JP2001058507A - Supporting structure of axle hub for industrial vehicle use and counter-balance type fork lift - Google Patents

Abstract

PROBLEM TO BE SOLVED: To support an axle hub with one radial bearing without using auxiliary parts such as collar. SOLUTION: A brake drum 24 is formed with an axle hub 32 in separate body, and it is fixed and linked to a coupling part 19 of an axle shaft 18 with an axle hub 23. By the fact that the axle hub 23 and the brake drum 24 pinch and support an outer wheel 20b of a radial axle box bearing 20 toward a thrust direction under the condition that they are coupled and fixed to the coupling part 19, they are fixed against the outer wheel 20b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an axle hub support structure for an industrial vehicle and a counterbalance type forklift provided with the axle hub support structure.

[0002]

2. Description of the Related Art Conventionally, a support structure for a front wheel of a forklift as an industrial vehicle has a fixed axle structure in which an axle shaft is inserted through an axle housing fixed to a housing of a differential gear. This fixed axle structure provides an axle hub support structure that rotatably supports the axle hub by means of a bearing fitted to the axle housing. The bearing has an inner ring fixed to the axle housing so as not to rotate relatively and an outer ring fixed to the axle hub so as not to rotate. In this axle hub support structure, an external force applied in the thrust direction to a wheel connected and fixed to the axle hub is connected to the axle hub supported by bearings by connecting a connection portion integrally provided at the tip of the axle shaft. So that it does not directly apply to the bearing via

[0003] As such an axle hub support structure,
For example, as shown in FIG. 4, there is a type in which an axle hub 52 is supported by a pair of tapered roller bearings 51 fixed to an axle housing 50. Axle hub 5
The second axle hole 53 is provided with a ridge 54 extending in the circumferential direction, and a pair of tapered roller bearings 51 is fitted on the axle housing 50 so as to sandwich the ridge 54.
Then, a pair of tapered roller bearings 51 externally fitted to the axle housing 50 are clamped by a stepped portion 55 provided on the axle housing 50 and a lock nut 56 screwed to a tip end portion thereof, thereby forming an axle hub. 52 are sandwiched between the outer races 51 a of the pair of tapered roller bearings 51. The axle hub 52 is connected and fixed to a connecting portion 58 provided at the tip of the axle shaft 57. Therefore,
The axle hub 52 is rotatably supported by a pair of tapered roller bearings 51 fixed to the axle housing 50 while being connected to the axle shaft 57 so as not to be displaced in the axial direction.

However, in this axle hub support structure, the axle hub 52 is supported by a pair of tapered roller bearings 51. Therefore, in order to reduce the number of parts and the number of assembling steps, as shown in FIG. 5, an axle hub supporting structure in which the axle hub 61 is supported by one radial bearing 60 is implemented. In this axle hub support structure, the inner ring 60a of one radial bearing 60 is connected to the stepped portion 6 on the outer peripheral surface of the axle housing 62.
3 and a lock nut 64 to fix the axle housing 62 to the axle housing 62, and to connect the outer ring 60 b to the stepped portion 6 provided on the inner peripheral surface of the axle hole 65 of the axle hub 61.
6 and the connecting portion 68 of the axle shaft 67, thereby connecting and fixing to the axle hub 61. In this axle hub support structure, since the axle hub 61 also serves as a brake drum, the outer ring 60b of the radial bearing 60 is held and fixed between the brake drum and the connecting portion 68.

In this axle hub support structure, a gap in the thrust direction is formed between the connecting portion 68 at the tip of the axle shaft 67 and the radial bearing 60 abutting on the stepped portion 66 of the axle hole 65. This is a lock nut 64 for holding the inner ring 60a of the radial bearing 60.
Is required to be screwed to the tip of the axle housing 62. For this reason, in the axle hub supporting structure in which the axle hub 61 is supported by one radial bearing 60, a collar 69 is provided between the connecting portion 68 and the outer ring 60b, and the outer ring 60b is connected between the connecting portion 68 and the step portion 66 by the collar 69. To be clamped together.

[0006]

However, in the axle hub support structure in which the axle hub 61 is supported by one radial bearing 60, when the axle hub 61 is mounted on the axle shaft 67, the collar 69, which is an auxiliary component and has a small size, is mounted. May be forgotten by the operator.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object that an axle hub can be supported by one bearing, and an operator may forget to assemble. An object of the present invention is to provide an axle hub support structure for an industrial vehicle that does not use an auxiliary part such as a collar, and a counterbalanced forklift provided with the axle hub support structure.

