is particularly effective in the case where the lead-out portion of the outside-case electric wire cable 65A is oriented coaxially with the connecting portion.

The drive unit to which the wiring connecting device having the above-mentioned structure is applied will be described below in detail. Figure 1
Reference numeral 0 denotes an axial cross section of only one side of a drive unit that can be mounted coaxially with a wheel of a vehicle by incorporating a motor body and a speed reducer substantially symmetrically with the differential device 5 sandwiched in the motor case 3. Therefore, in the following description and the drawings, the subscript English symbol is added only when the left and right are particularly distinguished, and the description of either one of them shown in the drawings below replaces the description of both.

This drive unit distributes and transmits a pair of left and right motor bodies 1, a pair of left and right speed reducers 7 for decelerating the rotations of the motor bodies 1 and amplifying the torque, and rotating torque of the motors for both left and right wheels of a vehicle (not shown). Both motor bodies 1
And a differential device 5 connected to both speed reducers 7 and arranged coaxially with both speed reducers 7.

The motor body 1 comprises a rotor 10 in which a magnet 12 is arranged on the outer circumference of a rotor drum 11, and a stator 15 in which a field coil 17 is wound around an armature core 16. The differential device 5 is arranged coaxially with the rotor 10 and the input element of the speed reducer 7 in order to distribute and transmit the rotational torque of the rotor 10 to the left and right wheels of a vehicle (not shown). The speed reducer 7 decelerates the rotation of the rotor 10 and amplifies the torque so that the sun gear S,
It has a planetary gear set consisting of a ring gear R and a carrier CR. The motor body 1, the differential device 5, and the speed reducer 7 are housed and supported in the motor case 3.

The motor case 3 has a pair of center cases 31 each having a cylindrical shape whose both ends are open, and their end faces facing each other are aligned and bolted together.
Cup-shaped side cases 32 are spigot-joined and bolted to the non-coupling side openings of both center cases 31, respectively. Partition walls 33 extending in the center direction from the peripheral walls of the center cases 31 are formed, a differential device chamber 30 is defined between the partition walls, and the differential device 5 is housed therein.

The partition wall 33 and the radial wall 3 of the side case 32
An electric motor chamber 35 is defined between the motor main body 1 and the electric motor 4, and the motor main body 1 is housed therein. The stator 15 of the motor body 1
Are fixed to the inner peripheral wall of the center case 31. That is, the armature core 16 of the stator 15 has its inner end (hereinafter, the internal / external relationship will be described with the mating portion of both center cases 31 as the inside) contacting the stepped portion 36 formed on the inner peripheral wall of the center case 31. It is supported by a rotation stopper fitted inside the peripheral wall of the center case 31.

In particular, the centering of the armature iron core 16 with respect to the motor case 3 has been devised. As shown in FIGS. 11 and 12, the stator press-fitting cylindrical portion of the center case 31 has several places (this example). In the above, the stress relief groove 37 is formed from the outer end of the center case 31 to the inside of the center case 31 with the center axis of the case interposed therebetween. The stress load on 31 is eased. With such a configuration, the press-fitting margin is set to a large value, cracking of the case during cold weather is prevented, and the amount of clearance between the motor case 3 and the stator 15 during thermal expansion is minimized over a wide temperature range. Because the stator 1
The coaxial accuracy of the rotor 5 and the rotor 10 is improved, and the gap between them is made uniform to improve the motor performance.

On the other hand, the rotor 10 of the motor body 1 has its rotor drum 11 supported by the differential device 5. The differential device 5 is rotatably rotatable with respect to a pair of differential cases 51 formed of a material having sufficient rigidity and integrally bolted to each other, a pinion shaft 50 disposed at a mating portion thereof, and a pinion shaft 50. The pinion 52 is arranged and a pair of side gears 53 meshing with the pinion 52. The side gear 53 is a differential case 5
1 is spline-fitted to the end of the drive shaft 54 so as to differentially rotate the rotation transmitted from the rotor 10 to the drive shaft 54 extending in the left-right direction of the vehicle. The differential case 51 has a tubular portion 56 that extends from the main body portions 55 so as to surround the drive shaft 54, and the tubular portion 56 supports the rotor drum 11.

The outer peripheral surface of the cylindrical portion 56 and the inner peripheral surface of the rotor drum 11 are spline-fitted, and a bearing 91 is provided between the outer peripheral surface of the base portion of the cylindrical portion 56 and the partition wall 33. The differential device 5 is rotatably supported and axially positioned. And the tubular portion 5
6 and the drive shaft 54 are rotatable relative to each other with an appropriate amount of clearance maintained between their inner and outer circumferences. Therefore, when the differential device 5 differentially rotates, the drive shaft 54 relatively rotates with respect to the tubular portion 56. A parking gear 57b is formed on the outer periphery of the main body 55b of the one differential case 51b.

A thrust collar 58 is fitted in the vicinity of the outer end of the drive shaft 54 so as to be immovable in the axial direction.
A thrust bearing 92 is disposed therebetween, and an outer end of the drive shaft 54 is in contact with an inner end of a transmission shaft 71, which will be described later, via a thrust bearing 93. Therefore, the drive shaft 54
Is positioned by being blocked from moving inward by the bearing 91 via the differential case 51 and being blocked from moving outward by the bearing 94 described later via the transmission shaft 71.

