Vacuum-cooled power tool

Claim 2

A power tool or the like comprising a rotatable, bearing mounted shaft; a motor for rotating said shaft; a casing surrounding said motor, said bearings and said shaft; and means for cooling said motor and said bearings which comprises: inlet means through which air can flow into said casing, said inlet means being located at one end of said casing, a vacuum manifold located at the opposite end of said casing from said inlet means, and means providing a path through said tool between and communicating with said inlet means and said vacuum manifold along which air can flow in heat transfer relationship to said motor and said bearings to absorb heat therefrom which comprises passage means between said casing and said motor and said casing and said bearings, said manifold being connectable to a vacuum source to thereby provide a pressure differential for effecting the flow of air through said passage means.

Claim 3

The power tool of claim 1, together with means for filtering the air before it flows from the ambient surroundings into the tool casing.

Claim 4

A power tool or the like comprising a casing having an opening in one end thereof; a shaft in said casing, said shaft extending through the opening in said one end of said casing to the exterior thereof and there being sufficient clearance between said casing and said shaft to allow the shaft to rotate freely relative to the casing; bearing means supporting said shaft in said casing; and a vacuum manifold at said one end of said casing, said manifold communicating with the opening through which the shaft extends and being located between said opening and said bearing means, said manifold being connectable to a vacuum source, whereby contaminants penetrating to the interior of said casing through said opening will pass into said manifoLd and be evacuated from said casing before said contaminants reach said bearing means.

Claim 5

A power tool or the like comprising a casing having an opening in one end thereof; a shaft in said casing, said shaft extending through the opening in said one end of said casing to the exterior thereof and there being sufficient clearance between said casing and said shaft to allow the shaft to rotate freely relative to the casing; bearing means supporting said shaft in said casing; and a vacuum manifold at said one end of said casing, said manifold communicating with the opening through which the shaft extends and being located between said opening and said bearing means, said manifold being connectable to a vacuum source, whereby contaminants penetrating to the interior of said casing through said opening will pass into said manifoLd and be evacuated from said casing before said contaminants reach said bearing means.

Claim 6

A power tool or the like, comprising a casing means; a shaft; bearing means supporting said shaft in said casing means; means for supplying a lubricant to said bearing means for circulation therethrough; and vacuum means for evacuating the lubricant from the casing means after it circulates through said bearing means, said bearing means comprising at least two bearings spaced along said shaft, there being a spacer between said bearings, and said lubricant supplying means comprising a first flow passage in said spacer intermediate the ends thereof, a second flow passage through said casing means communicating with said first flow passage, and means in said spacer providing fluid communication between said first flow passage and the ends of the spacer through which the lubricant can flow to the bearings between which the spacer is located.

Claim 7

A power tool or the like, comprising a casing means; a shaft; bearing means supporting said shaft in said casing means; means for supplying a lubricant to said bearing means for circulation therethrough; and vacuum means for evacuating the lubricant from the casing means after it circulates through said bearing means, said bearing means comprising at least two bearings spaced along said shaft, there being a spacer between said bearings, and said lubricant supplying means comprising a first flow passage in said spacer intermediate the ends thereof, a second flow passage through said casing means communicating with said first flow passage, and means in said spacer providing fluid communication between said first flow passage and the ends of the spacer through which the lubricant can flow to the bearings between which the spacer is located.

Claim 8

A power tool or the like, comprising a casing means; a shaft; bearing means supporting said shaft in said casing means; means for supplying a lubricant to said bearing means for circulation therethrough; and vacuum means for evacuating the lubricant from the casing means after it circulates through said bearing means which comprises a manifold providing a chamber in said casing means and means providing passages through which the lubricant can flow to said chamber from said bearing means after circulating therethrough, said manifold being connectable to a vacuum source to thereby provide a differential pressure force for effecting a flow of the lubricant from said casing means after it circulates through said bearing means.

Claim 9

A power tool or the like, comprising a casing means; a shaft; bearing means supporting said shaft in said casing means; means for supplying a lubricant to said bearing means for circulation therethrough; and vacuum means for evacuating the lubricant from the casing means after it circulates through said bearing means which comprises a manifold providing a chamber in said casing means and means providing passages through which the lubricant can flow to said chamber from said bearing means after circulating therethrough, said manifold being connectable to a vacuum source to thereby provide a differential pressure force for effecting a flow of the lubricant from said casing means after it circulates through said bearing means.