[0008]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, an axle hub is rotatably supported on an axle housing through which an axle shaft is inserted. The axle hub of an industrial vehicle is fixed to the outer ring of the radial bearing while the inner ring of the radial bearing is fixed and the axle hub is fixed to a connecting portion provided at the tip of the axle shaft. In the support structure, the axle hub is provided separately from the axle hub, and is fixed to the outer wheel by clamping the outer wheel in a thrust direction together with a brake drum fixed to the axle hub. It is a support structure.

According to a second aspect of the present invention, in the first aspect of the present invention, the brake drum and the axle hub are such that a drum portion of the brake drum to which a brake shoe slides is fixed to the axle hub. And the brake drum is formed such that the drum portion has an outer diameter larger than the inner diameter of the rim portion of the wheel.

According to a third aspect of the present invention, in the first aspect, the radial bearing is a single row ball bearing. According to a fourth aspect of the present invention, there is provided a counterbalance type forklift in which the axle hubs of the left and right front wheels are supported by the axle hub support structure of the industrial vehicle according to any one of the first to third aspects.

(Operation) According to the first aspect of the present invention,
The axle hub and the brake drum are fixed to the outer ring by clamping the outer ring of the radial bearing while being fixed to the connecting portion of the axle shaft. The axle hub and the brake drum fixed to the connection portion of the axle shaft are restricted in relative movement with respect to the axle housing in the thrust direction, and are supported rotatably with respect to the axle housing by radial bearings. It is driven to rotate. Therefore, the axle hub and the brake drum are rotatably supported by one radial bearing, and the outer ring of the radial bearing is connected and fixed to the axle hub side only by the axle hub and the brake drum having a large size instead of the auxiliary parts.

According to the invention described in claim 2, according to claim 1,
In addition to the operation of the invention described in the above, the outer diameter of the brake drum is not restricted by the inner diameter of the wheel. According to the third aspect of the invention, in addition to the function of the first aspect,
The axle hub is supported by a single row ball bearing with a simple configuration.

[0013] According to the invention described in claim 4, according to claim 1 of the present invention.
In addition to the function of the invention described in any one of claims 1 to 3, the axle hub of the left and right front wheels of the counterbalanced forklift has the function of the invention described in any one of claims 1 to 3. Supported by an axle hub support structure.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment in which the present invention is embodied in a front axle hub support structure of an electric counterbalance type forklift will be described below with reference to FIGS.

As shown in FIG. 3, the electric counterbalance type forklift 10 has front left and right wheels 11 supported by a drive unit 12 and rear left and right wheels 13 supported by a rear axle arm 14. Drive unit 12
Is an electric motor 15, a reduction gear train, and a differential device integrated.

As shown in FIG. 1, the drive unit 12
An axle housing 17 is fixed to the housing 16, and an axle shaft 18 extending from a differential device is inserted into the axle housing 17. The axle shaft 18 has a connecting portion 19 that expands in a plane perpendicular to the axis at a tip end extending from the tip of the axle housing 17.
Are provided integrally.

The axle housing 17 has one radial bearing 20 fitted on the outer peripheral surface at the tip end thereof. The radial bearing 20 is a single row ball bearing. The radial bearing 20 is provided with a stepped portion 17 a provided on the outer peripheral surface of the distal end portion of the axle housing 17.
The inner ring 20a is connected and fixed to the distal end portion of the axle housing 17 by being sandwiched by a lock nut 21 that is screwed into a female screw portion provided at the distal end of the step portion 17a. Note that an annular spacer 22 that fits over the axle housing 17 is interposed between the radial bearing 20 and the lock nut 21.

An axle hub 23 and a brake drum 24 are fixed to the outer ring 20b of the radial bearing 20. The axle hub 23 has its axle hole 25 fitted to the outer ring 20b from the outside. The axle hub 23 is fixed to the connecting portion 19 by a bolt 26 inserted from the outer surface of the connecting portion 19 with the inner surface of the connecting portion 19 abutting on the outer surface thereof. The axle hub 23 is provided with a plurality of embedded bolts 27 extending in the thrust direction so that the female screw portions protrude from the outer surface and the inner surface.

