JPH062649A - Plunger pump - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent vibration and noise of the motor housing of the drive motor of the plunger pump used as the hydraulic pressure source of the anti-lock brake system. [Structure] Eccentric drive shaft support shaft 3 in pump housing 30
Fix 1 An eccentric drive shaft 32 is rotatably fitted on the support shaft 31. The drive shaft 32 and the motor shaft 37 are connected by a coupling 36 so that only rotation is transmitted. An eccentric drive bearing 39 is provided on the outer circumference of the eccentric drive shaft 32.
Fit in. The pair of plungers 4, 5 of the plunger pumps 41, 42 are brought into contact with the outer ring 40 of the bearing 39 by the return springs 13, 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plunger type pump used as a hydraulic power source for an antilock brake system, and more particularly to prevention of vibration and noise generated from the plunger type pump during braking.

[0002]

2. Description of the Related Art Conventionally, a plunger type pump as shown in FIG. 7 has been used as a hydraulic pressure source of an antilock brake system. In this plunger type pump, an eccentric cam 2 is attached near the tip of a rotary shaft 1 of a motor (not shown) to form an eccentric drive shaft 3, and the eccentric cam 2 is sandwiched so that a pair of plungers 4 and 5 face each other by 180 °. Are arranged.

The plungers 4 and 5 are slidably fitted into plunger cases 11 and 12 provided at the front of a pump housing 9 of the antilock brake system by plunger plugs 6 and 7, respectively. Further, between the plungers 4 and 5 and the plunger cases 11 and 12, bearing means in which the tip ends of the plungers 4 and 5 are attached to the outer circumference of the eccentric cam 2 by the elastic force of the return springs 13 and 14, respectively. It is in contact with 15.

In the plunger type pump as described above, when the eccentric drive shaft 3 rotates, the plungers 4 and 5 are rotated.
Responds to the rotation of the eccentric cam 2 and reciprocates within the plunger cases 11 and 12.

Therefore, when the motor is driven during the antilock operation of the antilock brake system, the reciprocating motion of the plungers 4 and 5 sucks the working fluid from the suction port 17 side connected to the discharge valve 16 of the antilock brake system. The discharge port 2 that is connected to the master cylinder 19 side by compressing and pressurizing this hydraulic fluid in each spring chamber 21 and 22
Discharge from 0.

In FIG. 7, 23 is a hydraulic fluid storage tank, 24 is a brake pedal, and 25 is a wheel brake.

[0007]

In the conventional plunger type pump described above, the plungers 4 and 5 correspond to the rotation of the eccentric cam 2 in accordance with the rotation of the rotary shaft 1 as described above, and the plungers 5 to 5 correspond to each other. Reciprocating motion is performed in the cases 11 and 12, and the hydraulic fluid is compressed / pressurized in the spring chambers 21 and 22.

Therefore, the reaction force when the plungers 4 and 5 pressurize and compress the hydraulic fluid in the spring chambers 21 and 22 is transmitted to the motor rotating shaft 1 via the eccentric cam 2.

In the pump of this structure, since the rotary shaft 1 is sandwiched and the pair of plungers 4 and 5 are arranged to face each other by 180 °, the reaction force due to the pressurization / compression of the hydraulic fluid is in the state of the alternating load. Acts on the motor rotating shaft 1.

On the other hand, the reaction force transmitted to the motor rotating shaft 1 is supported by the bearing 26 attached to the tip of the motor rotating shaft 1 and the bearing provided inside the motor. The bearing 26 attached to the tip of the motor rotating shaft 1 is held by the pump housing 9.

A bearing provided inside the motor is held by the motor housing. Therefore, a large alternating load acts on the pump housing and the motor housing.

Some motors used in plunger type pumps used in anti-lock brake systems have a thin-walled sheet metal that has been deep-drawn for the motor housing in order to reduce weight and cost. However, when an alternating load is applied, the motor housing vibrates and a large operating noise is generated.

An object of the present invention is to solve the above problems and provide a plunger type pump with less vibration and noise.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, according to the present invention, an eccentric drive shaft support shaft is cantilevered on a pump housing of a plunger pump, and the eccentric drive shaft support shaft is attached to the eccentric drive shaft support shaft. The eccentric drive shaft is rotatably fitted and inserted through a bearing, and the motor shaft of the drive motor is connected to the eccentric drive shaft using a coupling so that the drive torque of the motor is transmitted to the eccentric drive shaft.

Further, the eccentric drive shaft support shaft is fixed to the pump housing by press fitting, a high sliding resin sheet is inserted between the tip of the eccentric drive shaft support shaft and the eccentric drive shaft, and the eccentric drive shaft. We also adopted a bearing in which a bearing that holds the eccentric drive shaft is sandwiched between the support shaft and a solid bearing material ring fixed, and a high slidable resin sheet inserted between the motor shaft tip and the eccentric drive shaft.

[0016]

Since the present invention has the above-described structure, when the rotation shaft starts to rotate by the motor during the antilock operation, this rotation torque is transmitted to the eccentric drive shaft through the coupling and drives the pair of plungers to drive the pump. Operate.