Claim 10

The tool of claim 5, wherein said bearing means comprises a plurality of bearings spaced along said shaft and including an insert surrounding and positioning said bearings in said casing means, there being passages extending from end-to-end of said insert through which the lubricant can flow to the vacuum manifold after circulating through at least the bearing furthest removed from the vacuum manifold.

Claim 11

The tool of claim 6, wherein said shaft extends through one end of the casing means and including a retainer fixed to said insert at the end thereof nearest that end of the casing means through which the shaft extends and a cover means fixed to said shaft adjacent said retainer, said vacuum manifold surrounding said retainer and said cover means and there being communicating passage means between said shaft and said retainer, said retainer and said cover means, and said cover means and said insert through which the lubricant can flow to said vacuum manifold from at least the bearing nearest the manifold after circulating through said bearing.

Claim 12

A power tool or the like comprising a casing means; a shaft adapted to have an accessory rotatably fixed thereto; bearing means spaced along said shaft and rotatably supporting the shaft in said casing means; an electric motor disposed in said casing means adjacent said shaft; means drive-connecting said motor to said shaft; means for cooling said motor which comprises an inlet in said casing means through which air can flow from the ambient surrounding into the casing means, said inlet means being located on the opposite side of said motor from said shaft, a vacuum manifold located on the opposite side of said bearing means from said motor, and means providing a path through the tool between the inlet means and the vacuum manifold along which air can flow in heat transfer relationship to said motor to absorb heat therefrom, said manifold being connectable to a vacuum source to thereby provide a pressure differential for effecting a flow of air into, through, and from the tool; and means for lubricating the shaft supporting bearing means which comprises means for supplying a lubricant to said bearing means for circulation therethrough and means providing fluid communication between each of said bearing means and the air flow path so located that the lubricant can flow into saiD path after it circulates through the bearing means.

Claim 13

A power tool or the like comprising a casing means; a shaft adapted to have an accessory rotatably fixed thereto; bearing means spaced along said shaft and rotatably supporting the shaft in said casing means; an electric motor disposed in said casing means adjacent said shaft; means drive-connecting said motor to said shaft; means for cooling said motor which comprises an inlet in said casing means through which air can flow from the ambient surrounding into the casing means, said inlet means being located on the opposite side of said motor from said shaft, a vacuum manifold located on the opposite side of said bearing means from said motor, and means providing a path through the tool between the inlet means and the vacuum manifold along which air can flow in heat transfer relationship to said motor to absorb heat therefrom, said manifold being connectable to a vacuum source to thereby provide a pressure differential for effecting a flow of air into, through, and from the tool; and means for lubricating the shaft supporting bearing means which comprises means for supplying a lubricant to said bearing means for circulation therethrough and means providing fluid communication between each of said bearing means and the air flow path so located that the lubricant can flow into saiD path after it circulates through the bearing means.

Claim 14

The power tool of claim 8, together with a spacer between said bearing means, said lubricant supplying means comprising a first flow passage in said spacer intermediate the ends thereof, a second flow passage through said casing means communicating with said first flow passage, and means in said spacer providing fluid communication between said first flow passage and the ends of the spacer through which the lubricant can flow to the bearing means between which the spacer is located.

Claim 15

The power tool of claim 9, together with an insert surrounding and positioning said bearing means in said casing, there being passages extending from end-to-end through said insert and communicating at one end thereof with the interior of the manifold and at the other end thereof with the interior of the casing means in the vicinity of the motor and at least the bearing means nearest said end of the insert, wherby the cooling air can flow from said motor through said passages to said vacuum manifold and can induce into said passages for flow to the manifold the lubricant which has circulated through at least one of said bearing means.

Claim 16

The tool of claim 8, together with an opening in one end of said casing means, said shaft extending through said end of said casing means and said tool further including an insert surrounding and positioning said bearing means in said casing means, a retainer means fixed to said insert at that end of the casing means through which the shaft extends, and a cover means fixed to said shaft adjacent said retainer means, said vacuum manifold surrounding said retainer means and said cover means and there being communicating passage means between said shaft and said retainer means, said retainer means and said cover means, and said cover means and said insert through which the lubricant can flow to said vacuum manifold from at least the bearing means nearest the manifold after circulating through said bearing means.

Claim 17

The power tool of claim 8, wherein the inlet means is an opening in the end of the casing means opposite that at which the vacuum manifold is located and including a filter supported from said casing means and means for confining the flow of air into said opening to a path through said filter.