Also, the brake drum 24 has its axle hole 2
8 is fitted to the outer ring 20b from the inside thereof. The brake drum 24 has a nut 29 screwed from the inner surface of the end wall to an embedded bolt 27 penetrating the end wall.
Thereby, the end wall is fixed to the axle hub 23 in a state where the outer surface of the end wall is in contact with the inner surface of the axle hub 23.

The axle hub 23 and the brake drum 24 are connected to each other so that the outer ring 20b of the radial bearing 20 is sandwiched in the thrust direction so that the outer ring 20b cannot rotate relative to the outer ring 20b and cannot move relative to the thrust direction. I have.

More specifically, as shown in FIG. 2, the axle hole 25 of the axle hub 23 has an outer small diameter portion 25a and an inner large diameter portion 25b. The small diameter portion 25a is formed with an inner diameter that is approximately the median between the inner diameter and the outer diameter of the radial bearing 20. On the other hand, the large-diameter portion 25b is formed with an inner diameter that is fitted to the outer ring 20b of the radial bearing 20. The large diameter portion 25b has a length in the thrust direction,
The radial bearing 20 is formed to have a thickness of about ３ of the axial thickness. The axle hub 23 is configured such that the step surface between the small diameter portion 25a and the large diameter portion 25b abuts on the outer surface of the outer ring 20b of the radial bearing 20, and the large diameter portion 2
5b is fitted on the outer ring 20b.

The axle hole 28 of the brake drum 24 is
It has an outer large diameter portion 28a and an inner small diameter portion 28b. The large-diameter portion 28a is formed with an inner diameter that is fitted to the outer ring 20b of the radial bearing 20. On the other hand, the small diameter portion 28b is formed with an inner diameter approximately equal to the inner diameter of the outer ring 20b. The large-diameter portion 28a of the brake drum 24 is externally fitted to the outer ring 20b in a state where the step surface between the large-diameter portion 28a and the small-diameter portion 28b contacts the inner surface of the outer ring 20b.

As shown in FIG. 1, a wheel 30 is detachably fixed to the axle hub 23 on its outer surface. The wheel 30 is fixed in a state of being in contact with the outer surface of the axle hub 23 by a nut 32 screwed from the outside of the disk portion 31 to an embedded bolt 27 penetrating the disk portion 31.

The axle hub 23 and the brake drum 24 are formed such that the drum 34 to which the brake shoe 33 slides is disposed closer to the vehicle than the rim 35 of the wheel 30 fixed to the axle hub 23. ing. In the brake drum 24, the drum portion 34 is formed with an outer diameter larger than the inner diameter of the rim portion 35 of the wheel 30.

The axle hub support structure and the counterbalance type forklift of this embodiment described in detail above include:
There are the following functions and effects. (1) The axle hub 23 and the brake drum 24
In a state where the outer ring 20b of the radial bearing 20 is held in the thrust direction in a state where the outer ring 20b is connected to and fixed to the connecting portion 19 of the axle shaft 18, the outer ring 20b is connected together with the connecting portion 19.
Fixed to The axle hub 23 and the brake drum 24 fixed to the connecting portion 19 of the axle shaft 18
The relative movement with respect to the axle housing 17 in the thrust direction is restricted, and is rotatably driven by the axle shaft 18 in a state of being rotatably supported by the axle housing 17 by the radial bearing 20.

Therefore, the axle hub 23 and the brake drum 24 are rotatably supported by one radial bearing 20, and the outer race 20b of the radial bearing 20 is formed by the axle hub 23 using only the large axle hub 23 and the brake drum 24, not auxiliary parts. Connected and fixed. As a result, one radial bearing 2
A collar 69 that can support the axle hub 23 with only zero and may cause the operator to forget to assemble it.
It can be configured without using auxiliary parts such as.

(2) Drum section 3 of brake drum 24
The axle hub 23 and the brake drum 24 were formed such that the wheel 4 was disposed closer to the vehicle than the rim 35 of the wheel 30, and the outer diameter of the drum 34 was larger than the inner diameter of the rim 35. Therefore, the drum portion 3 of the brake drum 24
4 is not restricted by the inner diameter of the wheel 30,
The brake drum 24 having a large capacity can be mounted without being restricted by the inner diameter of the wheel 30.

(3) The radial bearing supporting the axle hub 23 is a single row ball bearing. Therefore, the cost can be reduced as compared with a case where a radial bearing such as a self-aligning bearing is used.