Further, the planetary gear set of the reduction gear transmission 7 is disposed outside the thrust collar 58, that is, on the wheel side. The planetary gear set includes a sun gear S, a pinion P that meshes with the sun gear S, a carrier CR that supports the pinion P, and a ring gear R that meshes with the pinion P. The sun gear S is integrally formed with the drive shaft 54, and the ring gear R is the side case 32. It is bolted via a flange 59. In this planetary gear set, rotation is input from the drive shaft 54 to the sun gear S, and decelerated rotation is output from the carrier CR to the transmission shaft 71 and the wheel shaft 8.

Then, on the outer side in the axial direction of the carrier CR,
A transmission shaft 71 is continuously provided, and a yoke flange 8 that is rotatably supported by the side case 32 via a bearing 94 and takes out power from the motor case 3 is spline-fitted to the outer periphery of the transmission shaft 71. 71 and the yoke flange 8 are axially positioned on the side case 32 by sandwiching the inner race of the bearing 94 by tightening nuts. Thus, the carrier CR has a transmission shaft 7 integral therewith.
1. Through the yoke flange 8 that fits on the outer circumference of the shaft,
As a result, it is supported by the inner race of the bearing 94.

On the other hand, on the axially outer side of the ring gear R, a flange 59 is engaged with a spline portion on the outer periphery of the ring gear R by meshing with the inner peripheral teeth of the ring gear R with a snap ring. The inner diameter of the flange 59 is set so as to be closely fitted to the outer diameter of the outer race of the bearing 94, and the flange projecting radially inward at the inner end fits into the notched circumferential groove at the outermost innermost end of the outer race. ing. Thus, the outer race is
The axially outward movement is blocked by the side case 32, and the inward movement is blocked by the flange 59. The ring gear R is prevented from moving outward in the axial direction by the outer ends of the inner peripheral teeth, is blocked from moving inward by the snap ring, and is centered and supported by the outer race via the flange 59.

This drive unit is provided with a lubricating device for lubricating each part of the mechanism and for cooling the field coil 17 of the motor body 1, and an oil pump as a hydraulic pressure generating source thereof is provided in the axial center of the drive unit. Is disposed in the section. The oil discharged from the pump is sequentially supplied to each mechanism part to lubricate each part, and is also supplied from the oil passage 39 to the field coil 17 of the motor main body 1 to cool it and finally to the center. The oil is collected in the oil sump below the case 31. Therefore, the motor case 3 is in an oil-filled state.

In the drive unit constructed as described above, when one or both of the two motor bodies 1 are operated under the control of the motor driver, the rotation of the rotor 10 is spline-engaged with the differential case 51.
The rotation is transmitted to the drive shaft 54 via the side gears 53. Then, this rotation is input to the sun gear S of both planetary gear sets, decelerated there, and output from the carrier CR. The output rotation of the carrier CR is transmitted from the transmission shaft 71 through the yoke flange 8 to a wheel (not shown) connected thereto. The vehicle is driven by such rotation of the wheels.

Although the present invention has been described in detail based on the two embodiments, it goes without saying that the present invention can be implemented by appropriately changing the specific construction of each part within the scope of the claims. .

[Brief description of drawings]

FIG. 1 is an axial sectional view showing a wiring connection device of a first embodiment of the present invention.

FIG. 2 is an end view as viewed in the direction II of FIG.

FIG. 3 is an end view as viewed in the direction III in FIG.

FIG. 4 is an axial cross-sectional view of main parts of the wiring connection device.

FIG. 5 is an inner end view of main parts of the wiring connection device.

FIG. 6 is an outer end view of a main portion of the wiring connection device.

FIG. 7 is an axial cross-sectional view showing main parts of a wiring connection device according to a second embodiment of the present invention.

FIG. 8 is an end view as seen in the direction IIX of FIG. 7.

9 is an end view as seen in the IX direction of FIG. 7.

FIG. 10 is an axial sectional view of a drive unit to which the present invention is applied.

11 is an end view as seen in the XI direction of FIG.

12 is a partial side view of FIG. 11 as viewed in the XII direction.

[Explanation of symbols]

2 bush 3 motor case 4 adapter terminals 21 inner hole 22 Flange (fixing means) 28 O-ring 31 center case 38 through holes 41 screw hole (connection means) 42 eyes (connection means) 44,44A O-ring 61 Electric wire cable (electric wire) in the motor case 65 Motor case outer wire cable (electric wire)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masahiro Hasebe             10 Akane, Takane, Fujii-cho, Anjo City, Aichi Prefecture             N AW Co., Ltd. (72) Inventor Yoshihiko Sasaki             10 Akane, Takane, Fujii-cho, Anjo City, Aichi Prefecture             N AW Co., Ltd. F-term (reference) 5H605 AA08 AA20 CC02 CC06 DD05                       DD09 DD32 EC01 EC03 EC04                       EC08 GG06

Claims (3)

[Claims] 1. A motor case having a through hole penetrating through a case wall, an electrically insulating bush fitted into the through hole and fixed to the case wall so as not to come off, and an inner hole of the bush. And a conductive adapter terminal having a connecting means for connecting the ends of the electric wires inside and outside the motor case, wherein the bush has a fixing means to the motor case protruding in the radial direction, An O-ring seals between the inner peripheral surface of the hole and the outer peripheral surface of the bush and between the inner peripheral surface of the bush and the outer peripheral surface of the adapter terminal. A wiring connection device for a motor for a vehicle, characterized in that the ends of the electric wires are connected. 2. The wiring connecting device for a motor for a vehicle according to claim 1, wherein a joint surface of the fixing means with respect to the motor case is oriented perpendicular to an axial direction of the bush. 3. The wiring connecting device for a motor for a vehicle according to claim 1, wherein the motor case has a joint portion facing a fixing means of the bush near a through hole into which the bush is inserted.