As described above, the reaction force generated when the plunger operates to pressurize and compress the hydraulic fluid is received by the eccentric drive shaft support shaft fixed to the pump housing and is not transmitted to the rotary shaft.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment shown in FIG. 1, an eccentric drive shaft support shaft 31 is fixed in a non-rotatable manner so as to project into a recess of a pump housing 30. The eccentric drive shaft 32 is rotatably fitted in the eccentric drive shaft support shaft 31 via a bearing 34. The eccentric drive shaft 32 has a hole 35 on the pump driving motor (not shown) side as shown in FIG. 3, and a coupling 36 is mounted in the hole 35.

The coupling 36 has a pair of protrusions, and the protrusions engage with the pair of recesses of the hole 35, so that the eccentric drive shaft 32 and the coupling 36 together with some play. It is designed to rotate.

The flat end of the motor shaft 37 of the pump driving motor is inserted into the laterally long hole of the coupling 36 with some play, and the rotational torque of the motor is transmitted through the coupling 36 to the eccentric drive shaft. 32 can be transmitted. An eccentric drive bearing 39 is rotatably mounted on the outer periphery of the eccentric drive shaft 32, and an outer ring 40 of the eccentric drive bearing 39 is attached to the tip of each plunger 4, 5 of a pair of plunger pumps 41, 42. Are in contact.

Since the outer periphery of the eccentric drive shaft 32 is eccentric with respect to the eccentric drive shaft support shaft 31 as shown in FIG. 2, the outer ring 40 of the bearing 39 fitted therein is also eccentric.

Therefore, when the eccentric drive shaft 32 rotates, the plungers 4 and 5 which sandwich the eccentric drive shaft 32 reciprocate.

The construction and operation of the pumps 41 and 42 are shown in FIG.
Since it is the same as the conventional example, the same reference numerals are given and the description is omitted.

An annular ring 43 made of a solid bearing material is fixed to the eccentric drive shaft support shaft 31 so as to sandwich the bearing 34.
The movement of 4 in the axial direction is restricted. An annular ring 44 made of a solid bearing material is fixed to the eccentric drive shaft 32 so as to sandwich the eccentric drive bearing 39.
Is constrained from moving in the axial direction.

A high slidable resin sheet 45 such as PTFE is inserted between the tip of the eccentric drive shaft support shaft 31 and the end wall of the eccentric drive shaft 32. Similarly, a highly slidable resin sheet 46 such as PTFE is also inserted between the tip of the motor shaft 37 and the end wall of the eccentric drive shaft 32.

In the example shown in FIGS. 1 to 3, an eccentric drive bearing 39 is fitted on the eccentric drive shaft 32, and a counterweight portion 47 is provided to maintain a static balance with the eccentric portion of the eccentric drive shaft 32 itself. It is provided integrally.

1 and 2, the bearing 34 and the eccentric drive bearing 39 are drawn as needle roller bearings, but they may be deep groove ball bearings or solid bearings. It is also possible to form the eccentric drive shaft support shaft 31 itself with a solid bearing material and omit the bearing 34. It is also possible to omit the counter weight provided on the eccentric drive shaft 32. An example thereof is shown in FIGS.

In the embodiment shown in FIGS. 4 to 6, the eccentric drive shaft support shaft 31 is made of a solid bearing material, the eccentric drive shaft 32 is directly rotatably inserted, and the counter weight is omitted. Since the structure and operation of the above are the same as those of the embodiment of FIGS. 1 to 3, the same reference numerals are given and description thereof is omitted.

[0029]

The present invention occurs when the eccentric drive shaft support shaft, which is separate from the motor shaft as described above, is fixed to the pump housing and the plunger pump pressurizes and compresses the hydraulic fluid during antilock operation. Since the reaction force is prevented from acting on the motor shaft by receiving the reaction force on the eccentric drive shaft support shaft, the reaction force at the time of pump operation is not transmitted to the motor housing, and the motor housing is kept at the time of pump operation. It does not vibrate and generate noise.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of an embodiment.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is a vertical sectional front view of another embodiment.

5 is a sectional view taken along line CC of FIG.

6 is a sectional view taken along line DD of FIG.

FIG. 7 is a vertical sectional front view of a conventional example.

[Explanation of symbols]

 4 Plunger 5 Plunger 13 Return spring 14 Retan spring 30 Pump housing 31 Eccentric drive shaft support shaft 32 Eccentric drive shaft 37 Motor shaft 41 Plunger pump 42 Plunger pump 43 Solid bearing material ring 44 Solid bearing material ring 45 High Sliding resin sheet 46 High sliding resin sheet

Claims (5)

[Claims] 1. A plunger type pump comprising a pair of plungers arranged so as to face each other with an eccentric drive shaft sandwiched therebetween, wherein the plungers are biased by a return spring to contact the eccentric drive shaft. Is rotatably fitted into an eccentric drive shaft support shaft fixed to a pump housing, and the motor drive torque is transmitted to the eccentric drive shaft through a coupling. 2. The eccentric drive shaft support shaft is press-fitted and fixed to the pump housing.
Plunger pump described. 3. The plunger pump according to claim 1, wherein a highly slidable resin sheet is inserted between the tip of the eccentric drive shaft support shaft and the eccentric drive shaft. 4. The plunger type pump according to claim 1, wherein an annular ring made of a solid bearing material is fixed to the eccentric drive shaft support shaft so as to sandwich a bearing for holding the eccentric drive shaft. 5. The plunger pump according to claim 1, wherein a resin sheet made of high sliding material is inserted between the tip of the motor shaft and the eccentric drive shaft.