(4) In the axle hub support structure for supporting the axle hubs 23 of the left and right front wheels 11 of the counterbalance type forklift 10, the functions and effects described in the above (1) to (3) can be obtained. as a result,
According to (1), the assembly reliability at the time of manufacturing the vehicle can be improved, and (2) the brake drum 2 having a large outer diameter without increasing the inner diameter of the wheel 30 to be mounted.
4, high braking performance can be obtained. or,
According to (3), the manufacturing cost of the vehicle can be reduced.

Hereinafter, embodiments other than the above-described embodiment embodying the present invention will be listed as other examples. The brake drum and the axle hub may be formed such that at least a part of the drum portion of the brake drum is disposed at a position overlapping the rim portion 35 of the wheel 30. In this case, the thickness of the axle hub may be reduced, and the disk portion 31 of the wheel 30 may be largely offset outward. With this configuration, the width of the vehicle can be reduced by shortening the wheelbase.

The radial bearing is not limited to a single-row deep groove ball bearing as long as it can support a load in the shaft radial direction. In addition, for example, ball bearings such as magneto ball bearings, double row deep groove ball bearings, angular ball bearings, combined angular ball bearings, double row angular ball bearings, self-aligning ball bearings, or cylindrical roller bearings, tapered roller bearings, Roller bearings such as row tapered roller bearings, quadruple tapered roller bearings, self-aligning roller bearings, and needle roller bearings may be used.

The industrial vehicle implementing the axle hub support structure may be any industrial vehicle in which the axle shaft of the drive wheels driven via the differential device can be a fixed axle structure, and is not limited to a counterbalance type forklift. . In addition, the present invention may be applied to an axle hub support structure of a tractor shovel, a towing tractor, an aerial work vehicle, or the like.

[0033]

According to the present invention, the axle hub can be supported by one radial bearing, and an auxiliary component such as a collar which may be forgotten by an operator during assembly. It can be configured without using. Further, in the counterbalance type forklift, the reliability of assembly during vehicle manufacture can be improved.

According to the second or third aspect of the present invention, a large-capacity drum brake having a brake drum having an outer diameter larger than the inner diameter of the wheel can be used. Further, in a counterbalance type forklift, high braking performance can be obtained by a brake drum having a large outer diameter without increasing the inner diameter of a wheel to be mounted.

According to the third or fourth aspect of the present invention, a radial bearing can be provided at low cost. Further, in the counterbalance type forklift, manufacturing costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a front axle hub support structure of a forklift.

FIG. 2 is a schematic sectional view showing a main part of a front axle hub support structure.

FIG. 3 is a schematic plan view of a counterbalance type forklift.

FIG. 4 is a schematic cross-sectional view showing a front axle hub support structure of a conventional forklift.

FIG. 5 is a schematic sectional view showing a front axle hub support structure of a conventional forklift.

[Explanation of symbols]

10: counterbalanced forklift as an industrial vehicle, 11: front wheels, 17: axle housing, 18 ...
Axle shaft, 19 connecting part, 20 radial bearing, 20a inner ring, 20b outer ring, 23 axle hub, 24 brake drum, 25 axle hole, 30 wheel, 33 brake shoe, 34 drum part, 35
... Rim section.

Claims (4)

[Claims] An inner ring of a radial bearing that rotatably supports an axle hub with respect to the axle shaft is fixed to an axle housing through which the axle shaft is inserted, and the axle hub is provided at a tip of the axle shaft. An axle hub supporting structure for an industrial vehicle fixed to an outer ring of the radial bearing in a state fixed to the connected connection portion, wherein the axle hub is provided separately from the axle hub, and An axle hub support structure for an industrial vehicle fixed to the outer wheel by holding the outer wheel in the thrust direction together with a fixed brake drum. 2. The brake drum and the axle hub are formed such that a drum portion of the brake drum to which a brake shoe slides is disposed closer to a vehicle than a rim portion of a wheel fixed to the axle hub. The axle hub support structure for an industrial vehicle according to claim 1, wherein the brake drum has an outer diameter larger than an inner diameter of a rim of the wheel. 3. The axle hub support structure for an industrial vehicle according to claim 1, wherein the radial bearing is a single row ball bearing. 4. A counterbalanced forklift having an axle hub supporting structure for an industrial vehicle according to claim 1, wherein the left and right front wheel axle hubs are supported.